2021 Water Quality Engineering(Harbin Institute of Technology) 最新满分章节测试答案

本答案对应课程为:点我自动跳转查看
本课程起止时间为:2021-04-30到2021-07-26
本篇答案更新状态:已完结

【作业】1 Water cycle and water quality standards 1 Water cycle and water quality standards

1、 问题:How can we classify the pollutants in natural basing on particle size?
评分规则: 【 （1）Suspended solids: particle size larger than 1 μm
（2）Colloid: particle size between suspended solids and dissolved matter
（3）Dissolved matter: particle size less than 1 nm
】

1 Water cycle and water quality standards

1、 问题:The challenges of urban water resources include ( )
选项：
A:Urban water distribution renders large energy consumption.
B:Capital and operational costs of water supply for long distance transportation are high.
C:High risk of urban water pollution.
D:The standards of urban water quality are high due to the increasing concerns about the safety of urban water sources.
答案: 【Urban water distribution renders large energy consumption.;
Capital and operational costs of water supply for long distance transportation are high.;
High risk of urban water pollution.;
The standards of urban water quality are high due to the increasing concerns about the safety of urban water sources.】

2、 问题:It is relatively hard to separate salt from water, because ions such as Ca2+，Mg2+，K+ are tightly surrounded by water molecules.
选项：
A:正确
B:错误
答案: 【正确】

3、 问题:Lakes and reservoir waters usually have low water mobility, high turbidity, and relatively stable water quality. 
选项：
A:正确
B:错误
答案: 【错误】

4、 问题:Heavy metals can be concentrated in plant roots or aquatic animals, causing great danger to living organisms. 
选项：
A:正确
B:错误
答案: 【正确】

5、 问题:In the US, different sewage plants follow the same discharge standards.
选项：
A:正确
B:错误
答案: 【错误】

2 Coagulation theory and technology

1、 问题:Which one below belongs to organic coagulant ( )
选项：
A:polyacrylamide (PAM)
B:aluminum sulfate
C:lime glue
D:poly aluminum chloride (PAC)
答案: 【polyacrylamide (PAM)】

2、 问题:There are many ways for the control of coagulant dosage and automatic detection, including ( ).
选项：
A:establishing a mathematical model according to the quantity and quality of raw water
B:streaming current detector (SCD)
C:dosing according to experience
D:light transmission pulsation detector
答案: 【establishing a mathematical model according to the quantity and quality of raw water;
streaming current detector (SCD);
light transmission pulsation detector】

3、 问题:Increasing ionic strength would compress the electric double layer and increase the stability of the colloid.
选项：
A:正确
B:错误
答案: 【错误】

4、 问题:G value and GT value are employed to design coagulation tanks, because they can describe the coagulation process comprehensively.
选项：
A:正确
B:错误
答案: 【错误】

5、 问题:The hydraulic condition of the rotary baffle plate flocculation tank is better than that of the reciprocating type, and head loss of the rotary type is 40% less than that of the reciprocating type.
选项：
A:正确
B:错误
答案: 【正确】

【作业】2 Coagulation theory and technology 2 Coagulation theory and technology

1、 问题:Please discuss the factors influencing the performance of coagulation. How to enhance the performance of coagulation process.
评分规则: 【 Factors:(1) Temperature; (2) natural organic matters (NOMs); (3) pH value; (4) coagulants; (5) hydraulic condition
Measures: (1) Optimization of coagulants and optimization of the addition; (2) Coagulant aids; (3) Coagulation conditions and efficient equipment; (4) Optimization of the dosage
】

【作业】3 Theory and technology of sedimentation 3 Theory and technology of sedimentation

1、 问题:Please analyze the advantages and disadvantages of air flotation process.
评分规则: 【 Advantages: Small footprint; short hydraulic retention time; high efficiency of low-density pollutants; high efficiency during low temperature
Disadvantages: High capital cost; high operation cost; high maintenance; Not suitable for the removal of high-density particles
】

3 Theory and technology of sedimentation

1、 问题:Which of the following measure could not improve the settling efficiency in sedimentation tank? ( )
选项：
A:To recycle the sludge to improve the size of particles
B:To increase the surface area of the tank
C:To increase the flow rate
D:To improve the performance of flocculation before sedimentation
答案: 【To increase the flow rate】

2、 问题:Which of the following methods can recover the adsorption capacity of sludge in clarifier process? ( )
选项：
A:To generate a pulse to break the large flocs
B:To circulate the sludge mechanically
C:To discharge the sludge completely in the clarifier
D:To circulate the sludge by a water jet
答案: 【To generate a pulse to break the large flocs;
To circulate the sludge mechanically;
To circulate the sludge by a water jet】

3、 问题:θ presents the contact angle of water on the solid surface. Which of the pollutant(s) with the following value of the contact angle cannot be removed by air flotation process. ( )
选项：
A:θ=95°
B:θ=85°
C:θ=1°
D:θ=150°
答案: 【θ=85°;
θ=1°】

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