微藻处理城市污水反渗透浓水的条件优化  

Optimization of treatment conditions of reverse osmosis concentrate d wastewater from municipal sewage by microalgae

作　　者：夏瑜 常杰 李沅珈 王沛 申欣宇 胡怡然 何绪文[1] XIA Yu;CHANG Jie;LI Yuanjia;WANG Pei;SHEN Xinyu;HU Yiran;HE Xuwen(School of Chemical and Environmental Engineering,China University of Mining and Technology,Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)化学与环境工程学院,北京100083

出　　处：《环境工程学报》2023年第4期1365-1376,共12页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金青年项目(52100067);中国矿业大学(北京)“大学生创新性实验计划”项目(202103063)。

摘　　要：城市污水回用是缓解水资源危机的有效措施。反渗透工艺是生产优质再生水的重要方法,但在实际应用过程中,25%~50%的城市污水会转化成反渗透浓水(ROC)。ROC的总氮(TN)、总磷(TP)和硬度离子(Ca2+、Mg2+)质量浓度等指标较高。利用微藻去除氮、磷和Ca2+、Mg2+是城市污水ROC处理的有效途径之一,且可实现资源回收,但目前对其应用条件的优化研究仍较少。利用微藻Scenedesmus sp. FACHB-1 574处理城市污水ROC,在不同总溶解性固体(TDS)质量浓度(1.35 g·L^(-1)和2.70 g·L^(-1))、光暗时间比(12 h/12 h、16 h/8 h、20 h/4 h、24 h/0 h)、光强(25μmol·m^(-2)·s^(-1)、50μmol·m^(-2)·s^(-1)、100μmol·m^(-2)·s^(-1))和氮磷质量比(107:1、14:1、7:1)的条件下,研究了微藻对污水的处理效果及其生长状况。结果表明,Scenedesmus sp. FACHB-1 574可适应城市污水ROC中TDS质量浓度为2.70 g·L^(-1)的条件;对TN的去除速率随光照时间和光强的增加而增大;氮磷质量比为14:1时微藻对TN的去除速率及微藻生物量等性能均得以强化。在最优处理条件下(光暗时间比20 h/4 h,光强100μmol·m^(-2)·s^(-1),氮磷质量比14:1)处理10 d后,微藻对城市污水ROC中TN和TP去除率分别为92.83%和99.68%,藻密度、质量浓度(干重)、脂质含量分别为23.62×10^(6)cells·mL^(-1)、1.10 g·L^(-1)、34.55%。随着微藻的生长,在无CO_(2)的条件下,废水的pH值从7.5升高到10.7,并可去除52.7%的Ca^(2+)和33.9%的Mg^(2+)。本研究可为微藻在城市污水处理及资源化工艺中的应用提供参考。The reuse of municipal wastewater is an effective measure to solve the shortage of water resources.The reverse osmosis(RO)process has the characteristics of being efficient and easy to operate,which is an important method to produce high-quality reclaimed water.However,reverse osmosis concentrate(ROC)will be produced during the RO treatment process,which accounts for 25%~50% of the municipal wastewater treated.ROC contains high concentrations of total nitrogen(TN),total phosphorus(TP)and hard ions(Ca^(2+),Mg^(2+)).Microalgae can provide an effective way to simultaneously remove nitrogen,phosphorus,Ca^(2+)and Mg^(2+)from water,and can achieve resource recovery at the same time.However,there are still few studies on the condition optimization of municipal wastewater ROC treatment.In this study,Scenedesmus sp.FACHB-1574 was used to treat municipal wastewater ROC.The treatment efficiency and growth status of microalgae were studied under different total dissolved solid(TDS)concentrations(2.70 g·L^(−1) and 1.35 g·L^(−1)),light/dark time ratios(12 h/12 h,16 h/8 h,20 h/4 h,24 h/0 h),light intensities(25μmol·m^(−2)·s^(−1),50μmol·m^(−2)·s^(−1),100μmol·m^(−2)·s^(−1))and nitrogen/phosphorus mass ratios(107:1,14:1,7:1).The results showed that Scenedesmus sp.FACHB-1574 could adapt to the condition of 2.70 g·L^(−1) TDS in the investigated municipal wastewater ROC.The removal efficiency of TN increased with the increase of lighting intensity and time.Increasing the phosphorus content of ROC to achieve a nitrogen/phosphorus mass ratio of 14:1 could improve the TN removal efficiency and the biomass of microalgae.After microalgae treatment for 10 days under the optimal conditions(light/dark time ratio 20 h/4 h,light intensity 100μmol·m^(−2)·s^(−1),nitrogen/phosphorus mass ratio 14:1),the TN and TP removal efficiencies were 92.83% and 99.68%,respectively.The algal density,dry weight and lipid content were 23.62×10^(6) cells·mL^(−1),1.10 g·L^(−1) and 34.55%,respectively.During the growth o

关 键 词：反渗透浓水 微藻 总溶解性固体 光暗时间比 光强 氮磷质量比 CA2+ Mg2+ 

分 类 号：X703[环境科学与工程—环境工程]