ENVIRONMENTAL
RESEARCH
7.1 STANDARDIZATION OF METHODOLOGY
FOR PAH AND ASSESSMENT OF THEIR CONCENTRATION IN AMBIENT AIR PAH
(Polycyclic Aromatic hydrocarbon) are environmental carcinogens and constitute
an important class of organic aerosol components generated in a variety of combustion
process and are emitted into the atmosphere preferentially associated with sub
micron size particles. Human exposure to ambient PAH generally occurs in combination
with other substances, which are potentially carcinogenic substances. From above
discussion it is clear that PAHs have significant impact on human health. Considering
the above fact, the study was undertaken to assess the concentration of PAH compound
at different location. Methodology for measurement of PAH (9 compounds) based
on USEPA methodology was standardized for assessment of their concentration in
ambient air in particulate matter. Performance of GC, calibration, extraction
and clean-up of sample was thoroughly studied and reported. Recovery study was
repeated again for further perfection of the methodology. On having confidence
methodology was adopted to analyze the samples collected from Kolkata (West Bengal),
Ranchi (Jharkhand) and Mirik (West Bengal) and at various Steel Plants. The results
obtained are presented in Table 7.1. Table 7.1 Range
of concentration of PAH (ng/m3) at different locations
| PAH
Compound | Kolkata
Traffic Intersection | Mirik
Lake | Ranchi
Traffic Intersection | |
Anthracene |
BDL to 18 |
BDL |
BDL to 2.1 | |
Fluoroanthene |
1.0 to 20 |
BDL |
BDL to 2.8 | |
Pyrene |
BDL to 18 |
BDL |
BDL to 8.0 | |
Chrycene |
BDL to 29 |
BDL |
1.5 to 3.5 | |
Benzo(e)Pyrene |
1.0 to 13 |
BDL |
BDL to 3.7 | |
Benzo(a)Pyrene |
1.0 to 19 |
- |
1.0 to 6.5 | |
Phenanthrene |
- |
1.8 |
BDL to 2.3 | |
Benz Anthracene |
- |
- |
1.5 to 8.3 | |
Di benz Anthracene |
- |
- |
BDL | |
Benzo(g,h,i)Perylene |
- |
- |
BDL |
Not
done
BDL - Below Detection Limit All
Mirik lake (West Bengal) all the values of PAH compound were below detection level,
where as in Kolkata and Ranchi, values were comparatively high. Highest value
of Benzo(a)Pyerene was obtained at steel plant between from 21 ng/m3
to 248 ng/m3. Studies
will be continued for perfection of methodology and for generating baseline data
of PAH level in ambient air. 7.2 STANDARDIZATION
OF METHODOLOGY FOR PAH COMPOUNDS AND MEASUREMENT OF PAH IN AMBIENT AIR OF KOLKATA
Poly-cyclic aromatic hydrocarbons
(PAH) are important organic aerosol components generated in a variety of combustion
processes and emitted into the atmosphere preferentially associated with the sub-micron
size particles. Some species of PAH are known human carcinogens. Therefore, it
is felt to standardise the methodology for measurement of six PAH species initially
and to generate data regarding levels of PAH in ambient air of historical places
namely Dakshineswar, Belur and Victoria Memorial. 7.3 STUDIES
ON SULPHATES AND NITRATES IN THE AMBIENT AIR The
project studies was initiated to study the fate of acidic gases in the atmosphere.
The acidic gases like SOx and NOx are reactive and form sulphate, nitrates and
other secondary pollutants in the atmosphere during short time, which is not reflected
in routine measurements of air quality. In the first phase of the project, samples
at various atmospheres like problem areas, secured landfill sites, industrial
areas and residential areas have been collected for analysis of Sulphates and
Nitrates in ambient air in different seasons. Results indicated that at Subhanpura,
Vadodara (residential area), the monthly average values of sulphate in ambient
air varied between 0.84 µg/m3 and 9.9 µg/m3. 7.4
BTX PROFILE OF AMBIENT AND FUGITIVE EMISSIONS AT PANIPAT REFINERY The
Indian Oil Corporation Limited (IOCL) owns 10 refineries out of total 18 refineries
in the country. IOCL commissioned Panipat Refinery (PR) at Baholi village in Panipat
district of Haryana State. Panipat refinery is in operation since October 1988
with a design capacity to process 6 MMTPA crude oil. Panipat Refinery is configured
to take feedstock of indigenous Bombay High (BH) crude oil (3 MMTPA) and imported
Arab Mix (AM) crude oil (3 MMTPA). The total feed stock is received at the refinery
site through cross-country pipeline. The
active sampling was carried out to collect BTX samples during 21-22 August, 2003
at major process units operating at one of the IOC refinery at Panipat as follows.
The
adsorbent tube containing activated charcoal and thermal desorption tubes filled
with Tenax were used for collection of BTX samples of ambient air & fugitive
emissions using low flow pump. Tube conditioning before reuse of sample tube was
carried out. Sampling
flow rate was fixed between 20-25 ml/min for both ambient air and fugitive emissions
but sampling duration were kept between 5 min & 15 min for fugitive monitoring
and 2 hrs for ambient air monitoring
Samples
collected through active sampling technique (sorbent tubes) may be desorbed by
conventional solvent (generally carbon disulphide) or thermally (generally using
standard automated thermal desorption apparatus) and analyzed using gas chromatograph
(GC) fitted with capillary column and flame ionization detector (FID) . The
BTX profile of fugitive emissions at Panipat Refinery using ATD-GC-FID techniques
is presented in Table 7.2. Table
7.2 BTX Profile in Fugitive Emissions at Panipat Refinery
| S. No. |
SAMPLING LOCATION |
Benzene (mg/
m3) | Toluene
(mg/ m3) |
Xylene (mg/
m3) | |
1 |
Naphtha Splitter |
19.53 |
44.22 |
28.52 | |
2 |
CCRU |
16.28 |
11.36 |
4.90 | |
3 |
ETP Inlet |
19.46 |
14.55 |
16.61 | |
4 |
Crude oil tank |
3.16 |
1.80 |
0.65 | |
5 |
Wagon loading top |
78.59 |
169.91 |
-- | |
6 |
Truck loading area |
2.81 |
1.96 |
1.07 | |
7 |
Truck top loading |
306.07 |
812.40 |
195.46 | BTX
Profile of Ambient Air at Panipat Refinery Ambient
BTX was measured at three locations inside the premises and one in the township
area. Results are presented in Table 7.3. Table
7.3 BTX Profile of Ambient Air at Panipat Refinery
| S.No. |
Sampling location |
Benzene (mg/
m3) | Toluene (mg/
m3) | Xylene (mg/
m3) | | 1 |
A.M.S Near SMPL |
129 |
195 |
49 | |
2 |
Near Strom Water Pond |
190 |
301 |
66 | |
3 |
Township Guest House |
80 |
112 |
60 | 7.5 EPIDEMIOLOGICAL
STUDIES TO FIND THE EFFECT OF AIR POLLUTANTS ESPECIALLY RESPIRABLE SUSPENDED PARTICULATE
MATTER (RSPM) AND OTHER CARCINOGENS ON HUMAN HEALTH IN DELHI The
Epidemiological study has been undertaken in collaboration with Chittaranjan National
Cancer Institute (CNCI), Kolkata to find the Effect of Air Pollutants especially
Respirable Suspended Particulate Matter (RSPM) and other carcinogens on Human
Health in Delhi. The objectives of the study are as follows: To
prepare a database on air pollution related respiratory symptoms among the residents
of Delhi. To assess
the degree of lung function impairment in persons chronically exposed to city’s
air.- To explore the underlying mechanism of air
pollution related pulmonary dysfunction at the cellular and subcellular level.
The
scope of work involves health assessment including evaluation of respiratory symptoms
through questionnaire survey and clinical examination, assessment of lung function,
assessment of cellular lung response to air pollution, assessment of systemic
effects of Delhi’s air pollution, assessment of hematological profile, changes
in liver and kidney function, assessment of genotoxic effects and correlation
between health effect and air quality. Several health camps were organised in
different parts of Delhi. The areas covered included East Arjun Nagar, Mayur Vihar,
Rajinder Nagar, New Delhi Railway Station, Nehru Place, Okhla, Tughlakabad Institutional
Area. 7.6 STUDY
ON AMBIENT AIR QUALITY, RESPIRATORY SYMPTOMS AND LUNG FUNCTION OF CHILDREN IN
DELHI A study is being carried
out in Delhi on Health effects of air pollution on Children in Delhi. The study
is being carried out by Chittaranjan National Cancer Institute (CNCI), Kolkata.
