ENVIRONMENTAL STANDARDS

Development of Emission Standards and Stack Height Regulations for the Vertical Shaft Brick Kiln vis-a vis Pollution Control Measures

Vertical Shaft Brick Kiln (VSBK) is a vertical type kiln as against the traditional Bull Trench Brick Kiln (BTKs), which has horizontal kiln. The kiln is a natural draft system and uses no electricity for operation. Dry green bricks are loaded manually at the top of the kiln and `measured quantity' of crushed coal of specified size (5-20 mm) is sprinkled over the brick layers, Loading is done in batches after unloading, and each batch consists of 4 layers of bricks. The entire brick batches are supported by support by bars provided at the bottom. Normal cycle for brick production varies between 26-30 hrs. During unloading, the entire brick load is transferred to a screw jack system over which a trolly is rested one batch of brick is brought down to facilitate unloading. The support bars are put back to transfer the load back to them and the trolly is brought down. The production capacity of Vertical shaft brick kiln depends on shaft size and number of shafts. About 20 VSBKs are in operation in different regions of the country.

The Ministry of Environment and Forests based on recommendations of the Central Pollution Control Board has introduced emission standards for bull trench kiln during 1996. The standards also envisaged phasing out of moving chimney from BTKs. The Central Board took up the work of evolving emission standards stack height regulations vis-a-vis pollution control measures with active support of TERI, New Delhi.

The performance of VSBKs was monitored during the year 2002. The SPM concentration in the stack was measured between 77-372 mg/Nm3. Some of the advantages of the VSBK technology include 1) lower energy consumption (30-60% energy saving); 2) low SPM emissions; 3) less floor area requirement for construction of kilns; 4) flexibility in operation; 5) uniform quality of fired bricks; and 6) ability to operate throughout the year, as against BTKs. Keeping these factors in view, VSBK may offer as an alternate viable technology for moving chimney BTKs low capacity and also for clamps.

The energy performance of the VSBKs shows the average specific energy consumption of VSBKs is 0.9 MJ/kg fired bricks lower than the traditional firing technologies used in the country. The VSBK technology has lower emission levels, thus having good potential in the market.

Development of Comprehensive Industry Document

Development of Comprehensive Industry Document and Environment Standards for Refractory Industry

Refractories are materials, which can withstand high temperature. Their essential function is to serve as structural materials in kilns and thus, their usefulness depends on their ability to maintain mechanical properties at high temperature. In fact refractories are indispensable at almost all ferrous and non-ferrous industries, where high temperature furnaces or kilns are being used. The steel and metallurgical industries greatly depend on refractories involving high temperature application. Refractories are basically heat and corrosion resistant materials used in furnaces. The refractories find application in steel industry, cement, aluminum and glass industry. The steel industry accounts for nearly 75 percent of the consumption of refractories, whereas cement industry accounts around 11 percent. The aluminum and glass industry consumes around six and four percent of refractory products respectively. All other industries consume only four percent of refractory products. Today the refractory production capacity in India is sufficient to cater the national requirement quantitatively but for the quality imports are necessary, especially for steel industry. In India small refractory plants are mostly in unorganised sector, whereas, there are few large and medium capacity refractory plants producing various types of export quality refractory products.

Broadly, the refractory can be categorized based on the installed capacity. On the basis of plant capacity (Thousand Tonnes per Annum, TPA), the refractory plants are categorized as very small scale (up to 5000 TPA), small scale (5001-15000 TPA), medium (15001-50000 TPA) and large capacity (above 50000 TPA) refractory plant.

There are about 6 large, 17 medium scale and 63 refractory plants in the category of small or very small scale sector in the country. Because of sluggish demand from end-user industry and competition from quality imports, some of the refractory manufacturers are facing tough situation while few are on the verge of closure or have been closed. The use of high quality refractories has improved the lining life of furnaces and brought down the specific consumption per tonne of liquid steel resulting in a lower per tonne usage of refractories, which has adverse impact on traditional refractory manufacturing.

