【作者】 刘炎伟；

【导师】 张敬东；

【作者基本信息】 武汉大学 ， 环境工程， 2005， 硕士

【摘要】 膜处理技术已广泛的应用于水处理行业,超滤作为海水反渗透的预处理,相比于传统处理工艺,具有简单安全稳定优势,已在欧美国家和海湾等地区普遍应用。然而超滤在国内尚属起步阶段,超滤装置投入实际工程运行时,都必须针对不同水质进行现场中试试验,以保证达到后续的R0进水条件和运行稳定性。 本次中试选取了三种外压式超滤膜对我国东南部高浊度海水进行现场处理中试试验,通过稳定运行、参数优化和强化破坏性运行三个阶段的试验,对以下几方面进行了分析研究:高浊度海水的水质变化情况;超滤产水水质及对各种污染物质的去除率;超滤的整个阶段和周期内的通量衰减情况和清洗后恢复情况;三种超滤膜材料、运行工艺的对比;超滤产水SDI影响因素分析。 试验结果表明:超滤出水温度和pH相对膜前没有较多变化,对浊度和细菌基本有100%的去除率,对胶硅、铁和COD的去除率分别为30%—90%、80%—95%和0%—80%;膜污染过程中,A频繁的低剂量NaClO清洗,较好的防止了凝胶层的形成,B双皮层结构,导致了TMP较大,加剧了膜孔的堵塞,C浸没式膜难以控制凝胶层的形成,膜污染严重;A直接处理海水,膜的筛分截留原理使超滤膜对水质的去除效果同B和C趋于一致,双皮层膜和浸没式工艺都不适合高浊度海水的处理。 本文还对超滤出水SDI的影响因素进行了系统的分析研究:超滤出水SDI都在3以下,选择错流运行方式和低通量参数,可以缓解超滤出水的污染物质,降低其SDI值;pH在6—8之间和温度低于30℃时,SDI有最佳值;有机物会对造成膜污染并导致SDI增高,聚合硫酸铁浓度大于21mg/L或NaClO浓度大于6mg/L时,将导致SDI急速增高。更多还原

【Abstract】 The membrane processing technology has been widely applied in water treatment profession. As the seawater pretreatment prior to reverse osmosis membranes, ultrafiltration is simple, safe and stable, compared to conventional processing technology. Now ultrafiltration has been applied in Europe, American and Gulf region, but it is still the start stage in our country. When ultrafiltration is used in actual project, we must carry on the pilot study, aiming at different water quality, to guarantee the feed water condition and stability of reverse osmosis membranes.This pilot study selected three kinds of outside-in ultrafiltration to experiment on the southeast high turbidity seawater in our country. Through three stages experiments of stable running, parameter optimization and strengthened destructiveness, We analyze the following several aspects: the condition of high turbidity seawater quality; the permeate quality of ultrafiltration and removing rate of pollution matter; the attenuation condition of entire and cyclical stage and recovery after backwash; the comparison of three ultrafiltration material and running craft; the influence factors of permeate SDI.The pilot study indicates: the temperature and pH of ultrafiltration permeate don’t change more compared to feed water. Ultrafiltration has 100% removing on turbidity and bacteria, and 30%- 90%, 80%- 95%, 0%- 80% removing on silicon, iron and COD. In membrane pollution process, A prevents the gelatin coming into being better by frequent small dosage NaCIO backwash; The B double cortex structure has caused the TMP large and intensified the membrane hole block; The C immersion type membrane has controlled the gelatin difficultly and the membrane pollution is serious. When A directly processes seawater, the principle of ultrafiltration causes the same effect of pollution matter removing with B and C. The double cortex membrane and the immersion type craft are all not suit the pretreatment of high turbidity sea water.This article also studies and analyzes the influence factors of permeate SDI: the SDI of permeate are all below 3; the way of cross flow and the low flux parameter can alleviate the pollution matter of permeate, and reduces its SDI value; SDI has better value when pH is between 6-8 and temperature is lower than 30℃; the pollution of membrane caused by organic matter can results SDI high; when the concentration ofpolymerization iron sulfate is bigger than 21mg/L or the concentration of NaClO are bigger than 6mg/L, it will cause SDI increase rapidly.更多还原