The duration of the study is two years. The objective of the study is assessment
of the respiratory health status of school children chronically exposed to ambient
air pollution of Delhi and establishment of a database relating to pollution related
respiratory problems among children of the city. Prevalence, duration and severity
of respiratory symptoms will be determined from questionnaire responses and actual
tests on various physiological parameters like lung function tests etc. 7.7 STANDARDIZATION
OF METHODOLOGY FOR MEASUREMENT OF CERTAIN HAZARDOUS ORGANIC COMPOUNDS (POLYCHLORINATED
BIPHENYL) PCB’s are the group
of highly toxic, synthetic, chlorinated organics compounds constituting 209 individual
congeners. The PCB species are non-biodegradable, stable with high toxicity and
having tendency for bioaccumulation. It is believed that PCB’s do not occur naturally
and they are resistant to chemical and biochemical process. The PCB’s have received
much attention in recent years as ubiquitous environmental contaminants and their
overwhelming problem of continuing environmental impact. The
PCB’s have potential industrial applications where non-flammability and heat resistant
properties are desired and these compounds are more commonly used in heat transfer
system, hydraulics/lubricants, transformers, capacitors as plasticizer and as
petroleum additives. The PCB congeners, which contain fewer chlorine substitutions
in ortho position, are more toxic than those having more chlorine in other portions.
The most toxic PCB’s are tetra, penta and hexachlorobiphenyl congeners that are
un-substituted in the other position. The
laboratory of Central/State Pollution Control Board and other environmental laboratories
have limited technical expertise about measurements of residual PCB’s in environmental
matrices viz. waste waters, industrial effluents, sludge and soil. The project
standardization of Methodology for measurement of certain hazardous organic compounds
has therefore been undertaken with following objectives. To
develop facilities and Standardization of analysis of PCB’s in water, soil and
sediments. To standardize
procedure for extraction, clean up, concentration and pre-treatment of sample.
To standardize GC optimum conditions (oven temp. detector, injector flow etc.)
to achieve resolved peaks of individual PCB species.To
undertake spiking and recovery studies in the field samples.
The PCB’s congeners in Aroclor Standard Solutions have been
analyzed at CPCB Laboratories by Gas Chromatograph with Electron Capture Detector
(ECD). Peak profiles of six Aroclor mixtures and overlapping peak were observed
with GC-ECD. Qualitative analysis of Aroclor mixtures was also performed with
GC-MS. Retention times and mass spectra of 28 individual congeners of toxicological
significance were observed. Five levels of calibration (range 10 to 100 pg/µl)
were performed using dilutions of mixture containing 28 PCB’s congeners. Procedures
of sample extraction, extract cleanup (removal of co-extracted interfering compounds)
and GC-MS operating conditions were optimized for analysis of 28 selected congeners
of polychlorinated biphenyls (PCB’s) in surface water, wastewater and sludge samples. Water
and sludge samples collected from Delhi stretch of River Yamuna from five locations
and five major drains were analyzed. Total concentration of the PCB congeners
analyzed were ranging between 2.67 ng/l (Mazawali) to 18.79 ng/l (Okhla) in river
water, between 0.55 ng/g (Palla) to 8.70 ng/g (Nizamuddin) in river sludges and
between 0.05 ng/g (Najafgarh Drain) to 25.62 ng/g (Civil Mill Drain) in Drain
sludge samples. PCB’s were not found detectable in wastewater samples collected
from four major drains. 7.8 DEVELOPMENT AND STANDARDIZATION
OFMETHODOLOGY FOR ANALYSIS OF TRIHALOMETHANES (THM’S) IN ENVIRONMENTAL SAMPLES The
halomethanes include all one carbon compounds with substituted chlorine or bromine.
Halogenated hydrocarbons are formed as a result of using chlorine as a disinfectant
in the water treatment process. Trihalomethanes (THM’s) occur in drinking water
principally as a product of reaction of chlorine with naturally occurring material
and bromide that may also be present. Occurrence of natural organic matter such
as humic acid and fulvic acid in water are mainly responsible for the formation
of these disinfection by product (DBP’s). With respect to drinking water contamination,
four members of THM’s viz. chloroform, dichlorobromomethane, dibromochloromethane
and bromoform are important. World Health Organisation (WHO, 1993) has already
enacted the health related guidelines values in drinking water. In
order to standardization of measurement methodology and regularly monitor the
presence of these compounds in drinking water, the infrastructure facilities are
being developed and streamlined at CPCB Laboratories. 7.9 GEO-ACCUMULATION
AND BIOACCUMULATION OF HEAVY METALS AND PESTICIDES ON SOIL AND CROP VEGETATION
DURING WASTEWATER IRRIGATION With
increasing paucity of fresh water untreated/partially treated sewage water is
increasingly utilized for irrigation of soil and growing of crops. The sewage
wastewater generation from urban areas has been constantly increasing, while the
wastewater treatment capacity is quite less than the total wastewater generation.
The treated/untreated wastewater is increasingly utilized for irrigation of crops,
vegetation etc. With the view to study the impact of wastewater on geo-accumulation
and bio-accumulation on irrigated soil and crop vegetation in Delhi, the project
studies have been undertaken. The study undertaken between April, 2003 to March,
2004 included following aspects: Water,
soil, plants and vegetables such as Brinjal, Spinach, Bitter gourd, Lady’s finger
etc. have been collected and analyzed for trace metals and pesticides during consecutive
random sampling rounds.
The preliminary data during the study indicated
that sewage irrigated soil and vegetables have traces of heavy metals and pesticides
on vegetables, which may be harmful on consumption for human health. 7.10 PESTICIDES
RESIDUE ANALYSIS IN PACKAGED DRINKING WATER
Ten organo-chlorine and two organo-phosphorus
pesticides were analysed in packaged drinking water samples of ten common brands
randomly collected from various market places in Delhi. Out of ten brands of packaged
drinking water samples were analysed by GC-ECD for organo-chlorine
pesticides, α-HCH (α-BHC) was detected in the samples of four brands
in the range 4.358 ng/L to 9.950 ng/L. γ-HCH (γ-BHC) was detected in
two brands between 3.128 ng/L and 3.823 ng/L. p,p’DDE was detected only in one
brand of bottled water (3.300 ng/L). None of the two
organo-phosphorus pesticides were detected in ten brands of packaged drinking
water samples. The
maximum admissible concentration for pesticides residue in drinking water intended
for human consumption, as prescribed by the European Economy Community’s (EEC)
Directive 80/778/EEC, and adopted by the Bureau of Indian Standards (BIS) are
100 ng/L for individual pesticide residue and 500 ng/L for total pesticide residue
respectively. 7.11 PESTICIDES
RESIDUE ANALYSIS IN CARBONATED BEVERAGES The
Central Pollution Control Board has conducted a study to assess the levels of
pesticides in soft drinks during August 2003 on some of the leading brands of
soft drinks available in the market as a follow up of media reports of pesticides
residue in soft drinks. Samples of leading brands of soft drinks were collected
from various markets in Delhi and levels of pesticides in soft drinks were analysed.
The total pesticides in six brands of soft drinks were found exceeding the European
(EU) Standard. 7.12 PHYTOREMEDIATION
OF PARTICULATE MATTER FROM AMBIENT ENVIRONMENT THROUGH DUST CAPTURING PLANT SPECIES The
suspended particles in ambient air are commonly recognized as dust, which are
continuously agglomerated and deposited on various surfaces. The particulates
are also blown, washed off and deposited again continuously. The studies on phyto-remediation
of particulate matter through dust capturing plant species being undertaken by
CPCB in collaboration with PCRI (BHEL), Hardwar (Uttaranchal). The studies being
undertaken to identify plant species (Herbs, shrubs and trees), which have higher
potential of dust capturing from environment, while sustaining their well being,
which is an unique combination of concentration and exposure period, plant species,
plant age and various other environmental conditions. The objectives of the study
are as below: During
year 2003, the survey and identification of plant species having higher natural
capacity to capture particulate dust from ambient air was undertaken in vicinity
of thermal power plants, coal mine areas, lime kiln areas, urban areas and busy
traffic intersections at metropolitan cities. The morphometric measurement was
undertaken to assess dust capturing capacity of naturally grown plant species
at various identified monitoring locations. Based on the study, the checklist
of plant species suitable for phyto remediation of particulate matter from ambient
environment will be prepared. 7.13 CHARACTERIZATION
OF INDUSTRIAL EFFLUENT FOR ADSORBABLE ORGANIC HALOGEN (AOX) IN SELECTED INDUSTRIES Chemical
compounds often form a major cause of environmental pollution. One of the most
threatening groups of chemical compounds is formed by the organic halogens. This
group consists of more than 250 individual chemical compounds viz. PCB’s, pesticides,
Trihalomethanes (THM’s) and several other chloro bromo compounds. Some
of the organic halogen compounds are highly toxic, carcinogenic, bio-accumulative
and persistent. Monitoring of AOX compound as environmental parameter are therefore
of paramount importance in various confirmed, suspected sources and industries
with the objectives to generate base line data of AOX. To find the status of concentration
of AOX in industrial effluent i.e. wastewater of paint & varnish manufacturing
units, wastewater samples were collected from randomly selected six paint and
varnish manufacturing units located at West Bengal, Uttar Pradesh and Maharashtra.
