芦苇湿地系统对鸭粪废水中COD的模拟去除及纳污量核算

通过原状芦苇土柱灌溉鸭粪废水的室内模拟试验,探讨了芦苇湿地系统对鸭粪废水中COD的净化规律,并估算了芦苇湿地系统对COD的最大纳污量.结果表明,不同浓度的养鸭废水对芦苇的生物量影响不同,低、中、高浓度处理下芦苇生物量分别较对照增长36.1%、24.4%、24.3%;不同时期湿地系统对COD的净化效果不同,生长期要明显好于抽穗期和开花期;同一时期不同浓度处理条件下芦苇湿地系统对COD的净化效果亦存在明显差异,高浓度处理下湿地系统对废水中COD的去除率明显高于低浓度和中浓度处理.芦苇湿地系统对鸭粪废水中COD的净化可以用指数方程表示,而且在相同进水浓度下,降解常数(k)与温度成线性关系.高浓度处理条件下,估算出白洋淀芦苇湿地系统对COD的最大纳污量约为26629t·a-1.

Removal of COD in duck wastewater and capacity estimation in Baiyangdian Lake based on a simulated reed wetland system

An indoor experiment using undisturbed soil columns from Baiyangdian lake was carried out to understand the purification dynamics of chemical oxygen demand (COD) in a reed wetland system and estimated the COD capacity as well. The results showed that, compared with the control, the reed biomass in the low, medium and high concentrations of duck wastewater increased by 36.1%, 24.4%, 24.3%, respectively. The COD purification rates at different periods were different, indicating a better purification effects in growing period than heading stage and flowering stage. Moreover, apparent difference on the COD removal among different soil columns at the same period was obtained, showing that the COD removal rate of high COD column was greater than in low and medium concentrations. The COD purification dynamics of duck wastewater followed an exponential equation, where the degradation constant k was linearly related to temperatures with a fixed COD concentration. Based on the results from the high COD soil columns, the maximum COD capacity of Baiyangdian lake was estimated to be 26629 t·a^-1.