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GLOSSARY Air pollution Five major classes of pollutants are discharged into the air: carbon monoxide, particulates, sulfur oxides, hydrocarbons, and nitrogen oxides. In addition to the automobile, other major sources are from combustion of fuel in electric power plants, industrial processes, and space heating, from the combustion in solid-waste disposal, coal-waste fires, and agricultural burning.Aquaprivies Latrine An aquaprivy is a tank filled with water into which excreta fall via a drop pipe. Aquaprivies use a simple water seal to prevent odours getting out of the tank and have a soakaway to dispose of sullage and effluent. Its is important that the drop pipe reaches below the surface of the water in the tank to prevent the escape of odours. The tank should be watertight to prevent pollution of groundwater and requires emptying about every three years.Aerobic digester An aeration tank that is used to treat waste activated humus or primary sludges or a mixture of them, usually in a small plant with extended aeration or contact stabilisation treatment. A typical operational problem associated with an aerobic digester is pH control. For example, when pH drops, this may indicate normal biological activity or low influent alkalinity. This problem is corrected by adding alkalinity, i.e. lime, bicarbonate, etc.Agenda 21; global sustainable development The global sustainable development agenda set out in the Rio Declaration on Environment and Development, which was established at the Earth Summit in 1992. Agenda 21 consists of 40 chapters, and at its roots are 27 principles. There are four broad sections which cover a range of issues: social and economic dimensions; conservation and management of resources for development; strengthening the role of major groups; and implementation. Agenda 21 highlights the importance of national strategies with international cooperation. It concludes proposals for the integration of environment and development issues in decision making and provisions for international institutional arrangements and legal mechanisms. Agenda 21 is an important document which has broad support among nations on all aspects of environment related to social and economic growth.Anganwadi and school toilet facilities Schools and in particular Anganwadis [Anganwadi workers and helpers are the grassroot level functionaries at village level for delivery of services under Central and State Government (of India) Schemes] are equally important places to address the health issues of the children provided that necessary infrastructure is available. Improved health and quality learning are not possible in schools and Anganwadis as long as basic hygiene is lacking or sanitary facilities and water supply are missing or broken or not properly used. Lack of healthy environment is already resulting in high infant mortality and under five-mortality rate. There are approx. 6 lakh Anganwadi Centers in India and most of them are without toilet facilities. These Anganwadi Centers reach out to 12.5 million children (ICDS, MoHRD).Biochemical oxygen demand or BOD The quantity of oxygen utilized in the biochemical oxidation of organic matter under standard laboratory procedures for five days at 20 degrees Celsius, usually expressed as a concentration (e.g., mg/l).Biodegradable organic matter The organic matter, which is decomposed by bacteria, under biological action, is called biodegradable organic matter. Most of the organic matter present in sewage is biodegradable, and hence undergo biological decomposition.Biofilter: Sewage filtration In this the effluent is first sent back to the primary clarifier and then the trickling filter. The circulation may be continuous and any degree of treatment is achieved. This type is actually an improvement over the ordinary trickling filter. The trickling filter effluent is pumped into the primary clarifier and recirculated with the effluent of the primary clarifier and recirculated with the effluent of the latter. It is a shallow continually fed trickling filter. The single-stage complete treatment filter effluents approach standard-rate filter effluents. For strong sewages and good effluents, a two-stage bio-filter may be used.Biogas Biogas is a mixture of combustible gases mostly methane and carbon monoxide which is produced through anaerobic fermentation of organic wastes, mainly animal and human wastes but also of plant and crop residues and other wastes. Biogas is produced from anaerobic digesters, upflow anaerobic sludge blanket reactors and anaerobic fluidised bed reactors, etc. It contains about 65 to 70% methane by volume, 25 to 30% carbon dioxide and small amounts of hydrogen sulphide, nitrogen, hydrogen from sludge. Biogas has a specific gravity of approximately 0.86 referred to air. This gas can be stored either at low pressure in gas holders that use floating covers or at high pressure if gas compressors are used. This gas can be used as fuel and sludge as a fertilizer.Biogeochemical cycle (1) The cyclical series of transformations of a chemical element through the organisms in a biotic community and their physical environment. The more or less circular paths of chemical elements passing back and forth between organisms and environment are known as biogeochemical cycles. (2) Cycling of essential elements and water within or between ecosystems and throughout the biosphere.Biomass Biomass is a renewable source of energy, comprising agricultural wastes, crop residues and animal wastes. It can meet the basic energy needs of small rural communities. Biomass convertors produce biogas and fertilizers from fermentation, and char and oil from pyrolysis. (1) Material produced by the growth of microorganisms plants or animals. (2) Total weight of living matter in a population usually expressed in terms of dry weight per unit area. (3) The amount of live or dead material of living organism in a unit area or at a specific trophic level at a