Sea friends who achieve a score of 10 Wealth or 1 Charm or higher in the environmental protection zone are welcome to enter

(1) A lot has been said upstairs; I’ll just say one thing. For those of us who have limited knowledge and weak abilities, we come here mainly to learn*, and occasionally to help others. Therefore, I request that the moderators, or professionals assigned by them, provide relatively accurate answers to those request posts at an appropriate time. This can attract some newcomers to come and learn*. With so many people, how could it not be lively? http://bbs.hcbbs.com/viewthread.php?tid=329810&page=1#pid2061158 (II) It’s normal for there to be a smell, but it depends on whether that smell can cause harm to the human body and whether it meets environmental standards; it can’t be generalized. It’s not realistic either to have no smell at all. The main thing is to ensure that we meet the environmental requirements. http://bbs.hcbbs.com/viewthread. ... p;page=2#pid2036024 (III) 1. The maximum power consumption of a portable microcomputer monitor equipped with a USB interface when in energy-saving mode is (C) A≤10w B≤5w C=10w D=5w. 2. The plastics and metals used in portable microcomputer casings are technically (B) recyclable by weight. A 95% B 90% C 85% D 80%. 3. Digital multi-functional copying devices whose noise level during copying is greater than (B) should have instructions in their product manuals advising against using them in office areas. A60dB(A) B63dB(A) C70dB(A) D75 dB(A) 4. The noise limit for a digital multi-functional parallel color copier that can copy 10 A3-sized sheets per minute while in copying mode is (c) dB(A): A63 B64 C67 D75. 1. The maximum power consumption of a portable laptop display with a USB interface when in energy-saving mode is (C): A≤10w B≤5w C=10w D=5w. 2. The plastics and metals used in portable laptop casings are technically (B) recyclable: A95% B90% C85% D80%. 3. Digital multi-functional copiers whose noise level is greater than (B) during copying should have instructions in their product manuals advising against using them in office areas. A60dB(A) B63dB(A) C70dB(A) D75 dB(A) 4. The noise limit for a digital multi-functional parallel color copying device that can copy 10 A3-sized sheets per minute while in copying mode is (c) dB(A): A63 B64 C67 D75 http://bbs.hcbbs.com/thread-400941-1-1.html This post was last edited by david-2 on 2009-2-28 at 12:43

(1) Our company uses sea salt for chlor-alkali production. Before the adoption of membrane-based nitrate removal, the composition of the salt sludge was as follows: Mg(OH)2 at 6%, CaCO3 at 12%, BaSO4 at 28%, water at 35%, and NaCl at around 15%. There is no BaSO4 anymore. http://bbs.hcbbs.com/viewthread.php?tid=372023&page=1#pid1964880 (1) On environmental impact assessment engineers http://bbs.hcbbs.com/viewthread.php?tid=371675&page=1#pid1957836 (2) Consumption indicators for acid, alkali, and sodium hydride in the ion-exchange membrane caustic soda production process http://bbs.hcbbs.com/viewthread.php?tid=370860&page=1#pid1952638

Great idea, I’ll support it; I’ll organize it when I have time.

When you have time, come here more often to learn from everyone’s** experience, so that you can improve yourself.

Topic Post 1+ Six pieces of information for members who want to become environmental assessment engineers but are not from environmental engineering backgrounds + http://bbs.hcbbs.com/viewthread.php?tid=383207&highlight= Topic Post 2+ Chemical industry professionals, would you be willing to exchange ideas with environmental assessment experts? http://bbs.hcbbs.com/thread-393684-1-1.html Main thread: 3+ Survey: How do you view environmental impact assessment? http://bbs.hcbbs.com/thread-399652-1-2.html This post was last edited by libj520 on 2009-3-1 13:38 ]

It is recommended to simply write the topic posts as: 1, 2, etc. . . . . Reply post: 1, 2,. . . . . I’m still learning*; I read a lot but talk little. I’ll make up for it gradually

