污水处理中磷回收理论与技术

由于磷矿的开采和磷在自然界中近乎单向循环。磷资源日益枯竭。污水中含有大量的磷。我国污水排放中的磷量相当于磷矿产量的37．5％，经过处理回收可以转变为磷资源。又可以保护环境。当前磷的回收技术有沉积法、结晶法、土地利用等多种形式，除了土地利用外，其他技术都处于试验探索阶段，需要进一步开发研究。磷酸盐是磷回收的主要形式。鸟粪石和磷酸钙分别适合用作肥料和工业原料。

Theory and Techniques of Phosphorus Recovery from Wastewater Treatment

Owing to the exploitation of phosphorite and the unilateral circulation of phosphorus in nature, phosphorus resource is increasingly exhausted. However, there is large quantity of phosphorus in wastewater, which corresponds to 34.2% of the yearly phosphorite output in China. This part of phosphorus can be transformed into resource by recovery with the simultaneous result of environment protection. At present, there are several phosphorus recovery techniques such as chemical precipitation, crystallization, soil reuse and so on. Except for the soil reuse, other techniques are being explored and need further studying. Phosphate is the main form of phosphorus recovery, of which struvite and calcium phosphate are suitable for fertilizer and industrial material respectively.