Daily Question 2015.7.29 (EIA Discussion): 3 Wealth points for replies, plus 5 Wealth points for correct answers (single-choice question)
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This post was last edited by Zhang Xiaopeng on 2015-7-30 at 10:40. Workshop A of a certain enterprise generates 100 t/d of wastewater, with a pH value of 2.0 and a COD concentration of 2000 mg/L； The wastewater volume from Workshop B is also 100 t/d, with a pH value of 6.0 and a COD concentration of 1000 mg/L. When the wastewater from Workshops A and B is combined in the sewage treatment plant, the quality of the resulting wastewater is (). A. pH value of 4.0, COD of 1500 mg/L B. pH value of 4.0, COD of 1800 mg/L C. pH value of 2.3, COD of 1500 mg/L D. pH value of 3.3, COD of 1800 mg/L. Correct answer: C. The key is to understand the unit conversion for water – 1 m3 equals 1000 kg ； 1m3=1000L
C. pH value 2.3, COD 1500 mg/L
A. pH value 4.0, COD 1500 mg/L
The wastewater from workshops A and B mentioned above, after being mixed in the sewage treatment plant, has a water quality of c
This post was last edited by akroise on 2015-7-29 09:37. C.pH value: 2.3, COD: 1500 mg/L. Rule for calculating the pH of a mixed solution: 0.3 (when volumes are equal). “When the sum of the pH values of two solutions is 14, the pH of the mixed solution is 7.”； When the sum of the pH values of the two solutions is less than 13, the pH value of the mixture is the smaller of the original pH values plus 0.3 ； When the sum of the pH values of the two solutions is greater than 15, the pH value of the mixture is the larger of the original pH values minus 0.3.”
A, pH value 4.0, COD value 1500.
Workshop A of a certain enterprise generates 100 t/d of wastewater, with a pH value of 2.0 and a COD concentration of 2000 mg/L； The wastewater volume from Workshop B is also 100 t/d, with a pH value of 6.0 and a COD concentration of 1000 mg/L. When the wastewater from workshops A and B is combined at the sewage treatment plant, the resulting water quality is (C). A. pH 4.0, COD 1500 mg/L B. pH 4.0, COD 1800 mg/L C. pH 2.3, COD 1500 mg/L D. pH 3.3, COD 1800 mg/L
C.pH value 2.3, COD 1500mg/L
Workshop A of a certain enterprise generates 100 t/d of wastewater, with a pH value of 2.0 and a COD concentration of 2000 mg/L； The wastewater volume from Workshop B is also 100 t/d, with a pH value of 6.0 and a COD concentration of 1000 mg/L. When the wastewater from workshops A and B is combined in the sewage treatment plant, the resulting water quality is (A). A. pH 4.0, COD 1500 mg/L B. pH 4.0, COD 1800 mg/L C. pH 2.3, COD 1500 mg/L D. pH 3.3, COD 1800 mg/L
Workshop A of a certain enterprise generates 100 t/d of wastewater, with a pH value of 2.0 and a COD concentration of 2000 mg/L； The wastewater volume from Workshop B is also 100 t/d; the quality of this wastewater features a pH value of 6.0 and a COD concentration of 1000 mg/L. When the wastewater from workshops A and B is combined in the sewage treatment plant, the resulting water quality is that of type A
C.pH value 2.3, COD 1500mg/L