磷回收技术的研发现状及发展趋势

Situation and prospects of phosphorus recovery techniques

磷是地球上一种不可自然再生的有限资源,磷的这一属性近年来已诱使国际磷矿石价格一路飙升,较10年前翻了6番.与此同时,全球范围内普遍存在着陆地磷矿产资源日益匮乏与水环境中磷含量过高而导致水体富营养化这一矛盾.这样的资源与环境现状目前正推动着以"回收"磷代替"去除"磷之理念的快速传播与研发技术的实际应用;从污水以及动物粪尿中发掘"第二磷矿"的设想目前正被国际社会所日益青睐.2009年5月"第4届从污水中回收营养物国际会议"高度浓缩了当今世界有关磷回收技术的研发与应用现状.以此次会议内容为主线,结合其他方面最新研究与应用成果,首先对磷回收偏爱产物——鸟粪石形成的pH等重要反应条件之基础性研究成果进行了概述.其次,详细阐述了磷回收技术的研发进展,除传统的化学沉淀、结晶、吸附/解吸附等方法外,还着重介绍了尿液源分离、MBR、纳米技术、丝状聚磷微生物、生物浸取/生物富集、生物铁工艺等新型磷回收技术,以及动物粪尿磷回收、污泥及肉骨焚烧灰回收磷与生物质磷回收技术.最后,以实例说明磷回收产物在农业和水产养殖业方面的尝试效果,并对磷回收未来技术发展趋势进行了宏观展望.

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.