The primary pollutant of concern in refractory plant is particulate matter or dust in air emission apart from water pollution, solid wastes and noise pollution. Particulate matter in terms of fugitive dust generation takes place during crushing, grinding and screening operation in plant. During the study, the present status of pollution in refractory industry and their control, different technologies adopted by Indian refractory industry to combat pollution and finally to develop norms for pollution control. The study has been undertaken in collaboration with National Council for Cement & Building Materials. Ambient air quality, fugitive dust, stack emission, trade effluent, noise pollution & solid waste were monitored during the course of study.

Development of Comprehensive Industry Document and Emission Standards for Hot Mix Plants

Construction of roads play a vital role in Socio-economic development of the country. Ever since the Government of India declared infrastructure developmentas the thrust area, there has been predominant boom in the road construction sector. The construction and maintenance of major portion of the road network is undertaken using conventional hot bitumen-mixes. The hot bitumen mixes are prepared in hot mix plants, which emits significant emission containing particulate matter, sulphur dioxide besides carcinogenic poly-aromatic hydrocarbons. There are more than 1000 hot mix plants of different categories operating in different parts of the country. As per the survey undertaken by Central Building Research Institute (CBRI), Roorkee, plants are of stationary, drum- continuous type. The rated production capacity varies from 6-10 tphr to 10-120 tphr. The locations of these plants keep on changing. Burning of fuel, feeding of aggregates, heating of bitumen from large number of plants are bound to create environmental hazard because of emission of dust and volatile organic compounds like BTX, PAH and PCB's.

Central Pollution Control Board has initiated preparation of Comprehensive Industry Document (COINDS) on Hot Mix Plants in an effort to minimize the adverse environmental impacts by regulating emissions. Information on plant, process details, pollution control technology, emissions, plant location, etc. was collected through extensive field visits as well as questionnaire surveys. The COINDS includes development of environmental standards, suitable techno-economic pollution control device and guidelines for its operation and maintenance.

Development of Environmental Standards for Wheat Processing, Flour Mills, Pulse Grinding and Milling, Dry Rice Grinding and Rice Mills

There are a large number of units spread across the country engaged in pulse milling, dry rice and besan grinding, wheat processing and flour making mills and rice mills. These units mostly use conventional production technologies, which are not oriented towards minimising pollution by incorporation of in-plant control measures. These units give rise to substantial pollution of air, water, noise etc. The Central Board desires to evolve environmental standards for these mills with the help of the National Productivity Council, New Delhi.

The objective of the project is to study the problem of noise, emission and effluent disposal, best available technology not involving excessive cost to prevent, abate and control water, air and noise pollution and to develop standards for noise, emission and effluent including storm water disposal for wheat flour mills, pulses making mills, dry rice, pulses grinding mills and emission standards for rice mills. The scope of work for this project is:

· Literature survey/review of State-of-the art technologies; and

· Information collection from State Pollution Control Boards (SPCBs), Industry, etc.

About 20 plants (e.g., five in each category - wheat flour, wheat process, rice mill, rice & pulse grinding, pulse making units) have to be studied in depth by conducting monitoring for the following:

- Characteristics of emission and the quantity;

- Characteristics of effluent streams and the quantity;

- Characteristics of storm water run of; and

- Identification of source of noise pollution and noise measurement.

Technologies are being reviewed for abatement, prevention and control of water pollution, abatement, prevention and control of air pollution, handling of storm water within plant area, control of noise pollution at source, and assessment of adaptability of technologies in Indian context.

Development of COINDS for Tea Processing Industries

India is one of the major exporters of black tea. Tea is grown in certain districts of Assam, West Bengal, Kerala, Karnataka and Tamil Nadu and to some extent in Tripura, Uttar Pradesh and Himachal Pradesh. The average yield of tea was approximately 1670 kg/hectare during the year 2000 and total area under tea cultivation was about 5,00,000 hectares.

Source of air emission in the tea industry is basically the D.G. set which is operated only during the power shut-down period. The following efforts are needed from the management towards controlling the air emission.

· Use of low sulphur fuel for combustion purpose in D.G. sets.

· Use of tall stack.

· Avoiding frequent start-up and shut-down of D.G. sets.

