Suggestive Measures of Water Pollution

Industrial activities generate a large number and variety of waste products, which are generally discharged into water streams. The nature of industrial wastes depends upon the industrial processes in which they originate. The ultimate disposal of wastewater can only be onto the land or into the water. But whenever the watercourses are used for the ultimate disposal, the wastewater is given a treatment to prevent any injury to the aquatic life in the receiving water. Normally, the treatment consists of the removal of suspended and dissolved solids through different units of the treatment plants. Engineers can design a treatment plant to accomplish any degree of treatment. But a complete treatment or 100% removal of the pollution load is uneconomical and never aimed at in any waste treatment plant. Wastewater treatment technology should be developed and implemented area-wise. The watercourses can assimilate certain portion of the pollution load without affecting seriously the water quality and the environment. Suspended Solids (SS) and 5-day 200C BOD (BOD)5are the usual parameters of pollution, particularly in domestic wastewaters. However, with a greater amount of water use, more amount of solids per capita are expected to join the wastewater flow, but it remains fairly constant beyond a waste flow rate of about 450 litres/capita/day. The per capita contributions of SS, Total Solids and BOD5in different Indian cities are shown in Table 1.

The natural purification is a slow process and depends on various factors. When pollutants are discharge into a stream, a succession of changes in water quality take place, in the down-stream side of the point of pollution. The resulting pattern of change along the stream establishes a well-defined profile of pollution and self-purification, which again changes with seasons and hydrology. The removal of organics are accomplished by : (i) Settling and adsorption (ii) Micro-Biological activities.

INDUSTRIAL WASTEWATER TREATMENT

While a huge amount of water is required for different industrial processes, only a small fraction of the same is incorporated in their products and lost by evaporation; the rest finds its way into the watercourses as wastewater. Thus, the industries join the municipalities to contribute to the ―pollution‖ of the natural bodies of water.The industrial wastes either join the streams or other natural water bodies directly or are emptied into the municipal sewers. Thus, these wastes affect in some way or other, the

industrial wastes, due to its growing pollution potential arising out of the rapid industrialization of the country. We have three alternatives for the disposalof industrial wastes viz. (i) The direct disposal of waste into the streams without any treatment, (ii) Discharge of the wastes into the municipal sewers for combined treatment and (iii) Separate treatment of the industrial wastes before discharging the same into the water bodies. The selection of a particular process depends in various factors like the following: (i) Self-purification capacity of thestreams. (ii) Permissible limits of the pollutants in the water bodies, established by law. (iii) Economic interests of both the municipalities and theindustries. (iv) Technical advantages, if any, in mixing the industrial wastes with domesticsewage.

Unlike the domestic sewage, the industrial wastes are very difficult to generalize. The characteristics of the industrial wastes not only vary with the type of the industry, but also from plant to plant producing same type of end products. Difficult types of liquid wastes originate from various types of industrial processes. The pollutants include the raw materials, process chemicals, final products, process intermediates, process by-products and impurities in raw materials and process chemicals. Broadly, these pollutantscan be classified as follows: (a) Organic substances that deplete the oxygen content of the receiving streams and impose a great load on the biological units of the sewage treatmentplant. (b) Inorganic substances like carbonates, chlorides, nitrogen, etc. that render the water body unfit for further use and sometimes encourage the growth of some undesirable micro-plants in the body ofwater. (c) Acids or alkalis which make the receiving stream unsuitable for the growth of fish and other aquatic life there and cause serious difficulties in the operation of sewage treatmentplants. (d) Toxic substances like cyanides, sulphides, acetylene, alcohol, petrol, etc. which cause damage to the flora and fauna of the receiving streams, affect the municipal treatment processes and some tomes endanger the

(a) Color producing substances like dyes, which though not toxic, are aesthetically objectionable when present in the watersupplies. (b) Oil and other floating substances, which not only render the streams unsightly, but also interfere with the self-purification of the same, and the operation of the sewage treatmentplants. Characteristics of the wastes from some selected Indian industries are given in Table 3. Table 3: Pollution Characteristics of Different Industries

