Biological removal of Trace aromatics from water by immobilised peroxidase enzyme

The study aims at removal of toxic pollutants using cost effective processes. To reduce cost, peroxidase enzyme is extracted from different plant sources. Comparative study and cheapest sources was chosen for further studies.

Enzyme was further purified to 70 % by using ammonium sulphate salt and then immobilized by entrapment method using sodium alginate to increase stability and storage capacity. Loss of enzyme activity in these immobilized beads were calculated. Percentage phenol removal was studied and was observed 90 % removal by 10 unit /ml of enzyme and same was observed in one half time by immobilized enzyme.

Further, phenol degradation was studied at different pH, residence time. The effect of enzyme on pesticides and BTX will be studied during next year and cost analysis will be undertaken. Kinetics study and dose optimization in batch reactor will be studied in future.

Detoxification of paper mill effluent by using selective coagulants and chemical oxidants

The present study is aimed at the removal of toxic & coloring substances present in paper mill effluent before going to biological treatment using selective chemical coagulants/oxidants. Experimental work completed during the year 2003 are as follows:

1. Samples prepared from synthetic lignin and tannins were analysed and characterized.

2. Coagulants like alum, FeCl3, PAC, alongwith combinations like Alum + Lime, Alum + Lime + PAC, FeCl3 + PAC tested for optimum doses and observed 20-25 % removal of color and 18-23 % COD reduction.

3. 90-93 % color removal has been achieved when optimum dose of Na-Hypochlorite is given to the synthetic sample and 35-40 % reduction in COD has also observed after the treatment.

4. Effect of pH on Na-Hypochlorite tested and observed best reduction in color at pH 7.0-8.2.

5. Dose optimisation of Na-metabisulphite for the removal of residual chlorine followed by batch activated sludge process is under progress.

The percentage color removal and percent COD reduction after dose optimization of different coagulants/oxidants in a fixed concentration of lignin and tannic acid in the synthetic sample are presented in table below.

Use of ozone UV-light fenton's reagents, Hydrogen peroxide etc. for removal of color from paper mill effluents are proposed for further study.

Treatment of Municipal Wastewater Using SRP Technology

For complete treatment of sewage water, advance treatment processes are required that include chemical treatment with different stages like coagulation, flocculation, precipitation etc, but can also include advanced nutrient removal through nitrification/denitrification and removal of phosphorus. The major objective of the project is to reduce the cost of advance treatment process by recycling coagulants utilizing Sludge Reagent Product (SRP) Technology. If the chemical like coagulants consumption will be reduced in future, the sewage treatment plant may opt for chemical treatment in place of activated sludge process. Following experimental works has been completed during the year.

· Samples from various drains collected and characterised.

· Optimum dose of alum required was determined for coagulation test.

· The efficiency of the recovered alum (Sludge-Reagent Product) tested. It was observed that the efficiency of SRP is not significant after twelve times of recycling.
· The requirement of fresh alum to maintain the efficiency of SRP was also determined. The fresh alum requirement is about 15-20 % of total alum - requirement.

· The drain effluent treated with SRP Technology was further treated with chemical oxidants like H2O2, NaOCl and Fenton's Reagent etc, for further improvement in treated water quality.

Microorganisms in indoor and outdoor environment of some of the public places

Virtually any microorganism can be found within bio-aerosol. Most common microorganisms in terms of abundance are fungi, bacteria, and viruses. Once airborne, these cells can travel for hundreds or even thousands of kilometers. Other components of bio-aerosols include biochemical components of cell or spore walls that remain in the environment even after the cell dies and begin to decay. Each biological particle or an aggregate of particles may originate from any natural or man-made surface. In the present investigation, Office premises; Court; Hospital; Bank; School; Cinema Hall were selected as indoor environment while Kadkadi mod intersection and Seelampur intersection were selected as outdoor environment.

Gravity settling method was adopted for broad classification of the microorganisms. The agar plates were prepared and exposed for a pre-determined period. It has been observed that the microbial counts of various places exhibit variable patterns. However, the office premises have shown the least population as compared to other places. The highly contaminated indoor environment at Hospital and banks have shown poor sanitary conditions.

During a similar experiment, microflora was monitored for outdoor at 108 kundiya Agnihotra at Karwal Nagar, Delhi for about a week using the gravity settling method for quantification of bacterial, fungal populations, general microflora as well as pathogenic population. The sampling was started before the programme and continued after the Agnihotra was over. In general, it has been observed that the Agnihotra has significant impacts on the survival of the microflora. As compare to the background, the reduction in the total microbial population was observed upto 40%. There was a considerable reduction in the pathogenic count (upto 80%). However, there has been found an increase in the fungal population.

