Influence of flocculant polyacrylamide on concentration of titanium white waste acid by direct contact membrane distillation  

作　　者：Biao Hu Jintao Ouyang Lanying Jiang 

机构地区：[1]School of Metallurgy and Environment,Central South University,Changsha 410083,China [2]National Engineering Research Center for Control&TreatmentcfHeayy Metal Pollution,Changsha 410083,China [3]Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety,Changsha 410083,China

出　　处：《Chinese Journal of Chemical Engineering》2020年第9期2483-2496,共14页中国化学工程学报（英文版）

基　　金：National Natural Science Foundation of China(21176265);Hunan Provincial Science and Technology Department(2014GK3106);Chinese National Project for Overseas Experts in Culture,Education and Public Health。

摘　　要：Effort has been made to investigate the concentration of titanium white waste acid(TWWA) by direct contact membrane distillation(DCMD) and the focus is the influence of polyacrylamide(PAM) on membrane wetting and fouling.It was found that the presence of PAM in feed reduced membrane flux and retarded wetting development,even though its level in feed of H2 SO4 solution was only 0.0002 wt%.The difference between the tests using pure water and neat PAM aqueous solution,respectively,as feed also indicated the above effect registered with PAM.AFM results showed that the addition of PAM in feed solution changed the membrane shell surface morphology.However,conclusive proof of the PAM existence in membrane cross-section and inner surface was not obtained,probably due to its low concentration in feed solution.Two approaches were tried to recover membrane flux.In comparison with operation w/o any treatment,HCl solution rinsing did not lead to obvious improvement in membrane flux recovery,while rinsing combined with gas purge has clearly delayed the degradation in acid concentration factor.Nevertheless,even the latter could not ensure long term stability.High tortuosity and low hydrophobicity of the membranes used were suggested as underlying causes and should be addressed in the future.

关 键 词：Acid concentration DCMD PAM WETTING FOULING 

分 类 号：X788[环境科学与工程—环境工程]