Daily Question 2015.10.15 (EIA Discussion): 3 Wealth points for replies, plus 5 Wealth points for correct answers (single-choice question)

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The wastewater discharged from a proposed project has a temperature of 46°C and a pH of 7.8, and it contains four pollutants: mercury, zinc, copper, and lead. According to the \"Technical Guidelines for Environmental Impact Assessment – Surface Water Environment,\" when predicting the water environment impact of this project, the types of pollutants that need to be considered are ( ). A. Persistent pollutants, non-persistent pollutants, acid and alkali pollutants; B. Persistent pollutants, non-persistent pollutants, acid and alkali pollutants, waste heat; C. Persistent pollutants, acid and alkali pollutants; D. Persistent pollutants, waste heat. The correct answer is D. This question is poorly formulated, as discharging pollutants into surface water is different from discharging them into the sea. In the case of surface water: it is necessary to determine whether the wastewater affects the temperature of the surface water; only if the average weekly temperature increases by more than 1 degree or decreases by more than 2 degrees can it be determined whether there is thermal pollution ； A pH value of 6-9 is not considered polluted. In the case of seawater: according to the water quality classification for seawater areas, in categories 1 and 2, an increase in temperature of no more than 1 degree in summer and no more than 2 degrees in other seasons is considered not to be pollution; in categories 3 and 4, an increase of no more than 4 degrees is sufficient ； The pH value requirements are stricter: in zones 1 and 2, the pH of the wastewater discharged must be between 7.8 and 8.5, and it must not exceed the normal variation range of 0.2 pH units for that sea area; in such cases, it is not considered pollution. In zones 3 and 4, the pH of the discharged wastewater must be between 6.8 and 8.8, with no deviation exceeding 0.5 pH units from the normal range; under these conditions, it is also not considered pollution. So, strictly speaking, this question has no answer; one should choose D by process of elimination.