The chemical treatment should be provided only when it becomes unavoidable. The selection of the particular treatment process depends on the effluent requirements and the characteristics of thewaste.The situation of wastewater treatment is not satisfactory even in metropolitan cities. Proper collection and disposal of liquid and solid waste is very important for the overall health of urban cities. It is a pity to note that none of the cities in the country collects and disposes its solid waste in a safe manner. Besides the municipal solid waste, which is organic and inert in composition, the hospital waste,

i) The Govt. should immediately make laws banning industrial pollution. Failure to do so will lead to substantial penalties and fine. The Govt. of India has passed ‗The Water Act‘, ‗The Air Act‘ and‗EnvironmentalProtection Act, 1986. ii) The 90% water pollution in cities is due to human wastes, which can easily be avoided by using the wastes in the preparation of useful things, e.g. in America the house waste is used for constructing the roads. Recently C.B.R.I., Roorkee, has used the ashes of thermal power stations in preparing bricks. Thus wastes can be utilized for useful purposes. iii) The water treatment plants should be installed in ruralareas. iv) The rural inhabitants should try to avoid the use of pesticides in their fields. The DDT is the most harmful compound and hence must be completely banned inIndia. v) The effluent from the factories should be treated first before adding to the rivers. The excess harmful constituents of the effluent should be removed in the factory by designing various plants such as screw pumps, screens, settling tanks, thickness and aerators. For solid waste pollution, the dust free, smoke free and flash free incinerators can be recommended for organic and pathologicalwaste. vi) All small scale and big industries must have anti-pollutionunit. vii) Persons carrying on industry, operation, etc. not to allow emission or discharge of environmental pollutants in excess of thestandards. viii) Create the awareness about the effects of high concentration of nitrate, fluoride, solids and hardness amongvillagers. ix) Provide the knowledge of de-fluorination of water invillagers. x) The Government and Community should do better water management in conservingwater. xi) Through strict implementation of the Govt‘s water treatment programme. Water can be rendered safe fordrinking. xiii) Spending an equal amount on water supply systems as society would have spent in curing them can eliminate 75% of diseases that afflict Indian culture. xiv) Environmental courts should be set up in every district to deal with the cases relating to violations of environmentallaws.

CONCLUSION

1. Walton G., Survey of Literature Relating to Infant Methemoglobinaemia Due to Nitrate Contaminated Water, American Journal of Public Health, 41: 986–996(1951). 2. Fair G.M., J.C. Geyer and D.A. Okun, Water and Waste Water Engg.: Vol. 2, John Wiley – Toppan Co. Ltd.(1968). 3. Koziorowski B. and J. Kucharski, Industrial Disposal, PergamonPress (1972). 4. Hammer H.J., Water and Waste Water Technology, John Wiley Co. Ltd., New York(1975). 5. Rao M.N. and A.K. Datta, Waste Water Treatment, 2nd Edi., Oxford &IBH Publishing Co. Pvt. Ltd., New Delhi(1987). 6. Sharma H.S., Agrawal P.K. and Prabha S., Water Quality of Sewage Drains Entering Yamuna River at Mathura (U.P.), J. Environ. Biol., 21(4): 375–378 (2000).

Meerut(2005). 8. Singh Vijendra, Assessment of the Quality of Wastewater and Groundwater for Irrigation Purpose. Chemical and Environmental Research. 15(1&2): 165–168 (2006). 9. Singh Vijendra, Analytical Study of Heavy Metals of Industrial Effluents of Jaipur, Rajasthan. Journal of Environmental Science & Engineering. 48(2): 103–108 (2006). 10. Matta Gangan, Amit Chauhan, Avinash Kumar, Ajendra Kumar, Impact of industrial affiliate on groundwater and surface water quality. A case study of damper region (UP),India General of Chemical and Pharmaceutical Sciences, 9(2) : 709-713 (2016). 11. Singh Vijendra,Estimation of Heavy Metals in Groundwater at Residential Area Nearby Major Industrial Areas of Jaipur City. International Journal for Environmental Rehabilitation and Conservation. VIII(2): 82–87 (2017). 12. Singh Vijendra, Appraisal of Toxic Heavy Metals in Groundwater at Suburban Area Nearby Major Industrial Regions of Jaipur. Journal of Advances and Scholarly Researches in Allied Education. 16(4): 1288 – 1290 (2019).

Associate Professor, Department of Chemistry, Rajkiya Mahila Snatkottar Mahavidhyalaya, Kandhla (Shamli)