【作者】 贾桢桢；

【导师】 张景成；

【作者基本信息】 哈尔滨工业大学 ， 市政工程， 2009， 硕士

【摘要】 大蒜废水含有抗菌、杀菌活性物质天然大蒜油,对细菌具有很强的杀伤力,导致大蒜废水的可生化性较差,加之大蒜废水属高浓度有机废水更增加了大蒜废水处理的难度,致使以往的生化污水处理方法不能有效处理大蒜废水。目前国内外能有效处理大蒜废水的工艺还处于研究阶段,加工废水污染指标严重超标,严重制约和困扰着我国大蒜产业的健康、持续发展。因此加快对大蒜废水处理的研究迫在眉睫,如能开发一种高效、实用的大蒜废水处理工艺,则可以大大降低水体污染,保护水环境,并能有效缓解水质型水资源短缺等问题,创造出可观的经济效益和社会价值。研究需准确测定出大蒜废水(即被水大量稀释了的大蒜汁)中有机硫化物的含量。通过对国内外各种大蒜有机硫化物测定方法的分析研究和特点比较,最终确定采用吸光比浊法测定大蒜废水中的有机硫化物含量,并且利用试验室现有条件,采用COD快速测定仪代替紫外可见分光光度计测定吸光度,并对吸光比浊法作了适当的改进,优选出吸光比浊法测定大蒜废水中有机硫化物含量的最佳实验条件。此外,本文还对验证改进后的吸光比浊法的可行性和可靠性进行了试验研究,实验结果证明在一定实验条件下的吸光比浊法测定的有机硫化物是可以满足测定要求的。简要介绍酸碱预处理和加热处理预处理去除有机硫化物的相关理论,并相应的进行了试验研究。实验结果表明:加热预处理方法对有机硫化物的去除有一定的作用,但其作用效果并不能满足实际生产地需要;而酸碱预处理方法对去除大蒜废水有机硫化物是极为有效的,并且方法简便、适于推广。在酸碱预处理试验研究中发现,在强酸条件下大蒜废水由淡黄色变成白色,并产生大量白色絮体,大蒜废水中有机硫化物去除率可达到80%～90%,说明在弱酸条件下,有机硫化物对指示菌的抑制作用最强,在强酸条件下,绝大多数有机硫化物转化为白色絮体而被去除。采用絮凝、铁炭微电解和铁炭微电解-Fenton联合工艺降低大蒜废水中高浓度有机物含量。通过单因素影响试验确定絮凝试验最佳运行参数;运用正交试验法确定了微电解试验各影响因素的重要程度,并进一步通过单因素影响试验,确定微电解试验最佳的运行参数;论证铁炭微电解法和Fenton试剂氧化法联合的可能性,确定微电解-Fenton联合试验各影响因素的最佳实验值。絮凝试验表明:与该工艺处理其它废水的处理效果相比,絮凝实验对大蒜废水COD的去除效果并不乐观;微电解试验表明:铁炭比为4.0,进水pH值为3.0,反应时间为5h,采用曝气方式,当原水CODCr浓度为9000～13000 mg/ L时,在最佳条件下通过该法处理的废水,CODCr去除率可达50%以上;微电解-Fenton联合试验表明:pH值采用微电解出水pH=4.5,反应时间为60min,H2O2用量为4mL/L,H2O2的投加方式为滴加,当原水CODCr浓度为9000～13000 mg/ L时,在最佳条件下通过该法处理的废水,CODCr去除率可达60%以上。更多还原

【Abstract】 Garlic wastewater is the garlic juice mixed with a large number of water. Garlic wastewater contains bioactive substances, natural garlic oil, which has strong anti-bacterial effect. This has resulted in weak biodegradability of garlic wastewater. In addition, garlic wastewater is a high concentration organic waste, which increases the difficulty of garlic wastewater treatment. As a result, previous biochemical treatment of wastewater can not effectively deal with the garlic wastewater. The process that can effectively deal with garlic wastewater is still in the research stage internationally. Pollution index of processing wastewater seriously exceeded standards. Thus, this constrains the sustainable development of garlic industry in China. Therefore, it is very urgent to speed up the study of garlic wastewater treatment. If we can develop a highly efficient and practical garlic wastewater treatment process, then the water pollution can be greatly reduced, and the water environment can be protected. As a result, the shortage of water resources such as water quality can be effectively alleviated and considerable economic benefits and social values can be created.The concentration of organic sulfides in garlic wastewater is determined in current study. According to the comparison of various methods of measuring organic sulfides concentration in garlic oil, the absorptiophotometric turbidimetry was selected to determine the concentration of organic sulfides in garlic wastewater. At the same time, due to the limited laboratory facility, the absorbance was determined by COD rapid detector instead of UV-V is spectrophotometer. In this study, we have improved the determination of absorptiophotometric turbidimetry in the following two ways. First of all, we select the best conditions of the determination method. On the other hand, we also examined its feasibility and reliability. Experimental results show that the method of absorptiophotometric turbidimetry meets the requirements of experiments under certain experimental conditions.In this thesis, the theory on pH and pre-heat treatment to remove organic sulfides was introduced briefly. The experimental results show that pre-heat treatment method to remove organic sulfur is useful, but it can not meet the actual needs of production. However, pH pre-treatment method of wastewater to remove organic sulfur garlic is extremely effective, and it is simple and suitable for wide application.During the removal of bioactive substances in the pH pre-treatment, it was found that the color of garlic wastewater changed from yellow to white in the strong acid conditions. Meanwhile, a large number of white cotton like substances was generated. The removal efficiency of organic sulfides of garlic wastewater can be up to 80%-90%. This shows that the antibacterial activity of organic sulfides is the strongest in acidic conditions as compared with the weak acid. The majority of organic sulfides have turned into removable cotton like substances in the strong acidic conditions.To reduce the high concentration of organic matter in the garlic wastewater, we can use a series of processes such as flocculation, micro-electrolysis and Fenton reagent oxidation. The optimal operating parameters are determined by single factor flocculation experiment. The degree of importance of influence factors is determined by micro-electrolysis orthogonal experiment. And then the possibility of connecting micro-electrolysis with Fenton reagent oxidation is demonstrated in theory. At last, the optimal operating parameters are determined by single factor micro-electrolysis and Fenton reagent oxidation joint experiment.The experiment result of garlic wastewater indicates that the optimal operating parameters are different in various experiments.1. Flocculation experiments show that compared with the same wastewater treatment, the flocculation experiments reducing COD content is not optimistic.2. In the micro-electrolysis experiments, it has been shown that the optimal operating parameters are the following: the volume ratio of iron versus carbon is 4.0, pH value is 3.0, the reaction time is 5 hours, aeration mode, and the removal efficiency of COD is more than 50%.3. Micro-electrolysis and Fenton reagent oxidation: the optimal operating parameters are the following: pH value is 4.5, reaction time is 60 minutes, the dosage of hydrogen peroxide is 4ml/L, the dropwise manner of hydrogen peroxide use, and the removal efficiency of COD is more than 60%.更多还原