Chapter 15 Environmental pollution control 15.1 The goal of environmental pollution control 15.2 The types of environmental pollution control 15.3 The comprehensive treatment measures of environmental pollution 15.4 Case study 15.1 The goal of environmental pollution control 15.1.1 Environmental pollution and its characteristics Generally speaking,environmental pollutants is in lower concentration and long duration Environmental pollutants can be changed by the biological or chemical effect in environment 15.1.2 The goal of environmental pollution control Prevent pollutants going to water, atmosphere and soil system Restore the use function of natural ecosystem 15.2 The types of environmental pollution control Concentration control and total amount control Terminal control and process control Decentralized control and centralized control 15.3 The comprehensive prevention and control measures of environmental pollution 15.3.1 Water environmental pollution control (1) The principle and countermeasures of water pollution comprehensive prevention and control (2) Basic methods of water pollution control Physical method, chemical method, physicochemical method and biological treatment method (3) Wastewater reclamation Under natural conditions Aerobic treatment Water self purification Water self purification Natural water and oxidation ponds Soil purification Wastewater irrigation Suspended growth Activated sludge and its deformation Adnate growth Biological treatment Biological filter, Rotating biological contactor, Contact oxidation, Aerobic biological fluidized blanke Under natural conditions Anaerobic treatment High-temperature compost Anaerobic pond Suspended growth Septic tank, Upflow anaerobic sludge blanket Anaerobic digester Under artificially conditions Adnate growth Anaerobic biological fluidized blanket Figure 15-1 The classification method of sewage biological treatment primary settling tank aeration tank secondary sedimentation tank water-exit water inflow air Backflow sludge Surplus sludge Figure 15-2 Basic process of activated sludge process Figure 15-3 Land treatment system of waste water (4) The treatment process of waste water The main task of primary treatment is to remove suspended solids in sewage, adjust pH valve, reduce the task of subsequent treatment The task of secondary treatment is to remove the dissolved and colloidal organic pollutants significantly. It is maily used biological method. The purpose of tertiary treatment is to further remove the pollutants which are not removed in secondary treatment. secondary treatment Primary treatment Chemistry, adsorption, ion exchange, Biological aeration Grit chamber Sediment ation tank pool or biological filter Second sedimentation tank disinfection, equipment Backflow sludge Secondary treatment outlet tertiary treatment outlet Primary treatment outlet (emissions, irrigation) Surplus sludge Primary sludge wastewater grille tertiary treatment (emissions, irrigation) Sludge digestion pool Sludge (emissions, reoccupy) treatment or use dewatering Figure 15-4 Typical technological process of Municipal wastewater treatment (5) Wastewater utilization The renewed wastewater can be used in industrial water, agricultural irrigation, urban and groundwater recharge, water treatment.The affect of recycling and reuse in the entire water cycle is showed in figure 15-5 Figure 15-5 The effect of water treatment, regeneration and reuse to water-cycling system 15.3.2 The control of atmospheric environmental pollution (1)The comprehensive treatment measures of atmospheric pollution (2)Basic method of atmospheric pollution treatment The treatment of particle pollutants Treatment technology of gas polutants Cleaning particulate pollutants is usually used by duster device .Divided as its main mechanism,there are mechanical duster, wet duster, filter duster and electrostatic duster. Figure 15-6 Structure profile of cyclone precipitator and spray wet precipitator Figure 15-7 Operation simplified graph of bag dust collector The treatment of gas pollutant Absorption method Adsorption method Catalytic conversion process Combustion method Condensation method Biological method 15.3.3 Pollution control of solid waste (1)The definition and classification of solid waste (2)The treatment and disposal and utilization principle of solid waste harmlessness reduction resource (3)The treatment and resource method of solid waste The treatment and recycling technology of solid waste is mainly include crushing, sorting, thermochemical processing and biological treatment. (4) The final disposal technology of solid waste The final disposal method of solid waste can be divided to land disposal and ocean disposal according to the sites of waster disposal. The land disposal is a method based on the land and the soil layer to dispose the solid, divided into stockpiling method, land farming method, landfill method, deep perfusion method etc. The ocean disposal is to put the solid waster into the ocean by the capacity of ocean environment and its self-purification capacity. Figure 15-8 The structural graph of safe landfill (5)The treatment and disposal methods of hazardous waste The dangers of hazardous waste is mainly for inflammable, explosive, toxic, corrosive, radioactive and biological cumulative etc. The treatment and disposal methods of hazardous waste are as following Solidification and wrapping Incineration Safe land landfill 15.3.4 Pollution control of soil environment Pollution prevention measures of soil environment mainly including: Strengthen the source control and management of contaminated soil Technical measure of soil pollution treatment Physical improvement Chemical improvement Biological improvement 15.3.5 Other physical pollution control Noise pollution control Reform the technology, technics and equipments, reduce noise radiation intensity Reasonable city planning Strengthening noise management The technology to noise control Sound absorption: to reduce the nosie by absorbing sound through sound absorption material or sound absorption structures Sound insulation : impeding the noise transmitting to the space by sound insulation structure, or control the noise in a certain range. Sound elimination: reduce propagation of the noise in air by silencers Radioactive pollution control The main measures of radioactive pollution control are include: Strengthen the treatment of radioactive waste liquor Properly handling and disposal of radioactive solid wastes The treatment of radioactive waste gas Waste gas and liquid purification storage emissions curing packaging storage transportation proces sing Solid waste volume reduction treatment process Shielding isolation room Figure 15-9 Basic process of radioactive pollution control The control of electromagnetic radiation pollution Reduce the leakage of electromagnetic waves Adopt effective control measures. Improve urban planning to achieve region contral The control of light pollution Strengthen urban planning and management, rational arrangement of light source,reduce the source of light pollution Safe methods should be taken, such as using movable barriers surrounding the operating area to prevent the nonoperator from directly exposure in the harmful light source Take the necessary personal protection, such as wearing goggles and protective masks which is effective personal protective measures The control of heat pollution Improve thermal energy utilization ratio, reduce waste heat emissions Active develop and use clean energy Comprehensive utilization of waste heat Increase afforest area 15.4 Case study Shenzhen Xiaping Landfill (1) the process of landfill (2) the treatment process of landfill leachate (3) the treatment and usage of landfill gas (LFG) (4) the measure of hygiene management Spraying cars will spray the pesticides regularly, to kill the fly, to prevent the spread of bacteria.The sprinkler will sprinkes water regaularly to prevent the dust flying in the air and there is car washing equipment, to prevent polluting the road by the car’s sludge ,control dust, and also prevent taking pathogens outside.There are fence around the field to prevent light waster blown outside causing contamination. 调节池 吹脱 后期达到 厌氧 污泥 填埋场 城市二级 污水处理 厂指标后 A/O 系统 直接排入 混凝 污泥 填埋场 城市污水处理厂 达标排放 Figure 15-10 Technological process of waste leachate treatment LFG 收集井 汇流中转器 输气管 抽气机(或气泵) 气体净化设备 气体加压机 自动点燃放空 CO2 燃气轮机(或气体内燃机) 发电机 Figure 15-11 Treatment and utilization technology of landfill methane Thank you