太湖流域某市水源水及制水工艺中嗅味物质的动态变化研究

发布时间：2018-04-03 00:23

  本文选题：饮用水处理　切入点：嗅味物质　出处：《东南大学》2016年硕士论文

【摘要】：随着水体富营养化加重,自然水体中浮游生物尤其是藻类过度生长,藻类生长代谢产生嗅味物质,使水体产生难闻的气味。若作为饮用水水源,处理不当将严重影响饮用水质量。因此开展对水体中嗅味物质的研究和解决水体嗅味问题具有十分重要的意义。本研究建立了简便、有效的水中微量嗅味物质分析检测方法。对宜兴市主要水源横山水库、油车水库和西l?水中的典型嗅味物质浓度进行了系统分析,并考察了l?滨水厂制水工艺对嗅味物质的去除效果。结合宜兴市l?滨水厂现有制水工艺,研究了不同条件下混凝、活性炭吸附和臭氧氧化对嗅味物质的去除效果,探讨了其去除机理；并对臭氧氧化嗅味物质过程中的中间产物进行了鉴定,初步分析其可能的降解途径。采用顶空固相微萃取结合气质联用法测定水中的土臭素、二甲基异莰醇、β-环柠檬醛和β-紫罗兰酮。4种嗅味物质在宜兴市主要水源中均有检出,均表现出春季、夏季浓度较高,冬季浓度较低的特点。二甲基异莰醇和β-紫罗兰酮是横山水库、油车水库以及西l?水的主要致嗅污染物。水厂制水工艺对GSM、2-MIB、β-换柠檬醛和β-紫罗兰酮的去除率分别在34～42%、34～55%、14～40%、61～69%之间。混凝实验发现,混凝对嗅味物质的直接去除效果不佳,但能通过沉淀有效去除水中藻细胞,进而去除藻细胞体内的嗅味物质。粉末活性炭可有效吸附去除水中的嗅味物质,其吸附过程均符合Freundlich吸附等温线模型,对β-紫罗兰酮的吸附容量最大,2-MIB的吸附容量最小。原水中天然性有机物对嗅味物质的吸附去除产生了竞争吸附作用。增加活性炭投加量可提高嗅味物质的去除率,在极酸和极碱环境下,4种嗅味物质的去除率差异较大。水中加入腐殖酸会抑制嗅味物质的吸附去除。PAC对嗅味物质的吸附过程符合伪二级吸附动力学,4种嗅味物质的初始吸附速率常数随嗅味物初始浓度增加而上升,随腐殖酸浓度增加而下降,PAC最大吸附量随着腐殖酸投加量增加而减小。水中含有的有机物越多,对嗅味物质的吸附去除越不利。臭氧氧化可有效去除水中的嗅味物质,其氧化过程符合伪一级反应动力学。反应速率常数从大到小顺序为：β-紫罗兰酮(0.0821S-1)β-环柠檬醛(0.0611S-1)GSM(0.0366S-1) 2-MIB(0.0184S1)。在臭氧充足条件下(03/嗅味物质≥0.03mg/ng),4种嗅味物质均有较高的反应速率,且去除率达到90%以上。当原水的天然性有机物含量较高时,嗅味物质的氧化去除效率下降。在嗅味物质的氧化过程中,羟基自由基起主要作用,臭氧分子起次要作用。当水中存在HCO3-离子和叔丁醇等自由基抑制剂时,嗅昧物质的氧化作用被抑制。较低浓度的腐殖酸(1-2.5mg/L)能提高臭氧对嗅味物质的去除效率,而高浓度的腐殖酸(≥5mg/L)对氧化作用产生抑制。4种嗅味物质会被臭氧氧化产生一系列小分子的酸、酮、醛、醇,最后被氧化生成C02和H20。
[Abstract]:With the increase of eutrophication, plankton, especially algae, overgrow in the natural water body, and the growth and metabolism of algae produce odorous substances, which make the water body produce bad smell.As a drinking water source, improper treatment will seriously affect the quality of drinking water.Therefore, it is of great significance to study and solve the problem of odorous substances in water body.In this study, a simple and effective method for the determination of trace odorous substances in water was established.The main water source of Yixing City Hengshan Reservoir, Oil truck Reservoir and West lst?The concentration of typical odorous substances in water was systematically analyzed, and l?Removal of odorous substances by waterfront water preparation process.Combined with Yixing City?In this paper, the effects of coagulation, activated carbon adsorption and ozone oxidation on the removal of odorous substances under different conditions were studied, and the removal mechanism was discussed, and the intermediate products in the process of ozonation of smelling substances were identified.The possible degradation pathway was preliminarily analyzed.Headspace solid phase microextraction (SPME) combined with GC-MS was used to determine the odorous substances of soil odor, dimethyl isocamphene, 尾 -cyclocitral and 尾 -ionone in the main water sources of Yixing City.The characteristic of low concentration in winter.Dimethyl isobenol and 尾 -ionone are Hengshan Reservoir, Oil truck Reservoir and West lst?The main sniffing contaminants of water.The removal rates of GSMN 2-MIB, 尾 -exchange citral and 尾 -ionone in water plant were between 3442 and 3455 and 611.69%, respectively, for GSM2-MIB, 尾 -exchanged citral and 尾 -ionone.The results of coagulation experiments showed that the direct removal of odorous substances by coagulation was not good, but it could effectively remove algae cells from water by precipitation, and then remove odour substances in algae cells.Powder activated carbon can effectively adsorb and remove odorous substances in water. The adsorption process accords with the Freundlich adsorption isotherm model, and the adsorption capacity of 尾 -ionone is the largest and the adsorption capacity of 2-MIB is the smallest.The natural organic matter in raw water has a competitive adsorption effect on the removal of odorous substances.The removal rate of odorous substances could be improved by increasing the dosage of activated carbon, and the removal rates of four kinds of odorous substances were different under the conditions of polar acid and extreme alkali.Humic acid in water could inhibit the adsorption of odorous substances. The adsorption process of PAC to odorous substances was in accordance with pseudo-second-order adsorption kinetics. The initial adsorption rate constants of four kinds of odorous substances increased with the increase of initial concentration of odors.The maximum adsorption capacity of PAC decreased with the increase of humic acid concentration.The more organic matter in the water, the more unfavorable to the adsorption and removal of odorous substances.Ozone oxidation can effectively remove odorous substances in water and the oxidation process accords with pseudo-first-order reaction kinetics.The order of reaction rate constant is: 尾 -ionone 0.0821S-1) 尾 -Cyclocitral 0.0611S-1 GSM 0.0366S-1) 2-MIB 0.01844S1.Under the condition of sufficient ozone, the reaction rate of the four odorous substances was higher than 0.03mg / ngGN, and the removal rate was more than 90%.When the content of natural organic compounds in raw water is high, the removal efficiency of odorous substances decreases.Hydroxyl radicals play a major role and ozone molecules play a secondary role in the oxidation of odorous substances.When free radical inhibitors such as HCO3- and tert-butanol exist in water, the oxidation of smelling substances is inhibited.A lower concentration of humic acid (1-2.5mg / L) improves the removal efficiency of odorous substances by ozone, while a high concentration of humic acid (鈮，

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