There are generally two methods for measuring COD: the potassium dichromate method and the potassium permanganate method. Each method corresponds to a specific calculation procedure, as follows: In the potassium dichromate method, a certain amount of potassium dichromate is used in a strong acid solution to oxidize the reducing substances in the water sample. The excess potassium dichromate is then titrated back using an ammonium ferrous sulfate standard solution, with ferroin serving as an indicator; the amount of this solution used helps to calculate the oxygen demand associated with the reducing substances in the water sample. CODcr(O2, mg/L) = (V – V0) / V0, where V0 is the volume of ammonium ferrous sulfate standard solution consumed during the blank titration in ML, V1 is the volume of ammonium ferrous sulfate standard solution consumed when titrating the water sample in ML, V is the volume of water in ML, 8 is the molar mass of oxygen. CODMn = {M * 8 * 1000} / 100. V1 represents the volume of potassium permanganate standard solution used for titrating the water sample. K is the correction factor (the number of milliliters of sodium oxalate standard solution equivalent to each milliliter of potassium permanganate standard solution). M is the concentration of sodium oxalate standard solution in mol/L. What is the approximate range of COD values you measure, and what is the cleanliness level of the water samples? For clean water samples, when the COD is greater than 500, the HACH method can be used. The method of using potassium permanganate to determine chemical oxygen demand (COD) is known as the permanganate index IMn; it is expressed as the number of milligrams of oxygen consumed per liter of sample (O2, mg/L). IMn={x10x8x1000}/100 V1 —— After heating, add 10.00 mL of sodium oxalate solution with a concentration of 0.010 0 mol/L until the solution becomes colorless. Titrate while hot with potassium permanganate solution until a pink color just appears, and maintain it for 30 seconds without it fading. Record the volume of potassium permanganate solution consumed, volume of potassium permanganate solution used, mL ； V2 — Blank test: 10.00 mL of sodium oxalate solution is added to the solution after titration. If necessary, heat the solution to 80°C. Continue titrating with potassium permanganate solution until a pink color just appears, and maintain it for 30 seconds without it fading. Record the volume of potassium permanganate solution consumed, in mL ； C — Sodium oxalate standard solution, 0.0100 mol/L. Only the result calculations are provided here; for the specific procedure, refer to the **Standard of the People’s Republic of China – Determination of permanganate index in water quality, GB 11892—89**: http://bbs.hcbbs.com/viewthread.php?tid=193318&page=2#pid2069977. This post was last edited by zsy_lucky on 2009-2-14 09:27

Reply: (1) I think it’s completely impossible for us to handle this with our own efforts. I remember that year when a village in our area faced mass **due to water pollution issues; the interview vehicles from Focus Interview had already set up their antennas, but the city party secretary stepped in personally to resolve the situation. To be honest, small local enterprises do have some form of support, especially in remote areas. Of course, in HaiChuan, many people are engaged in chemical engineering design; if those of us who work in design pay special attention to pollution issues from the very beginning, I think the pollution problems in chemical plants will gradually improve. http://bbs.hcbbs.com/viewthread.php?tid=397797&page=1#pid2124822 Reply: (II) 1 is to continue with evaporation crystallization separation ； 2 is cold crystallization separation; 3 is evaporation and concentration after neutralization to produce inorganic salts ； After neutralization, it is diluted with water before being discharged. Current discharge standards do not specify any requirements regarding the concentration of inorganic salts; as long as the receiving water body is large enough, the water quality will not be affected ； 5 According to the process requirements, it is returned for use in the process. I’m not sure if these 5 methods will be helpful. http://bbs.hcbbs.com/viewthread.php?tid=349722&page=1#pid2143557