Three rounds of samples were collected, analyzed and results being compiled. 7.14 DETERMINATION
OF TOXICITY IN THE EFFLUENTS GENERATED FROM PAINT AND VARNISH INDUSTRIES The
use of summary parameters such as Toxicity test is gaining importance for the
regulation of quality of industrial effluent discharges. The United State Environmental
Protection Agency (USEPA) has also recommended the use of WET test (Whole Effluent
Toxicity Test) as a complement to the chemical specific analysis for the assessment
of effluent discharges and to express permit limit. Realising the significance
of toxicity parameters & to transform the toxicity test method more user friendly,
new method was developed and validated by Central Pollution Control Board under
a collaborative project. The new method has also been adopted by Bureau of Indian
Standard (IS: 6582 Part-2: 2001). During the past few years using the method toxicity
level of industrial effluent generated from Pesticides, Bulk drugs, Dye and dye
intermediates, Textiles, Pulp and paper industries, Tanneries had been evaluated. During
the year 2003-2004 the study was initiated with the objectives to find out the
toxicity levels in treated and untreated effluent generated by Paint & varnish
industries and to determine the efficiency of effluent treatment plants in the
reduction of toxicity level. Generation of data for the evaluation of toxicity
based standard (MINAS) was also an objective of the study. The three laboratories,
two CPCB Labs at Delhi & Kanpur and one SPCB Laboratory viz. Gujarat Pollution
Control Board Laboratory at Gandhinagar have participated in the study. Seven
ETP’s located in the State of West Bengal (Howrah), Uttar Pradesh (Bulandshahar
and Kanpur) and Maharashtra (Mumbai and New Mumbai) were selected for the study.
The monitoring of treated
and untreated effluent samples from selected ETP’s was jointly carried out alongwith
the participating laboratories thrice. The test results indicate that the Toxicity
Factor (TF) in the untreated effluent ranged between 2-500, whereas
in treated effluent, the toxicity factor ranged between 1 to 8. It was also observed
that the effluent generated from resin manufacturing section was highly toxic
comparing with the effluents from other sections. The range of percent toxicity
reduction after treatment varied between 0 to 100 percent. 7.15 PERFORMANCE
MONITORING OF OXIDATION POND BASED SEWAGE TREATMENT PLANTS IN UTTAR PRADESH UNDER
YAMUNA ACTION PLAN The monitoring
of Oxidation Ponds based Sewage Treatment Plants in Uttar Pradesh as identified
by National River Conservation Directorate (NRCD), Ministry of Environment &
Forests being undertaken by Central Pollution Control Board Laboratories in addition
to STP’s already being monitored. Grab Samples are collected on monthly basis
from inlet and outlet of each Oxidation Pond and analyzed for discharge (analyzed
in field), temperature (Analyzed in field), pH, Total Dissolved Solids, Total
Suspended Solids, Chemical Oxygen Demand, Bio-chemical Oxygen Demand and Dissolved
Oxygen (Analyzed in the field) apart from bacteriological parameters viz. Total
Coliforms and Faecal Coliforms. Following seven Oxidation ponds (Table 7.4), as
identified by National River Conservation Directorate (NRCD) are being monitored
on monthly basis since January, 2002: Table 7.4 Oxidation
Pond Based Sewage Treatment Plants in Uttar Pradesh Monitored
by CPCB
|
S. No. |
STP Location |
Capacity (MLD) |
| 1. |
Main Town, Vrindavan |
4.0 | |
2. |
Kaliadah, Vrindavan |
0.5 | |
3. |
Trans Yamuna, Mathura |
14.0 | |
4. |
Masani, Mathura |
14.0 | |
5. |
Trans Yamuna, Agra |
10.0 | |
6. |
Buria Ka Nagla, Agra |
2.5 | |
7. |
Main Town, Etawah |
10.0 |
7.16 EFFICIENCY
TESTING OF AUTOCLAVES USED FOR HOSPITAL WASTE TREATMENT BY SPORE TESTING METHODOLOY The
Biomedical Waste (Management & Handling) Rules, 1998 stipulates that the hospitals
and health establishments have to install treatment facilities like incinerators,
autoclaves, etc. for treatment of bio-medical wastes generated to ensure safe
treatment & disposal of infectious hospital waste. These treatment facilities
should operate at designed efficiency level. The
project was undertaken by Central Pollution Control Board for assessment of treatment
efficiency of autoclaves used during hospital waste treatment based on standardized
spore testing methodology. The objectives of the study was in-situ assessment
of the efficiency of autoclaves and hydroclaves installed at various hospitals
to ascertain 4 Log 10 reduction of Bacillus stereothermophilus biological
indicator. The standardized spore
testing methodology using Bacillus Stereothermophilus as biological indicator
has been continuously used to assess efficiency of autoclaves and hydroclaves
installed at health establishments at Delhi and Kanpur. Based on the studies,
the report on `Bio-medical Waste Management – A Case Study of NCT Delhi’ has been
prepared and submitted for publication. 7.17 WATER
QUALITY ASSESSMENT OF RAW WATER INTAKE SOURCES AT WATER TREATMENT PLANTS IN NCT
– DELHI For production and distribution
of clean drinking water in NCT – Delhi, the Delhi Jal Board (DJB) under the control
of Municipal Corporation of Delhi is responsible and undertaking the task. Central
Pollution Control Board has been conducting bimonthly studies on water quality
of raw water intake points at Wazirabad, Haiderpur, Bhagirathi, Chandrawal, Nangloi
and Okhla Water Works. Various surface
as well as sub-surface water sources act as raw water sources in order to meet
the ever growing clean drinking water demand of NCT – Delhi. The installed water
treatment capacity is 631 MGD and on average about 650 MGD potable water is supplied.
DJB has provided 13.47 lacs water connection in the city till 1.4.2001. The estimated
water availability at NCT – Delhi from surface water sources viz. Yamuna, Ganga
and Western Yamuna Canal is about 1150.2 mcm. River Yamuna contributes a substantial
part. About 275 million m3 of water is abstracted from River Yamuna
at Wazirabad for water supply. River Yamuna acts as raw water source for Chandrawal-I
& II, Wazirabad and partly to Bhagirathi Water Treatment Plant. Apart from
this various Ranny wells have been dug in Yamuna River bed to augment drinking
water supply. In near future the River Yamuna water is also proposed to be supplied
to 635 MGD water treatment capacity Sonia Vihar Water Treatment Plant, which is
presently under construction. Initially,
major part of potable water was treated at Wazirabad and Chandrawal Water Treatment
Plants till 1993. Later water treatment was augmented by installation of Haiderpur
and Bhagirathi Water Treatment Plants. Western Yamuna Canal tail tributary acts
as raw water source to Haiderpur Water Treatment Plant. This plant has 2 phases
of 100 MGD each Phase-I (commissioned in 1977) and Phase-II (commissioned in 1993-94).
Each phase has two clear water pump houses – North clear water pump house and
South clear water pump house. The raw water at Bhagirathi Water Treatment Plant
(commissioned in 1983) is drawn from Upper Gang Canal originating from Haridwar.
The water from Upper Gang Canal is drawn into a by-pass to Muradnagar Head Works
and from there to Bhagirathi Water Treatment Plant through 25 km conduit pipe
of 2800 mm dia. A part of raw water is also taken from River Yamuna. The Western
Yamuna Canal, which is a source of raw water to Haiderpur Water Treatment Plant
also acts as a raw water source from Bawana to Nangloi Water Treatment Plant.
