Situation and prospects of phosphorus recovery techniques
磷回收技术的研发现状及发展趋势

Phosphorus is a nonrenewable resource which is becoming rarer. The international price of phosphorus ore has dramatically increased by 6 times within 10 years. At the same time, there is a contradiction between the lack of phosphorus resources on the continents and the constantly high phosphorus contents in surface water, resulting in eutrophication. This status of the resource and the environment is driving phosphorus recovery instead of removal forward, by exploiting the secondary phosphorus resource from wastewater and animal manure. The 4th international conference on nutrient recovery from wastewater streams held in May 2009 concentrated on the global R & D and applications of phosphorus recovery techniques. Based on the conference and other achievements, key factors such as pH, which control the reaction forming pure struvite, are firstly addressed. Next, the R & D progress of phosphorus recovery techniques are reviewed in detail, including such the traditional methods as chemical precipitation, crystallization, adsorption/desorption, etc. and also emerging techniques like urine source separation, MBR, nanotechnology, filamentous bacteria, bioleaching/bioaccumulation, the BioIronTech process as well as novel phosphorus recovery techniques from animal manure, sludge and animal meat bone ash and biomass ash. Finally, recovered phosphates applied in agriculture and aquaculture are demonstrated by case studies, and the prospects for phosphorus recovery techniques are summarized.