3种人工载体净化富营养化水体能力的比较

通过野外模拟实验,对比3种不同理化性状人工载体(立体填料、生物绳和尼龙纱网)净化太湖梅梁湾富营养化水体的能力,并探讨影响人工载体水质净化能力的生物与非生物因素.结果表明:(1)所选择的3种人工载体均能显著降低水体的浊度,其中尼龙纱网处理组中水体浊度下降了94.2％,其单位质量载体净化量最高(36.18NTU/g);(2)与对照组相比,各人工载体处理组中,水体中藻类的生长都受到极显著抑制;(3)3种人工载体对水体中TN、TP的去除效果差异极显著,其对TN累积去除率分别为25.55％、10.21％、51.54％,对TP累积去除率分别为38.93％、38.33％、62.98％;(4)载体理化性状、附着藻类与细菌的生物量和活性、挂载量以及载体上溶解态营养盐的释放是影响人工载体水质净化能力的重要因素.综上,尼龙纱网因具备单位质量附着生物的生物量与活性高、自身滞留溶解态营养盐少以及质量轻且价格经济等优势成为净化富营养化水体较为理想的人工载体.

Comparison of the abilities of three artificial substrates in purifying eutrophic waters

The abilities of three artificial substrates (solid filler, bio-cord and nylon gauze) on purifying the eutrophic waters were compared in relation to the biotic and abiotic influencing factors based on a field microcosm experiment in Meiliang Bay of Lake Taihu. The results were as follows:(1) all of the three artificial substrates could significantly reduce the water turbidity. In comparison, water turbidity of the nylon gauze treatment group decreased by 94.2%, which was the highest decrease by per unit mass substrate (36.18 NTU/g); (2) comparing with the control group, the growth of algae in all three treatment groups were significantly inhibited; (3) the removal amounts of total nitrogen and phosphorus by the artificial substrates were significantly different among the three treatment groups respectively, with a 25.55%, 10.21%, 51.54% accumulative removal of total nitrogen, and a 38.93%, 38.33%, 62.98% accumulative removal of total phosphorus for the solid filler, bio-cord and nylon gauze, respectively; and (4) substrate physicochemical characteristic, biomass and activity of periphytic algae and bacteria, substrate quantity, and the releasing of dissolved nutrients attached on substrates are the key factors affecting the abilities of artificial substrates to purify eutrophic waters. In conclusion, nylon gauze has advantages over the other two substrates with high biomass and microbial activity by per unit mass periphyton, less dissolved nutrients attached on itself, lighter weight and cheaper price. Hence we suggest that nylon gauze is an ideal artificial substrate in purifying eutrophic waters.