State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an 710048, P.R. China.
State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an 710048, P.R. China.
Sci Total Environ. 2021 Oct 10;790:148052. doi: 10.1016/j.scitotenv.2021.148052. Epub 2021 May 27.
Algal blooms caused by high concentrations of nutrients (especially phosphorus) limit the use of recycled water (RW) for replenishing landscape ponds in the context of global water scarcity. Previous studies have demonstrated that alum sludge is a low cost phosphorus sorption medium, which could potentially be applied in constructed wetlands and sewage treatment plants. However, whether alum sludge can be used for algae inhibition in reclaimed water urban landscape ponds (RWULPs) should be explored. In this study, phosphorus removal and algae inhibition by alum sludge were investigated in a RWULP in China. The results highlight that there is a serious risk of algal blooms in RWULPs. The algal density was found to be 1.58 × 10 cell·mL, which is 6.84 times higher than that of the surface water ponds. The algal blooms presented a Cyanophyta-Chlorophyta-Bacillariophyta-type, and the dominant algae species were Microcystis flos-aquae (Wittr.) Kirchner, Chlorella vulgaris, and Scenedesmus quadricauda. Moreover, the removal rate of phosphorus by alum sludge was as high as 98% and eventually leads to phosphorus stress, which has an important effect on algae growth and algae inhibition rate of 80%. In addition, the proportion of phosphorus and nitrogen in the adsorbed alum sludge increased by 3.12% and 0.32%, respectively, and Al was reduced by only 2.18%. Alum sludge is a potential inhibitor of algae in RWULPs that does not negatively impact the environment. These results are of great importance in algal bloom control of RWULPs and may help alleviate the problem of urban water resource scarcity.
富营养化（尤其是磷）引起的藻类大量繁殖限制了再生水（RW）在全球水资源短缺背景下用于补充景观池塘。先前的研究表明，铝污泥是一种低成本的磷吸附介质，可能应用于人工湿地和污水处理厂。然而，铝污泥是否可以用于抑制再生水城市景观池塘（RWULP）中的藻类，尚需探讨。本研究在中国的一个 RWULP 中研究了铝污泥的除磷和抑藻作用。结果突出表明 RWULP 存在严重的藻类大量繁殖风险。藻类密度为 1.58×10 个细胞·mL，比地表水池塘高 6.84 倍。藻类大量繁殖呈现蓝藻-绿藻-硅藻型，优势藻种为铜绿微囊藻（Wittr.）Kirchner、普通小球藻和四尾栅藻。此外，铝污泥对磷的去除率高达 98%，最终导致磷胁迫，这对藻类生长和 80%的抑藻率有重要影响。此外，吸附铝污泥中的磷和氮的比例分别增加了 3.12%和 0.32%，而 Al 仅减少了 2.18%。铝污泥是 RWULP 中藻类的潜在抑制剂，不会对环境造成负面影响。这些结果对 RWULP 中藻类大量繁殖的控制具有重要意义，并可能有助于缓解城市水资源短缺问题。
