鸟粪石结晶法去除餐厨沼液中氨氮的研究  

Removal of ammonia nitrogen in anaerobically digested food-waste slurry by struvite crystallization approach

作　　者：杨德坤 颜成[1] 邬振江 梁剑茹[1] 王电站[1] 周立祥[1] YANG Dekun;YAN Cheng;WU Zhenjiang;LIANG Jianru;WANG Dianzhan;ZHOU Lixiang(College of Resources and Environmental Sciences,Nanjing Agricultural University,Nanjing 210095,China)

机构地区：[1]南京农业大学资源与环境科学学院,江苏南京210095

出　　处：《南京农业大学学报》2019年第2期300-307,共8页Journal of Nanjing Agricultural University

基　　金：国家自然科学基金项目(21637003)

摘　　要：[目的]本文旨在采用鸟粪石结晶法去除餐厨沼液中的氨氮。[方法]以餐厨沼液为处理对象,研究温度,反应时间,起始pH值,镁、磷摩尔比和磷、氮摩尔比等因素对鸟粪石结晶法处理餐厨沼液,优化去除餐厨沼液中氨氮的影响因素,并分析起始pH值与恒定pH值对鸟粪石结晶法处理餐厨沼液的影响。[结果]通过调节起始pH值而无需保持整个试验期间pH值即可有效去除氨氮并获得较高纯度的鸟粪石。在温度28℃、起始pH 9.0、反应时间90 min的条件下,当镁、磷、氮的摩尔比为1.43∶1.3∶1时,鸟粪石结晶法去除餐厨沼液中氨氮的效率最高,通过对反应后沉淀进行检测,确定其主要成分为鸟粪石。[结论]在最佳条件下氨氮去除率可达到98%左右,残留氨氮及水溶性磷浓度分别为48.74和35.35 mg·L^(-1),并且处理后的餐厨沼液化学需氧量/总氮含量(COD/TN)提高约8倍,有利于后续生化处理。[Objectives] In this paper,struvite crystallization approach was used to treat anaerobically digested food-waste slurry in order to recover ammonia nitrogen.[Methods] We investigated the effects of temperature,the reaction time,initial pH value,and the molar ratio of magnesium to phosphorus to nitrogen on the recovery of ammonia nitrogen by struvite crystallization approach.Furthermore,struvite crystallization effectiveness of keeping a constant pH value throughout the trial and only adjusting initial pH value were also compared in the study.[Results] The results showed that adjusting initial pH value instead of keeping constant pH value was beneficial to removing or recoving ammonia nitrogen due to the struvite formation of a higher purity.Optimum parameters including reaction temperature of 28 ℃,initial pH of 9.0,the reaction time of 90 min,and the mole ratio of magnesium,phosphorus and nitrogen with 1.43 ∶ 1.3 ∶ 1 were observed for obtaining the highest removal efficiency of ammonia nitrogen,and the main component of the precipitate was identified as struvite by detection.[Conclusions] Under the optimal conditions,the removal rate of ammonia nitrogen can reach 98%.After struvite crystallization,the residual ammonia nitrogen and phosphate in anaerobically digested food-waste slurry were drastically reduced to 48.74 and 35.35 mg · L^-1,respectively.As a result,the ratio of the chemical oxygen demand(COD)to total nitrogen content(TN)in slurry was enhanced by about 8 times,which would improve subsequent wastewater purification by activated sludge process.

关 键 词：餐厨垃圾 沼液 鸟粪石 氨氮去除 

分 类 号：X703[环境科学与工程—环境工程]