given time. (4) The amount of living matter in a given area. (5) Total dry weight of all organisms in a particular habitat or area.Biotechnology (1) The use of genetically modified organisms and/ or modern techniques and processes with biological systems for industrial production. (2) Biotechnology is the integration of natural sciences and engineering sciences in order to achieve the application of organisms, cells, and molecular analogues for products and services. (3) A scientific and technical description focussing on the development and improvement of biological system. (4) It deals with the technical manipulation of living organisms so as to get required products both in quality and quantity at low-cost in massive scale.Bore hole latrine This type of latrine is constructed where the space available is very little. It consists of a circular hole of 0.30 to 0.40 m diameter and 5.0 to 6.0 m deep, dug in the ground by means of auger. The bore hole is covered with a suitable concrete squatting slab with a central opening and foot rests of about 0.85 m dia. Once the bore is filled up, the squatting slab and the super structure have to be moved to a new bore and the old bore should be filled up with the earth excavated from the new bore. Disadvantages with this type of latrines are foul smell and breeding of flies and mosquitoes.Bucket/dry latrine The excreta is manually removed periodically - varying from daily to few days interval, by the scavengers to a trench for composting. A bucket or any other suitable container is placed either on the floor in between the foot rests or in small vault under the latrine floor. In the latter case the latrine servicing can be done from outside, without entering the latrine cubicle. The initial cost of the bucket latrine is low, but the servicing cost by the scavengers is high. In addition, it has several other disadvantages like, major health hazards and social stigma for the scavengers, foul smell, breeding of flies and mosquitos. Therefore, this practice should be stopped and the existing bucket/dry latrines should be converted into low cost pour flush latrines with leach pits or connected to sewers, wherever feasible.Chemical Oxygen Demand or COD the measure of the oxygen consuming capacity of inorganic and organic matter present in the water or wastewater expressed in milligrams per liter (mg/l) as the amount of oxygen consumed from a chemical oxidant in a specific test, but not differentiating between stable and unstable organic matter and thus not necessarily correlating with biochemical oxygen demand.Centrifugal pumps Centrifugal pumps are most widely used for lifting sewage, as they can be easily installed in pits and sumps, and can easily transport the suspended matter present in sewage without getting clogged so often. Centrifugal pumps include radial, axial, and mixed flow units. A radial flow pump is commonly referred to as a straight centrifugal pump. The most common type is the volute pump. Fluid enters the pump near the axis of an impeller rotating at high speed. The fluid is thrown radially outward into the pump casing. A partial vacuum is created that draws more fluid into the pump. The velocity head imparted to the fluid by the vanes of the impeller is converted into pressure head in a progressively widening spiral casing, flow is continuous.Chaska; dry toilets Ladakhis nourish their soil with organic manure to provide in the texture needed to retain water. The manure comes from traditional dry toilets, called chaska.These toilets, essential to every Ladakhi household, especially in villages, are two-storey structures. The first floor has a hole that is surrounded with loose earth. After defecation, liberal handfuls of earth are thrown down the hole. This prevents odour and allows the faecal matter to break down into compost over a period of time. The extreme winter cold inhibits unwarranted microbial activity, ensuring that the dry toilet doesn’t become a health hazard. Every year, just before the agricultural season, the compost is taken out by the community and carried over to the fields. Chlorination; sewage treatment Chlorination of treated sewage has one major purpose to reduce the coliform group of organisms. Sufficient chlorine to satisfy demand and provide a residual of 2.0 mg/liter should be added. The following magnitude of dosage is possible. Primary effluent, 20 mg/liter; trickling filter plant effluent, 15 mg/liter; activated sludge plant effluent, 8 mg/liter; sand filter effluent, 6 mg/liter. The contact period should be at least 15 min at peak hourly flow.Chute A vertical pipe system passing from floor to floor provided with ventilation and inlet openings for receiving refuse from successive flats and ending at the ground floor on the top of the collection chamber.Coagulation; water treatment Fine particles and colloidal material are combined into masses by coagulation. These masses, called floc, are large enough to settle in basins and to be caught on the surface of filters. Waters high in organic material and iron may coagulate naturally with gentle mixing. The term is usually applied to chemical coagulation, in which iron or aluminium salts are added to the water to form insoluble hydroxide floc. The floc is a feathery, highly absorbent substance to which colour producing colloids, bacteria, fine particles, and other substances become attached and are thus removed from the water.Compost Rotted leaves, plant stalks, bark, twigs, etc., a material of low bulk density that improves poor soils, whether clays or sands. Like a sponge, can hold 30 to 35 percent water by weight, and its organic content encourages earthworms that further improve the soil.Composting latrines Composting latrines are shallow vaults, into which kitchen waste and similar materials are added as well as excreta. The waste and excreta break down together to produce a compost which can be dug out and used as fertilizer.The advantages of a composting latrine are that it does