Source of wastewater in the tea industry is the domestic sector, since the industrial process is basically dry in nature. It is recommended that the generated domestic waste be treated in simple treatment system prior to its final disposal. The wastewater so generated may be treated in Septic Tank. Partially treated effluent from the septic tank should either be disposed of in soak pits or to be further treated in up-flow anaerobic filter (UFAF) treatment unit. The treated effluent from the UFAF could be discharged into any inland surface water or can be used for gardening purpose. Apart from such treatment the management should also practice the following : (1) Reduced wastage of water, (2) Reduced volume of water use, (3) Use of treated water for gardening purpose.

The tea plants provide some green manure from leaf-fall; where shade trees are planted their leaves also form green manure. The waste from factories amounting to about 2% of total production may either be recycled in the process, returned to the field as fertilizer or may be reprocessed for by-product recovery. -Tea industry produces solid waste, which amounts to about 2.0% of the black tea production. 0.3% of this waste is recycled using some special technique. The balance 1.7% of the solid waste does not have any use value to the black tea producers and is normally sold to selected reprocessing units, where some chemical byproducts are recovered from this waste.

National Emission Standards for Petrochemical Plants

Air emissions from a petrochemical complex are crucial with respect to pollution control as some emissions are hazardous in nature. Fugitive air emissions from pumps, valves, flanges, storage tanks, loading and unloading operations, and wastewater treatment accounts for 85 to 95 % of total hydro carbon emissions and are of major concern, due to its volume and carcinogenic nature. Therefore, in order to prioritise the pollution control programme, air pollutants from petrochemical industries have been classified into high, medium, and just priority pollutants.

Besides the control technologies, in respect of combustion, process, fugitive, emissions, and flare management have been reviewed for their suitability. The technical inputs from the expatriate experts is also being taken to strengthen the process development of techno-economically feasible standards.

National Emission Standards for Pesticides Manufacturing Industry

In pesticides industry, pollution generates in all forms i.e. emissions, wastewater and solid/hazardous waste due to thermodynamic limitations, incomplete reaction, failure of stoichiometric requirement of raw material in the process operation, impurities present in raw materials, etc. Gaseous emissions could be channelized i.e. coming out through vent/stack from specific production process or fugitive in nature (leaks spills etc.), containing several gaseous pollutants. Handling of emissions being sensitive with respect to impact, the emphasis is often given to adopt appropriate pollution control technologies.

Pesticides industry is critical in terms of nature of raw material usage and final products/by-products, thus demands special care/attention. It is well established that the process of development of industry-specific-standards considers techno-economic feasibility as the criteria. This criteria demands the review of technologies for control of pollutants emanating from the industries and cost implications due to such pollution control equipment and bearing on health & environment. Therefore, looking at the complexity, the findings of the study, have been reviewed through a foreign consultant to suggest the best practices being followed in advanced countries, and options for improvement in terms of technologies (best available & best practicable) suitable to Indian pesticides industries.

The Central Board has identified priority pollutants, control technologies, efficiency of control and presently achievable standards. Besides studying the existing technologies, a review of best available technologies has been made through an expatriate consultant considering the best practicable technologies, while considering the economic feasibility for the purpose of arriving at suitable emission standards. The standards proposed will be finalised through consultation process.

Development of Rationale for Prescribing Location Specific Standards

The Central Pollution Control Board took up a project to study the existing practices in prescribing stringent location specific standards by various State Pollution Control Boards and to develop a rationale for the same.

For application of the strategy for location specific standards in the field, two sites In Andhra Pradesh have been chosen i.e. one at Rajahmundry, where plenty of dilution available in the river (Godavary) and the other at Patancheru, where limited dilution available in the river (Manjeera) and large number of industries are situated.

Under this programme, emphasis has been given to assess the assimilative capacity of the environment with respect to air and water pollution. Several models have been reviewed for their suitability and a compilation of the above studies coupled with choice of control technologies, affordability is being considered to formulate rationale. In this process, the experiences of developed countries are being taken through Wisconsin University, USA.

These studies will suggest rationale to be followed in areas where the ambient requirements demand stricter standards.

