Department of Environmental Engineering, Federal University of Lavras (UFLA), Lavras, MG 37200-900, Brazil E-mail:
Department of Environmental Engineering, Federal University of Lavras (UFLA), Lavras, MG 37200-900, Brazil.
Water Sci Technol. 2023 Aug;88(4):922-931. doi: 10.2166/wst.2023.247.
Conventional wastewater treatment plants (WWTPs) present low phosphorus (P) removal capacity. Conversely, water treatment plants (WTPs) produce sludge with great P sorption from wastewater; however, directly adding the sludge into the wastewater treatment system could increase the effluent turbidity. As a novel approach, the present study evaluated the performance of WTP sludge within paper sachets for P removal from treated sewage. Different sludge concentrations (2-30 g L) and contact times (1-27 d) were applied to treat sewage from a university WWTP outlet. The sludge was characterized by P, Fe, and Al content. Larger sludge masses showed higher P removal efficiencies due to their high Fe content, especially at longer contact times (up to 100% at the final of the experiment). However, there is a more significant P reduction in the first 10 d (more than 90% in the most efficient treatment - 30 mg L). Based on the kinetic and isotherm analyses and the sludge chemical composition, precipitation proved to be a mechanism of great importance in P removal. Therefore, WTP sludge sachets can be a promising way to remove P from sewage, and the formed solid waste might be reused as an alternative fertilizer.
传统的废水处理厂（WWTP）的磷（P）去除能力较低。相反，水处理厂（WTP）从废水中产生具有很大 P 吸附能力的污泥；然而，直接将污泥添加到废水处理系统中会增加出水浊度。作为一种新方法，本研究评估了 WTP 污泥在纸小袋内从处理后的污水中去除 P 的性能。不同的污泥浓度（2-30 g L）和接触时间（1-27 d）被应用于处理来自大学 WWTP 出水口的污水。污泥的特性由 P、Fe 和 Al 含量决定。由于较高的 Fe 含量，较大的污泥质量表现出较高的 P 去除效率，尤其是在较长的接触时间（在实验结束时高达 100%）。然而，在最初的 10 天内 P 的减少更为显著（最有效的处理方法中超过 90% - 30 mg L）。根据动力学和等温线分析以及污泥的化学成分，沉淀被证明是 P 去除的一个重要机制。因此，WTP 污泥小袋可以成为从污水中去除 P 的一种很有前途的方法，形成的固体废物可能被重新用作替代肥料。