Raw Water quality is monitored at Bawana before being supplied to the water treatment
plant. Subsurface water through Ranny
wells (V & P series) is supplied as raw water to Okhla Water Works. The Okhla
Water Works commissioned during year 1952 with a treatment capacity of 2 MGD,
which has been augmented to 12 MGD presently. Iron and Ammonia removal had been
challenging task at this water works. The water works operation is based on biological
treatment process. The water treatment plants, their installed water treatment
capacities, raw water sources and areas of clear water supply are presented in
Table 7.5. Most of the water treatment plants follow a common process for water
treatment, which is depicted in the flow diagram (Fig. 7.1). Table
7.5 Water Treatment Plants in NCT - Delhi
| S.
No. |
Water Treatment
Plant | Installed Water
Treatment Capacity |
Raw water
source | Clear
Water Supply Areas | | MCM/day |
MGD/day | |
1. |
Chandrawal I & II |
0.410 |
90 |
River Yamuna |
11 service Reservoirs – Flagstaff,
Hindu Rao, Jeetgarh, Jhandewalan, Ridge Road, Talkatora, Palam, Hasanpur, Rajendra
Nagar, Shadipur, Narayana, (One booster pump station at Patel road) |
| 2. |
Wazirabad I, II, III |
0.546 |
120 |
River Yamuna |
Sonia Vihar, Wazirabad, Civil Lines,
Connaught Place, Model Town, Rajendra Nagar | |
3. |
Haiderpur I & II |
0.910 |
200 |
Western Yamuna Canal |
North West Delhi (Rohinia, Saraswati
Vihar, Ashok Vihar, Lawrence Road), Part of South Delhi and entire West Delhi |
| 4. |
Bhagirathi |
0.455 |
100 |
Upper Ganga Canal, U.P. |
East Delhi, Trans Yamuna, Parts of
South Delhi (Okhla, Maharani Bagh, Lajpat Nagar, Kalkaji, Sukhdev Vihar), also
to Okhla Water Works | | 5. |
Nangloi |
0.182 |
40 |
Western Yamuna Canal |
West Delhi- Uttam Nagar, Dwarka,
Papappankalan, Jhandewalan, Talkatora, Patel Nagar, Ridge Road, Malkaganj, Nangloi,
Najafgarh | | 6. |
Okhla | 0.055 |
12 |
Renny Wells on River Yamuna Bed |
Kalkaji, Okhla, New Friends Colony |
| 7. |
Sonia Vihar |
2.889 |
635 |
River Yamuna |
Under construction |
| 8. |
Sub-Surface Water |
0.369 |
81 |
Ranny Wells/Tube wells |
- | |
9. |
Bawana | - |
- |
River Yamuna |
- |
Fig.
7.1 Depictory Flow Diagram - Water Treatment Plants
| Delhi
Jal Board has been upgrading the water treatment process and adopting modern techniques.
The Biological Nitrification (BNO Plant - Biological Nitrification Oxidation plant)
and Ozone treatment has been introduced at Okhla Water Works to treat contaminated
potable water in order to improve its colour, taste and the bacteriological characteristics.
Pulsator clarifiers and Aquazur V Filters have been installed at Sonia Vihar Treatment
Plant (under construction). With
increasing population and rapid urbanization in the city, drinking water demand
is increasing day by day. The quality of drinking water supplied in the city is
checked by Delhi Jal Board at verious stages of treatment from raw water intake
point to storage reservoirs and also in the distribution system at the consumer’s
end to ensure and check contamination of potable water at any stage. The findings
on physico-chemical quality and heavy metal residue in raw water and treated water
are presented in Table 7.6 & 7.7. 7.18 STUDY
OF "POSSIBLE SOLUTION FOR WASTEWATER TREATMENT & DISPOSAL IN SMALL &
MEDIUM SCALE PULP & PAPER INDUSTRY OF MAHARASHTRA" The
small & medium scale pulp & paper industries are in predominance in Maharashtra
as compared to other part of western zone. The small & medium scale pulp &
paper industries are looking for technological solutions for wastewater treatment
& disposal to meet the statutory requirements. The problem has aggravated
due to lack of financial strength, non-availability of appropriate technology.
An effective control of liquid hazardous wastes is of paramount importance for
proper health and environment protection and natural resource management. The
technical issues pertaining to wastewater treatment and disposal for small &
medium scale pulp & paper industries need to be strengthened and the technology-input
requirement is essential to be worked out. The project was intended to study the
present practices in small & medium scale pulp & paper industries including
identification of sources of pollution, characteristics of the waste/effluent
generated etc. and management options like minimization, re-use, recovery, treatment
and disposal of waste. In
agro based chemical pulp and paper mill, it was found that the industry uses baggasse
and wastepaper both to meet the quality criteria and cost economics for paper
manufacturing. Thickener of baggage pulp, thickener of wastepaper pulp, centri-cleaner,
pulp & paper machine combined wastewater streams are the major wastewater
streams, which are partly recycled. The characteristics of theses streams show
BOD >500 mg/l and COD > 1600 mg/l. The characteristics of wastewater streams
generated from utilities like co-generation, FBC boiler, DM plant etc. show COD
<500 and BOD < 100 mg/l. Hence, the resultant characteristics of the combined
wastewater stream had BOD level around 600 and COD level around 1800 mg/l. The
black liquor generated in the process is concentrated by evaporation and used
for recovery of Sodium Hydroxide and Calcium Carbonate. In agro based paper industry
with chemical recovery system, % Na, SAR, RSC and BOD, COD were found high and
unfit for land application because of inadequacy of biological treatment system.
In wastepaper based paper mill, it was
found that the industry uses Indian and imported wastepaper both to meet the quality
criteria and cost economics for paper manufacturing. In a paper industry with
100% water reuse, thickener and wire mill were found as the major source of wastewater
with BOD >20000 mg/l, COD >30000 mg/l and TDS > 25000 mg/l. Build-up
of high concentration of various physico-chemical parameters indicates the actual
reuse and recycle of wastewater concentration of three important parameters (%Na,
SAR & RSC) in wastewater of wastepaper based industries are found fairly suitable
for agricultural use but unfit because of high concentration of other parameters.
Moreover, the industry is reusing the entire generated wastewater for hydro pulping
of wastepaper and not discharging any effluent. Characteristics
of various stream of wastewater and present practices of water use and wastewater
generation in industries revealed wide variation in water consumption pattern
in paper industries. Fresh water consumption in bagasse based paper mill is found
in the range of 60 to 175 m3/tonne of production. Fresh water consumption in waste
paper based paper mill is found in the range of 2.6 to 63.2 m3/tonne of production.
Water consumption is more in the industries, where fresh water is easily available.
More than 90% of water is possible to recycle in wastepaper-based industry. 7.19 STUDIES
ON MUNICIPAL WASTE DUMPING SITES IN VADODARA The
Vadodara city is located in Gujarat on Ahmedabad – Mumbai National highway No.8.
It is located in latitude 20017’59"N and longitude 730 15’18E
with total area approximately 108 sq kms and about 15 lakhs population. The Vadodara
city is known as cultural capital of Gujarat. River Vishwamitri flows through
the center of the city. The major causes for environmental degradation in the
city may be attributed to growing population, rapid urbanization, burgeoning vehicular
traffic and industrial development. Apart
from the mighty industrial giants like Gujarat Refinery, IPCL, GSFC, GACL, there
are few industrial estates also such as Nandesri Industrial estate, Gorwa Industrial
estate and Makarpura Industrial estate. The
municipal corporation is responsible for proper handling and scientific disposal
of the wastes. Poor handling and management may result in the contamination of
ground water due to leaching, obnoxious smell due to burning of wastes, and spreading
of epidemic diseases due to mixing of biomedical waste with municipal waste. During
the monsoon period the wastes are washed away to nearby water body, which degrade
the water quality adding to pollutants present in the waste. A typical composition
of municipal solid waste, published by CPCB and physical characteristic of municipal
solid waste in Vadodara as reported by Vadodara Municipal Corporation are presented
in Table 7.8 and 7.9 respectively. Table
7.8 Typical composition of municipal solid waste as reported by CPCB
| Type
of waste | Percent
by weight | |
Vegetable, leaves |
40.15 |
| Grass |
3.80 |
| Paper |
0.81 |
| Plastic |
0.62 |
| Glass/ceramics |
0.44 |
| Metal |
0.64 |
| Stones/ashes |
41.81 |
| Miscellaneous |
11.73 |
Table
7.9 Physical characteristics and composition of municipal solid waste in Vadodara
city
| Type
of waste |
Percent by weight |
| Bio
degradable waste |
50 |
| Recyclable |
10 |
| Inert
waste | 08 |
| Moisture
content |
20 |
| Unclassified
debris | 12 |
Following significant observations on the
management of municipal solid waste have been made which needs urgent attention.
