六氯苯对水体微型生物群落的影响及其吸附行为

Impact and adsorption of hexachlorobenzene on aquatic microbial species

研究了六氯苯(HCB)对微型水生生物群落的影响及其吸附、传递过程。测定了群落的耗氧量和不同粒经颗粒物的生物量及HCB变化。试验结果显示,在6μg/L HCB影响下,群落的呼吸作用受到抑制,生物量减少。试验第1天,30.0%(质量分数,下同)的HCB以溶解态存在,26.3%吸附在0.22～2μm的颗粒物(以细菌为主)上,22.1%吸附在2～8μm的颗粒物(以鞭毛虫和藻类为主)上,21.6%吸附在大于8μm的颗粒物(以藻类和大型原生动物为主)上。48h后,溶解态的HCB逐渐减少,并由食物链低营养级向高营养级传递。最后74.9%的HCB都吸附在微型生物群落等颗粒物上,只有25.1%的HCB以溶解态存在。

Experiments were conducted to study the effect of hexachlorobenzene （HCB） on aquatic microbial species as well as the distribution/transport of HCB in the microbial community. Presence of HCB at 6 μg/L inhibited cumulative oxygen consumption and lowered biomass of microplankton,phytoplankton and protozoa （〉8μm）, it had variable effects on smaller organisms. Relative to the control, flagellate （2-8 μm） biomass increased first but then declined,while more bacteria （0.22-2μm） were observed except on the last day of sample. After 24 h,30.0% of the spiked HCB remained dissolved （〈0.22μm）, the rest was adsorbed on the microbial species （26.3% to the bacterial fraction,22.1% to the flagellate fraction and 21.6% to the phytoplankton and protozoa）. After 48 h,25.1% of HCB remained soluble while the reminder was more concentrated in the higher trophic level flagellate and 〉8μm fractions.