Professional Foundation in 09 —— Transition

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1. The correct classification of surface water is as follows: A. Habitats for rare aquatic animals; natural reserves belong to Class I areas. B. Wintering grounds for fish and shrimp, spawning areas for them, and primary protection zones for surface water sources used for drinking water belong to Class II areas. C. Migration channels, aquaculture areas, and swimming areas belong to Class III areas. D. Water used for general landscaping and recreational purposes where direct human contact is not involved belongs to Class IV areas. Answer: C

2. The diameter of a pipe is D = 150 mm, and the flow velocity of water in the pipe is u = 3 m/s. If the friction coefficient along the pipe is λ = 0.015 and the dynamic viscosity of water is μ = 1.139×10^-3, then the shear stress τ at a distance of r/2 from the pipe’s center is: (I can’t remember the options; my calculated value is 16.89 N. I’m not sure if it’s correct.)

3. Using an Osterwald analyzer, it was determined that after combustion, the percentages of gases in a certain substance are CO2 at 10.7%, O2 at 7.2%, and CO at 1%. What is the air excess factor during combustion? A. 1.58 B. 1.46 C. 1.40 D. 1.09 (My calculated value was 1.23, which isn’t among the options, so I guessed C.)

4. A electrostatic precipitator currently has a dust removal efficiency of 90%. If this efficiency needs to be increased to 99%, what should be the area of the collection plates compared to the original size? A. 5 times B. 4 times C. 3 times D. 2 times Answer: D

5. A wastewater treatment plant processes 300,000 m³ of wastewater per day. The retention time in the aeration tank is 8 hours. The sludge concentration in the aeration tank mixture is 4000 mg/L, while the sludge concentration at the bottom of the secondary sedimentation tank is 8000 mg/L. The SS concentration in the effluent from the secondary sedimentation tank is 10 mg/L. The sludge age is 20 days. How much sludge needs to be removed from the secondary sedimentation tank each day? (I can’t remember the options; my calculated value was around 2000, so I chose D.)

6. There are 10 devices in a factory that generate noise at 60 dB each, one device that generates noise at 70 dB, and one device that generates noise at 73 dB. What is the total noise level? (I can’t remember the options; my calculated value was 76 dB.)

7. The ammonia nitrogen concentration in a solution is 2 mg/L. If the breakpoint chlorination method is used, and the desired residual chlorine level in the solution is 3 mg/L, how much chlorine needs to be added? (I can’t remember the options; my calculated value was 18.2 mg/L, so I chose D.)

8. The composition of a certain type of waste is C60H94.3O37.8N. Organic matter accounts for 65% of the total solid content, the moisture content of the waste is 20%, 50% of the organic matter can be biodegraded, and the biodegradation efficiency is 90%. What is the volume of biogas produced from 1 ton of this waste under standard conditions? (I can’t remember the options; my calculated value didn’t match the answer, so I guessed randomly.)

9. In the process of fermenting glucose to produce acetic acid, how much acetic acid can be produced from 0.5 g of glucose? (I can’t remember the options; my calculated value was also 0.5 g, so I chose that option. I’m not sure if it’s correct.)

10. The concentration of a certain microorganism in a culture medium was measured to be 1×10^5 CFU/ml after 30 minutes, and it increased to 1×10^12 CFU/ml after 330 minutes. What is its doubling time? (I can’t remember the options; my calculated value was 12.9 minutes.)

11. During wastewater treatment, if a large number of rotifers are found in the water, it indicates: A. High organic content in the water, indicating good treatment efficiency. B. Low organic content in the water, indicating good treatment efficiency. C. High organic content in the water, indicating poor treatment efficiency. D. Low organic content in the water, indicating poor treatment efficiency. (I chose B, but I’m not sure.)

12. Entities involved in coastal engineering projects must conduct scientific investigations of the marine environment. Based on natural and social conditions, they must prepare: A. An environmental impact report. B. An environmental impact statement. C. An environmental impact registration form. D. An environmental impact registration card. Answer: A

13. Regarding sulfur dioxide in the atmosphere, which of the following statements is correct? A. Human-induced emissions of sulfur dioxide mainly come from the burning of fossil fuels. B. Naturally occurring sulfur dioxide emissions are primarily due to volcanic activities, and their amounts are much smaller than those from human activities. C. I can’t remember. D. Sulfur dioxide easily forms sulfuric acid mist under the action of sunlight and ultraviolet rays. (Answer: A)

14. Mercuric sulfate is added during COD testing to: (Answer: Eliminate the interference of chloride ions.)

15. Sodium azide is added during the iodometric method for measuring dissolved oxygen to: (Answer: Eliminate the influence of nitrites.)

