27 real Environmental & Effluent Design questions from the Process Design bank, as asked in Indian campus drives and tech interviews. Every question has a verified answer and an AI-tutor explanation on placd — free to start.
1. What is ETP unit operations?
Junior
A.recovery train of pre-treatment, RO, multiple-effect or MVR evaporator and crystalliser so no liquid effluent leaves site, mandated in textile and distillery clusters
B.sequence of screening, equalisation, neutralisation, primary clarification, biological treatment (ASP or MBBR), secondary clarification and tertiary polishing
C.thermal or catalytic oxidiser, activated carbon adsorption, condensation or vapour recovery unit, chosen by concentration and flow
D.CPCB rule H = 14·Q^0.3 metres for SO2 emissions with Q in kg/h, subject to a minimum of 30 m for process stacks
2. Which term means: "sequence of screening, equalisation, neutralisation, primary clarification, biological treatment (ASP or MBBR), secondary clarification and tertiary polishing"?
A.ETP unit operations — CPCB rule H = 14·Q^0.3 metres for SO2 emissions with Q in kg/h, subject to a minimum of 30 m for process stacks
B.ETP unit operations — BOD5 is oxygen consumed by microbes over five days at 20 °C; COD measures all chemically oxidisable matter and is always higher and quicker to test
C.ETP unit operations — recovery train of pre-treatment, RO, multiple-effect or MVR evaporator and crystalliser so no liquid effluent leaves site, mandated in textile and distillery clusters
D.ETP unit operations — sequence of screening, equalisation, neutralisation, primary clarification, biological treatment (ASP or MBBR), secondary clarification and tertiary polishing
A.BOD5 is oxygen consumed by microbes over five days at 20 °C; COD measures all chemically oxidisable matter and is always higher and quicker to test
B.CPCB rule H = 14·Q^0.3 metres for SO2 emissions with Q in kg/h, subject to a minimum of 30 m for process stacks
C.MoEFCC rule classing projects as Category A (central appraisal) or B (state SEIAA), requiring scoping, public hearing and EMP for prior environmental clearance
D.recovery train of pre-treatment, RO, multiple-effect or MVR evaporator and crystalliser so no liquid effluent leaves site, mandated in textile and distillery clusters
5. Which term means: "BOD5 is oxygen consumed by microbes over five days at 20 °C; COD measures all chemically oxidisable matter and is always higher and quicker to test"?
A.BOD vs COD — BOD5 is oxygen consumed by microbes over five days at 20 °C; COD measures all chemically oxidisable matter and is always higher and quicker to test
B.BOD vs COD — MoEFCC rule classing projects as Category A (central appraisal) or B (state SEIAA), requiring scoping, public hearing and EMP for prior environmental clearance
C.BOD vs COD — CPCB rule H = 14·Q^0.3 metres for SO2 emissions with Q in kg/h, subject to a minimum of 30 m for process stacks
D.BOD vs COD — thermal or catalytic oxidiser, activated carbon adsorption, condensation or vapour recovery unit, chosen by concentration and flow
A.inland surface water norms of pH 5.5–9, BOD 30 mg/L, COD 250 mg/L, TSS 100 mg/L and oil and grease 10 mg/L
B.recovery train of pre-treatment, RO, multiple-effect or MVR evaporator and crystalliser so no liquid effluent leaves site, mandated in textile and distillery clusters
C.thermal or catalytic oxidiser, activated carbon adsorption, condensation or vapour recovery unit, chosen by concentration and flow
D.sequence of screening, equalisation, neutralisation, primary clarification, biological treatment (ASP or MBBR), secondary clarification and tertiary polishing
A.CPCB general discharge limits — packed or venturi tower where gas contacts caustic or water to absorb acid gases such as HCl, SO2 and Cl2 with removal typically above 95%
B.CPCB general discharge limits — inland surface water norms of pH 5.5–9, BOD 30 mg/L, COD 250 mg/L, TSS 100 mg/L and oil and grease 10 mg/L
C.CPCB general discharge limits — MoEFCC rule classing projects as Category A (central appraisal) or B (state SEIAA), requiring scoping, public hearing and EMP for prior environmental clearance
D.CPCB general discharge limits — BOD5 is oxygen consumed by microbes over five days at 20 °C; COD measures all chemically oxidisable matter and is always higher and quicker to test
A.BOD5 is oxygen consumed by microbes over five days at 20 °C; COD measures all chemically oxidisable matter and is always higher and quicker to test
B.CPCB rule H = 14·Q^0.3 metres for SO2 emissions with Q in kg/h, subject to a minimum of 30 m for process stacks
C.recovery train of pre-treatment, RO, multiple-effect or MVR evaporator and crystalliser so no liquid effluent leaves site, mandated in textile and distillery clusters
D.rules requiring SPCB authorisation, manifest tracking, a 90-day storage limit and disposal to an authorised TSDF or co-processing
11. Which term means: "recovery train of pre-treatment, RO, multiple-effect or MVR evaporator and crystalliser so no liquid effluent leaves site, mandated in textile and distillery clusters"?