- There is no segregation of garbage at
sources
- The haphazard
dumping of waste on roadside at various unauthorized places have been noticed.
This results in logging of rainwater in most areas of the city.
- Drainage
system in the major part of the city is poor.
- Practice
of burning garbage by rag pickers at various sites gives obnoxious smell and creates
severe air pollution.
- There
is no scheduled time fixed by VMC for collection of domestic wastes from dustbins
- At
Vadsar dumping site, mixed garbage is burnt on the banks of the river Vishwamitri,
which disturbs the flora and fauna of the ecosystem and also deteriorates the
river water quality.
The
monitoring was carried out to understand the levels of contamination in different
seasons. The results indicate that ground water have high COD, Conductivity, alkalinity
and TDS during monsoon and winter season. The
Vishwamitri River passing near the dumping site found highly contaminated during
monsoon and winter season both. Analysis of river water samples shows the presence
of very high TKN, Ammonical Nitrogen, Conductivity, COD and Organic load. The
measured dissolved oxygen was observed as nil throughout the river stretch. The
Ambient Air quality was also monitored during rainy and winter season. The results
indicate that the values of RSPM, SO2 and NO2 measured in
winter at downwind direction of dumping site were higher compared to monsoon season.
However, measured ammonia did not show similar trend like other gases but higher
values of ammonia was encountered during rainy season at upwind direction of dumping
site. 7.20 STUDY OF
IMPACT OF IDOL IMMERSION ON WATER BODIES Immersion
of Idols of Gods & Goddesses is an issue, which involves both cultural practices
and environmental pollution. Therefore it has been considered important to study
the issue to know the actual impact of immersion on the water bodies and provide
mitigation methods. In Kolkata immersion is carried out in thousands of water
bodies and any findings of such study will be helpful for all the users and ecology
of those bodies. The quantification of raw materials used for making the idol
has been done to assess the impact of these materials on water bodies. Based
on analytical data, attempt was made to ascertain the changes of concentration
of metals in ponds before and after immersion but due to heavy rain just before
and after immersion no trend could be highlighted. However, based on simulation
study, annual contribution of metals through idol immersion was assessed considering
three times (as safety factor) of expected metals from idols. The
study revealed that contribution of metals from idol immersion was negligible.
Other material like fruits, flowers, leaves earthen pots etc. which are generally
disposed with idols may cause deterioration of water quality. But this problem
was avoided by immediate removal of these substances after immersion. Accumulation
of metals in fish was also studied to assess the possibility of contamination
through food chain. But this study indicated no evidence of bio-accumulation of
heavy metals in fishes in the ponds. Simulation study was conducted to assess
the metal input due to immersion. Based on this study it may be inferred that
total amount of metals that is released into the pond is quite meagre and the
increase in metal concentrations is quite low to be considered. This
study indicated that actual measurable impact of idol immersion on ponds would
only practically tufened since the yearly contribution is meager. Moreover periodic
de-sludging of ponds nullify the cumulative effect. 7.21 CHARACTERIZATION
OF GROUND WATER IN ARSENIC AFFECTED DISTRICTS Elevated
concentration of arsenic in ground water used for drinking have been resulting
the symptoms of chronic arsenic poisoning in local population in nine districts
out of 18 districts of West Bengal. The inclined trend of arsenic effected areas
has become a major concern in West Bengal. People are using arsenic contaminated
water unknowingly and suffering from arsenic related diseases. Considering the
above, CPCB zonal office Kolkata carried out a programme to make the people aware
about the status of tubewell water through analyzing the water collected by the
owner of the tube wells. The results were regularly reported to the individual
about the status Arsenic in groundwater of their own tube wells. The 478 samples
were analyzed among which 89 samples were found having Arsenic level above permissible
limit (i.e. 0.05 mg/l). In few villages
in Bhojpur district in Bihar, reportedly arsenic effected area, 205 samples (about
60% of total tubwell) were also collected and analysed at the CPCB zonal office
laboratory, Kolkata. Out of which 45 percent samples were found having Arsenic
more than permissible limits i.e. 0.05 mg/l. Another
study was simultaneously conducted to characterize the ground water in arsenic
effected areas (West Bengal) in terms of other chemical parameters and also to
establish the relationship of other chemical parameters with arsenic. The results
revealed that pH values are more or less same in all the four districts varying
from 6.9 to 7.6 except in few cases where pH was more than 8.0. Distribution of
salt with respect to average values of conductivity and TDS was found more or
less uniform in all the three districts where as in Nadia district some values
were slightly lower. The carbonate & bicarbonate Alkalinity Hardness, Calcium
and Magnesium content was more or less same in all the four districts. Where as
in Malda hardness, Ca & Mg were almost doubled. The carbonate hardness is
equal to total hardness. Nitrate was considerably low in 24 Parganas (south) compared
to other three districts. Phosphate was found high comparatively in 24 Parganas
(south) and low in Nadia among the four districts. Fluoride content was very low
in all the districts (Average values varied between 0.09 to 0.28 mg/l). Sodium
was comparatively higher in Malda and South 24-Parganas and lower in Nadia and
Murshidabad. The similar trend was found in Potassium in all the four districts.
Arsenic and Iron values were comparatively high in South 24-Parganas and low in
Nadia but in Malda and Murshidabad the average values were almost uniform. However,
prevailing concentration of all the parameters in ground water revealed that in
most of the cases hardness, calcium, magnesium, Iron and Arsenic exceeded the
permissible limit as per IS-10500-1983. The corelation coefficient of Arsenic
with other chemical parameter indicated that there is no significant relationship
of arsenic with other chemical parameters exists except with iron and phosphate
to some extent. It was observed
that concentration of iron and arsenic was higher at shallow depth and decrease
with depth in some arsenic effected areas. Though the coexistence of iron and
arsenic was observed in some effected areas, but in some areas no relationship
exists at all. The scatterness of metals, phosphate and nitrate in each district
was very wide with respect to other parameters (Except in few cases) as reflected
from coefficient of variation. Further study in details is most essential to ascertain
the behaviour of arsenic in effected areas with other parameter to establish the
possible reason for such calamities. 7.22 IMPACT
OF QUALITY ASSURANCE (QA) PROGRAMME ON DATA QUALITYEvaluation
of quality system always encourages the proper implementation of analytical methods
and provides supporting documentation to demonstrate method performance. During
evaluation, some common deficiencies are noted to generate analytical data of
sufficient quality. Therefore need for control of error by taking care of these
deficiencies is being increasing recognized during last decade by many countries
and organization. Considering the above fact, the CPCB zonal office laboratory
Kolkata took attempt to adopt effective Quality Assurance System for measurement
of metals in different matrix. For that purpose, emphasis was given on the following:
- Latest and valid method
- Performance
of Instrument (AAS)
- Quantitative measure of
precision and accuracy
In addition to above, necessary importance was provided on
the following: - Consistency
in laboratory support equipment
- High purity
water.
