摘要
药剂成本过高是阻碍磷酸铵镁结晶技术推广应用的关键难题之一。通过改变结晶反应的初始条件,采用廉价氧化镁为镁盐,有效回收废水中的氨氮。研究结果表明,起始pH为2时,氧化镁为镁盐时,废水氨氮去除效率达到90%以上;采用Mg2＋：4NH＋：34PO-摩尔比为1：1：1,煅烧温度在200~400℃时,氨氮回收率超过82%;XRD和FTIR分析结果表明,不同温度条件下,氧化镁的晶体结构出现畸变,导致MgO键键长出现变化,红外光谱出现红移及蓝移现象,而MgO键键长的变化与沉氨效率存在直接的相关性。
The high cost of magnesium is one of the key problems for the practical application of struvite chemical precipitation. Ammonium in wastewater was recycled by changing the initial conditions of struvite precipitation with cheap magnesia. The results showed that when the initial pH was 2, the removal rate of ammonium was above 90% by struvite precipitation technology with cheap magnesia as magnesium, which was above 82% at the conditions of the mole ratio of Mg2＋：4NH＋：34PO-, 1：1：1 and calcination temperature of magnesia of 200—400℃. The XRD and FTIR results also showed that the crystal structure of magnesia was distorted with changed bond length of MgO at different calcination temperature, leading to redshift and blueshift. A direct correlation was found between MgO bond length and ammonium removal ratio.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2015年第12期5040-5044,共5页
CIESC Journal
基金
国家自然科学基金项目(51178216)~~
关键词
廉价氧化镁
磷酸铵镁
化学过程
回收
废水
cheap magnesia
struvite
chemical processes
recovery
wastewater
