School of Energy and Environment, Southeast University, No. 2 Sipailou Road, Nanjing 210096, China; ERC Taihu Lake Water Environment (Wuxi), No. 99 Linghu Road, Wuxi 214135, China.
School of Energy and Environment, Southeast University, No. 2 Sipailou Road, Nanjing 210096, China; ERC Taihu Lake Water Environment (Wuxi), No. 99 Linghu Road, Wuxi 214135, China; School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212018, China.
Chemosphere. 2018 Apr;197:768-781. doi: 10.1016/j.chemosphere.2018.01.098.
The presence of phosphorus (P) in discharged wastewater can lead to water pollution events and eutrophication. Given the increasing consumption of phosphate (PO) rocks, wastewater containing large quantities of P is deemed as a potential source of P recovery. Crystallization of P is an ideal way to recover P because of its simple design, ease of operation, high efficiency, and limited environmental impact. This paper provides a comprehensive review of P recovery by crystallization processes with respect to the mechanisms involved, operational parameters that influence the quality of the crystal, and available seed materials for inducing crystallization. Various operational parameters including pH, molar ratio of participating ions, mixing intensity, reactor type, and seeding conditions, were detailedly investigated. Different kinds of seeds were reviewed critically with regard to their principal properties, application, and long-term prospects. Crystallized products with a high P content can be used directly as slow-release fertilizers for agricultural production, and some test methods have been developed to determine their efficiency as a fertilizer and to evaluate their availability for plants. Further, the feasibility of P recovery by crystallization was evaluated in terms of economic benefits and environmental sustainability. This work serves as a basis for future research of P recovery by crystallization processes and responses to the increasingly stringent problems of eutrophication and the growing depletion of P resources.
污水中磷 (P) 的存在会导致水污染事件和富营养化。鉴于磷酸盐 (PO) 矿石的消耗量不断增加，含有大量 P 的废水被认为是回收 P 的潜在来源。磷的结晶是回收 P 的理想方法，因为其设计简单、操作方便、效率高且对环境的影响有限。本文就结晶过程中涉及的机制、影响晶体质量的操作参数以及可用的晶种材料等方面，对通过结晶过程回收 P 进行了全面的综述。详细研究了各种操作参数，包括 pH 值、参与离子的摩尔比、混合强度、反应器类型和晶种条件等。本文还对不同种类的晶种进行了批判性的评价，涉及它们的主要性质、应用和长期前景。高磷含量的结晶产品可直接用作农业生产的缓释肥料，并且已经开发出一些测试方法来确定它们作为肥料的效率，并评估它们对植物的可用性。此外，还从经济效益和环境可持续性方面评估了通过结晶回收 P 的可行性。这项工作为今后通过结晶过程回收 P 的研究以及应对日益严格的富营养化问题和 P 资源日益枯竭的问题提供了基础。
