新型海菜花调蓄湿地对模拟农田径流处理效果研究

发布时间：2018-11-18 08:17

【摘要】：洱海是我国典型的富营养化初期湖泊,入湖污染物主要来源于流域西部和北部。大理州以农业为主,农业种植模式以大蒜-水稻、蚕豆-水稻、蔬菜-蔬菜为主,化肥的大量施用导致农田残留氮磷较多,在雨水冲刷下,农田中大量氮磷流失,成为洱海流域污染物的主要来源。本课题以洱海流域农田低污染水及降雨径流为研究对象,探究进水硝酸盐氮浓度(Nitrate Concentration,ρ(NO_3~--N))分别为1、5和10 mg/L时,海菜花湿地对低污染水的处理效率及海菜花生长情况。并通过改变冲击过程湿地出水水位,建立4组海菜花调蓄湿地,研究非调蓄湿地(Non-Regulated Ottelia Acuminata Constructed Wetlands,NROCWs)和调蓄湿地(Regulated Ottelia Acuminata Constructed Wetlands,ROCWs)在水力冲击负荷分别为0.50、0.75和1.00 m3/(m2·d)时,模拟低污染水、降雨初期径流及降雨径流冲击后NROCWs和ROCWs对污水中氮磷的去除效果。主要结论如下:(1)进水ρ(NO_3~--N)(平均值±方差)为1.52±0.48、5.62±0.41和9.78±0.24mg/L时,湿地运行稳定后出水ρ(NO_3~--N)分别为0.24、0.30和0.55 mg/L,去除率分别为87.26%、94.98%和94.48%,海菜花湿地能有效去除低污染水中的硝氮;(2)进水ρ(NO_3~--N)为1.52±0.48 mg/L和5.62±0.41 mg/L时,海菜花在湿地中可正常生长;海菜花对硝氮有一定的耐受性,但ρ(NO_3~--N)较高(9.78±0.24mg/L)时对海菜花生长具有明显抑制作用。洱海流域为低污染水,其ρ(NO_3~--N)低于5 mg/L,上述结果表明:海菜花可作为湿地植物处理洱海低污染水;(3)冲击负荷为0.50 m3/(m2·d)时,ROCWs出水氮磷在10天内达稳定状态,稳定时间均小于NROCWs,冲击负荷为0.75 m3/(m2·d)和1.00 m3/(m2·d)时,ROCWs和NROCWs后期恢复时间均大于10天;(4)冲击负荷为0.50 m3/(m2·d)和0.75 m3/(m2·d),冲击时间为1天时,ROCWs对氮磷的截留率分别达50%和57%以上,比NROCWs高3~28%;冲击结束后10天内ROCWs对氮磷的去除量均高于NROCWs。综合考虑,调蓄体积为湿地有效体积1/3,降雨径流量产生的冲击负荷小于0.75 m3/(m2·d),且冲击时间小于1天时,ROCWs对径流中氮磷去除可达50%以上;(5)湿地在试验期间产生的经济收益为3.95×104元/(hm2·a),经济效益较好,降雨冲击过程对海菜花生长影响较小,湿地在处理低污染水时可以选用海菜花作为湿地植物,但湿地运行期间需对海菜花进行维护,使海菜花在湿地中占绝对优势。
[Abstract]:Erhai Lake is a typical eutrophication lake in China. In Dali Prefecture, agriculture is dominated by agriculture, while garlic rice, broad bean and rice, vegetables and vegetables are the main patterns of agricultural cultivation. The heavy application of chemical fertilizers leads to more nitrogen and phosphorus residues in farmland. Under Rain Water's scouring, a large amount of nitrogen and phosphorus is lost in farmland. It has become the main source of pollutants in Erhai River Basin. In this paper, the low pollution water and rainfall runoff in Erhai Basin were used as the research objects, and the (Nitrate Concentration, 蟻 (NO_3~--N) of the influent nitrate nitrogen concentration was 1 5 and 10 mg/L, respectively, when the nitrate concentration in the water was 1 ~ 5 and 10 mg/L, respectively. Treatment efficiency of low pollution water and growth of sea cauliflower in sea cauliflower wetland. By changing the effluent water level of wetland during impact, four groups of sea cauliflower storage wetland were established, and the unregulated wetland (Non-Regulated Ottelia Acuminata Constructed Wetlands,NROCWs) and regulated wetland (Regulated Ottelia Acuminata Constructed Wetlands, were studied. When the hydraulic shock load was 0.50m ~ (3 / (m ~ 2 ~ 2) d), the removal efficiency of nitrogen and phosphorus in wastewater was simulated by simulating low pollution water, initial runoff and NROCWs and ROCWs after rainfall runoff impact. The main conclusions are as follows: (1) when the influent 蟻 (NO_3~--N) (mean 卤variance) is 1.52 卤0.48U 5.62 卤0.41 and 9.78 卤0.24mg/L, The removal rates of 蟻 (NO_3~--N) of outlet water were 87.2694. 98% and 94. 48% respectively after the wetland operation was stable, and the removal rates of 蟻 (NO_3~--N) were 0. 24 and 0. 55 mg/L, respectively. Sea cauliflower wetland can effectively remove nitrate from low pollution water. (2) when the influent 蟻 (NO_3~--N) was 1. 52 卤0. 48 mg/L and 5. 62 卤0. 41 mg/L, cauliflower could grow normally in the wetland; Sea cauliflower has some tolerance to nitrate nitrogen, but 蟻 (NO_3~--N) is higher (9.78 卤0.24mg/L) has obvious inhibitory effect on the growth of sea cauliflower. The 蟻 (NO_3~--N) of Erhai Basin is lower than 5 mg/L,. The results show that cauliflower can be used as wetland plant to treat low pollution water in Erhai Lake. (3) when the impact load was 0.50 m3 / (m2 d), the effluent nitrogen and phosphorus of ROCWs reached a stable state within 10 days, and the stabilization time was less than that of 0.75 m3 / (m 2 d) and 1.00 m 3 / (m 2 d) of NROCWs, impact load. The late recovery time of ROCWs and NROCWs was more than 10 days. (4) when the impact load was 0.50 m3 / (m2 d) and 0.75 m3 / (m2 d), impact time was 1 day), the rejection rate of ROCWs to nitrogen and phosphorus reached more than 50% and 57% respectively, which was higher than that of NROCWs. The removal rate of nitrogen and phosphorus by ROCWs was higher than that of NROCWs. within 10 days after impact. When the storage volume is about 1 / 3 of the effective volume of the wetland, the impact load caused by rainfall runoff is less than 0.75 m3 / (m2 d),) and the impact time is less than 1 day, the removal of nitrogen and phosphorus in runoff by ROCWs can reach more than 50%. (5) the economic benefit of wetland during the experiment is 3.95 脳 10 ~ 4 yuan / (hm2 a),) is good, the effect of rainfall impact on the growth of sea cauliflower is small, the wetland can choose sea cauliflower as wetland plant when treating low pollution water. However, it is necessary to maintain sea cauliflower during wetland operation to make sea cauliflower take the absolute advantage in wetland.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X52

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