16. Malonic acid inhibits succinate dehydrogenase. Its main mechanism of inhibition is: A. Competitive inhibition. B. Non-competitive inhibition. C. Uncompetitive inhibition. D. Other. (Answer: A)

17. Flammable gases generated in industrial production should be recycled. If recycling isn’t possible and these gases are released into the atmosphere, they should be: A. Treated to prevent pollution. B. Burned completely. C. I can’t remember. D. Purified. (Answer: A)

18. In aerobic wastewater treatment, the main modes of nutrition for protozoa are: A. Animal-based nutrition and plant-based nutrition. B. Animal-based nutrition and saprophytic nutrition. C. Plant-based nutrition and saprophytic nutrition. D. None of the above. (I chose B, but I’m not sure.)

19. In areas where residential and educational facilities predominate, the allowable noise levels during day and night are: (Answer: 55 dB and 45 dB.) That’s all I can remember. I hope others can provide corrections or additional information. I remember another question: As shown in the diagram, a container is placed in the atmosphere, with water flowing freely out from the lower end. Ignoring head losses, what is the liquid pressure at point A, which is 4 meters below the opening? (Recollections from basic exam questions from the afternoon.) 1. 300,000 m³/day, retention time of 8 hours. The activated sludge concentration in the tank is 4000 mg/L, while the sludge concentration at the bottom of the sedimentation tank is 8000 mg/L. The effluent from the secondary sedimentation tank contains 10 mg/L of solids. To maintain a sludge age of 20 days, how much sludge needs to be removed each day? The answer is 2500 m3/d (it seems to be B? ), the amount carried away by the supernatant is negligible. Q = (300,000 ÷ 24 × 8) × 4 ÷ 20 ÷ 8 = 2,500 m3/d. 2. For waste-to-energy generation, the answer is A: 4MW. 3. The question on clean production: … use pesticides and fertilizers reasonably, (). A, Transgenic plants; B, Transgenic animals; C, Plant hormones; D, Animal hormones. My choice is “Plant hormones”. 4. For that trapezoidal channel, with m=1.5, base width of 34m, and height of 3.2m (with 0.5m extra headroom), if the flow rate from the upstream side is 60 m3/s, then what is the remaining flow capacity for other uses? Choose B (2 m3/s). The flow rate in the trapezoidal channel is 62 m3/s; therefore, the flow rate available for other purposes = 62 – 60 = 2 m3/s. 5. What does the presence of rotifers in activated sludge indicate? Indicative organisms with low organic matter concentrations and good performance in biological wastewater treatment. Textbook version from Tianjin University, page P48: 6. A certain location wishes to discharge wastewater with a BOD concentration of 110 mg/L and a flow rate of 0.2 m3/s into a river whose flow rate is 2.5 m3/s and whose BOD concentration is 0. The secondary discharge standard is 100 mg/L, while the BOD standard for Class IV surface water is 40 mg/L. Then ( ). I chose the answer that meets the surface IV water requirement. 7. If the initial efficiency of that electrostatic precipitator is 90% and it needs to be increased to 99%, what should the minimum area be? ( ) I chose 2 times (it seems to be D). The manual provides the formula η=1-exp(-AW/Q); according to the textbook on page P333, A2/A1=ln(0.1)/ln(0.01)=2. 8. When did environmental impact assessment start in our country? It was probably 1979; it seems to have been a C. I initially guessed C, but later changed it to D (in 1982). Hey, I lost 2 points because of that. 9. What are the noise standards for cultural, educational, and commercial areas ()? It should be B, 55 dB during the day and 45 dB at night. 10. Regarding the question on activated carbon adsorption: the thickness of the activated carbon is 0.6 m, and its bulk density is 450 kg/m3 (I think so?) ), gas flow velocity of 4 m/s, concentration of 150 g/m3 (can’t remember the unit), 0.15 m (I think it’s called the dead zone), equilibrium static activity * (forgot), determine the protection time of the bed layer (). I saw the Hilov equation in the exam manual; it must be used to solve this problem. Based on that calculation, the time required seems to be 22.1 hours (which should correspond to option B). 11. For arsenic testing, 20 ml of the water sample was taken and 2.5 ml of a standard solution with a concentration of 20 mg/L was added; the resulting absorbance was 0.434. Another 20 ml of the water sample was taken, with distilled water added to it, and the absorbance in this case was 0.214. The absorbance for a standard solution with a concentration of 1 mg/L was 0.230. …… What is the recovery rate after spiking? I can’t calculate it; haha, I just guessed 93% (which seems to be a D). 12. At a flow rate of 0.5 L/min, pumping for 30 minutes, with an ambient temperature of 18°C and a pressure of 101.1 kp, the slope of the curve is 0.0766. The measured absorbance is *, what is the concentration? () Grandma’s question was clearly harder than last year’s; last year the mass of the pollutant was given directly, but this time I had to calculate it myself. The problem was that I wasn’t sure whether A=Kc or C=KA. In the end I didn’t seem to arrive at an answer either. I switched to standard conditions, but I’ve forgotten which one I chose. 