The microflora were also studied inside newly constructed operation theatre. The samples were collected from various sections in the operation theatre through gravity settling methods as well as swab sampling before fumigation, during fumigation and after fumigation. The observation data indicate that there exist significant microbial population in the operation theatre. The hospital is required to be equipped for UV-system for complete indoor sterilization.

Spore Testing Methodology for Efficiency Testing of Autoclaves

It is mandatory under the Bio-medical Waste Rules that the nursing homes and hospitals have to install incinerators, autoclaves etc. for treatment of bio-medical waste.

For assessment of efficiency of autoclaves used for hospital waste treatment, spore testing methodology developed by Central Pollution Control Board has been employed. Spores of Bacillus Stereothermophilus were used for efficiency testing of autoclaves, which also act as biological indicator. The assessment of efficiency of autoclaves installed at various hospitals of NCT - Delhi was undertaken. The findings indicated that the bio-medical waste treatment undertaken using autoclaves at various hospitals (where study has been undertaken) was bacteriologically safe for disposal.

Determination of Effluent Toxicity from Tanneries

For the development of toxicity based Minimal National Standards (MINAS) for Tanneries, a collaborative project study had been carried out during year 2003 in collaboration with six laboratories viz. National Institute of Occupational Health (NIOH), Ahmedabad; National Environmental Engineering Research Institute (NEERI), Nagpur; Gujarat Pollution Control Board, Gandhi Nagar; Karnataka State Pollution Control Board, Bangalore; Andhra Pradesh State Pollution Control Board, Hyderabad and CPCB Laboratories at HQs Delhi and Zonal Office - Kanpur.

As per the recommendations of PEER & CORE Committee, the study at vegetable tanneries has been elaborately undertaken again during the year 2002-2003 to monitor additional common effluent treatment plants (CETP's) and effluent treatment plants (ETP's).

The analytical results reflect that the toxicity factor (TF) in the untreated effluent received as influent by CETP & ETP ranged between 8 and 125, whereas Toxicity factor in treated effluent ranged between 1 and 64. The range of toxicity reduction after treatment varied from 50 to 100%.

The proposed toxicity factor (TF) standard derived through the project study is 8, which is much higher than the standard evolved for other categories of industries. The main reason for this is the presence of high amount of Total dissolved solids in tanneries effluent, which is contributed significantly by sodium chloride used during the process for preservation of raw hides. For ETP's the proposed Toxicity Factor (TF) standard further increase to TF 16. It will be more environmental friendly, if the tanneries divert their treated wastewater again into CETP for further treatment, instead of direct discharge into receiving water bodies.

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 salient objectives of the study are as below:

- To Study relative exposure vs. dust capturing capacity of various identified plant species through natural and controlled exposure.

- To evaluate the rate of dust deposition/capture capacity of different plant species (Herbs, Shrubs & Trees)

- To identify Plant species with high potential for Control of Dust/Suspended Particulate Matter in Ambient Air.

- To prepare checklist of Plant species suitable for Phytoremediation of particulate matter from ambient environment.

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.

Geo-accumulation and Bio-accumulation of Heavy Metals and Pesticides

With increasing paucity of fresh water, untreated/partially treated sewage water is increasingly utilized for irrigation. The sewage 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 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.

Development of Methodology for Measurement of Trihalomethanes (THM's) in Drinking Water

Halogenated hydrocarbons are formed as a result of using chlorine as a disinfectant in the water treatment process. Occurrence of natural organic matter such as humic and fulvic acids in water are mainly responsible for the formation of these disinfection byproduct (DBP's). Trihalomethane (THM's) are most commonly occurring and toxic DBP's found in chlorinated waters. World Health Organization (WHO, 1996) have regulated the health related guidelines value for such compounds in drinking water. In order to continuously monitor the presence of these compounds in drinking water, the infrastructure facilities are being developed and streamlined at CPCB Laboratory.

Characterization of Industrial Effluent for Adsorbable Organic Halogen (AOX) in Selected Industries

Chemical compounds often are 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 AOX concentration 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.

Standardization of Analytical Methodology for Polychlorinated Biphenyls (PCB's)

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 analysed. Total concentration of the PCB congeners analysed were ranging between 2.67 ng/L to 18.78 ng/L in river water, between 0.55 ng/g to 8.70 ng/g in river sludges and between 0.05 ng/g to 25.62 ng/g in Drain sludge samples. PCB's were not found detectable in wastewater samples collected from four major drains.

