蓝铁矿法回收生物膜富集的城市污水中的磷

Vivianite crystallization method to recover phosphorus in municipal sewage enriched by biofilm method

磷资源因具有不可再生性和污染性,需要进行磷回收.目前污水处理厂使用的传统磷回收方法多是鸟粪石法,但存在利用价值低、磷回收率不高等缺点.本课题组提出了一种新的磷回收工艺系统,即在生物膜法高倍富集城市污水中的磷的基础上,通过蓝铁矿的形式回收磷,具有经济价值高、磷回收率高等优势.本实验研究主要通过探讨蓝铁矿法回收富磷溶液的过程中获得高磷回收率和蓝铁矿纯度的反应条件,并进行X-射线衍射仪(XRD)、扫描电子显微镜—能谱(SEM-EDS)定性表征最优条件下的蓝铁矿.结果表明,最优反应条件是pH值为7.00—7.50、氧化还原电位(ORP)降到-100 mV左右、铁磷离子物质的量物质的量比为3∶1,此时蓝铁矿法的磷回收率约为95.00%,蓝铁矿纯度为88.35%,蓝铁矿为沉淀回收物中主要晶相且晶型较好.

Phosphorus resources need to be recycled due to their non-renewability and pollution.At present,the traditional phosphorus recovery method used in sewage treatment plants is mostly struvite method,but there are disadvantages such as low utilization value and low phosphorus recovery rate.Our research group proposed a new phosphorus recovery process system,which is based on the high enrichment of phosphorus in urban sewage by the biofilm method,and recovers phosphorus in the form of vivianite,which has high economic value and phosphorus recovery rate.Higher advantage.This experimental study mainly explores the reaction conditions for obtaining high phosphorus recovery rate and vivianite purity in the process of recovering phosphorus-rich solution by vivianite crystallization,and performs XRD and SEM-EDS to qualitatively characterize vivianite under optimal conditions.The results show that the optimal reaction conditions are pH 7.00—7.50,ORP drops to about-100 mV,and iron-phosphorus ion molar ratio of 3∶1.At this time,the phosphorus recovery rate of the vivianite crystallization is about 95.00%,the purity of vivianite is 88.35%and vivianite is the main crystal phase in the recovered precipitate and has a good crystal form.