- Trained analyst
- Sufficient
space, proper house keeping
- Cleaning of glassware
- Labeling
of reagent containers
- Adequacy of log book
- Inter-laboratory
comparison studies
The
flame AAS was carefully calibrated using certified standard solution (Combined
standard uncertainty not more than 2 mg/l for 1000 mg/l of concentration). The
measurement technique was validated including a linearity check, using serially
diluted calibration standards, precision check and bias check using an independently
prepared reference solution. Since the random error is unavoidable to certain
extent, there are limits to the detection and determination of element inherent
to the procedure used. In most of the cases, the detection limit is calculated
considering the series of results obtained against blank. This calculation would
make no sense if there were no signal. Therefore estimation of detection and determination
limit of all the metals was done from the results obtained through calibration
exercise and presented in Table 7.10. Table
7.10 : Estimation of Calibration parameters with detection
and determination limit
| | |
Pb |
Cu |
Cd |
Zn |
Ni | |
Mean of conc. |
X |
65 |
186 |
54 |
83 |
288 | |
SD of conc. |
S¶
x | 60 |
111 |
29 |
36 |
105 | |
Mean of signal |
Y |
.025 |
0.025 |
0.022 |
0.065 |
.02 | |
SD of signal |
S¶
y | .021 |
0.015 |
0.012 |
0.027 |
.007 | |
Slope |
m |
3.4x10-4 |
1.36x10-4 |
4.2x 10-4 |
7.71x10-4 |
6.9x10-5 |
| Intercept | |
2.4x10-3 |
-4.6x 10-6 |
-5.67x 10-4 |
1.7x 10-3 |
2.9x10-4 |
| Standard error
of estimate | SE |
8.1x10-4 |
3.4x10-4 |
2.5x 10-4 |
2.4x 10-3 |
2.4x10-4 |
| Detection
limit, µg/L | XN |
18 |
18 |
4.0 |
22 |
22 | |
Determination Limit, µg/L |
XB |
28 |
25 |
6.0 |
32 |
34 | |
Conc.(x) of Abs 0.2 plus confidence limit | |
51 ±
9 | 146
± 8 |
49 ±
1.9 | 24
± 10.6 |
284 ±
10 | SD
= Standard Deviation The
parameter like mean and standard deviation was used to assess scatterness of calibration
range in terms of concentration and absorbance. Slope and intercept was used to
calculate the concentration against absorbance obtained. Importance of detection
and determination limit has been already defined. Confidence limit was used to
assess the uncertainty in measurement of concentration through calibration. Based
on the confidence limit and linearity, measured value was maintained within a
linear range. Precision was verified
by processing sample using attended reagent, distilled water, glassware containers
etc. Accuracy was verified through studying the recovery of metals using Internal
Reference Materials (IRM) prepared through inter-laboratory comparison. The results
obtained in this laboratory conformed our requirement. Accuracy and precision
were documented as per the NABL guideline. X-chart and R-chart were used to present
accuracy and precision data. It is mentioned that attention to quality began by
ensuring technical competence of the staff assigned responsibilities. Checking
of requirements for analysis such as cleanliness, reagent, distilled water, logbook
etc was conducted in such a way so that early detection and correction of those
anomalies did not adversely effect data quality during data generation process.
As a result no reporting of out-of-control data was observed in the laboratory.
Large quantity of ground water,
river water, industrial, drain and pond water was filtered to make them homogenous,
and preserved with acid. These samples were processed by multi-method approach
i. e. different digestion method (Microwave, Pressure and by using different acids)
and analysed by AAS with flame and graphite furnace (wherever possible). Trials
were continued by three analyst to have good agreement on the closeness of the
values of each metals expected values (less than 10% coefficient of variation).
Variability among reagent blanks values of different digestion method was remarkably
significant. After deducting the blank value, closeness of the values obtained
by different methods was satisfactory. After this exercise, these samples were
considered as Internal Reference Materials (IRM), Then IRM were sent to different
laboratory for inter-laboratory comparision. The results submitted by the laboratories
were processed to calculate the mean, standard daviation and cofficient of variation
to prepare control chart for acceptibility of the analytical results in future
routine analysis. The mean, SD and CV are presented in Table 7.11 & 7.12 respectively. Table
7.11 Inter-laboratory Comparison of Analytical Results of River, Pond, Drain,
Ground, Industrial Effluent Water and Sediment
| S.
No. | Sample
Matrix | Parameter
| Mean
( PPM ) | SD |
CV | |
1 |
Ground Water |
Iron | 0.46 |
0.06 |
3 | |
Zinc | 1.07 |
0.07 |
7 | |
Cadmium |
.05 |
- |
- | |
Lead | - |
- |
- | |
Copper | 0.09 |
0.01 |
11 | |
2 |
River Water |
Iron | 1.48 |
.17 |
11 | |
Zinc | .11 |
.011 |
14 | |
Cadmium |
.039 |
.008 |
20 | |
Lead | .34 |
.04 |
12 | |
Copper | 1.96 |
.04 |
2 | |
3 |
River Sediment |
Iron | 26944 |
3637 |
13 | |
Zinc | 87 |
5 |
6 | |
Cadmium |
1.48 |
.3 |
20 | |
Lead | 40.5 |
3 |
7 | |
Copper | 25.54 |
4 |
16 |
Table 7.12 Inter-laboratory Comparison
of Analytical Results of River, Pond, Drain, Ground, Industrial Effluent Water
and Sediment
| Sample
Code | Statistical Parameter |
Pb |
Cd |
Hg |
Cu |
Ni |
As |
Cr |
Mn |
Fe |
Zn | |
IRM/DEC/ Riv/M/1 |
Mean (mg/l) |
0.52 |
0.40 |
0.02 |
0.49 |
0.45 |
0.03 |
1.05 |
1.11 |
9.00 |
0.51 | |
SD |
0.08 |
0.03 |
0.00 |
0.04 |
0.05 |
0.02 |
0.11 |
0.13 |
0.44 |
0.06 | |
CV |
15.9 |
6.7 |
12.0 |
7.8 |
11.8 |
76.8 |
10.8 |
11.3 |
4.9 |
12.3 | |
IRM/DEC/ Pond/M/2 |
Mean (mg/l) |
0.62 |
0.25 |
0.13 |
0.53 |
0.48 |
0.02 |
1.05 |
1.16 |
6.79 |
0.50 | |
SD |
0.18 |
0.02 |
0.19 |
0.07 |
0.17 |
0.02 |
0.16 |
0.18 |
0.18 |
0.07 | |
CV |
29.4 |
8.3 |
143.0 |
12.6 |
35.1 |
92.8 |
15.0 |
15.8 |
2.7 |
13.2 | |
IRM/DEC/ DW/M/3 |
Mean (mg/l) |
0.92 |
0.24 |
0.12 |
0.53 |
0.66 |
0.02 |
0.75 |
1.07 |
6.34 |
0.57 | |
SD |
0.52 |
0.07 |
0.17 |
0.08 |
0.28 |
0.02 |
0.55 |
0.24 |
0.89 |
0.14 | |
CV |
56.1 |
30.3 |
139.6 |
15.1 |
42.1 |
84.8 |
73.4 |
22.1 |
14.0 |
24.5 | |
IRM/DEC/ IND/M/4 |
Mean (mg/l) |
0.61 |
0.24 |
0.01 |
0.54 |
0.88 |
0.02 |
1.15 |
1.53 |
26.10 |
1.21 | |
SD |
0.15 |
0.09 |
0.00 |
0.10 |
0.28 |
0.02 |
0.18 |
0.19 |
9.80 |
0.17 | |
CV |
24.6 |
35.2 |
76.4 |
17.7 |
32.2 |
89.8 |
15.8 |
12.6 |
37.6 |
14.0 | |
IRM/DEC/ GW/M/5 |
Mean (mg/l) |
0.58 |
0.41 |
0.03 |
0.53 |
0.81 |
0.02 |
1.10 |
1.97 |
7.10 |
1.36 | |
SD |
0.14 |
0.28 |
0.00 |
0.09 |
0.31 |
0.02 |
0.12 |
0.15 |
0.14 |
0.11 | |
CV |
24.9 |
68.0 |
16.1 |
17.0 |
38.0 |
83.9 |
11.0 |
7.8 |
2.0 |
7.9 |
The results revealed that coefficients of variation in case
of arsenic and mercury were significantly high may be due to low concentration
of the metals and methodology (Not by VGA) adopted by the other laboratories.
Based on the results it may be mentioned that though CV were significantly high,
the standard deviation at such low level of concentration. may be acceptable particularly
for metals like Pb , Cd, Ni, if samples are analysed by flame AAS. Considering
this aspect, both upper and lower limit covering twice the standard deviation
in control chart has been fixed for routine analysis with this method (Digestion
followed by AAS.) If more reliability is required depending on the objectives
of the analysis at these level, other method i.e. Graphite AAS would be adopted. 7.23 METAL
CONCENTRATION IN EDIBLE FISH TISSUE COLLECTED FROM SEWAGE FED PONDS The
metals have the tendency of Bioaccumulation in different concentration in fish
muscle irrespective of necessity, if aquatic environment is enriched with metals.
Accumulation of metals in fish muscle and their subsequent transfer to man through
the food chain may cause health hazard particularly in fish eating public. The
numbers of such incidents have been reported time to time all over the world.
With the increasing rate of metal pollution in river, ponds and sea, possibility
of accumulation cannot be ruled out. Considering
this aspect, a study on coastal sea fish was undertaken during previous year while
the studies on fishes rearing in sewage fed ponds and fresh water pond were undertaken
in current financial year. The varieties of fish collected from sewage fed ponds
were not available from fresh water ponds. Sizes were also not comparable because
fish in sewage fed ponds are generally harvested after rearing for 3-4 months
to maximize the production considering the depth of water. Therefore as such comparison
cannot be drawn. However, analytical results obtained are presented in Table 7.13.
