k-C*模型的人工湿地模拟研究

采用自由表面流人工湿地,对广东省中山市某小区对应段的河涌进行生态修复改造。基于k-C*模型的计算结果表明,在对现有河涌的面积的利用下,TP和NH4+-N的去除效果受到限制。采用多因素正交实验对模型的计算结果进行实验验证和分析,研究了4种植物、4种基质,分别在2、4、6和8 d水力停留时间(HRT)下对TP和NH4+-N的去除效果,得到影响TP和NH4+-N去除效果的因素主次顺序分别为基质→植物→HRT和基质→HRT→植物;各因素的最佳水平条件分别为:风车草、颗粒活性炭、4 d(HRT)。在最佳水平条件下进行实验,结果表明,TP和NH4+-N的浓度均可达到出水排放标准浓度指标。k-C*模型的计算值总是比实验值偏高,但两者之间的误差在一个数量级范围内。

Modeling of k-C* model for constructed wetland

Surface flow constructed wetland was conducted for the ecological restoration of a river in Zhongshan City,Guangdong Province.The predicted results based on k-C* model showed that the removal effects of TP and NH+4-N were restricted under the present utilized area of the river.Three-factors-four-levels orthogonal experiment was used to verify and analyze the predicted results of k-C* model.Four plants and four substrates were selected to investigate the removal effects of TP and NH+4-N under 2,4,6,8 d hydraulic retention time(HRT).The influencing factors on the removal effects of TP and NH+4-N in sequence were as follows: substrate→plant→HRT and substrate→HRT→plant,respecfively.The optimal levels of experiments were Cyperus alternifolius granular activated carbon,HRT(4 d).Experimental results under optimal levels indicated that both the residual TP and NH+4-N achieved the Chinese effluent standard.The comparison between experiment and model indicated that the predicted results were over-estimated,but error was within one order magnitude.