http://bbs.hcbbs.com/thread-396206-1-1.html

(1) My answers: 1 B, 2 B, 3 B, 4 A. http://bbs.hcbbs.com/viewthread.php?tid=397777&page=4#pid2125629 (2) 1. Environmental incidents refer to sudden events in which the _____ environment is polluted, human health is compromised, and socio-economic interests as well as the property of the public suffer losses due to economic and social activities and behaviors that violate environmental protection laws and regulations, as well as the impact of accidental factors or irresistible natural disasters, thereby causing adverse social effects. (Fill-in-the-blank question) 2. The following (A or C) event is a major environmental incident. A. 10 deaths, 30 or fewer people affected; B. 30 deaths; C. 50 cases of poisoning, 100 or fewer people affected; D. 100 cases of poisoning. 3. (D) insurance should be provided for emergency response workers working in the environment. A. Work-related injuries B. Medical care C. Pension benefits D. Accidental injuries 4. The local emergency response agency for sudden environmental incidents is determined by (B). A. Local environmental protection departments B. Local people’s governments C. Local work safety supervision and management departments 1. An environmental incident refers to a sudden event in which the _____ environment is polluted, human health is harmed, and socio-economic interests as well as the property of the public are damaged, as a result of economic and social activities and behaviors that violate environmental protection laws and regulations, as well as the impact of accidental factors or irresistible natural disasters, thereby causing adverse social effects. (Fill-in-the-blank question) 2. The following (A or C) event is a major environmental incident. A. 10 deaths, 30 or fewer people affected; B. 30 deaths; C. 50 cases of poisoning, 100 or fewer people affected; D. 100 cases of poisoning. 3. (D) insurance should be provided for emergency response workers working in the environment. A. Work-related injuries B. Medical care C. Pension benefits D. Accidental injuries 4. The local emergency response agency for sudden environmental incidents is determined by (B). A. Local environmental protection departments B. Local people’s governments C. Local work safety supervision and management departments 1. An environmental incident refers to a sudden event in which the _____ environment is polluted, human health is harmed, and socio-economic interests as well as the property of the public are damaged, as a result of economic and social activities and behaviors that violate environmental protection laws and regulations, as well as the impact of accidental factors or irresistible natural disasters, thereby causing adverse social effects. (Fill-in-the-blank question) 2. The following (A or C) event is a major environmental incident. A. 10 deaths, 30 or fewer people affected; B. 30 deaths; C. 50 cases of poisoning, 100 or fewer people affected; D. 100 cases of poisoning. 3. (D) insurance should be provided for emergency response workers working in the environment. A. Work-related injuries B. Medical care C. Pension benefits D. Accidental injuries 4. The local emergency response agency for sudden environmental incidents is determined by (B). A. Local environmental protection departments B. Local people’s governments C. Local work safety supervision and management departments 1. An environmental incident refers to a sudden event in which the _____ environment is polluted, human health is harmed, and socio-economic interests as well as the property of the public are damaged, as a result of economic and social activities and behaviors that violate environmental protection laws and regulations, as well as the impact of accidental factors or irresistible natural disasters, thereby causing adverse social effects. (Fill-in-the-blank question) 2. The following (A or C) event is a major environmental incident. A. 10 deaths, 30 or fewer people affected; B. 30 deaths; C. 50 cases of poisoning, 100 or fewer people affected; D. 100 cases of poisoning. 3. (D) insurance should be provided for emergency response workers working in the environment. A. Work-related injuries B. Medical care C. Pension benefits D. Accidental injuries 4. The local emergency response agency for sudden environmental incidents is determined by (B). A. Local environmental protection departments B. Local people’s governments C. Local work safety supervision and management departments 1. An environmental incident refers to a sudden event in which the _____ environment is polluted, human health is harmed, and socio-economic interests as well as the property of the public are damaged, as a result of economic and social activities and behaviors that violate environmental protection laws and regulations, as well as the impact of accidental factors or irresistible natural disasters, thereby causing adverse social effects. (Fill-in-the-blank question) 2. The following (A or C) event is a major environmental incident. A. 10 deaths, 30 or fewer people affected; B. 30 deaths; C. 50 cases of poisoning, 100 or fewer people affected; D. 100 cases of poisoning. 3. (D) insurance should be provided for emergency response workers working in the environment. A. Work-related injuries B. Medical care C. Pension benefits D. Accidental injuries 4. The local emergency response agency for sudden environmental incidents is determined by (B). A. Local environmental protection departments B. Local people’s governments C. Local work safety supervision and management departments. http://bbs.hcbbs.com/viewthread.php?tid=392287&page=1#pid2091134 (III) 1. Before being reused for refilling toner, aside from components such as the photoconductive drum that directly affect printing quality, the recycled parts should account for at least (A) of the quality of the original parts. A、75% B、80% C、85% D、90% 2、When recovering and processing recycled toner cartridges, the correct methods are (ABC). A、Enterprises should establish a recycling system for used toner cartridges; these cartridges need to be collected by the manufacturers for further processing and reuse ； B. For components that cannot be used for technical reasons, manufacturing enterprises are allowed to use alternative materials that meet the relevant standards, and the materials taken out from the original toner cartridges must be disposed of properly ； C. The method of recycling and the recycling points should be specified in the instructions ； D. Enterprises should recycle the remaining toner or store it in sealed containers for landfill disposal. 3. The power consumption of a standard printer that prints 30 A4 pages per minute in sleep mode should be (C) kilowatt-hours. A、≤30 B、≤40 C、≤0.03 D、≤0.04 4. A standard printer that can print 14 A4 pages per minute shall not have a maximum sound pressure level exceeding (D) in its operating, standby, and sleep modes. A、≤67 dB(A) B、67 dB(A) C、≤62 dB(A) D、62 dB(A) http://bbs.hcbbs.com/viewthread.php?tid=390568&page=3#pid2085488