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Electrical Energy Management
Electricity or electric power is produced by generators. The generators are operated by the turbines attached to it. The turbines are rotated by steam, moving water or wind power to produce electricity.
Conservation of electrical energy
The following measures can be taken even at home and school to save electricity
(i) Use energy efficient appliances to save electricity like Compact Fluorescent Lamps (CFL), Light Emitting Diode (LED)bulbs and other electric equipments.
(ii) Switch off the lights and fans, television and other electrical appliances when not in use.
(iii) Switch of the mobile phone chargers when not in use.
(iv) Maximize the use of solar radiation. Solar water heating system can be used instead of electric geysers.
(v) Minimize the use of air conditioners.
E-Wastes and its Management
E-wastes are generally called as electronic wastes, which includes the spoiled, outdated, non-repairable electrical and electronic devices. These wastes contain toxic metals like lead, cadmium, chromium and mercury, though also contain iron, copper, silicon, aluminum and gold which can be recovered. Neverthless, only 5 % of e-wastes produced are recycled.
Sources of e-wastes
Electronic devices: Computers, laptops, mobile phones, printers, monitors, televisions, DVD players, calculators, toys, sport equipments, etc.
Household electrical appliances: Refrigerators, washing machine, microwave oven, mixer, grinder, water heater, etc.
Accessories: Printing cartridges, batteries and chargers.
Environmental impact of e-wastes
Disposal of any kind of electrical and electronic devices without knowledge can become the landfill and water pollutants.
Electronic equipments contain many hazardous heavy metals such as lead, cadmium that can cause severe soil and groundwater pollution.
E-waste dumping yards and the places nearby are polluted and cause severe health hazard.
Untreated sewage or wastewater generated from domestic and industrial process is the leading polluter of water sources in India. Sewage water results in agricultural contamination and environmental degradation.
Sources of Sewage/wastewater
• Domestic purpose or household activities
• Dye and textile industries
• Leather industries
• Sugar and breweries industries
• Paper and pulp industries
The conventional wastewater treatment methods involve the following steps
(c) Sludge Management and
(d) Water Reuse.
Pre-screening: Wastewater generated from domestic and industrial activities is screened to remove soil and solid particulates.
Aeration: Screened wastewater is then pumped to an aeration tank. Here the microbial contaminants are removed by the biological degradation that occurs in the presence of air.
Sedimentation process: In this process, the solid particles in suspension form are allowed to settle. The particles that settle out from the suspension is known as sludge.
Sludge removal: The sludge generated by the degradation process is transferred periodically from the tank for safe disposal.
Disinfection: Chlorination and ultraviolet (UV) radiation of treated water is required to remove any microorganism
Water recycling: The water will then be supplied for domestic or industrial purposes.
Solid Waste Management
Solid wastes mainly include municipal wastes, hospital wastes, industrial wastes and e-wastes etc. The solid wastes are dumped in the soil which results in landscape pollution.
Solid-waste management involves the collection, treatment and proper disposing of solid material that is discarded from the household and industrial activities.
Methods of solid wastes disposal
(i) Segregation: It is the separation of different type of waste materials like biodegradable and non biodegradable wastes.
(ii) Sanitary landfill: Solid wastes are dumped into low lying areas. The layers are compacted by trucks to allow settlement.The waste materials get stabilized in about 2-12 months. The organic matter undergoes decomposition.
(iii) Incineration: It is the burning of non-biodegradable solid wastes (medical wastes) in properly constructed furnace at high temperature.
(iv) Composting: Biodegradable matter of solid wastes is digested by microbial action or earthworms and converted into humus.
Recycling of wastes
• Papers from old books, magazines and newspapers are recycled to produce papers in paper mills.
• Agricultural wastes like coconut shells, jute, cotton stalk, bagasse of sugarcane can be used to make paper and hard board. Paddy husk can be used as livestock fodder.
• Cow dung and other organic wastes can be used in go-bar gas plant to provide bio-gas and manure for fields.
The 3R approach such as Reduce, Reuse and Recycle may be followed for effective waste management.