臭氧—活性炭工艺中溴酸盐的生成控制研究

发布时间：2019-04-07 15:54

【摘要】：南水北调东段供水工程对保证山东省内工农业生产、人民安定生活有着重要的意义。随着水质条件的恶化以及人们对水质日益提高的要求,臭氧工艺被越来越多的应用到水厂给水处理中,随之而来的溴酸盐消毒副产物问题也日益严峻。为了探究南水北调东段各蓄水地水厂实际运营时臭氧工艺溴酸盐生成风险的影响,原水水质在此工艺中对溴酸盐生成量的影响,高锰酸钾-氨氮预氧化、臭氧分次投加对溴酸盐生成量的控制作用以及活性炭对溴酸盐的去除作用。本文研究了以下内容:1、将南四湖水样分别与东平湖水样、西城水库水样、双王城水库水样、长江水样等比掺混,通过混凝改善混合水样水质条件,并将混凝前后的水样分别进行臭氧氧化处理。其中混凝剂投加量为24 mg/L,臭氧投加量为0-10mg/L,试验水样体积为2L。经离子色谱法测定可知,混凝前后混合水样溴酸盐生成量达到10μg/L时,臭氧投加量均在8-10mg/L之间。且臭氧投加量相同时,混凝后水样溴酸盐生成量均比未混凝时增多。混合水样经臭氧处理后,大部分水样DOC、氨氮等成分有一定幅度增大,UV_(254)、浊度随臭氧投加量增大而减小。2、以南四湖水样、东营水库水样等南水北调山东段沿线各水源地原水为基础进行臭氧氧化试验,分别调节水样中溴离子浓度、氨氮浓度、有机物浓度、pH、过氧化氢浓度及臭氧氧化处理的预氧化工艺和臭氧投加方式。经测定可知:(1)由于有机物等的作用,原水中臭氧浓度衰减速度明显高于纯水中的衰减速度;(2)臭氧投加量不变,水样中溴离子浓度越高,溴酸盐生成量越大。臭氧投加量设为5mg/L,当溴离子浓度从250μg/L增加到450μg/L时,溴酸盐生成量增加了40%;(3)因臭氧工艺对UV_(254)有着较高的去除率,对DOC的去除效果较差,原水经臭氧氧化后出水的SUVA值降低。进水水样SUVA值越低,溴酸盐生成量越多,当臭氧投加量为5mg/L时,SUVA值降低10%,溴酸盐生成量增加61%。(4)臭氧投加量不变,pH越高,溴酸盐生成量越大。臭氧投加量为5mg/L,当pH从8.5下降到7.5时,溴酸盐生成量减少32%。(5)过氧化氢可以有效抑制溴酸盐的生成。当臭氧投加量为5 mg/L时,在原水中投加不同量的过氧化氢,溴酸盐生成量分别下降20%-100%。(6)高锰酸钾预氧化可以抑制臭氧工艺中溴酸盐的生成,且氨氮可以提高高锰酸钾的预氧化的抑制作用。臭氧投加量为8mg/L,当高锰酸钾/氨氮浓度均为1mg/L时,与未进行预氧化的水样相比,溴酸盐抑制率接近68%。高锰酸钾浓度均为1mg/L,当氨氮浓度从0.6mg/L提高到1mg/L时,溴酸盐的抑制率提高了54%。(7)采用多点投加臭氧的方式可有效抑制溴酸盐的生成。臭氧投加量为8mg/L时,两点投加对溴酸盐的抑制率约为76%;三点投加对溴酸盐的抑制率可达95%以上。且臭氧总投加量越大,分次投加对溴酸盐生成的抑制率越明显。3、使用活性炭柱探究了活性炭对溴酸盐的连续吸附作用。同时,探究了经超声和微波两种方试再生的活性炭对溴酸盐的吸附作用。经分析可知:(1)活性炭柱的停留时间和进水溴酸盐浓度均与去除率呈正相关关系且在连续运行条件下,活性炭可以有效去除溴酸盐,但一段时间后去除效果明显下降。连续运行的活性炭柱8天后溴酸盐去除率直线下降直至接近于零。(2)活性炭吸附溴酸盐时,共存的硝酸盐离子与溴酸盐存在竞争关系。溴酸盐浓度为200μg/L,硝酸根浓度为20-60mg/L时,活性炭对溴酸盐的去除率下降约30%。(3)饱和活性炭经再生后,可以有效恢复其吸附溴酸盐的能力。微波再生炭去除溴酸盐的效果可达到新炭的80%。超声再生炭仅能达到新炭的10%左右。
[Abstract]:The water supply project of the east section of the South-to-North Water Transfer Project is of great significance to the guarantee of the industrial and agricultural production and the people's stability in Shandong Province. With the deterioration of water quality and the increasing demand of people for water quality, the process of ozone is more and more applied to the water treatment of water plant, and the problem of the by-products of bromate disinfection is becoming more and more serious. In order to study the effect of the generation risk of the ozone process bromate during the actual operation of the water works in the east section of the South-to-North Water Transfer Project, the effect of the raw water quality in the process on the generation of bromate, the pre-oxidation of potassium permanganate and ammonia nitrogen, The control effect of the addition of ozone on the generation of bromate and the removal of bromate by activated carbon. In this paper, the following contents are studied:1. The water samples of the Nansihu Lake are mixed with the water sample of Dongping Lake, the water sample of Xicheng Reservoir, the water sample of Shuangwang City and the water sample of the Yangtze River, and the water quality of the mixed water sample is improved by the coagulation, and the water samples before and after the coagulation are respectively subjected to ozone oxidation treatment. The dosage of the coagulant is 24 mg/ L, the dosage of the ozone is 0-10mg/ L, and the volume of the test water sample is 2L. It was found that when the amount of bromate produced before and after coagulation was 10. m u.g/ L, the dosage of ozone was between 8 and 10 mg/ L. And the amount of bromate in the water sample after the coagulation is increased when the amount of the ozone is the same. After the mixed water sample has been treated with ozone, the amount of DOC and ammonia nitrogen in most of the water sample is increased, and the UV _ (254) and turbidity decrease with the increase of the amount of ozone. The concentration of the bromine ions, the concentration of the ammonia nitrogen, the concentration of the organic matters, the pH, the concentration of the hydrogen peroxide and the pre-oxidation process and the ozone adding method of the ozone oxidation treatment