not need to be moved and new vaults do not have to be dug. The compost produced is a good fertilizer and soil conditioner, and the latrine also disposes of kitchen waste. Composting latrines are, however, more expensive and more difficult to build than pour flush or VIP latrines. As with all latrines, if they are not used properly then there is a risk of transmission of diseases. Contaminant Contaminant means something that renders unfit for use by the introduction of unwholesome or undesirable elements. In many developing countries, ground waters have become infiltrated by industrial, urban and agricultural contaminants.Domestic sewage Waterborne wastes normally discharged from the sanitary conveniences of dwellings, including apartments, houses and hotels; office buildings; factories; and institutions, free from stormwater, surface water and industrial wastes.Decomposer An organism such as a carrion bettle or a fungus that feeds upon and breaks down, dead organic matter.Defecation The process by which the fecal wastes that reach the lower colon and rectum are evacuated from the body. Although the contents of the feces are complex and variable, the body loses the following general types of material via this excretory route : (1) small amounts of water; (2) undigested and unabsorbed residues of ingested food; (3) substances excreted from the body into the digestive tract, particularly inorganic salts; (4) compounds secreted into the intestine as part of the digestive process; (5) living and dead microorganisms that normally inhabit the alimentary tract; and (6) products resulting from the chemical breakdown of the above mentioned materials.Degradable and nondegradable wastes The complete mixtures in the waters of rivers and lakes include many unknown chemicals. For practical purpose they may be divided into degradable and nondegradable wastes.Degradable wastes in water are those that are reduced in quantity by natural processes. These include organise wastes and thermal discharges. A great source of organic materials in water is domestic sewage. If these materials do not constitute too heavy a load, they are converted into stable inorganic materials by bacteria and other organisms. The degradation process uses the oxygen in the water and constitutes natural “self-purification.” If, however, the waters are too loaded with organic matter, degradation without sufficient free oxygen produces offensive odours, such as hydrogen sulfide and methane. Nondegradable wastes are salts-soluble in water-soluble gases, or particulate matter (tiny, suspended particles). These wastes may include a wide range of toxic metals arising from complex manufacturing processes; cadmium, mercury, and lead are examples. Generally, the effects of these substances on life is not fully understood, and permissible levels are not properly known. There have been incidences, however, of permanent neurological impairment and death among persons eating fish from waters heavily polluted by mercury. Diarrhoea Researchers have showed the four most important issues related to the greatest reductions in diarrhoea. These are:-Safe disposal of excreta; Household and personal hygiene, especially hand washing; Quantity of water used; Quality of water. In regard to safe excreta disposal, infectious diarrhoea such as dysentery, cholera and typhoid, is caused by agents such as bacteria and parasites. These agents get into human via the mouth. Parasitic infections such as intestinal worms or hookworms also get in through the mouth or skin and are passed out in excreta. Digested Sludge Sewage sludge which has undergone anaerobic sludge digestion or passed through an aerobic digester should have a fibrous structure and a peaty smell which is not unpleasant, unlike raw sludge, but it still may contain organisms that cause disease. Digested sludge is usually more difficult to de-water than raw sludge, although many texts state the opposite.Discharge tank Discharge tank is a surge device, which is provided in situations where the pipeline profile is considerably close to the hydraulic gradient line. Discharge tank would normally be situated on the first rise along the pipeline and possibly on subsequent and successively higher rises, which is efficient in reducing the pressure variations. The function of discharge tanks is to fill any low pressure zone caused by pump stoppage, thus preventing water column separation. It will operate only if the water surface is above the lowest level to which the head in the pipeline would otherwise drop to negative pressure following pump stoppage.Disease An alteration of the dynamic interaction between an individual and his environment sufficient to be deleterious to the well-being of the individual. The cause of a disease may be environmental, or an altered reactivity of the individual to his environment, or a combination of both.Disinfection; water treatment There are several methods of treatment of water to kill living organisms, particularly pathogenic bacteria; the application of chlorine or chlorine compounds is the most common. Less frequently used methods include the use of ultraviolet light, ozone, or silver ions. Boiling is the favourite household emergency measure.Distillation A process in which water is vapourised by boiling and the vapours subsequently condensed to produce a purified form of the water. Distillation is a natural part of the hydrological cycle.Domestic wastewaters Domestic wastewaters result from the use of water in dwellings of all types, and include both water after use and the various waste materials added : body wastes, kitchen wastes, household cleaning agents, and laundry soaps and detergents. The solid content of such waste water is numerically low and amounts to less than 1 lb per 1000 lb of domestic wastewater. Still, the character of these waste materials is such that they cause significant degradation of receiving waters, and they may be a major factor in spreading waterborne diseases, notably