Utilization of Industrial Solid Wastes in Cement Manufacturing

A study on "Assessment of Utilization of Industrial Solid Wastes in Cement Manufacturing" was completed in association with the National Council for Cement and Building Material, Ballabhgarh. The study suggested that following industrial solid wastes may be utilized for cement manufacturing:

· Fly-ash generated from coal-based thermal power plants
· Granulated blast furnace slag generated from iron & steel industry
· Steel slag from iron & steel industry
· Red mud generated from aluminium industry
· Lime sludge generated from paper, acetylene, sugar, fertilizer, sodium chromate and soda ash industries
· Lead-zinc slag generated from zinc industry
· Phosphogypsum, a byproduct waste generated from fertilizer industry
· Jerosite obtained from zinc industry
· Kimberlite obtained in the process of diamond mining
· Pet coke, solid residue generated from oil refineries

Study on Environmental Contamination with Polychlorinated Dioxins

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are created inadvertently by a host of industrial activities in which chlorine based compounds are exposed to a high heat in the presence of organic material. There are 75 positional PCDDs and 135 PCDFs.

The Central Board has taken up a project and engaged NEERI, Nagpur for the study on environmental contamination with polychlorinated dioxins. Standardisation of analytical techniques for the determination of residue levels of PCDDs and PCDFs in water, waste mass and soil samples has been completed and collection of samples from various sources is underway to estimate the levels of TCDDs in water, waste mass and soil samples of the contaminated sites.

Review of Mathematical models for Water Quality Management in Lakes and Ponds

The Central Board has taken up a project to review the mathematical models for water quality management in lakes and ponds. Under the project, six identified models - CE-QUAL-R1, CE-QUAL-W2, WASP-5, BATHTUB, DYRESM and AQUATOX - were critically reviewed. Among these six models, CE-QUAL-R1 has been selected for validation with respect to lakes and ponds. Rabindra Sarovar Lake and Jadavpur University Pond have been selected for model validation. This is a dynamic uni-dimensional model to stimulate vertical profiles of water quality in ponds and lakes. This model is not applicable to flowing water bodies. This model is recommended for regulatory purposes after thorough scrutiny of applicability for the water quality parameters, in different zones of India.

Testing and Validation of BOD Bio-sensor

Biochemical Oxygen Demand (BOD) is the most important parameter in water quality monitoring. The test takes considerable time - 3 days at 270C or 5 days at 200C - as well as consumes lots of energy in incubation. To overcome these constraints, attempts are being made to carry out the test in short time through the techniques using Biosensor probes. This technique involves selection of suitable microbial composition for using bio-sensor so as to degrade the wide range of wastes. The Central Board is attempting, in association with the Centre of Biochemical Technology, Delhi, to develop bio-sensor for BOD tests. Trial analysis was carried out for various effluent samples and the results are compared with BOD values obtained from conventional BOD analysis.

Development and Standardization of Soil and Solid Waste Analysis

A project was initiated to standardize the analysis of soil and solid waste for analytical quality control (AQC). During the year 2003, characterization of electroplating waste has been carried out. For next round, it is planned to analyze flyash and tannery waste covering physicochemical and heavy metal parameters.

Comparative Studies on Analysis and Characterization of Hazardous Waste

A project has been initiated to carryout a comparative study on various leachate test procedures using wastes generated from different units like tannery, lead and zinc recovery, pesticides, basic drugs, dyes and dye-intermediates and landfill sites for deriving a better choice of method in the light of the Hazardous Waste Management and Handling Rules, 2000 (Amended). The main objectives of the study are:

· To assess the merits and demerits of various leaching procedures;
· To estimate variations in the levels of leaching under various test methods; and,
· To suggest a suitable test procedure for toxicity characterization to be followed uniformly in the country

During the year 2003, solid waste samples from electroplating units have been collected, homogenized, extracted under various extraction procedures and then analyzed for metals. In addition, total metal contents of the sample were also analyzed for comparison purpose. The general characteristic of the waste in terms of pH, conductivity, total water soluble solids, loss on ignition and organic carbon were carried out. Further studies are in progress.

Technology Development of Specific Microbial Packages for Treatment of Paper & Pulp Industrial Waste

The efficiency of industrial wastewater treatment depends upon the nature of wastes and their reaction with microbes present. There are specific group of bacteria, which act effectively with specific type of waste and degrade the waste in a fast and efficient manner. Keeping this fact in view, a project was initiated in collaboration with Centre for Biochemical Technology, CSIR with sponsorship from Department of Biotechnology, New Delhi. Samples from pulp and paper mill were collected and analyzed and characterization has been made for screening the suitable and efficient bacterial composition. These microbes have been developed and it is planned to study the efficiency of the consortium in pilot plant study.