The results revealed enormous variability among the species from both the sources.
Species to species variation in concentration may be attributed to the feeding
habits of different species and physiological condition. It has been observed
that concentration is little higher in sewage fed ponds but size of the species
was smaller < (1/6 th weight) in Rohu fish (Lobeo rohita). Therefore rate of
accumulation with respect to size is higher in sewage fed pond. Based on available
standard stipulated by other countries (Wet weight basis), It may be mentioned
that concentration of metals (dry weight Basis) in fishes from both sources are
not out the alarming level. However, in case of prawn and crab values were on
the higher side. Table 7.13 Mean Metal Concentration
(µg/gm dry weight basis) in Edible Fish Tissue Sewage
Fed Pond
| Fish
Name | Pb |
Cu |
Zn |
Mn |
Fe |
Cd |
Ni |
Hg |
As | |
Katla |
NT |
6 |
29 |
2 |
56 |
NT |
4 |
0.28 |
1.05 | |
Lailyntica |
NT |
6 |
48 |
8 |
62 |
NT |
5 |
1.03 |
0.93 | |
Rohu Chara |
NT |
10 |
54 |
4 |
88 |
1.0 |
7 |
0.26 |
0.89 | |
Silver Cup |
NT |
17 |
37 |
5 |
96 |
1.5 |
5 |
0.24 |
0.17 | |
Folie |
NT |
7 |
26 |
2 |
36 |
1.4 |
5 |
0.33 |
0.31 | |
Tilapia |
NT |
5 |
28 |
7 |
35 |
1.8 |
5 |
0.20 |
0.54 | |
American Rohu |
NT |
5 |
65 |
2 |
46 |
2.2 |
7 |
0.39 |
0.61 | |
Crab |
NT |
36 |
80 |
40 |
350 |
2.9 |
13 |
1.12 |
0.42 | |
Mrigel Chara |
NT |
18 |
47 |
4 |
60 |
NT |
NT |
0.83 |
0.11 | |
Rohu Chara |
NT |
11 |
40 |
4 |
11 |
NT |
NT |
0.75 |
0.08 | |
Lailyntica |
NT |
8 |
54 |
3 |
142 |
NT |
NT |
0.69 |
0.12 | |
American Rohu |
NT |
5 |
65 |
5 |
132 |
NT |
NT |
0.94 |
0.21 | |
Fresh Water Pond | |
Common Name |
Pb |
Cu |
Zn |
Mn |
Fe |
Cd |
Ni |
Hg |
As | |
Rohu |
NT |
15 |
29 |
4 |
55 |
NT |
NT |
0.69 |
0.13 | |
Bhetki |
NT |
6 |
26 |
8 |
50 |
NT |
NT |
0.89 |
0.03 | |
Puti |
NT |
3 |
15 |
1 |
38 |
NT |
NT |
0.69 |
0.14 | |
Sol |
NT |
7 |
28 |
8 |
56 |
NT |
NT |
0.91 |
0.13 | |
Prawn |
NT |
123 |
53 |
18 |
29 |
4.7 |
NT |
1.14 |
0.21 | |
Seafood heavy metal standards(µg/g) Wet Weight
Basis | |
Country |
*Standard |
Zn |
Cu |
Cd |
Hg |
As | |
America |
NAS |
- |
- |
2 |
- |
- | |
Australia |
NHMRC |
1000 |
30 |
2 |
- |
- | |
Canada |
- |
- |
100 |
- |
- |
- | |
America |
USFDA |
- |
- |
3 |
1.0 |
86 | |
U.K |
MAFF |
50 |
20 |
- | | |
*NAS= National Academy of Science,
NHMRC= National Health Medical Research Council,
NAFF= Ministry of Agriculture,
Fisheries and Food
USFDA= United States Food & Drug Administration ( 2001)
Correlation-ship among the metals
in fish tissue was evaluated separately for sewage fed pond & fresh water
pond by estimating correlation coefficient and shown in Table 7.14. Significant
positive relationship at 0.01 level exists among each other of Cu, Zn, Mn, Fe,
Cd, and Ni in fish tissue from sewage fed ponds, whereas such significance was
not observed in fresh water ponds. Therefore accumulation of metals may be due
to enrichment of metals in aquatic environment and contamination of food consumed
by fish. Table 7.14 Co-relationship among the metals
in edible fish tissue
| Metal |
Cu |
Zn |
Mn |
Fe |
Cd |
Ni |
Hg |
As | |
A |
B |
A |
B |
A |
B |
A |
B |
A |
B |
A |
B |
A |
B |
A |
B | |
Copper |
1 | 1 |
S | S |
S | S |
S | NS |
S | NS |
S | NS |
NS | NS |
NS | NS |
| Zinc | | |
1 | 1 |
S | S |
S | NS |
S | NS |
S | NS |
S | S |
NS | NS |
| Manganese | | | | |
1 | 1 |
S | NS |
S | NS |
S | NS |
NS | NS |
NS | NS |
| Iron | | | | | | |
1 | 1 |
S | NS |
S | NS |
NS | NS |
NS | NS |
| Cadmium | | | | | | | | |
1 | 1 |
S | NS |
NS | NS |
NS | NS |
| Nickel | | | | | | | | | | |
1 | 1 |
NS | NS |
NS | NS |
| Mercury | | | | | | | | | | | | |
1 | 1 |
NS | NS |
| Arsenic | | | | | | | | | | | | | | |
1 | 1 |
A- Sewage Fed Pond, Level
of significance is 0.39 at 0.01 (A)
B- Fresh Water Pond, Level
of significance is 0.83 at 0.01 (B)NS
- Not Significant, S – Significant. 7.24 UNCERTAINTY
IN MEASUREMENT OF BOD AND ITS ACCEPTABILITYThe
Biochemical Oxygen Demand (BOD) is generally measured to assess the quantity of
biodegradable substances present in any water. This measurement is being practiced
since long for planning and management of water quality. Though BOD measurement
is the best way to evaluate the organic matter actually being utilized by microorganisms
but maintaining standard condition in all measurements by all laboratories is
difficult. Therefore the data generated even by adopting standard method (APHA)
cannot be compared with the data generated in other laboratories. As a result,
use of BOD values for design of wastewater treatment plant, assessment of biodegradable
organic load, determination of assimilation capacity of streams, lakes etc is
losing its importance and also causes lot of confusion among the decision makers.
Without knowing the analytical error, sometimes important decision is taken by
regulatory authority. One example
can illustrate the impact of uncertainty on accepting the BOD values without knowing
its magnitude of error. Let us assume that the permission limit of BOD for discharging
the wastewater to river is 30 mg/l and error from all sources (Not identified)
at this level is ±8 mg/l. If we report the value at the level of 37 mg/l, it is
difficult to decide about the compliance. Several such problems were noted in
number of cases while reporting the BOD values. Though in other parameters uncertainty
prevails due to several reasons but that can be minimized to large extent, because
methods are based on chemical reactions. But procedures for BOD measurement are
based on biological activity, some of the factors cannot be controlled as can
be done in other chemical test methods. Therefore uncertainty in measurement of
BOD must be calculated after identifying the sources of error and minimizing these
error. Considering the above fact,
a detail study was conducted starting from sampling to reporting of data with
the following aims by CPCB zonal office laboratory, Kolkata: - Identification
of sources of error and accounting for them by appropriate precision and accuracy
studies
- Evaluation of insignificant source for
elimination, if negligible
- Expression of uncertainty
contribution to the appropriate rules for combined standard uncertainty
- Application
of coverage factors to give expanded uncertainty
The
experiments were designed to asses impact of the factors such as seed, diluent
water, level of DO, dilution, homogeneity, type of sample, condition of incubation
etc on BOD measurement and feasibility to achieve perfection in measurements.