are respectively regulated in the water sample. It can be found that: (1) The ozone concentration in the raw water is obviously higher than that of pure water due to the action of the organic matter and the like; (2) the ozone dosage is not changed, the higher the bromine ion concentration in the water sample, and the larger the bromate production amount. The dosage of ozone is 5 mg/ L, and when the concentration of bromine ions is increased from 250. m/ L to 450. m u.g/ L, the generation of bromate is increased by 40%; (3) because of the high removal rate of the ozone process to the UV _ (254), the removal effect on the DOC is poor, and the SUVA value of the discharged water after the oxidation of the raw water is reduced. The lower the value of SUVA in the water sample, the more bromate production, when the dosage of ozone is 5 mg/ L, the value of SUVA is reduced by 10%, and the generation of bromate is increased by 61%. (4) The higher the dosage of ozone, the higher the pH, the greater the production of bromate. The dosage of ozone is 5 mg/ L, and when the pH is reduced from 8.5 to 7.5, the generation of bromate is reduced by 32%. (5) hydrogen peroxide can effectively inhibit the generation of bromate. When the dosage of ozone is 5 mg/ L, different amounts of hydrogen peroxide are added to the raw water, and the generation of bromate is reduced by 20-100%, respectively. (6) the pre-oxidation of potassium permanganate can inhibit the generation of bromate in the ozone process, and the ammonia nitrogen can increase the inhibition of the preoxidation of the potassium permanganate. The dosage of ozone is 8 mg/ L, and when the concentration of potassium permanganate/ ammonia nitrogen is 1 mg/ L, the inhibition rate of bromate is close to 68% as compared with the water sample which is not pre-oxidized. The concentration of potassium permanganate was 1 mg/ L, and when the concentration of ammonia nitrogen increased from 0.6 mg/ L to 1 mg/ L, the inhibition rate of bromate increased by 54%. (7) The generation of bromate can be effectively inhibited by the method of multi-point addition of ozone. When the dosage of ozone is 8 mg/ L, the inhibition rate of bromate is about 76% at two points, and the inhibition rate of the three-point addition of bromate can reach more than 95%. And the higher the total ozone dosage, the more obvious the rate of inhibition of bromate formation, and 3, using the activated carbon column to explore the continuous adsorption of the activated carbon to the bromate. At the same time, the adsorption effect of activated carbon on bromate by both ultrasonic and microwave was explored. The results showed that: (1) The retention time of activated carbon column and the concentration of bromate were positively correlated with the removal rate, and under the condition of continuous operation, the activated carbon can effectively remove bromate, but the removal effect after a certain period of time is obviously reduced. The removal rate of bromate after 8 days of continuous operation of activated carbon column was reduced until close to zero. (2) There is a competitive relationship between the co-existing nitrate ion and the bromate when the activated carbon adsorbs the bromate. When the concentration of bromate was 200 & mu; g/ L and the concentration of nitrate was 20-60 mg/ L, the removal rate of bromate was reduced by about 30%. And (3) after the saturated active carbon is regenerated, the ability of the saturated active carbon to adsorb the bromate can be effectively recovered. The effect of removing the bromate by the microwave regenerated carbon can reach 80% of the new carbon. The ultrasonic regenerated carbon can only reach about 10% of the new carbon.
【学位授予单位】：山东建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU991.2

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