Isomer and Enantioselective Degradation of Hexachlorocyclohexane Isomers in Sewage Sludge under Anaerobic Conditions

Perfluoroalkyl substances and organochlorine pesticides in sediments from Huaihe watershed in China

“…Differences in relative concentrations of HCH isomers or DDT congeners can be used to determine possible sources. Typically, the technical mixture of HCH consists of 60%-70% α-HCH, 5%-12% β-HCH, 10%-15% γ-HCH and 6%-10% δ-HCH, respectively (Buser and Muller, 1995). In this study, γ-HCH and δ-HCH were not detected and the detection rate of α-HCH was only 27.8%.…”

China's water pollution by persistent organic pollutants

“…Values of a-HCH/g-HCH in the range of 3.7e11 indicate historical use of technical HCH mixture . In contrast, values of a-HCH/g-HCH in the range of 0.2e1 are indicative of recently applied lindane as degradation of g-HCH is faster relative to the other three HCH isomers (Buser and Müller, 1995). Values of a-HCH/g-HCH for six of the 13 sites where data is available (Yellow, Huaihe and Qiantang Rivers, Chaohu Lake, Guanting Reservoir, and Macau Harbor) ranged from 0.20 to 1 (Fig.…”

Concentrations and potential health hazards of organochlorine pesticides in shallow groundwater of Taihu Lake region, China

“…Generally, technical HCH consists of 60-70% α-HCH, 5-12% β-HCH, 10-15% γ-HCH, and 6-10% δ-HCH and the α-HCH/γ-HCH ratio is in the range of 4-7 (Iwata et al, 1993;Buser and Müller, DF, detection frequency; BDL, below detection limit; ΣHCHs, sum of α-, β-, γ-and δ-HCH isomers; ΣDDTs, sum of p, p′-DDE, p, p′-DDD and p, p′-DDT; ΣHeptachlors, sum of heptachlor and heptachlor epoxide; ΣAldrins, sum of aldrin and dieldrin; ΣEndrins, sum of endrin and endrin aldehyde. 1995; Li and Macdonald, 2005).…”