The statistical technique adopted in this study were mean, CV, least square regression,
ANOVA , quadratic equation etc. The
experiments were designed to assess the impact of these factors on BOD measurement
and feasibility to achieve perfection in measurements. The wastewater was always
diluted to levels, which can ensure the availability of oxygen throughout the
period of the test. For this purpose atleast two dilutions were always made for
each sample considering the COD values of that sample. The samples collected from
different sources were fortified with synthetic samples whose concentrations were
earlier measured with certainty. The outcome of these experiments was processed
using different statistical technique. The seeds were prepared in this laboratory
by Activated Sludge Process and also collected from sewage treatment plant for
suitability studies. Another type of seed was cultured with the addition of sample
( to be analyzed for BOD measurement) fortified with glucose of approximately
30 mg of BOD per liter for acclimatization of micro organisms with sample before
using them as seed. This seed is called acclimatized seed. The diluent water used
in this study are rain water, distilled water fortified with nutrient and unpolluted
river water. Loss of BOD during transportation was studied by analysis of sample
at 2 hrs interval upto 16 hrs from the time of sample collection. Measurement
of oxygen was also done by winkler's method and WTW DO electrodes to study the
difference between them. To study the homogeneity of sample, filtered and unfiltered
sample of same source were analysed. BSB controller (Respirometric method) were
used to assess the impact of dilution because in this system dilution is not required.
BOD bottles were put inside the BSB controller putting magnetic stirrer on. All
the bottles used for test were equipped with glass stoppers grounded to a point
to prevent trapping of air during insertion of stopper. Bottles were thoroughly
cleaned to make them free of organic matter. During incubation the bottles were
water-sealed to prevent air from entering the bottle during incubation. Based
on above experiments the sources caused significant influence on the measured
values were identified by analysing synthetic samples and samples from different
sources in 10 replicates presented in Fig. 7.2 The preliminary estimate of the
values of uncertainty components such as homogeneity, inhibitory effect, transportation,
storage, dilution, seeding etc was made, and insignificant components were eliminated.
Ultimately the values atributed to each significant components, uncertainty were
estimated and expressed at the one standard deviation level. Combined standard
uncertainty were calculated and multiplied by a coverage factor selected on the
basis of the level of confidence required to determine an expanded uncertainty.
Fig.
7.2 Factors for Uncertainty in BOD Measurement Expanded
uncertainty were also estimated for different types of sample with a view to assess
the contribution of uncertainty due to homogenity, seeding effect etc. The calculated
uncertainty for different samples is presented in Table 7.15. The results revealed
that almost in all the cases expanded uncertainty were more than 10 percent despite
minimizing the error from different sources. Table
7.15 Calculated Expanded Uncertainty for Various Samples
| S.
No. | Sample
Source |
Concentration (
mg/l) | Expanded
Uncertainty ( mg/l) |
| 1 |
Glucose + Sodium glutamate (Artificial Sample) |
27 |
2.5 | |
2 |
Distillery unit |
10320 |
1500 | |
3 |
Dairy unit |
565 |
40 | |
4 |
Tannery unit |
147 |
23 | |
5 |
Pharmaceutical unit |
48 |
11 | |
6 |
Pond |
9 |
1 | |
7 |
Drain |
42 |
7 | |
8 |
River |
9 |
1 | 7.25 PERFORMANCE
OF ARSENIC REMOVAL UNIT (ARU) INSTALLED AT ARSENIC AFFECTED DISTRICTS Use
of ground water containing arsenic concentration significantly above the permissible
limit and consequent exposure of local population to such elevated level of arsenic
causes acute arsenic poisoning. Several treatment options (already published by
CPCB) are available for arsenic removal to level of existing permissible limit.
The selection of appropriate treatment option for desired water supply will depend
on number of factors including the stipulated arsenic concentration, the existing
treatment system, acceptability to user, maintenance cost and other water quality
parameters. In West Bengal, number of treatment units already attached with tubewells
have been installed at various locations. Performance of these units was not always
satisfactory as reported. Considering the above fact, the study was undertaken
by Central Pollution Control Board Zonal Office Kolkata to assess the performance
of Arsenic Removal Unit and also the impact on water quality after treatment in
terms of other chemical parameters. Nine types of treatment units were considered
in different districts for this study. Samples
collected from inlet and outlet of more than 100 ARU of different types were analyzed
for measurement of arsenic and other chemical parameters such as pH, Conductivity,
TDS, Ca, Mg, Total Hardness, NO3-N, PO4-P, Na, K, Iron,
Manganese and Zinc (Table 7.16). This study focussed on changes of above chemical
parameters along with arsenic after treatment. For each type of ARU, number of
units was considered for sampling and analysis. The analytical results obtained
were processed to evaluate the percentage of increase and decrease of chemical
parameters with the removal of arsenic and other metals for each type of ARU.
The range of percent of removal of Arsenic and Iron and changes (Range of percentage)
of other water quality parameters, No significant changes were observed in case
of pH, Conductivity, TDS, Na, K, Fluoride in most of the cases. But in few cases,
changes were either positive or negative though not significant. In particular
type of ARU, Calcium has been increased where as magnesium decreased. Such random
behaviour was also observed in case of Chloride. These random changes (either
increase or decrease) after treatment may be due to accumulation of substances
through adsorption during continuous operation of ARU followed by desorbtion of
these substances. But effective removal was observed in case of Arsenic, Iron
and Phosphate. Significant increase of nitrate was observed at all types of ARU.
There was reduction in water level of Zinc in most of the cases however in one
case slight increase in zinc level in treated water was noticed may be due to
leach from the media.
Table 7.16 Changes (Range of percentage) of different parameters
including arsenic after treatment
| ARU
Type | Range |
Cond |
TDS |
Cl |
Ca |
Mg |
TH |
NO3-N |
PO4-P |
Na |
K |
As |
Fe |
Zn |
Mn | |
Type -1 |
Min |
-10 |
-8 |
-4 |
-14 |
3 |
2 |
131 |
-84 |
7 |
-25 |
-97 |
-99 |
-80 |
-99 | |
Max |
5 |
3 |
8 |
21 |
21 |
17 |
151 |
-36 |
89 |
18 |
-36 |
-97 |
-13 |
-27 | |
Type - 2 |
Min |
-17 |
-17 |
1 |
-19 |
1 |
-10 |
80 |
-95 |
1 |
- 25 |
- 96 |
-99 |
-56 |
-67 | |
Max |
17 |
4 |
40 |
20 |
16 |
5 |
83 |
-85 |
47 |
9 |
- 51 |
N.A |
N.A |
-20 | |
Type - 3 |
Min |
-3 |
-13 |
-6 |
0 |
-18 |
-6 |
N.A |
N.A |
3 |
0 |
-98 |
-99 |
-99 |
-98 | |
Max |
4 |
2 |
0 |
4 |
-14 |
-5 |
N.A |
N.A |
34 |
17 |
-97 |
-96 |
-80 |
-88 | |
Type - 4 |
Min |
-10 |
-13 |
-5 |
-27 |
-54 |
-13 |
21 |
N.A |
-6 |
-20 |
-97 |
-98 |
-98 |
-96 | |
Max |
1 |
-8 |
29 |
62 |
0 |
18 |
558 |
N.A |
1 |
-20 |
-96 |
-96 |
-98 |
-91 | |
Type- 5 |
Min |
-7 |
-7 |
-9 |
-44 |
-29 |
-5 |
-83 |
-71 |
-21 |
-11 |
-99 |
-99 |
-99 |
-99 | |
Max |
12 |
9 |
41 |
19 |
3 |
83 |
240 |
1 |
15 |
20 |
-18 |
-98 |
-27 |
-4 | |
Type - 6 |
Min |
-2 |
-5 |
7 |
-29 |
-13 |
-16 |
N.A |
-96 |
-22 |
-15 |
-95 |
-99 |
-81 |
-50 | |
Max |
7 |
3 |
15 |
-20 |
15 |
-4 |
N.A |
-76 |
2 |
1 |
-76 |
-99 |
40 |
500 | |
Type - 7 |
Min |
2 |
1 |
1 |
8 |
-24 |
-8 |
N.A |
-96 |
N.A |
N.A |
N.A |
-96 |
N.A |
N.A | |
Max |
46 |
42 |
27 |
89 |
-11 |
36 |
N.A |
-80 |
N.A |
N.A |
N.A |
-59 |
N.A |
N.A | |
Type - 8 |
Min |
4 |
1 |
1 |
-18 |
-17 |
-5 |
N.A |
-98 |
-8 |
-38 |
-90 |
-99 |
-99 |
-78 | |
Max |
6 |
4 |
111 |
55 |
18 |
21 |
N.A |
-73 |
-3 |
1 |
-87 |
-97 |
-99 |
-11 |
NA=
Data Not adequate
Therefore
except Arsenic, Iron, Phosphate and Nitrate, no systematic trend was observed
for other parameters. The percentage of removal was also varying among the units
of each type and among the types. Performance of ARU must be maintained, particularly
at high concentration of Arsenic in inlet water. Otherwise there will be chances
of consumption of unsafe water in case of decrease of efficiency. |
|
|
