以水化硅酸钙为基质的人工湿地系统除磷研究

添加水化硅酸钙作为人工湿地的基质,旨在强化湿地系统对磷的去除能力,减轻水体富营养化.采用模拟试验系统考察了水化硅酸钙粒径、投加量及水力停留时间对除磷效果的影响.结果表明,在水化硅酸钙粒径为4目、投加量为80 g时系统达到最佳的除磷效果,一个月后去除率稳定在75%左右,与对照人工湿地相比,去除率可提高20%以上;停留时间越长,系统对磷的去除效果越好,停留时间为4 d的去除率比停留时间为2 d和1 d的分别高约5%和20%;水化硅酸钙对植物的生长和除磷能力有明显的促进作用.同时,湿地植物代谢可以有效控制水化硅酸钙本身对出水pH的影响,使水体pH值稳定在8.2左右.

Phosphorus Removal in Constructed Wetland Using Calcium Silicate Hydrate as Substrate

The aim of adding calcium silicate hydrate as substrate in constructed wetland is to enhance phosphorus removal capacity of constructed wetland and reduce water eutrophication. The influence of particle size and dosage of calcium silicate hydrate and HRT on phosphorus removal efficiency was in-vestigated in a simulation experiment system. The results show that when the particle size of calcium silicate hydrate is 4 mesh, and its dosage is 80 g, the system reaches the optimal phosphorus removal efficiency. After a month, the removal rate of phosphorus is about 75% and is increased by more than 20% compared to conventional constructed wetland. The longer the HRT is, the better the phosphorus removal efficiency is. The removal rate of phosphorus with HRT of 4 d is 5% and 20% higher than that of 2 d and 1 d. The calcium silicate hydrate has an obvious promotion on growth of plants and phosphorus removal efficiency. Additionally, calcium silicate hydrate increases the pH of the effluent. The hydrophytes can reduce this effect and maintain pH at around 8.2.