雪硅钙石诱导结晶法同步去除与回收污水中磷的研究  

Research on simultaneous removal and recovery of phosphorus from sewage by tobermorite induced crystallization

作　　者：卿卓霖 邹天森[1,4] 钱锋 卢彩彩[2] 宋志伟 宋永会 QING Zhuolin;ZOU Tiansen;QIAN Feng;LU Caicai;SONG Zhiwei;SONG Yonghui(State Key Laboratory of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences;Department of Chemical Engineering,Shangdong University of Science and Technology;Heilongjiang University of Science and Technology;College of Water Sciences,Beijing Normal University)

机构地区：[1]环境基准与风险评估国家重点实验室,中国环境科学研究院 [2]山东科技大学化学工程系 [3]黑龙江科技大学 [4]北京师范大学水科学研究院

出　　处：《环境工程技术学报》2022年第2期513-519,共7页Journal of Environmental Engineering Technology

基　　金：长江干流及典型城市环境保护综合方案与管理平台研究项目(2019-LHYJ01-0104);国家水体污染控制与治理科技重大专项(2017ZX07401-004,2018ZX07601-003);国家自然科学基金项目(51078339)。

摘　　要：通过水热法合成雪硅钙石晶体,利用扫描电镜、X射线衍射仪和傅里叶变换红外光谱对晶体进行表征;以模拟厌氧消化液为处理对象,分析合成雪硅钙石作为晶种诱导磷酸钙结晶法去除污水中磷的效率,并对该晶种减轻反应过程中CO_(3)^(2-)影响的作用进行研究。结果表明,合成的雪硅钙石纯度较高,且具有较强的pH和钙离子析出能力,在超纯水和自来水中分别投加2 g/L晶种后,溶液pH最终达到11.7和9.1,Ca^(2+)浓度达到43和30 mg/L;体系中含有CO_(3)^(2-)时,合成雪硅钙石诱导磷酸钙结晶反应符合晶体生长界面控制模型,且结晶反应仍符合二级方程(n=2);CO_(3)^(2-)的存在会抑制磷酸钙结晶反应过程中的除磷效率;但投加合成雪硅钙石晶种后,CO_(3)^(2-)的抑制作用减轻,磷酸钙结晶反应效率和速率大幅提高,在试验设定CO_(3)^(2-)浓度最大条件下,磷的去除率由4.6%大幅升至76.7%,速率常数(k)由0.76 L/(mol·min)提高至67.74 L/(mol·min);合成雪硅钙石重复利用4次之后,对磷的去除效果仍然高于未投加合成雪硅钙石时磷的去除效果,表现出良好的可重复利用性。A synthetic tobermorite crystal was obtained by hydrothermal method and characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD)and Fourier transform infrared spectrometry(FTIR).Taking the simulated anaerobic digestion liquid as the treatment object,the performance of synthetic tobermorite-induced crystallization in removing phosphorus from wastewater was analyzed,and the effect of the seed crystal on CO_(3)^(2-) reduction was studied.The results showed that the purity of synthetic tobermorite was high,resulting in higher pH and the release of a large amount of Ca^(2+) in the water.After adding 2 g/L seed crystals into ultra-pure water and tap water,respectively,pH of the solutions could reach 11.7 and 9.1,with the concentration of Ca^(2+) reaching 43 and 30 mg/L,respectively.The Interface-controlled crystal growth model well described the removal process of phosphorus by synthetic tobermorite-induced calcium phosphate crystallization,and the reaction conformed to the second-order equation(n=2).The presence of CO_(3)^(2-) could inhibit the performance and rate of phosphorus removal in the crystallization reaction of calcium phosphate.However,it was found that the phosphorus removal rate and reaction rate were improved quickly after adding synthetic tobermorite seed,which had a certain eliminate with the interference of CO_(3)^(2-) in the precipitation reaction of calcium phosphate.Under the condition of maximum CO_(3)^(2-) concentration,the phosphorus removal rate increased significantly from 4.6%to 76.7%,and the rate constant k increased from 0.76 L/(mol·min)to 67.74 L/(mol·min).Moreover,after the synthetic tobermorite was reused for four times,the phosphorus removal efficiency was still higher than that without adding synthetic tobermorite,thus showing its good reusability.

关 键 词：长江经济带 磷去除和回收 合成雪硅钙石 生活污水 碳酸根 

分 类 号：X703[环境科学与工程—环境工程]