本文選題：厭氧膜生物反應器　切入點：正滲透　出處：《江南大學》2017年碩士論文

【摘要】：作為一種新型的膜生物反應器技術,厭氧正滲透膜生物反應器(AnOMBR)受到越來越多的關注。AnOMBR采用正滲透(FO)膜替換傳統(tǒng)厭氧膜生物反應器(AnMBR)中的微濾(MF)膜或超濾(UF)膜。與傳統(tǒng)的AnMBR相比,AnOMBR借助FO膜的高效截留性能,出水水質(zhì)更好,可以直接進行回用;由于FO膜的低污染特性,在一定程度上緩解了膜污染。然而,AnOMBR仍然存在著鹽度積累和膜污染等問題。本文主要針對AnOMBR中的FO膜污染,在采用MF膜緩解鹽度的基礎上構(gòu)建穩(wěn)定運行的AnMF-OMBR裝置,考察膜污染對通量衰減的貢獻,從有機污染、無機污染以及生物污染等方面全面解析FO膜污染機理,探索物理清洗和化學清洗對FO膜污染的控制效果,最終構(gòu)建AnMF-OMBR中FO膜污染的控制措施。主要研究內(nèi)容和結(jié)果如下:(1)基于MF膜允許溶解性鹽透過的特性,將MF膜與AnOMBR進行耦合構(gòu)建AnMF-OMBR,在鹽度控制的基礎上探索FO膜污染的機理及其對通量衰減的貢獻。結(jié)果表明,MF膜的加入能夠有效的控制鹽度積累,在AnMF-OMBR的整個運行過程中鹽度始終維持在2-3 mS/cm。由于聚酰胺材質(zhì)的FO(TFC-FO)膜對總有機碳(TOC)和總磷(TP)具有較好的截留性能,出水中的TOC和TP的濃度分別小于4 mg/L和0.5 mg/L。然而,由于氯化鈉(NaCl)作為汲取液時FO膜兩側(cè)發(fā)生了唐南平衡,TFC-FO膜對氨氮(NH4+-N)沒有任何截留。TFC-FO膜在AnMF-OMBR中遭受了嚴重的膜污染,導致TFC-FO膜的通量從7.99 LMH衰減到2 LMH。對膜污染的分析結(jié)果表面,TFC-FO膜的污染主要以有機污染和生物污染為主,且生物污染的主要組分是微生物、蛋白質(zhì)和α-D-吡喃多糖。(2)探索TFC-FO污染膜的水沖洗、超聲清洗、物理反沖洗和周期性清洗等物理清洗手段對膜通量恢復的效果。結(jié)果表明,水沖洗不能去除TFC-FO膜表面的污染物。超聲清洗雖然可以去除膜污染物,但是會破壞TFC-FO膜的完整性,也不適用于TFC-FO膜污染的清洗。在物理反沖洗和周期性清洗都無法恢復TFC-FO膜的過濾性能。(3)考察檸檬酸、鹽酸(HCl)、氫氧化鈉(NaOH)、十二烷基硫酸鈉(SDS)、乙二胺四乙酸二鈉(EDTA-2Na)和過氧化氫(H2O2)六種常用化學清洗劑對TFC-FO污染膜的清洗效果。結(jié)果表明,檸檬酸、HCl、NaOH、SDS和EDTA-2Na對膜污染的去除效果不佳,而H2O2可以有效地恢復TFC-FO污染膜的通量。進一步對H2O2的清洗條件進行優(yōu)化,結(jié)果發(fā)現(xiàn),最佳的化學清洗方案為使用0.5%的H2O2在25℃下清洗6 h,,清洗后的TFC-FO膜初始通量幾乎恢復到新膜的水平。將化學清洗后的TFC-FO膜重新放入AnMF-OMBR中運行,其通量下降速率與新膜相似,對TOC、TP以及NH4+-N的去除效果與新膜一致。這說明經(jīng)過H2O2清洗后的TFC-FO膜完全恢復了新膜的水平,可以繼續(xù)應用于AnMF-OMBR的運行。
[Abstract]:As a new membrane bioreactor (MBR), Anombor membrane bioreactor (AnOMBR) has attracted more and more attention. AnOMBR has been used to replace the microfiltration membrane (MF) or ultrafiltration membrane (UFF) in the traditional anaerobic membrane bioreactor (AnMBR).Compared with the traditional AnMBR, Ano MBR has better effluent quality and can be reused directly with the help of FO membrane, which can alleviate the membrane fouling to some extent because of the low fouling characteristics of FO membrane.However, AnOMBR still has some problems such as salinity accumulation and membrane fouling.Aiming at FO membrane fouling in AnOMBR, a stable AnMF-OMBR device was constructed on the basis of using MF membrane to alleviate salinity, and the contribution of membrane fouling to flux attenuation was investigated.The mechanism of FO membrane fouling was analyzed in the aspects of inorganic pollution and biological pollution. The control effect of physical cleaning and chemical cleaning on FO membrane fouling was explored. Finally, the control measures of FO membrane fouling in AnMF-OMBR were constructed.The main contents and results are as follows: 1) AnMF-OMBR is constructed by coupling MF membrane with AnOMBR based on the characteristics of MF membrane allowing soluble salt to permeate. The mechanism of FO membrane fouling and its contribution to flux attenuation are explored on the basis of salinity control.The results showed that the addition of MF membrane could effectively control the salinity accumulation, and the salinity remained at 2-3 MS / cm ~ (-1) during the whole operation of AnMF-OMBR.The TOC and TP concentrations in the effluent were less than 4 mg/L and 0.5 mg / L, respectively, due to the good retention properties of the polyamide-based FOA TFC-FOO membrane for total organic carbon (TOC) and total phosphorus (TP).However, when sodium chloride was used as the solution, the Tangnan equilibrium TFC-FO membrane had no serious membrane fouling in AnMF-OMBR, and the flux of TFC-FO membrane decreased from 7.99 LMH to 2 LMH.The results of membrane fouling analysis showed that the fouling of TFC-FO membrane was mainly caused by organic and biological pollution, and the main components of biological pollution were microorganism, protein and 偽 -Dpyran polysaccharide. 2) to explore the water washing and ultrasonic cleaning of TFC-FO contaminated membrane.Effects of physical backwashing and periodic cleaning on membrane flux recovery.The results showed that water washing could not remove pollutants from the surface of TFC-FO membrane.Although ultrasonic cleaning can remove membrane contaminants, it will destroy the integrity of TFC-FO membrane and is not suitable for TFC-FO membrane fouling cleaning.Citric acid was investigated when both physical backwashing and periodic cleaning could not recover the filtration performance of TFC-FO membrane.The cleaning effects of six common chemical cleaning agents, such as hydrochloric acid, sodium hydroxide, sodium dodecyl sulfate, EDTA-2Naand hydrogen peroxide, on TFC-FO fouling membrane were studied.The results showed that the removal of membrane fouling by sodium citrate and EDTA-2Na was not good, while H2O2 could effectively restore the flux of TFC-FO fouled membrane.The cleaning conditions of H2O2 were further optimized. It was found that the best chemical cleaning scheme was to use 0.5% H2O2 at 25 鈩，

本文編號：1730644