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摘要
采用硫酸铵镁沉淀法回收硫酸铵废水中高浓度氨氮,考察了V(乙醇)∶V(溶液)、溶液pH、n(N)∶n(Mg)、反应时间、晶种投加等因素对氨氮回收效果的影响。结果表明,投加镁盐和无水乙醇可以实现一步化处理硫酸铵废水,在n(N)∶n(Mg)=1.5、n(N)∶n(S)=0.9、V(乙醇)∶V(溶液)=1.0、反应时间为5 h的条件下,初始质量浓度为2 500 mg/L的氨氮溶液的回收率可达到70.1%,其结晶产物硫酸铵镁可作为硫肥施用于农田。晶种的投加对氨氮回收率并无显著提高,但部分晶种的投加可以使晶体团聚在一起并以晶簇形式存在。动力学分析显示,该反应符合准二级动力学方程,相关系数为0.998 7。
Abstract
Magnesium ammonium sulfate precipitation method is used to recover high concentration of ammoniacal nitrogen in ammonia sulfate wastewater.The influences of various factors,such as the volume ratio of ethanol to solution,pH of solution,n(N):n(Mg),reaction time and seed crystal dosage on the recovery efficiency of ammoniacal nitrogen are investigated.The results indicate that the additions of magnesium sulfate and anhydrous ethanol can treat ammonia sulfate wastewater in one step.The recovery rate can reach 70.10% and the obtained crystalline product magnesium ammonium sulfate can be used as sulfur-containing fertilizer in farmland when n(N):n(Mg)=1.5,n(N):n(S)=0.9,the volumetric ratio of ethanol to solution is 1.0,reaction lasts for 5 h and the initial concentration of ammoniacal nitrogen is 2,500 mg·L-1.The addition of seed crystal cannot improve significantly the recovery rate of ammoniacal nitrogen,but the addition of some seed crystal can make the crystals agglomerate together to form clusters.Dynamics analysis shows that this reaction conforms to the Pseudo-second-order kinetics equation with a correlation coefficient of 0.998 7.
关键词
硫酸铵镁
/
硫肥
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回收
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高浓度氨氮
Key words
magnesium ammonium sulfate
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sulfur-containing fertilizer
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recovery
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concentrated ammoniacal nitrogen
Author summay
郭琳(1993-),女,硕士研究生,主要从事工业废水治理及资源化的研究,1048020354@qq.com。
硫酸铵镁沉淀法回收稀土硫酸铵废水中高浓度氨氮试验研究[J].
, 2018, 38(8): 73-76,78 DOI:10.16606/j.cnki.issn0253-4320.2018.08.015