废磷酸盐与蒸氨废液共处理工艺研究  

Study on co-treatment process of waste phosphate and steam ammonia waste liquid

作　　者：熊萍 杨文振 李桥[1,2] 孙秀云 韩卫清[1,2] XIONG Ping;YANG Wenzhen;LI Qiao;SUN Xiuyun;HAN Weiqing(School of Environmental and Biological Engineering,Nanjing University of Science and Technology,Nanjing 210014,China;Key Laboratory of Chemical Pollution Control and Resource Utilization of Universities of Jiangsu Province)

机构地区：[1]南京理工大学环境与生物工程学院,南京210014 [2]化工污染控制与资源化江苏省高校重点实验室

出　　处：《无机盐工业》2022年第2期95-100,共6页Inorganic Chemicals Industry

基　　金：江苏省环境保护厅环保科研计划:医药中间体产生废盐的综合利用和安全填埋关键技术与管理政策研究及工程示范(2017004)。

摘　　要：废磷酸盐(PW)是一种主要成分为Na_(3)PO_(4)的固体废物;蒸氨废液(DW)是一种主要成分为CaCl_(2)的高pH(一般高于11)的废液。两种废物均产生量大且处理处置难度大,目前关于两者资源化的研究均较少。研究基于PW高磷含量和DW高钙含量、高pH的特点,提出一种废物共处理工艺,通过沉淀法同步回收磷和钙资源。PW经预处理制得磷储备液与DW共处理,探究了n(Ca)/n(P)、加药顺序、DW的浓度、pH及陈化时间对Ca、P回收率和产物的影响,并研究了产物的应用可能性。结果表明,n(Ca)/n(P)=1.67、蒸氨废液加入磷储备液(Ca→P)为共处理最佳反应条件,该条件下,回收率均大于98.90%;DW的浓度和pH变化对回收率影响较小,Ca、P回收率变化均小于2.00%;随陈化时间延长,钙回收率增大而磷回收率减小,产物由无定形磷酸钙(ACP)逐步转化为羟基磷灰石(HAP),且其n(Ca)/n(P)增加。不同陈化时间所得产物均具应用潜能。该研究为PW、DW的资源化利用提供了新思路。Waste phosphate(PW) is a kind of solid waste mainly composed of Na_(3)PO_(4).Steam ammonia waste solution(DW) is a waste solution with high pH(generally higher than 11) mainly composed of CaCl_(2).Both kinds of wastes are produced in large quantities and are difficult to be treated and disposed.At present,there is few research on the recycling of them.Based on the characteristics of PW with high phosphorus content and DW with high calcium content and high pH,a waste co-treatment process was proposed,in which phosphorus and calcium resources were recovered synchronously by precipitation method.The phosphorus reserve solution was prepared by pretreatment of PW and co-treatment with DW.The effect of n(Ca)/n(P),dosing sequence,DW concentration,pH and aging time on the recovery of Ca and P and the products was investigated,and the application possibility of the products was also studied.The results showed that n(Ca)/n(P)=1.67 and adding the ammonia waste liquor to phosphorus reserve solution(Ca→P) was the best reaction conditions for co-treatment.Under these conditions,the recoveries were greater than 98.90%.The concentration and pH of DW had little effect on the recovery,and the recovery rates of Ca and P were less than 2.00%.With the increasing of aging time,the recovery rate of calcium increased and the recovery rate of phosphorus decreased.The product was gradually transformed from amorphous calcium phosphate(ACP) to hydroxyapatite(HAP),and the molar ratio of n(Ca)/n(P) increased.The products obtained by different aging time had application potential.This study provides a new idea for the resource utilization of PW and DW.

关 键 词：废磷酸盐 蒸氨废液 共处理 

分 类 号：TQ126.3[化学工程—无机化工]