A.Zero liquid discharge — inland surface water norms of pH 5.5–9, BOD 30 mg/L, COD 250 mg/L, TSS 100 mg/L and oil and grease 10 mg/L
B.Zero liquid discharge — BOD5 is oxygen consumed by microbes over five days at 20 °C; COD measures all chemically oxidisable matter and is always higher and quicker to test
C.Zero liquid discharge — recovery train of pre-treatment, RO, multiple-effect or MVR evaporator and crystalliser so no liquid effluent leaves site, mandated in textile and distillery clusters
D.Zero liquid discharge — rules requiring SPCB authorisation, manifest tracking, a 90-day storage limit and disposal to an authorised TSDF or co-processing
A.thermal or catalytic oxidiser, activated carbon adsorption, condensation or vapour recovery unit, chosen by concentration and flow
B.inland surface water norms of pH 5.5–9, BOD 30 mg/L, COD 250 mg/L, TSS 100 mg/L and oil and grease 10 mg/L
C.CPCB rule H = 14·Q^0.3 metres for SO2 emissions with Q in kg/h, subject to a minimum of 30 m for process stacks
D.MoEFCC rule classing projects as Category A (central appraisal) or B (state SEIAA), requiring scoping, public hearing and EMP for prior environmental clearance
A.Stack height — MoEFCC rule classing projects as Category A (central appraisal) or B (state SEIAA), requiring scoping, public hearing and EMP for prior environmental clearance
B.Stack height — CPCB rule H = 14·Q^0.3 metres for SO2 emissions with Q in kg/h, subject to a minimum of 30 m for process stacks
C.Stack height — packed or venturi tower where gas contacts caustic or water to absorb acid gases such as HCl, SO2 and Cl2 with removal typically above 95%
D.Stack height — inland surface water norms of pH 5.5–9, BOD 30 mg/L, COD 250 mg/L, TSS 100 mg/L and oil and grease 10 mg/L
A.packed or venturi tower where gas contacts caustic or water to absorb acid gases such as HCl, SO2 and Cl2 with removal typically above 95%
B.MoEFCC rule classing projects as Category A (central appraisal) or B (state SEIAA), requiring scoping, public hearing and EMP for prior environmental clearance
C.sequence of screening, equalisation, neutralisation, primary clarification, biological treatment (ASP or MBBR), secondary clarification and tertiary polishing
D.thermal or catalytic oxidiser, activated carbon adsorption, condensation or vapour recovery unit, chosen by concentration and flow
17. Which term means: "packed or venturi tower where gas contacts caustic or water to absorb acid gases such as HCl, SO2 and Cl2 with removal typically above 95%"?
A.Wet scrubber — BOD5 is oxygen consumed by microbes over five days at 20 °C; COD measures all chemically oxidisable matter and is always higher and quicker to test
B.Wet scrubber — MoEFCC rule classing projects as Category A (central appraisal) or B (state SEIAA), requiring scoping, public hearing and EMP for prior environmental clearance
C.Wet scrubber — packed or venturi tower where gas contacts caustic or water to absorb acid gases such as HCl, SO2 and Cl2 with removal typically above 95%
D.Wet scrubber — recovery train of pre-treatment, RO, multiple-effect or MVR evaporator and crystalliser so no liquid effluent leaves site, mandated in textile and distillery clusters
20. Which term means: "thermal or catalytic oxidiser, activated carbon adsorption, condensation or vapour recovery unit, chosen by concentration and flow"?
A.VOC control options — MoEFCC rule classing projects as Category A (central appraisal) or B (state SEIAA), requiring scoping, public hearing and EMP for prior environmental clearance
B.VOC control options — thermal or catalytic oxidiser, activated carbon adsorption, condensation or vapour recovery unit, chosen by concentration and flow
C.VOC control options — rules requiring SPCB authorisation, manifest tracking, a 90-day storage limit and disposal to an authorised TSDF or co-processing
D.VOC control options — inland surface water norms of pH 5.5–9, BOD 30 mg/L, COD 250 mg/L, TSS 100 mg/L and oil and grease 10 mg/L
A.BOD5 is oxygen consumed by microbes over five days at 20 °C; COD measures all chemically oxidisable matter and is always higher and quicker to test
B.packed or venturi tower where gas contacts caustic or water to absorb acid gases such as HCl, SO2 and Cl2 with removal typically above 95%
C.MoEFCC rule classing projects as Category A (central appraisal) or B (state SEIAA), requiring scoping, public hearing and EMP for prior environmental clearance
D.rules requiring SPCB authorisation, manifest tracking, a 90-day storage limit and disposal to an authorised TSDF or co-processing
23. Which term means: "MoEFCC rule classing projects as Category A (central appraisal) or B (state SEIAA), requiring scoping, public hearing and EMP for prior environmental clearance"?
A.EIA Notification 2006 — inland surface water norms of pH 5.5–9, BOD 30 mg/L, COD 250 mg/L, TSS 100 mg/L and oil and grease 10 mg/L
B.EIA Notification 2006 — packed or venturi tower where gas contacts caustic or water to absorb acid gases such as HCl, SO2 and Cl2 with removal typically above 95%
C.EIA Notification 2006 — rules requiring SPCB authorisation, manifest tracking, a 90-day storage limit and disposal to an authorised TSDF or co-processing
D.EIA Notification 2006 — MoEFCC rule classing projects as Category A (central appraisal) or B (state SEIAA), requiring scoping, public hearing and EMP for prior environmental clearance
26. Which term means: "rules requiring SPCB authorisation, manifest tracking, a 90-day storage limit and disposal to an authorised TSDF or co-processing"?
A.Hazardous and Other Wastes Rules 2016 — MoEFCC rule classing projects as Category A (central appraisal) or B (state SEIAA), requiring scoping, public hearing and EMP for prior environmental clearance
B.Hazardous and Other Wastes Rules 2016 — inland surface water norms of pH 5.5–9, BOD 30 mg/L, COD 250 mg/L, TSS 100 mg/L and oil and grease 10 mg/L
C.Hazardous and Other Wastes Rules 2016 — CPCB rule H = 14·Q^0.3 metres for SO2 emissions with Q in kg/h, subject to a minimum of 30 m for process stacks
D.Hazardous and Other Wastes Rules 2016 — rules requiring SPCB authorisation, manifest tracking, a 90-day storage limit and disposal to an authorised TSDF or co-processing
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