论文部分内容阅读
池塘常在冬季排水清塘,导致大量富营养化废水进入周围环境造成污染,因此研究低温下净化养殖废水对于保护环境、实现渔业可持续发展具有重要意义.采用室内模拟试验比较低温条件下(3.3-17.2℃)不同生物量的豆瓣菜浮床对池塘养殖废水中氮磷营养盐、高锰酸盐指数和叶绿素a的去除效果.试验共设置5个梯度水平,包括1个对照组(0 g/m~2)和4个处理组(100、200、300、400 g/m~2).结果显示豆瓣菜浮床能够降低水体p H值、溶解氧、电导率、氮磷营养盐浓度、高锰酸盐指数和叶绿素a浓度.试验第28和35天处理组4总氮去除率显著高于其他组(P<0.05).NH4-N去除率呈现先上升后下降的趋势,各组NH4-N去除率间没有显著差异.第7和14天各处理组的NO2-N去除率均显著高于对照组(P<0.05),且随着生物量的增加去除速率逐渐升高.第7天处理组1-3的NO3-N去除率显著高于对照组(P<0.05),但试验后期各组NO_3-N去除率间无显著差异.第7天处理组2和处理组4中总磷去除率显著高于对照组(P<0.05),后期各组间无显著差异.第21天对照组高锰酸盐指数去除率显著高于处理组3和4(P<0.05),但与处理组1和2没有显著差异.第21天处理组2的叶绿素a去除率显著高于其他各组(P<0.05).综上认为豆瓣菜可作为低温条件下净化池塘养殖废水的浮床植物,综合考虑成本和净化效率其种植生物量为200 g/m~2较适宜.
Pond often drains clear ponds in winter, resulting in a large number of eutrophication wastewater into the surrounding environment causing pollution, therefore, to study the purification of aquaculture wastewater at low temperature for the protection of the environment, to achieve sustainable development of fisheries is of great significance.Using indoor simulation tests at low temperatures (3.3 -17.2 ℃) The removal efficiencies of nitrogen and phosphorus nutrients, permanganate index and chlorophyll a in pond culture wastewater with floating bed of watercress with different biomass were tested.The experiment consisted of five gradient levels including one control group (0 g / m ~ 2) and four treatment groups (100,200,300,400 g / m ~ 2) .The results showed that the floating bed of watercress could reduce the p H value, dissolved oxygen, conductivity, N and P nutrient concentration, Acidity index and chlorophyll a concentration.The total nitrogen removal rate of treatment group 4 on the 28th and 35th days was significantly higher than that of the other groups (P <0.05) .The NH4-N removal rate first increased and then decreased, and the NH4-N There was no significant difference between the two treatments on the 7th and 14th days.The NO2-N removal rates of all treatments were significantly higher than those of the control (P <0.05), and the removal rate increased with the increase of biomass. The NO3-N removal rates of group 1-3 were significantly higher than those of the control group (P <0.05), but were late in the experiment There was no significant difference in the NO_3-N removal rate between the two groups.After 7 days, the total phosphorus removal rate in treatment group 2 and treatment group 4 was significantly higher than that in control group (P <0.05) The removal rate of manganese oxide index was significantly higher than that of treatment groups 3 and 4 (P <0.05), but not significantly different from that of treatment groups 1 and 2. The removal rate of chlorophyll a of treatment group 2 on day 21 was significantly higher than that of other groups (P <0.05) .To sum up, watercress can be used as a floating bed plant for purifying pond wastewater under low temperature conditions, and the suitable planting biomass of 200 g / m ~ 2 is suitable considering the cost and purification efficiency.