3种天然材料改造直立式护岸对河道水质净化能力的影响

Influences of three natural materials on self-purification capacity of rivers with vertical revetments

在具有直立式护岸的人工模拟河道中,把蚝壳、竹片和椰壳纤维垫3种天然材料分别直接覆盖在护岸表面,以研究其对提高河道自净能力的影响。结果表明:试验启动21 d后,3种材料覆盖后河道COD去除率分别达到93%,74%,94%,高于对照组的60%;NH3-N的去除率均达到95%,高于对照组的59%;NO-3-N质量浓度在3种材料护岸和对照护岸分别升高至5.9 mg/L,5.0 mg/L,5.8 mg/L和3.9 mg/L,而TP去除率分别达到71%,37%,78%,对照组为64%,3种材料对提高河道水质净化能力均有明显效果。竹片表面附着的微生物磷脂含量和脱氢酶活性最大,分别为12 nmol/cm和45.0μg/(mL·h),分别是蚝壳的3.4和1.6倍,是椰壳纤维垫的4.8和4.5倍,3种天然材料均能为微生物附着生长和繁殖提供空间,促进河道中污染物的降解。

In order to study the influences of three natural materials （oyster shells, bamboo pieces, and coir mats） on improvement of the self-purification capacity of rivers with vertical revetments , these natural materials were used to cover the surface of the vertical revetment in an artificial river .The results show that , after the experiments lasted for 21 days, the removal rates of COD with the three kinds of revetments reached 93%, 74%, and 94%, respectively , higher than the level of 60%in the control river .The removal rates of NH 3-N with the three kinds of revetments all reached 95%, higher than the level of 59%in the control river .The concentrations of NO-3-N with the three kinds of revetments increased to 5.9 mg/L, 5.0 mg/L, and 5.8 mg/L, respectively, while that in the control river increased to 3.9 mg/L.The removal rates of TP with the three kinds of revetments reached 71%, 37%, and 78%, respectively , while that in the control river reached 64%.The three kinds of revetments played a significant role in improving the self-purification capacity of the river . The lipid phosphorus content and dehydrogenase activity （ DHA） of the microbial film on the surface of bamboo pieces were 12 nmol/cm and 45.0μg/（ mL· h） , respectively , 3.4 and 1.6 times higher than those of oyster shells , and 4.8 and 4.5 times higher than those of coir mats , respectively .These three natural materials can provide a habitat for microbial growth and reproduction , and can promote the degradation of pollutants in rivers .