GAS AND LECHATE MOVEMENT AND CONTROL IN LANDFILL

GAS MOVEMENTMostly 90 % of gas produced from decomposition of solid waste includes methane and carbon dioxide. The methane in air in the concentration of 5 to 15 % is explosive. In case of high concentration of methane in landfill, there is no oxygen present so there is no danger of explosion. Most of the methane releases into the atmosphere. Both methane and carbon...

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REACTIONS OCCURRING IN COMPLETED LANDFILL

Solid waste in sanitary landfill is undergone by many chemical, biological and physical changes. The most important changes are as follows:Biological decay of organic material either aerobically or anaerobically with the emission of gases and liquidsChemical oxidation of materialsRelease of gases from the landfill and lateral diffusion of gasesMovement of liquids by differential...

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LANDFILLING METHODS AND OPERATIONS

The methods used for landfilling dry areas are classified into area, trench and depression.1) AREA METHODArea method is used when the land is not suitable for the excavation of trench where solid waste is placed. In this method the waste is unloaded and spread in the long narrow strips in layers that vary in depth from 16 to 30 in. Each layer is compacted in...

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SITE SELECTION PARAMETERS FOR A SANITARY LANDFILL SITE

The following considerations are taken while designing a sanitary landfill site:SITE SELECTIONFactors considered while evaluating the potential of solid waste disposal sites are:availability of land areaProcessing and resource recovery impactsHaul distancesoil conditions and topographyclimatic conditionssurface water hydrologygeologic and hydrologic conditionslocal environmental...

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INTRODUCTION AND ADVANTAGES, DISADVANTAGES OF SANITARY LANDFILL SITES

INTRODUCTIONFor the waste that has no use after its collection and after its processing and recovery of conversion products, something must be done. There are two alternatives for the long term handling of solid waste: One is disposal on or in the earths mantle and second is disposal at the bottom of the ocean. Disposal on land is most commonly used method today. Disposal...

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SECONDARY TREATMENT OF WATER BY FILTERATION

FILTRATIONThe most important stage in water treatment is filtration. In filtration the water is passed through he thick layer of sand. Through filtration following effects are seen:Chemical properties of water are changed.Suspended and colloidal impurities in finely divided state are removed. The number of bacteria are also reduced.The filtration is based on four actions:1)...

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COAGULATION AS PRIMARY TREATMENT OF WATER

Coagulation is the process used to make bigger sized particles by adding certain chemicals called as coagulants. These coagulants attach and react with the impurities in water and convert them into settled sizes. GENERAL COAGULANTSSome coagulants that are used for coagulation are as follows:Aluminium sulphate Chlorinated copperasFerrous sulphate and limeMagnesium...

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PRE TREATMENT OF WATER

If the raw water has good quality than it can be directly goes in secondary treatment processes of flocculation/ coagulation and sedimentation. Prior to the secondary treatment some steps are followed. They are as follows:ScreeningStorageChemical pre-treatmentSCREENINGCoarse screens with inclined bars of 25 mm in diameter and 100 mm spacing avoid the large floating materials...

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INTRODUCTION OF WATER TREATMENT PROCESSES

Modern technologies have greatly reduced the spread of waterborne diseases such as cholera and typhoid fever. These diseases are not much a concern now for public health as they were before. The main key for this advancement is the recognition that human wastes are the source of contamination of public water and it could be eliminated by effective water treatment strategies...

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TREATMENT OF AIR PARTICLE EMISSION BY BAGHOUSE COLLECTORS AND ELECTROPRECIPITATORS

BAGHOUSE COLLECTORSBaghouse or fabric collectors are same like vacuum cleaner on large scale. Through these collectors dry particles are removed from dry and low temperature gas stream (0 to 275 degree centigrade). Cloth sock of about 15 cm in diameter or up to 10 m long is suspended in the chamber. The air is forced to pass through the sock...

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AIR PARTICLE EMISSION BY SCRUBBERS

Scrubbers or wet collectors are designed to increase the particle size by using water or slurry droplets because it is easy to collect the larger particles. Wet ScrubberThere are various types of scrubbers but two types are discussed here:Conventional ScrubbersVenturi ScrubbersThere are several modes of particle collection in scrubbers. In the upper part of scrubber the...

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USE OF GRAVITATIONAL SETTLING CHAMBERS AND CYCLONES COLLECTORS FOR AIR EMISSION CONTROL

The air particles emission must control the particles emissions ranging in size from 1 µm to more than 100 µm in diameter. Collectors are designed according to the physics of collecting mechanisms.GRAVITATIONAL SETTLING CHAMBERSThese are simple chambers and expensive. In this gravitational forces dominate vertical particle motion. These are simple expansions in duct where...

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INTRODUCTION AND OBJECTIVES OF AIR QUALITY CONTROL

INTRODUCTION OF AIR POLLUTION CONTROL Air pollution control s defined as the measures taken to achieve the certain standards of emissions.When the standards are met, it is said that pollution is in control. The measures taken are as follows:change in processeschange in raw materialsmodification of equipmentinstallation of treatment device at the end of processing equipmentThe...

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