Control of Volatile Organic Compounds in Industrial Emissions

The Central Board has identified Volatile Organic Compounds (VOCs), as one of the parameters in industrial emissions, which needs to be controlled to protect the quality of the receiving environment. Considering usage of various solvents and other raw materials in chemical and other specific industries, there is a need to specify control parameters, to govern the volatile compounds.

The selected industrial sectors such as oil refineries, petrochemicals, drugs & pharmaceuticals, pesticides and electronic industries are being studied for existing control measures for VOCs in order to suggest choice of better control technologies/practices to evolve common minimum programme.

Besides, with respect to hazardous air pollutants, there is a need to change the fittings such as valves, pumps, joints, etc which eliminates fugitive emissions due to leakages. A Leak detection and repair (LDAR) programme is required to be introduced. With this understanding, guidelines/norms are being developed.

Review of Environmental Statements

The Ministry of Environment and Forests, Government of India issued notification for submission of 'Environmental Statements' (ES) by the industries to the respective State Pollution Control Boards (SPCBs) in April, 1992 and further amended in April, 1993. ES is a pro-active tool for self-examination of the industry itself to reduce/minimise pollution by adopting process modifications, recycling and reuse of the resources. The regular submission of ES will indicate the systematic improvement in conservation of resources and environmental pollution control being achieved by the industry. ES can also be used as a set of environmental performance indicators for relative comparison, implementation and to promote better practices.

In order to assess the ES, a project has been taken-up by the Ministry of Environment & Forests for "Review of Environmental Statements Submitted by the industries" and this is being undertaken by the Central Pollution Control Board (CPCB). CPCB, in turn, has included Experts with respect to eleven sectors: i) tanneries ii) bulk-drug industries iii) thermal power stations iv) sugar industries v) cement industries vi) iron & steel plants vii) textile industries viii) pesticides industries ix) petrochemical plants x) pulp & paper industries and xi) oil refineries. The review for sugar industry has been completed and others are in the process of finalisation. The outcome of the exercise has been utilised for setting environmental benchmarks for attainment by all the industries. A similar exercise is being done in other sectors also, to promote systematic improvement.

Status of Water Treatment Technologies including Consumption of Chemicals/ Disinfectants in Water Treatment Plants and Management of Wastewater/ Sludge

The municipalities and corporations are under stress to provide adequate basic amenities such as water supply, sanitation and infrastructure to cope-up with pace of urbanisation. Urban activities do have a negative influence on quality of intake water. Besides the rejects from water treatment plants i.e. filter back-wash water and sludge generated from treatment units require proper disposal. The quantity of the backwash water varies with the influent quality, which ranges from 3 to 5% i.e. a plant of 100 MGD capacity will generate 3 to 5 MGD back wash water. The amount of chemical consumption varies from plant to plant and often there is a lack of control on chemical consumption. With this background, the Central Pollution Control Board has taken-up the project to study the chemical consumption and waste management patterns in the water treatment plants. Under the study, many treatment plants have been visited for dry and wet studies. Some specific field studies at fluorosis and arsenic affected areas are also under the progress. The broad observations on the treatment plants indicate that there is a need for rationalising the process and disposal mechanism, which may require, administrative and operational measures.

Development of Toxicity Factor as a Governing Parameter

The cumulative governing parameters are preferred in environmental sampling such as AOx for all halides. Synergistic and Antagonistic effects of different combinations of pollutants will not be addressed, if individual standards are prescribed for each pollutant, thus The governing parameters indicate the necessity of having detailed analysis of each constituent and as such represents the cumulative effects. Thus, such parameters are encouraged for regulatory purpose for ease in checking the compliance. Therefore, with the same perception, a common parameter to represent the toxicity has been developed by the Central Pollution Control Board i.e. Toxicity Factor. It is defined as the dilution factor of the effluent at which 100% survival of Zebra fish (Brachidanio rerio - Halilton Buchanan) ensured for 48 hours. Means, toxicity factor 1 represents the effluent sample without dilution with water, Toxicity factor 2 represents addition of same amount of water with the effluent (1:1); Toxicity Factor 4 represents (1:3 - one part effluent and 3 parts of water) etc.

