Abstract:Effects of pH and water hardness on the acute toxicities of 2,4,6-trichlorophenol (2,4,6-TCP) and pentachlorophenol (PCP) to Daphnia magna were evaluated. The results showed that pH had a significant effect on the acute toxicities of the two chlorophenols (CPs). In the tested pH range (pH6~10), the acute lethal toxicities of the two CPs were decreased with the increase of water pH, which were attributed to the speciation distribution of CPs in different pH.It had been reported that the toxicities of CPs were contributed by their unionized forms.The elevated solution pH will cause the transformation of their unionized fractions to ionic fractions, and hence decrease their toxicity. Compared with pH, the effect of water hardness on the acute toxicities of the two CPs to Daphnia magna had certain influence, but the impact was relatively insignificant. Therefore, the effect of water hardness was not an important factor in the determination of the water quality criteria and standards of CPs.
李建华, 阚海峰, 毛亮, 高士祥. pH值和硬度对两种氯酚类化合物对大型溞急性毒性的影响[J]. 中国环境科学, 2013, 33(12): 2251-2256.
LI Jian-Hua, HAN Hai-Feng, MAO Liang, GAO Shi-Xiang. Effects of pH and water hardness on the acute toxicity of two chlorophenols to Daphnia Magna. CHINA ENVIRONMENTAL SCIENCECE, 2013, 33(12): 2251-2256.