typhoid and dysentery.Drainage (1) It is an arrangements for the removal of used water for the purpose of safe disposal. The drainage is so designed as to cause no stagnation at the maximum discharge rate for which the different units are designed. (2) The removal of excess surface or ground water from soil by means of surface or subsurface drains. (3) Removal of surface water or ground water from a given area by gravity or by pumping.Drainage Systems There may be three types of drainage systems, i.e. (i) combined system, in which foul water and surface water are conveyed by the same sewers and drains; (ii) separate system, in which the foul water and surface water are conveyed by separate sewers and drains; (iii) partially separate system, in which part of the surface water is conveyed by the foul water sewers or drains.Eco-sanitation system Eco-sanitation is a kind of man-nature metabolism system dominated by technological and social behaviour, sustained by natural life support system, vitalised by ecological process. It interacts with human settlement system, wastes management system, hygiene and health care system and agricultural system.Ecology A study of the relation of organisms to their environment, or in more simple terms, environmental biology. Ecology is concerned especially with the biology of groups of organisms and with functional processes on the lands, in the oceans and in fresh waters. Ecology is the study of the structure and function of nature [mankind being considered part of nature]. Ecology is one of the basic divisions of biology which are concerned with principles or fundamentals common to all life.Effluent Effluent means liquid discharged as waste. Industries discharge effluents into water and air, causing pollution. So does sewage disposal.Environment Ecologically, the environment is the sum of all external conditions and influences affecting the life and development of organisms. (1) The sum total of external conditions which influence an organisms. (2) The sum total of all the external forces or factors, both abiotic and the biotic that affects the physiological behaviour or performance of an organism or a group of organisms.Environmental audit An assessment of the extent to which an organization is observing practices which seek to minimize harm to the environment.Environmental engineering The discipline which evaluates the effects of humans on the environment and develops controls to minimize environmental degradation. The technology which provided society with all the necessities and luxuries of life is now expected to continue providing these services without degradation to the environment.Eutrophication It is the process whereby lakes become enriched with nutrients that make the water undesirable for human use, both for water supplies and recreation. The process of eutrophication is directly related to the aquatic food chain. Algae use carbon dioxide, inorganic nitrogen, orthophospate and trace nutrients for growth and reproduction.Excrement Excrement means waste matter discharged from the body. The disease and death traceable to environmental pollution by human excrement dwarfs the known toll taken by industrial pollutants. Raw excrement is the principal conveyor of the intestinal infections that collectively constitute a leading cause of death in countries that together contain two-thirds of world’s people.Fats means primarily fatty acid esters of the alcohol glycerol, also called acylglycerols, neutral fats, natural fats, or glycerides. They are the major components of depot, or storage, fats in plant and animal cells, especially in the adipose or fat cells of vertebrates. This term may include any synthesized substance of a like nature.Feces The waste material eliminated by the gastrointestinal tract. The components and form of feces vary with diet, metabolic activities, and the state of health; illness, changes in diet or water intake and excretion, emotional stimuli and many drugs and chemicals may alter the feces both qualitatively and quantitatively.In general, the feces contain undigested food materials and excretions and secretions of the digestive system, including salts, pigments, bile products, and cellular debris. Food passes from the small intestine to the lower bowel (large intestine) in a semi liquid state; nutrients and water are absorbed in the bowel, and the feces reached the ileocecal valve, 99% of the carbohydrate, 99% of the protein, and 97% of the fats have been absorbed. Water normally remains a large component (about 65% by weight) alongwith the high content of saprophytic bacteria which are normal intestinal flora. Feces constitute important objective evidence in disease. Filtration Filtration is a process for separating suspended and colloidal impurities from water by passage through a porous medium or porous media. Filtration, with or without pretreatment, has been employed for treatment of water to effectively remove turbidity [e.g., silt and clay], colour, microorganisms, precipitated hardness from chemically softened waters and precipitated iron and maganese from aerated waters. Removal of turbidity is essential not only from the requirement of aesthetic acceptability but also for efficient disinfection which is difficult in the presence of suspended and colloidal impurities that serve as hideouts for the microorganisms.Fluorides in drinking water Excessive fluorides in drinking water may cause mottling of teeth or dental fluorishes, a condition resulting in the discoloration of the enamel, with chipping of the teeth in severe cases, particularly in children. In Indian conditions where the temperatures are high, the occurrence and severity of mottling increases when the fluoride levels exceed 1.0 mg/1. With higher levels, skeletal or bone fluorishes with its crippling effects are observed.Garbage means animal and vegetable wastes and residue from preparation, cooking and dispensing of food and from the handling, processing, storage and sale of food