The tests for Toxicity factor have been carried out with respect to wastewaters arising from pesticides, bulk-drugs, dye & dye intermediates, textiles and tanneries. The results have been processed statistically to assess the present percent level of achievement by the respective industrial sectors.

Standards for Generator Sets

Noise Limits for Diesel Generator Sets

Revised noise limits for Diesel Generator sets (upto 1000 KVA) were notified, vide GSR 371(E), May 17, 2002. This regulation requires mandatory provision of acoustic enclosure at the manufacturing stage for all new diesel generator sets, effective from July 1, 2003. The maximum permissible sound pressure level for new generator sets (upto 1000 KVA) run on diesel, according to this new regulation shall be 75 dB(A) at 1 m from the enclosure surface.

For existing diesel generator sets, the noise from the DG set shall be controlled by providing an acoustic enclosure or acoustic treatment of the room for DG sets. Such acoustic enclosures/acoustically treated rooms, shall be so designed for minimum 25 dB(A) insertion loss or for meeting the ambient noise standards, whichever is on higher side.

Compliance Procedure for Noise Limits for Generator Sets

Petrol/Kerosene Generator Sets

Compliance procedure for noise limits for generator sets run on petrol/kerosene has been finalised. The implementation of the standards has commenced with effect from September 1, 2002.

Diesel Generator Sets (upto 1000 KVA)

Compliance procedure for noise limits for generator sets run on diesel has been finalised and will be circulated to the concerned testing agencies.

New Diesel Generator Sets (upto 800 KW)

Compliance procedure for emission limits for new diesel engines (upto 800 KW) for genset applications is being developed.

Generator Set Emissions

Emission limits for new diesel engines (upto 800 KW) for generator sets applications were notified. This regulation specifies the emission limits for different ratings.

Emission standards for diesel engines rating more than 800 KW for power plant, generator set applications and other requirements were notified.

Development of Guidelines for Environmental Clearance to Proposed Distilleries

A group of experts was constituted for recommending criteria/technology for environmental clearance to the distilleries. Experts and officers of CPCB & MoEF had discussion on various issues and based on detailed discussion, the the following is recommended;

The Expert Group has classified distilleries in two groups based on their capacity of alcohol production :

Class I : Distilleries having capacity of less than 45 kld; and

Class II : Distilleries having capacity more than 45 kld.

For class I distilleries, i.e. distillery having capacity less than 45 kld

Following alternative technologies are recommended to be adopted for treatment and disposal of spent wash for allowing new distilleries :

i. Bio-methanation followed by composting;

ii. Composting of spentwash directly;

iii. Evaporation and drying/incineration of spent wash; and

iv. Bio-methanation followed by evaporation and drying/incineration

Distilleries may also be allowed to adopt evaporation followed by composting of concentrated liquor. This will have a beneficial effect of reducing press mud requirement.

A minimum storage capacity to store spent wash of one months production will have to be created by the distillery so that spent wash can be stored during rainy season

For Class-II distilleries; i.e. distilleries having capacity more than 45 kld

The Expert Group recommended that distilleries having capacity more than 45 kld may be allowed to operate with evaporation and drying/incineration technology for the treatment and disposal of spent wash. This may be alongwith or without bio-methanation process. Alternatively, the industry may also opt for evaporation and composting of the concentrated spent wash.

Quantity of Spent wash from Distillery Plant :

The generation of spent wash should be limited to 8-10 kl/kl of Rectified Spirit(RS). This may be achieved either by adoption of the continuous fermentation technology or by providing reboiler. In the case of incineration preceded by bio-methanation system, spentwash generation upto 15 kl per kl of RS production may be allowed.

In case, the distillery is situated near the coastal area, its disposal with proper treatment will have to be analysed in detail considering marine biological aspect of the area as well as other considerations, i.e. dilution effect of the seawater etc.

Development of requirement for Compost plant in Distilleries

The 3- Member Committee constituted by the Hon'ble Supreme Court in the matter of Distilleries in Haryana State had taken assistance of technical experts, consultants, officers form Central Pollution Control Board and Haryana State Pollution Control Board to decide the requirements/specification for surface compost process utilizing distillery spent wash and press mud. The general requirements/specification for surface compost process by utilizing spent wash and press mud were evolved.

