【作者】 沙布（Sagbo Omer）；

【导师】 顾平；

【作者基本信息】 天津大学 ， 环境工程， 2007， 博士

【摘要】 鉴于水污染的加剧和饮用水标准的日益严格,为适应原水水质特性的波动并去除特定的污染物,常规给水处理工艺需要被持续优化以满足要求。对地表水处理和海水预处理工艺进行改进,对饮用水生产变得非常重要。集混凝、微滤、粉末活性炭(PAC)吸附的一体式膜混凝反应器(MCR)被用于研究渤海海水的处理,评估其最为海水反渗透预处理的可行性。实验结果表明,经预处理后的海水,其参数(SDI、浊度、总铁和pH值)完全满足了RO进水的要求,除CODMn随原水水质波动以外,其它参数非常稳定。PAC投量、曝气冲洗时间、气水比、曝气冲洗频率等因素对膜污染及预处理能力的影响依次递减。实验中优化的工艺参数为:不投加PAC、20 min曝气冲洗、气水比为10、每8 h进行曝气冲洗一次。膜清洗实验表明,化学清洗能够恢复污染膜的比通量。然而,膜比通量衰减的主要原因是膜表面滤饼层的形成和溶解性有机物,含有镁、铝、硅、钙和铁的化合物为主要的无机污染物,其对膜比通量的衰减几乎没有没有影响,同时微生物污染也并不明显。同时,MBR处理微污染湖水的研究证实,MBR不仅对有机物和氨氮具有较高的去除率,而且还能以二级基质利用和NOM协同机理去除2,4,6-三氯酚(TCP)。原水TCP浓度为40-385μg/L时,TCP的平均去除率96.2%,处理水中平均TCP浓度低于4μg/L,能够满足《城市供水水质标准》的要求。间歇序批实验表明,生物降解是去除TCP的主要机理,遵循零级反应动力学,反应速率常数为1.65μg/(L·min),基质最大比利用速率qmax和亲和力常数Ks分别为0.060 d-1和0.235 mg/L。此外,能够在MBR中培养得到亲和TCP的微生物。本研究证明MBR系统和MCR工艺分别具有替代常规给地表水处理工艺和传统海水反渗透预处理工艺的潜力。更多还原

【Abstract】 Currently, due to surface water pollution and stringent drinking water quality standards, conventional water treatment processes need to be continuously optimized to remove certain pollutants and to deal with fluctuating raw water characteristics. It is crucial to develop innovative techniques for surface water treatment and seawater pretreatment for their application in drinking water production.Under such circumstances, an integrated membrane coagulation reactor (MCR) process combining coagulation, microfiltration and/or powdered activated carbon (PAC) adsorption was investigated for Bohai seawater pretreatment prior to the RO desalination membrane, to evaluate its feasibility to be used as the seawater reverse osmosis (SWRO) pretreatment. Long-term performance results showed that the parameters of the pretreated seawater (silt density index/or SDI, turbidity, total iron concentration and pH value) were absolutely superior to RO feed water requirements and even more consistent, excluding the chemical oxygen demand (CODMn), which varied with the raw seawater quality. The orthogonal experiment has shown that some factors has affected the membrane fouling and decreased the pretreatment capacity in decreasing order as: PAC dosage, duration of air scouring, ratio of air to permeate, and frequency of air scouring. As a result for this lab-scale test, the pretreatment capacity was optimized under the following conditions: no PAC dosage, 20 minutes of air scouring duration, ratio of air to permeate is 10, and air scouring every 8 hours. Membrane cleaning experiments have shown that the fouled membrane specific flux could be ultimately restored after chemical cleaning. However, the main reason for membrane specific flux decline lies in the formation of the cake layer on the membrane surface, and dissolved organic matters is considered as the main foulants. Compounds of magnesium, aluminum, silica, calcium and iron are the inorganic foulants on the membrane surface, which cause little decline of membrane specific flux, while fouling due to microorganism is almost unapparent.On the other hand, continuous lab-scale membrane bioreactor (MBR) tests have proven that, MBR treating micro-polluted lake water could attain a good quality of treated water in terms of the removal of organic pollutants and ammonia nitrogen. MBR process for micro-polluted surface water treatment could not only remove the organic pollutants, but could simultaneously remove TCP with the mechanisms of secondary substrate utilization and NOM inducing effect. For the raw water TCP concentration ranged between 40μg/L and 385μg/L, the average removal efficiency was 96.13%, and the average TCP concentration of treated water lower than 4μg/L and met the requirement of Drinking Water Quality Standard of China (CJ/T206-2005) issued by the Ministry of Construction. In addition, a series of intermittent batch tests showed that biological degradation plays a major role in the removal of phenolic compounds by MBR and the TCP biodegradation follows zero-order kinetics with a rate constant of 1.65μg/(L.min). The maximum specific utilization rate qmax and the affinity constant Ks of TCP were determined by fed-batch reactor tests and the values were 0.060d-1 and 0.235 mg/L respectively. The result showed that, microoganisms with good affinity for TCP could be cultivated in the MBR process, which was favorable for the biodegradation of trace TCP.This research confirmed that the MBR system and the MCR integrated coagulation-microfiltration process both have the potential to efficiently substitute the conventional surface water treatment and SWRO pretreatment processes respectively.更多还原