products and produce.Greywater It is estimated that 42 to 79 percent of household greywater comes from bathrooms, 5 to 23 percent from laundry facilities, 10 to 17 percent from the kitchen sink and 5 to 6 percent from the bathroom sink. Various studies have indicated that the amount of greywater generated per person per day varies from 96 to 172 litres. That’s a huge amount of water being wasted in the world every year.Greywater contains recyclable organic materials such as nitrogen, phosphorous and potassium. These materials are pollutants when discarded into the environment. When responsibly recycled, however, they can be beneficial nutrients. Methods have been devised to use greywater for landscape irrigation, certain types of kitchen, gardens, soilbeds, soilboxes and ponds. But as greywater may contain large numbers of bacteria that could be disease-causing organisms, care needs to be taken to utilise and channel it properly. Grit; sewage Grit in sewage is obtained from domestic sewage, floors of garages and service stations, first storm of the season etc.The volume or quantity of grit is determined by diverse factors such as area of unpaved surfaces in the locality, characteristics of ground, design of grit chambers, intensity of cleaning the streets, location of grit chambers, method of cleaning the streets, occurrence of storms and their intensity, provision of catch basins and system of sewage, combined or separate.Groundwater After the precipitated water soaks into the soil, a part of it may percolate downward to reach the water table, becoming groundwater in the zone of aeration. Because this percolated water is derived originally from precipitation, it is termed meteoric water. In many arid areas with underground drainage, the major source of meteoric water is seepage from stream runoff and lakes. Besides the meteoric water, groundwater is also contributed in small quantities by some minor sources of water located in the earth’s crust.Gully trap; sewage A gully trap is usually made of stoneware and a cast iron grating is provided at its top. The gully trap is fitted inside a masonry chamber. A water seal of about 60 mm to 70 mm is provided at the gully trap. The gully trap forms the starting point of horizontal flow of sewage. It is usually situated near the external face of wall and it is kept slightly higher or even in line with pavement or ground level.The gully trap leads the sewage either to sewer or to inspection chamber or to manhole. A well-designed gully trap may serve two or three connections from the Nahiri traps. The top of the gully trap chamber is provided with a cover usually of cast iron, which is taken out to clean the trap. Hard water Alkaline water containing dissolved salts that interfere with some industrial processes and prevent soap from lathering.Heat treatment; sludge Two processes of heat treatment (not drying) of sludge exist. In the process developed originally by Porteous, the sludge is heated with live steam at 1800C and high pressure of 10 to 15 atm, for 30 minute or so. The smell can be disposed of by discharging the gases under the boiler grate as combustion air for the boiler. The liquor resulting from the filter presses is also foul, with a high BOD and must be returned for biological treatment.Heavy metals; water pollution The term heavy metal is less precisely defined. In chemical terms it can refer to metals with specific gravity greater than about 4 or 5, but more often, the term is simply used to denote metals that are toxic. The list of toxic metals includes aluminum, arsenic, beryllium, bismuth, cadmium, chromium, cobalt, copper, iron, lead, manganese, mercury, nickel, selenium, strontium, thallium, tin, titanium, and zinc. Some of these metals, such as chromium and iron, are essential nutrients in our diets, but in higher doses are extremely toxic.Humus A complex organic component of the soil, resulting from the decomposition of plant and animal tissue; it gives soil its characteristically dark colour and is of great importance for plant growth. The term is also used for a dark brown or almost black complex organic material residue left after the completion of biochemical processes in sewage treatment works.Industrial waste Waste resulting from any process of industry, manufacturing, trade or business; from development of any natural resource; from any mixture of the waste with water or normal wastewater; and wastewater containing pollutants in higher concentrations than normal domestic sewage as defined in this section.Incinerator Incinerator is a furnace or a container for incinerating waste materials. Incinerator emits effluents to the skies.Industrial wastewaters; water pollution There is no general uniformity of substances found in domestic wastwaters, industrial wastewaters show increasing variation as the complexity of industrial processes rises. It is an account of biological treatment processes are ordinarily employed in water-pollution control plants, large quantities of industrial wastewaters can interfere with the processes as well as the total load of a treatment plant. The organic matter present in many industrial effluents often equals or exceeds the amount from a community.Inspection chamber; sewer In order to carry out inspection or clearance etc., a chamber is provided in a sewer and is called inspection chamber.Junction; sewers A junction occurs where one or more branch sewers enter a main sewer. The angle of entry may be 30 degrees or 45 degrees with reference to axis of main sewer, whenever ratio of branch sewer diameter to main sewer diameter is one half or less. Junctions are sized so that the velocities in the merging streams are approximately equal at maximum flow.Juvenile water It is water that has come to the earth surface from great depths for the first time. It is derived from magma.Kyoto protocol This the first substantial agreement to set greenhouse gas emission limits in 1997. The Kyoto Protocol is an important step towards