College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China.
College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China.
Bioresour Technol. 2018 Jan;247:537-544. doi: 10.1016/j.biortech.2017.09.136. Epub 2017 Sep 22.
Excessive discharge of phosphate (P) into the surface water is the key factor to cause the eutrophication, so its removal has aroused much attention in recent years. In this study, different iron modification (chemical co-precipitation of Fe/Fe or FeCl impregnation) was used to improve the phosphate adsorption capacity of waste activated sludge (WAS)-based biochar. Comparative tests demonstrated that the FeCl-impregnated WAS-based biochar exhibited much superior phosphate adsorption capacity (111.0mg/g) in all as-prepared samples and performed well even under the interferences with pH and coexisting ions. X-ray diffraction (XRD) analyzes indicated that the iron in FeCl-impregnated WAS-based biochar existed mainly in amorphous phase, as hematite and amorphous hydroxides forms, which was of great benefit to the phosphate adsorption. Besides, ligand exchange plays important role in the adsorption of phosphate. The WAS-based biochar kept over 60% phosphate removal efficiency after five recycles.
过量的磷酸盐（P）排入地表水是导致富营养化的关键因素，因此近年来去除磷酸盐引起了广泛关注。在本研究中，采用不同的铁改性（Fe/Fe 共沉淀或 FeCl 浸渍）来提高基于废活性污泥（WAS）的生物炭的磷酸盐吸附能力。对比实验表明，在所有制备的样品中，FeCl 浸渍的 WAS 基生物炭表现出优异的磷酸盐吸附能力（111.0mg/g），即使在 pH 和共存离子的干扰下也能很好地发挥作用。X 射线衍射（XRD）分析表明，FeCl 浸渍的 WAS 基生物炭中的铁主要以无定形相存在，呈赤铁矿和无定形氢氧化物的形式，这对磷酸盐的吸附非常有利。此外，配体交换在磷酸盐的吸附中起着重要作用。WAS 基生物炭在五次循环后仍保持超过 60%的磷酸盐去除效率。
