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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 pollution15.4 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 polluti
on comprehensive prevention and control (2) Basic methods of water pollution controlPhysical method, chemical method, physicochemical me
thod and biological treatment method (3) Wastewater reclamation
Figure 15 - 1 The classification method of sewage biological treatment
Biological treatment
Aerobic treatment
Anaerobic treatment
Under natural conditions
Water self purification
Under natural conditions
Under artificially conditions
Water self purification
Soil purification
Suspended growth
Adnate growth
Natural water and oxidation ponds
Wastewater irrigation
Activated sludge and its deformation
Biological filter, Rotating biological contactor,
Contact oxidation, Aerobic biological fluidized blanket High-temperature compost Anaerobic pond
Suspended growth
Adnate growth
Septic tank, Upflow anaerobic sludge blanket
Anaerobic digester
Anaerobic biological fluidized blanket
Figure 15 - 2 Basic process of activated sludge process
Backflow sludge Surplus sludge
water-exit water inflow
air
primary settling tank secondary sedimentation tank aeration tank
灌入污水
下土层
根 区
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 s
uspended solids in sewage, adjust pH valve, reduce t
he task of subsequent treatment
The task of secondary treatment is to remove the
dissolved and colloidal organic pollutants significantl
y. It is maily used biological method.
The purpose of tertiary treatment is to further re
move the pollutants which are not removed in secon
dary treatment.
Figure 15 - 4 Typical technological process of Municipal wastewater treatment
wastewater
Primary treatment
Pri
mar
y sl
udge
treatment or use
Sur
plus
slu
dge
grille Sedimentation tank
Grit chamber
Biological aeration
pool or biological filter
Second sedimentation tank
Chemistry, adsorption, ion exchange,
disinfection, equipment
Secondary treatment outlet
(emissions, irrigation)
Primary treatment outlet
(emissions, irrigation)
tertiary treatment outlet
(emissions, reoccupy)
Sludge
digestion pool
Backflow sludge
Sludge
dewatering
secondary treatment tertiary treatment
( 5 ) Wastewater utilization The renewed wastewater can be used in industrial water, agricultura
l irrigation, urban and groundwater recharge, water treatment.The
affect of recycling and reuse in the entire water cycle is showed in fig
ure 15-5
废水回收
地下水回注 地下水 地下水
水处理
地表水
废水 城市用水 工业用水
废水
工业回用 排入地表水
农业回用
地表水
灌溉
降水
大气中水蒸汽
Figure 15-5 The effect of water treatment, regeneration and reuse to water-cycling system
15.3.2 The control of atmospheric environmental pollutio
n ( 1 ) The comprehensive treatment measures of atmospheric pollution
( 2 ) Basic method of atmospheric pollution treatme
nt 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, ex
plosive, toxic, corrosive, radioactive and biological cumulative
etc. The treatment and disposal methods of hazardous waste a
re as following
Solidification and wrapping
Incineration Safe land landfill
15.3.4 Pollution control of soil environment
Pollution prevention measures of soil environment main
ly including:
Strengthen the source control and management of
contaminated soil
Technical measure of soil pollution treatment
Physical improvementChemical improvementBiological 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 w
astes
The treatment of radioactive waste gas
Figure 15-9 Basic process of radioactive pollution control
Solidwaste
volume reduction
packaging storage transportation
emissions
proces
sing
Waste gas and liquid
treatment process
Shielding isolation room
storage curing
purification
The control of electromagnetic radiation pollution
Reduce the leakage of electromagnetic wavesAdopt effective control measures.Improve urban planning to achieve region contral
The control of light pollutionStrengthen urban planning and management, rational arrangement of light source,reduce the source of light pollutionSafe methods should be taken, such as using movable barriers surrounding the operating area to prevent the non-operator from directly exposure in the harmful light sourceTake 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.
Figure 15-10 Technological process of waste leachate treatment
调节池
吹脱
厌氧
A/O 系统
混凝
城市污水处理厂
污泥 填埋场
污泥 填埋场
达标排放
后期达到城市二级污水处理厂指标后直接排入
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
燃气轮机(或气体内燃机)
发电机
自动点燃放空
LFG
CO2
Figure 15-11 Treatment and utilization technology of landfill methane
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