achieving the aim of the United Nations Framework Convention on Climate Change [FCCC], that of preventing dangerous anthropogenic or human-made interference with the climate system.Kubel test; water A test for small amounts of organics in water, which involves boiling the water with potassium permanganate for 10 minutes. The value is about three times as high as that obtained in 4 hours at 270C in permanganate value test.Limnology It is the scientific study of physical, chemical, meteorological and biological conditions in fresh water, especially of ponds and lakes.Maximum allowable discharge limit The maximum concentration of a pollutant allowed to be discharged at any time, determined from the analysis of any discrete or composited sample collected, independent of the industrial flow rate and the duration of the sampling event.Medical wastes Isolation wastes, infectious agents, human blood and blood products, pathological wastes, sharps, body parts, contaminated bedding, surgical wastes, potentially contaminated laboratory wastes, and dialysis wastes.Microwave toilet In a significant development in the history of toilet is the availability of microwave toilet of the USA. It runs on electricity and negates use of water and quickly burns human excreta into a spoonful of ash.Millennium Development Goals Recognizing the problems, world leaders at the United Nations Millennium Summit in September 2000 expressed an unprecedented determination to end world poverty. They declared their commitment not only to the people of their own countries but to the people of the world. The 189 countries at the summit adopted the Millennium Declaration, committing themselves to do their utmost to achieve key objectives of humanity in the 21st century, including eradicating poverty, promoting human dignity and achieving peace, democracy and environmental sustainability. Stemming from the Declaration were the Millennium Development Goals — a set of 8 goals, 18 targets and 48 indicators — that establish concrete, time-bound targets for advancing development and reducing poverty by 2015 or earlier (see Index to Millennium Development Goal indicators at the end).Municipal solid waste management Economic development and prosperity are accompanied by the generation of large amount of wastes that must be reused in some way or disposed in landfills. Waste generation can be reduced to some extent by improved design of products and packing material and by increasing intensity of service per unit mass of material used.Solid wastes can be classified into municipal (residential and commercial), industrial, construction and demolition wastes. The Municipal Solid Wastes (MSW) are the most non-homogeneous since they consists of the residues of nearly all materials used by humanity: of other organic wastes, papers, plastics, fabrics, leather, metals, glass and miscellaneous other materials. Processing or disposal of MSW requires separating the MSW into a number of streams and subjecting each stream to the most appropriate method of resource recovery. The separation of MSW components can take place at the source, i.e. at households or businesses or at Materials Recovery Facilities (MRFs) using manual and electromechanical methods. Nutrients; water pollution Nutrients are chemicals, such as nitrogen, phosphorus, carbon, sulfur, calcium, potassium, iron, manganese, boron, and cobalt, that are essential to the growth of living things. In terms of water quality, nutrients can be considered as pollutants when their concentrations are sufficient to allow excessive growth of aquatic plants, particularly algae. When nutrients stimulate the growth of algae, the attractiveness of the body of water for recreational uses, as a drinking water supply, and as a viable habitat for other living things can be adversely affected.Open defecation Where there are no latrines people resort to defecation in the open. This may be indiscriminate or in special places for defecation generally accepted by the community, such as defecation fields, rubbish and manure heaps, or under trees.Open defecation encourages flies, which spread faeces related diseases. In moist ground the larvae of intestinal worms develop, and faeces and larvae may be carried by people and animals. Surface water run-off from places where people have defecated results in water pollution. In view of the health hazards created and the degradation of the environment, open defecation should not be tolerated in villages and other built-up areas. There are better options available that confine excrete in such a way that the cycle of reinfection from excrete-related diseases is broken. Osmosis Certain natural and synthetic membranes have the property of permitting the solvent (e.g.water) to get through them but not the solute (the substance on solution) . Such semi-permeable membranes permit the separation of solute from solvent. This phenomenon is known as ‘osmosis’.Osmosis, through the semi-permeable membranes, which surround individual cells, helps to control the flow of water through living organisms. This process is expensive but effective. Reverse Osmosis Reverse osmosis is a membrane permeation process for separating relatively pure water (or other solvent) from a less pure solution.The solution is passed over the surface of an appropriate semi permeable membrane at a pressure in excess of the effective osmotic pressure of the feed solution. The permeating liquid is collected as the product and the concentrated feed solution is generally discarded. The membrane must be highly permeable to water, highly impermeable to solutes, and capable of withstanding the applied pressure without failure. Because of its simplicity in concept and execution, reverse osmosis appears to have considerable potential for wide application in water and waste water treatment. Pathogen Any agent capable of causing disease. The term pathogen is usually restricted to living agents, which include viruses, rickettsia, bacteria, fungi, yeasts, protozoa, helminths, and