Development of requirements for Treatment & Disposal of Distillery effluent

The 3 - member Committee Constituted by the Hon'ble Supreme Court in the matter of Distilleries of Haryana State had taken assistance of technical experts and officers of CPCB to decide requirements for treatment & disposal of distillery effluents. The requirements for treatment & disposal of distillery effluent have been prepared in detail.

Colour Removal from Black Liquor of Agro-Based Pulp & Paper Mills

Colour in the effluent from agro-based pulp & paper mills is caused by discharge of black liquor containing lignin. A study has been undertaken on removal of colour from the black liquor by removing lignin using electro-flocculation process. The study in the laboratory has been undertaken on black liquor generated as well as on black liquor collected from the mills manufacturing unbleached as well as bleached grade of paper.

The results of analysis shows that iron electrode has been found effective in removal of colour, lignin and COD. Removal to the extent of 98%(lignin) and 86%(colour) achieved at a 6.0 pH and temperature of 400C. The optimum time requirement was 40 min for complete electro-flocculation process. The process was carried out at different total solid concentration ranging between 0.5% to 2% and optimum results were at 1.5% concentration.

The trial was also done with the black liquor sample collected from paper mill manufacturing bleached and unbleached grade of paper. The black liquor was subjected to electro-flocculation using different volumes i.e. 2 l, 5 l and 7 l under optimum conditions.

Pollution Control in Slaughter House

The slaughter houses are mainly water polluting units. They also cause air pollution by way of foul smell and generate substantial quantity of solid wastes. It is therefore, necessary that these units should install proper treatment systems.

The Central Pollution Control Board has asked the State Pollution Control Boards and Pollution Control Committees to take action against slaughter houses and related units which are not complying with the pollution control requirements. In order to speed up pollution control implementation, directions have been issued to the State Boards under Section 18(1)(b) of the Water (Prevention and Control of Pollution) Act, 1974 for taking action in case of such slaughter houses and related industries. The State Boards have been directed to issue following directions to slaughter houses/ meat processing industries, which don't have requisite effluent treatment plants:

· To submit a time schedule for installation of effluent treatment plant to State Pollution Control Board within one month from the date of issue of the direction;

· To install requisite effluent treatment plant as per the time schedule agreed by State Pollution Control Board; and

· To submit quarterly progress report on installation of the effluent treatment plant to State Pollution Control Board.

Pollution Control in Industries

Pollution Control in Ginning Industries

Cotton ginning is an interface between farming and industrial sectors from cotton to textile production, and engaged in the process of separation of cotton fibres from Cotton balls. Ginning industries are mostly small units located in semi-rural and small towns. During the ginning process, dust fibres and lint are generated which cause air pollution. Studies were carried out in ginning industries to identify pollution problems and suggest remedial measures.

Prospects and Status of Natural Dyes

To assess the prospects and status of natural dyes, the study has been initiated which includes availability of raw materials, process technologies, current demand, usage and problems in development/manufacture of natural dyes.

Review of Standards for Oil Refineries

The standards for discharge of effluent and emissions from oil refineries were notified in the years 1986 and 1990 respectively. There is need to include additional parameters such as oxides of nitrogen, volatile organic compounds etc. Since developments has taken place in the refining technology and pollution control. New process units are also being added to meet the improved fuel quality standards.

The project has been taken up for the revision of the standards for oil refineries based on performance as well as technology based approach and include mass based and concentration-based standards for various process operations of refineries. A leak detection and repair (LDAR) programme and specific requirements for minimizing vapour losses from storage tanks and product loading/unloading facilities are being considered to regulate the fugitive emissions of volatile organic compounds.

Control of acid mist from Sulphuric Acid Plants

Sulphuric Acid plants emit oxides of sulphur and acid mist in the atmosphere. Presently emission limits are prescribed as 4.0 kg/tonne of concentrated acid produced for SOx and 50 mg/nm3 for acid mist. A study was undertaken to study the possibilities of technology upgradation in existing sulphuric acid plants and use of state-of-the-art technology in new plants to further reduce and control oxides of sulphur and acid mists.