What is waste…………..!!???In simple words it is…Any thing eliminated or discarded as no longeruseful or required after the completion of a process.
Kinds of WastesSolid wastes: domestic, commercial and industrial wastes Examples: plastics, Styrofoam containers, bottles, cans, papers, scrap iron, and other trashLiquid Wastes: wastes in liquid form Examples: domestic washings, chemicals, oils, waste water from ponds, manufacturing industries and other sources Classification of Wastes according to their Properties Bio-degradable can be degraded (paper, wood, fruits and others) Non-biodegradable cannot be degraded (plastics, bottles, old machines, cans, styrofoam containers and others)Classification of Wastes according to their effect Hazardous waste Non hazardous waste
Sources of Wastes Households Commerce and Industry
EFFECTS OF WASTE IF NOT MANAGED WISELY• Affects our health• Affects our socio-economic conditions• Affects our coastal and marine environment• Affects our climate
ENVIRONMENTAL MANAGEMENT SYSTEMS: EMS What is an EMS? An EMS is a formal set of policies and procedures that define how an organization will evaluate, manage, and track its environmental impact. It follows the basic model: Plan > Do > Check > Act This facilitates cost-effective environmental performance by defining and continuously improving the process and actions that an organization undertakes to meet its environmental goals.
Different methods for treating Solid wasteThermal treatmentThis refers to processes that involve the use of heat to treat waste. Listednext are descriptions of some commonly utilized thermal treatment processesIncinerationIncineration is by far the most commonly used process for destroyingorganic compounds in industrial wastes.Incineration basically involves heating the sediments in the presence ofoxygen to burn or oxidize organic materials, including organic compounds.A critical component of the overall treatment process is the emission controlsystem for the gases produced by the process.
If boilers are so connected with this process along with turbines this process can be named as WASTE TO ENERGY technology
PyrolysisIn contrast to incineration, pyrolysis involves the heating of solids in the absence ofoxygen.A pyrolysis system consists of a primary combustion chamber, a secondary combustionchamber, and pollution control devices. High temperatures, ranging from 540 to 760deg.C,cause large, complex molecules to decompose into simpler ones.The resulting gaseous products can then be collected or destroyed in an afterburner at1,200deg.C.Vitrificationvitrification is an emerging technology that uses electricity to heat and destroy organiccompounds and immobilize inert contaminants. A typical unit consists of a reaction chamber divided into two sections: the upper sectionintroduces the feed material containing gases and pyrolysis products, while the lowersection contains a two-layer molten zone for the metal and siliceous components of thewaste.Wastes are vitrified by passing high electrical currents through the material. Electrodesare inserted into the waste solids, and graphite is applied to the surface to enhance itselectrical conductivity. A large current is applied, resulting in rapid heating of the solids andcausing the siliceous components of the material to melt. The end product is a solid, glass-like material that is very resistant to leaching. Temperatures of about 1,600deg.C aretypically achieved
Very common and very harmful process Open burning is the burning of unwanted materials in a manner that causes smoke and other emissions to be released directly into the air without passing through a chimney or stack.
Dumps and LandfillsSanitary landfillsSanitary Landfills are designed to greatly reduce or eliminate the risks that wastedisposal may pose to the public health and environmental quality. They areusually placed in areas where land features act as natural buffers between thelandfill and the environment.Method of operation:Solid waste is deposited on the surface , compacted , then coevered with alayer of compacted soil at the end of a working day.major gaseous products in results of icrobial decomposition emitted fromlandfill are CH4 and CO2. in which methane posses economic value. Forwhich different gas collection methods are adopted such as collectionpipes, gas treatments etc
Landfill leachate: Liquid that passes through the landfill and that has extracted dissolved and suspended matter from it, is called leachate liquid enters the landfill from external sources such as rainfall . Surface drainage , ground water , and the liquid in and produced from the decomposition of the waste . There is also a collection system installed to collect this leachate Composting material : Biodegraded material in landfiling can be used as composting material which has a very nice effect on cultivating crops or gardening
Landfill AdvantagesA specific location for disposal that can be monitored.When a landfill is complete, it can be reclaimed, built on or used asparks or farming land.Waste going to a properly designed landfills can be processed toremove all recyclable materials before tipping.Waste going to a properly designed landfills can be processed toremove organic material and use it for compost or natural gas(methane) productionProperly managed landfills can capture the natural gas (methane)produced by the decomposing material underground.Properly managed landfills can minimize and/or capture theleachate produced by the decomposing material underground.
Landfill Disadvantages and ProblemsA poorly designed or operated landfill shares many problems observed at uncontrolleddumping areas:Landfills and the surrounding areas are often heavily polluted.Landfill can pollute the water, the air, and also the soil.It is difficult to keep dangerous chemicals from leaching out into the surrounding land.Dangerous chemicals can spread into the water table or into waterways.Landfill can attract animals and insects to come such as raccoons, rats, mosquitoes,cockroaches, and seagulls.Landfill can also cause sicknesses, illnesses, and diseases which might spread incommunities.Landfill can increase the chances of global warming by releasing methane, a dangerousgreenhouse gas.
Landfills are taking up lots of our land and that can also take awayhabitats for other animals.Landfills contain a lot of kitchen scraps and organic material. As thelandfill is constantly being covered with new garbage the organic materialdecomposes anaerobically (that is, without air). Anaerobic decompositionproduces methane, which is a 20 times more dangerous greenhouse gasthan carbon dioxide.