3种晶种对鸟粪石沉淀法去除污泥上清液氮磷的影响  

Effect of Three Crystal Species on the Removal of Nitrogen and Phosphorus from Sludge Supernatant by Struvite Precipitation

作　　者：林海芝 李映雪[2] 任静雯 徐德福[1] LIN Hai-zhi;LI Ying-xue;REN Jing-wen;XU De-fu(School of Environmental Science and Engineering,Nanjing University of Information Science and Technology,Nanjing 210044,China;School of Applied Meteorology,Nanjing University of Information Science and Technology,Nanjing 210044,China)

机构地区：[1]南京信息工程大学环境科学与工程学院,江苏南京210044 [2]南京信息工程大学应用气象学院,江苏南京210044

出　　处：《生态与农村环境学报》2022年第8期1084-1092,共9页Journal of Ecology and Rural Environment

基　　金：江苏高校“青蓝工程”项目(20161507);江苏省“六大人才高峰”项目(R2016L06);南京市六合区科技成果推广项目(2020SX00000002)。

摘　　要：将剩余污泥中的固态氮和磷转变为可溶性氮和磷,是剩余污泥中氮磷处理或资源化利用的关键。该文研究了pH值对剩余污泥中氮磷的释放效果及不同晶种(蛭石、椰壳炭和石英砂)对鸟粪石沉淀法去除氮磷的影响,另外考察了单独使用晶种以及晶种与镁盐协同处理对污泥上清液氮磷的去除效果的影响。结果表明,当剩余污泥上清液的pH值由7.45上升至12时,上清液中ρ(PO_(4)^(3-)-P)从15.83上升至188.20 mg·L^(-1),ρ(NH_(4)^(+)-N)由48.97上升至166.46 mg·L^(-1)。在镁磷摩尔比为1.2、pH值为10、搅拌时间30 min、静置30 min条件下,蛭石、椰壳炭和石英砂的投加量分别为2、2和0.5 g·(100 mL)^(-1)时,3种晶种对上清液中NH_(4)^(+)-N和PO_(4)^(3-)-P的去除效果均较好。3种晶种中,椰壳炭诱导鸟粪石沉淀法去除NH_(4)^(+)-N和PO_(4)^(3-)-P的效果比蛭石和石英砂好。当椰壳炭投加量为2 g·(100 mL)^(-1)时,上清液中PO_(4)^(3-)-P和NH_(4)^(+)-N的去除率分别为82.48%和74.98%,相比未投加晶种分别提高9.14%和13.38%。采用X射线衍射和扫描电子显微镜对沉淀产物进行分析,发现生成的沉淀主要为鸟粪石,具有较高的回收价值。Transforming nitrogen and phosphorus in sewage sludge from solid to dissolution is the key for the treatment or resource utilization of nitrogen and phosphorus.In this paper,the effects of pH value on the release of nitrogen and phosphorus from sewage sludge,and the effects of different crystal seeds(vermiculite,coconut-shell biochar and quartz sand)on the removal of nitrogen and phosphorus by struvite precipitation were studied.In addition,the effects of only crystal seeds and the co-treatment of crystal seeds and magnesium salts on removal efficiency of nitrogen and phosphorus in the supernatant of sewage sludge were also investigated.Results show that when the pH of the supernatant increased from 7.45 to 12,the concentration of phosphate(PO_(4)^(3-)-P)in the supernatant increased from 15.83 to 188.20 mg·L^(-1),and ammonia nitrogen(NH_(4)^(+)-N)increased from 48.97 to 166.46 mg·L^(-1).There is better removal efficiency of NH_(4)^(+)-N and PO_(4)^(3-)-P when n(Mg)∶n(P)=1.2,pH=10,followed by stirring and standing both for 30 min,then adding vermiculite,coconut shell biochar and quartz sand with 2,2 and 0.5 g·(100 mL^(-1)),respectively.Among the three crystal seeds,the removal efficiency of NH_(4)^(+)-N and PO_(4)^(3-)-P was higher by coconut shell biochar than those by vermiculite and quartz sand based on struvite precipitation induction.Compared to non-addition of crystal seed,when adding coconut shell biochar with 2 g·(100 mL^(-1)),the removal rates of PO_(4)^(3-)-P and NH_(4)^(+)-N reached to 82.48%and 74.98%and increased by 9.14%and 13.38%,respectively.The results of X-ray diffraction and scanning electron microscopy(SEM)analysis show that the precipitates are mainly struvite which has high recovery value.

关 键 词：鸟粪石 晶种 污泥上清液 氮磷 

分 类 号：X52[环境科学与工程—环境工程]