摘要
为了回收黄水中的氮、磷营养盐,构建电化学鸟粪石沉淀反应装置,试验结果表明,当电流密度为2.5 mA/cm^2时,磷回收速率及总回收率都为最高,反应4 h时磷回收率达到97.2%,沉淀产物中鸟粪石晶体的纯度为95.7%;氨氮去除率随电流密度的升高而增加,但电化学沉淀法对氨氮的最大去除率仅为21.6%。利用改性凹凸棒-膨润土复合黏土对电化学沉淀后黄水中的氨氮进行吸附,发现其对氨氮的吸附过程更符合拟二级动力学模型,对氨氮的平衡吸附量可达到15.30 mg/g。扫描电子能谱分散显微镜(SEM-EDS)分析表明,从实际黄水中回收的产物多为棱柱状晶体,晶体表面杂质较多,且含有一定量的钾型鸟粪石。
An electrochemical struvite reaction device was constructed to recover nitrogen and phosphorus nutrients from the yellow water. When the current density was 2. 5 mA/cm2,the recovery efficiency of phosphorus was the highest,and the recovery rate of phosphorus was 97. 2% and the purity of struvite was 95. 7% after 4 h reaction. The removal rate of NH4+ -N increased with the increase of current density,while the maximum removal rate of NH4+ -N by the electrochemical deposition was only 21. 6%. The modified attapulgite-bentonite composite clay was used to adsorb NH4+ -N in yellow water after the precipitation of struvite. The adsorption process of NH4+ -N was more consistent with the pseudo-second-order kinetic model,and the equilibrium adsorption capacity of NH4+ -N was up to 15. 30 mg/g. SEM-EDS analysis showed that recovered products from real yellow water were mostly prismatic crystals,and the crystal surface had many impurities and contained certain potassium struvite.
作者
吕弈成
刘洪波
方月英
孙圣广
Lü Yi-cheng;LIU Hong-bo;FANG Yue-ying;SUN Sheng-guang(School of Environment and Architecture,University of Shanghai for Science and Technology,Shanghai 200093,China;Suzhou Industrial Park Qingyuan Hong Kong&China Water Co.Ltd.,Suzhou 215021,China)
出处
《中国给水排水》
CAS
CSCD
北大核心
2020年第3期1-7,共7页
China Water & Wastewater
基金
国家重点研发计划项目(2018YFD1100502-01)。
关键词
黄水
营养盐回收
电化学沉淀法
鸟粪石
电流密度
改性复合黏土
yellow water
recovery of nutrients
electrochemical deposition method
struvite
current density
modified composite clay