剩余污泥破解提取液沉淀低浓度离子型稀土研究  

Precipitation of Low Concentration Ion-Absorbed Rare Earth by Excess Sludge Extract

作　　者：王俊峰 李海 钟常明 唐林旺 邱廷省 刘亚奇 阮翔 刘志文 Wang Junfeng;Li Hai;Zhong Changming;Tang Linwang;Qiu Tingsheng;Liu Yaqi;Ruan Xiang;Liu Zhiwen(College of Resources and Environmental Engineering,Jiangxi University of Scienee and Technology,Key Laboratory of Jiangxi Province's Mining and Metallurgy Environmental Pollution Control,Ganzhou 341000,China)

机构地区：[1]江西理工大学资源与环境工程学院,江西省矿冶环境污染控制重点实验室,江西赣州341000

出　　处：《中国稀土学报》2018年第6期719-725,共7页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(51674125);江西省科技支撑计划项目(20151BBG70016);江西省教育厅科技项目(GJJ160640);江西理工大学基金重点项目(NSFJ2014-K09)资助.

摘　　要：离子吸附型稀土矿开采过程中易产生大量低浓度稀土溶液,亟待对其有效回收处理。采用"臭氧+超声波"联合工艺处理城市剩余污泥,从剩余污泥破解后的上清液中获得提取液。通过光学显微镜和扫描电镜研究反应时间对剩余污泥絮体结构变化的影响,利用单道ICP和X荧光分析提取液成分及沉淀效果。结果表明:剩余污泥破解后,SCOD由1052 mg·L^(-1)增加至5088 mg·L^(-1),多糖和蛋白质含量分别增加215. 26,115. 55 mg·L^(-1);三维荧光检测出剩余污泥提取液含有大量类腐殖酸类物质;当反应时间为60 min时,剩余污泥形态由团状变成了颗粒状,污泥表面出现褶皱,具有空隙和层状结构,粒径减小,呈现碎片化;相对于NH_4HCO_3和草酸,提取液具有优秀的沉淀效果,稀土元素沉淀率均在89%以上;絮状沉淀物中Nd,Y,La和Ce等稀土元素占有比例相对较高,含量主要在3%～8%(质量分数)。It is easy to produce a large number of low-concentration rare earth solutions during the mining process of ion-absorbed rare earth ore,which needs urgently to be effectively recycled. The "ozone + ultrasonic"combined process was applied to treat the city’s excess sludge,and the extract was obtained from the supernatant of cracked excess sludge. The effect of reaction time on the change of floc structure of the excess sludge was investigated by light microscope and scanning electron microscope. The composition and precipitation effect of the extract were analyzed by single-channel ICP and X-ray fluorescence. The results indicated that after the excess sludge cracked,SCOD increases from 1052 to 5088 mg·L-1,the content of polysaccharides and proteins increases by 215. 26 and115. 55 mg·L-1 respectively; a large number of humic acids contained in excess sludge extract by three-dimensional fluorescence detection; when the reaction time is 60 min,the excess sludge morphology changes from lumps to granules,the surface of the sludge is wrinkled,with voids and layered structure,and the particle size decreases,presented fragmentation; compared with ammonium bicarbonate and oxalic acid,the extract has excellent precipitation effect,and the rare earth element precipitation rate is above 89%; the proportion of rare earth elements such as Nd,Y,La,and Ce in flocculent sediments is relatively high,and the percentage is mainly in the range of 3%to 8%.

关 键 词：离子型稀土 剩余污泥 溶胞 沉淀 回收 

分 类 号：X751[环境科学与工程—环境工程]