certain insect larval stages.Pesticides; water pollution The term pesticide is used to cover a range of chemicals that kill organisms that humans consider undesirable and includes the more specific categories of insecticides, herbicides, rodenticides, and fungicides.There are three main groups of synthetic organic insecticides: organochlorines (also known as chlorinated hydrocarbons), organophosphates, and carbamates. In addition, a number of herbicides, including the chlorophenoxy compounds 2,4,5-T (which contains the impurity dioxin, which is one of the most potent toxins known) and 2,4-D are common water pollutants. Pipelines Pipelines normally follow the profile of the ground surface quite closely. Gravity pipelines have to be laid below the hydraulic gradient. Pipes are of cast iron, steel, asbestos-cement, prestressed concrete, reinforced cement concrete, plastic etc. Pipes are to be protected against corrosion.Pour flush latrines Pour flush latrines use a pit for excreta disposal and have a special pan which is cast in the floor slab and provides a water seal of 20-30 millimetres. This ensures that smells cannot escape into the shelter. Sometimes a vent pipe, which should have a fly screen, is fitted to the pit. The pit may be below or offset from the shelter. Pour flush latrines can also be installed with the pan in the house and the pit outside.Pump A machine that draws a fluid into itself through an entrance port and forces the fluid out through an exhaust port. A pump may serve to move liquid, as in a cross-country pipeline; to lift liquid, as from a well or to the top of a tall building; or to put fluid under pressure, as in a hydraulic brake.Quaternary treatment It is an advanced stage of waste water treatment. It aims to remove all kinds of organic and inorganic contaminants present in the wastewater to enable the wastewater treated quality to the portable water standards.Recycling The return of discarded or waste materials to the production system for utilisation in the manufacture of goods, with a view to the conservation as far as practicable of non-renewable and scarce resources.Remote sensing The essence of remote sensing is to acquire information about an object without keeping the measuring device in physical contact with the object. Today, remote-sensing techniques of scientific invention are beginning to yield information about the emitted radiation or force fields of an object by means of suitable detectors sensitive to the radiation or force. In hydrology, for example, it is possible to spot diseased crops, polluted water, or the flow of hot springs with infrared cameras, to survey ice thickness and distribution with microwave detectors, and to measure soil moisture and rainfall intensity and distribution in thunderstorms by radar.Sanitary landfill A method of waste disposal by spreading the waste over land and covering them with a seal of earth. Communities often use landfills to reuse wastes, to help fill low areas, or to build recreational facilities.Sanitary sewer A public sewer that conveys domestic wastewater or industrial wastewater or a combination of both and into which stormwater, surface water, groundwater, and other unpolluted wastes are not intentionally passed.Sewage Domestic or industrial waste carried in the drains and pipes of the sanitary sewer.Stormwater Any flow occurring during or following any form of natural precipitation and resulting from such precipitation, including snowmelt. This term also includes other types of surface runoff and drainage, such as but not limited to lawn watering; vehicle washing; pavement and sidewalk wash-off; and drainage from swimming pools, water beds, and hot water heaters and structure cleaning.Sewage systems Sewage systems are physical systems for the collection of waste water and its treatment before discharge back into the environment. Domestic waste water includes the used water of businesses and office buildings as well as dwellings; industrial waste water is that discharged during industrial operations. In addition to waste water, sewage systems also handle the flow of storm water, either separately or, more commonly, as part of a single system.Sewerage A physical arrangement of pipes and plant for the collection, removal, treatment, and disposal of liquid wastes.This is an art of collecting, treating and finally disposing of the sewage; whereas the mixture of water and waste products, popularly called sewage. Sludge Inorganic or inert solid materials and the by-products of bacterial digestion sink to the bottom of the tank and form a layer, commonly called “ Sludge”.Solids settled out from water, but containing from 55 to 99% water. Apart from the many industrial and waterworks sludges there are several types of sewage sludge, most of which have over 95% water before thickening. Slurry A watery mixture of insoluble matter that results from some pollution control techniques.Solid wastes Anything solid discarded for any reason, whether part of all of the substance will be recycled - rubbish, trash, scrap, fecal matter, harvest leavings, sewage sludge, bottles, cans, tyres, paper, chemicals, slage, used cars and machinery, mining, scrap metal, etc.Sullage The term sullage is used to indicate the wastewater from bathrooms, kitchens etc. It is merely wastewater and does not create bad smell.Surface water A term commonly used to designate the water flowing in stream channels. The term is sometimes used in a broader sense as opposed to ‘subsurface water’. In this sense, surface water includes water in lakes, marshes, glaciers, and reservoirs as well as that flowing in streams. In the broadest sense, surface water is all the water on the surface of the Earth and thus includes the water of the oceans.Tank A container for storing liquids or gases. A tank may be constructed of ferrous or nonferrous metals or alloys, reinforced concrete, wood or filament wound plastics, depending upon its use.Total Oxygen Demand [TOD] It is an instrumental method used to measure the organic content of wastewater. In this test organic substances and to a minor extent, inorganic substances are converted to stable end products in a platinum catalysed combustion chamber. TOD is determined by monitoring the oxygen content present in the nitrogen carrier gas. This test can be carried out rapidly.Toxicity A number of compounds which may be present in industrial wastes are reported to be toxic to methanogenic organisms. Anaerobic bacteria like most micro-organisms can be acclimated to different levels of various toxicants. However, because of their slow growth rate the acclimatization period may be comparatively longer. Industrial wastewaters should be evaluated for their toxic effects before anaerobic treatment is adopted.Ultrafiltration; advanced waste water treatment This is similar in operation to reverse osmosis save that the membrane is coarser and the pressure lower. The process removes finely divided rather than dissolved solids, but has openings sufficiently small to remove colloidal particles as well. Ultrafiltration will remove all of the suspended solids and virtually 100 percent of the BOD, COD, and TOC remaining in treated waste water.Urinals Urinals can be of different forms and shapes. The common varieties are of the bowl type or the basin type and the stall type or the slab type. The bowl type is generally used for private houses or buildings, and the stall type is generally used for public buildings and municipal toilets. A third type, called squatting plate type, is used specifically in ladies toilets, only in high classes.Urine An aqueous solution of organic and inorganic substances, mostly waste products of metabolism. The kidneys maintain the internal milieu of the body by excreting these waste products and adjusting the loss of water and electrolytes to keep the body fluids relatively constant in amount and composition.The urine normally is clear and has a specific gravity of 1.017-1.020, depending upon the amount of fluid ingested, perspiration and diet. The chemical and physical composition of the urine frequently reflects pathological changes not only in the genitourinary tract but disease processes in other parts of the body. Vent pipe A vertical pipe or stack in a building which allows ventilation of the stack or sewer. For domestic buildings less than 10 storeys the vent pipe is 50 mm diameter. The vent pipe can also be important to maintain atmosphere pressure in the sanitary pipe work. Discharges of wastewater running from the upper levels of a high rise building can produce high velocities in the discharge stack and may induce lower pressures resulting in siphonage of water seals from other utilities in the building. A vent pipe assists in overcoming this problem.Waste Any matter, whether liquid, solid, gaseous, or radioactive, which is discharged, emitted, or deposited in the environment in such volume, constituency or manner as to cause an alteration of the environment.Waste disposal The activity to get rid of the wastes either by putting the same in a landfill or incinerated or recycled etc.Waste treatment Physical, chemical and biological processes employed to remove dissolved and suspended solid from waste water.Wastewater Liquid and water-carried industrial wastes and sewage from residential dwellings, commercial buildings, industrial and manufacturing facilities, and institutions, whether treated or untreated, which are contributed to the publicly owned treatment works. Stormwater, surface water, and groundwater infiltration may be included in the wastewater that enters a publicly owned treatment works.Wastes; industrial Anything, including heat, discarded or released from industrial operations of any kind, including the food processing industry. The decision to release or discard a particular waste has traditionally been made strictly on economic grounds, that is, whether it is cheaper to release or throw something away than to recover a marketable product.Wastewater treatment plant Mean that portion of the publicly owned treatment works which is designed to provide treatment of municipal sewage and industrial waste.Wastes; municipal Substances discarded by private households, offices, shops, etc., as unusable. Generally collected by a local authority for disposal by dumping, sanitary landfill, composting or pyrolysis. It is used as a fuel for power production in large incinerators. Typically composed of paper, organic matter, plastics, metals and non-metallic minerals [ash].Water-borne disease Disease transmitted by drinking water or by contact with potable or bathing water. Certain bacterial, protozoan, and helminthic diseases of men are commonly or exclusively water-borne. The bacterial and protozoan pathogens are not normal to the water environment and do not multiply in natural waters. They gain entrance to water primarily from pollution by human excrement and less significantly from pollution by domestic and wild animals. In contrast, the helminthic pathogens may have a water animal as an intermediate host and may have a temporary free-living stage in water.Water conservation The protection, development, and efficient management of water resources for beneficial purposes. Water is combined with carbon dioxide by green plants in the synthesis of carbohydrates, from which all other foods are formed. It is a highly efficient medium for dissolving and transporting nutrients through the soil and throughout the bodies of plants and animals. It can also carry deadly organisms and toxic wastes, including radio-activity.Water softening A water-treatment process by which undesirable cations [of calcium and magnesium] are removed from hard waters. The presence of these cations in water is undesirable for household purposes, boiler feed, food processing, and chemical processing, because of reactions that form soap scum, boiler scale, and unwanted by-products. |
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