13. Acrylic acid (I think so?) ）The catalyst competition for succinic acid belongs to (）? I forgot the question title; for the answer I chose D, which means “none of the above”. Hehe, I don’t know how to do this. 14. There are two sound signals, one with an echo time of 4.5 s and the other with an echo time of 1.2 s. By how much is the noise reduced? I can’t do the calculations; I came up with an answer by using 10lg**, which is a value that often appears in cases of noise. △=10lg(4.5/1.2)=5.7dB. Hehe, I suddenly realized that this value might be related to distance The distance reduction formula is △=10lg(r1/r2), as stated in Tianjin University’s textbook on page P193. Since the speed of sound remains constant, the echo time is proportional to the distance traveled. Haha, it’s indeed possible to calculate using this formula. 15. When measuring dissolved oxygen, what is the purpose of adding sodium azide? Tianjin University textbook, P122: The modified iodometric method involves the use of sodium azide to eliminate the interference of nitrites on the measurement results. 16. 0.5 kg of glucose, anaerobic acetogenesis – how much acetate is produced ()? I chose A (0.5 kg). M = (0.5/180) × 6 ÷ 2 × 60 = 0.5 kg. 180 is the molecular weight of glucose, C6H12O6 {(CH2O)6}, and 60 is the molecular weight of acetic acid {CH3COOH}. 17. Given that the mass concentration of NO2 is *, what is its volume concentration under standard conditions? I calculated it directly by using mass concentration ÷ molecular weight × 22,4; it seems that C is the correct answer, while options D are not feasible due to insufficient information. 18. Regarding the issue of flammable gas emissions, what measures should be taken if they cannot be recovered? ( ) The question is more or less like that; I chose the option regarding complete combustion. It’s from page 434 of the Tianjin University textbook. I selected this answer because I saw the chimneys at Guangzhou Petrochemicals, which were constantly emitting smoke due to combustion, haha. 19. As for polymer compounds, they seem to be polymers of some kind of ester; which statement is incorrect? I chose an ionic compound, but this shouldn’t be considered an ionic compound. Fainted. I meant to continue editing the post above, but it ended up as a new reply, and I can’t delete it either. It’s frustrating; please just read it as is. 20. What requirements must the initial design file meet? () I chose “to meet the requirements for the depth of construction drawing documents,” which seems to be B. 21. The centrifugal pump pumps water into a tall tower; the water level rises while the flow rate decreases. What is the reason for this? The reason I chose it is the translation of the pipeline curve. According to the textbook from Tianjin University, page 26, he = △z + △p/ρg + △u²/2g + hf; in other words, he = A + BQ². When the liquid level rises, △z increases, which means A increases as well, causing the curve to shift upward. This results in the intersection point with the pump’s performance curve shifting to the left, leading to a decrease in Q and an increase in H. The loan for the construction period is 10 million yuan, with no interest paid during this time. The payments are 2 million yuan in the first year, 5 million yuan in the second year, and 3 million yuan in the third year. The interest rate is 7%. How much interest needs to be paid during the construction period? () I chose the answer of 1.38 million yuan. I=200×(1.07^3-1) + 500×(1.07^2-1) + 300×0.07 = 1.38 million yuan. What is the minimum height required for the chimney of a newly built boiler according to the standards for atmospheric pollutant emissions? And for boilers that emit cyanide (I think it’s cyanide), what is the minimum height required? I chose the 15m and 20m options; it seems to be D. Only one answer appeared, which was 15m. I remember that number quite clearly, so I selected it without hesitation, even without paying close attention to the rest of the question. Hehe. In the spectrophotometric method using molybdenum disulfide to measure total phosphorus, what is the substance added to eliminate the interference caused by turbidity? What I chose was the addition of sulfuric acid and ascorbic acid. 1. Which of the following statements regarding the classification of surface water is correct? A. Habitats for rare aquatic animals; natural reserves are classified as Category I areas. B. Wintering grounds for fish and shrimp, spawning areas for them, as well as sources of surface water used for drinking water fall under Category II areas. C. Migration routes, aquaculture areas, and swimming areas are classified as Category III areas. D. Water used for general landscaping purposes and for recreational activities where direct human contact is not involved is classified as Category IV water. The answer should be D, right? Water used for general landscaping purposes is actually classified as Category V water