【作者】 陈琳；

【导师】 龙腾锐；

【作者基本信息】 重庆大学 ， 市政工程， 2008， 硕士

【摘要】 苯胺基乙睛化工废水是一种高浓度难生化降解的有毒性废水;其主要成分为苯胺类物质及氰化物,毒性强,危害大。本研究主要针对此废水生物处理前的预处理进行了试验研究。膨润土是以蒙脱石为主要成分的一类含水铝硅酸盐粘土矿物,由于其具有特殊的物理化学性能,经过有机改性或重金属改性后的膨润土对废水具有较好的处理效果,在对含有机污染物、重金属的废水处理中,改性膨润土是一种高效吸附剂。因此,改性后的膨润土产品在废水处理中的应用受到了广大环保工作者的关注与开发。本研究首先以原膨润土矿为原料,经过提纯后,采用微波辐射法制备了钠化1膨润土,钠化的工艺条件为:以NaCl为钠化改性剂,改性剂用量与膨润土投加量比为0.6:5(g/g),溶剂使用量与膨润土投加量比7:5(ml/g),反应时间为4min,结果表明,制备所得的钠基膨润土的阳离子交换容量由62.4mmol/100g土提高到93mmol/100g土,有利于后续的有机化改性及铁交联柱撑改性。其次,以钠基膨润土为原料,经阳离子表面活性剂CTMAB改性,制备获得有机膨润土,并在试验过程中考察了有机膨润土的适宜制备条件以及有机膨润土对苯胺基乙腈车间废水中污染物的去除性能。试验结果表明,有机膨润土适宜的制备条件为:有机改性剂用量为90CEC,微波辐射时间采用2min,溶剂使用量与膨润土投加量比6:1(ml/g);有机膨润土处理苯胺基乙腈车间废水的较优工艺条件为:有机膨润土投加量为20g/L,处理系统pH值为6.0,吸附温度为30℃,吸附时间为60 min,处理效果为:CODcr及苯胺去除率分别达到了23.3%及54.4%,可生化性BOD5/CODcr可提高到0.11左右,并且有机膨润土对废水有机污染物的吸附符合Linear等温吸附模型和伪二级动力学模型,而采用原土矿处理苯胺基乙腈生产废水,CODcr及苯胺的去除率仅达到3.4%及8%,可生化性BOD5/CODcr难以测出,说明有机膨润土吸附能力有很大的提高,但是由于苯胺基乙睛生产废水浓度高,毒性强,采用有机膨润土对此废水的处理能力有限,去除率不高,难以满足后续生化处理的要求。因此,本研究尝试采用铁交联膨润土与H2O2联合氧化处理苯胺基乙腈废水,并且考察其对污染物的去除性能。试验结果表明,相对于有机膨润土的吸附方法,铁交联膨润土-H2O2氧化法对废水的处理能力大大提高,铁交联膨润土-H2O2氧化吸附处理苯胺基乙腈废水的较适宜的工艺条件为废水pH值为4.0、过氧化氢投加量为6.66g/L、交联膨润土投加量为20g/L、处理温度为30℃、处理时间为60min,与有机膨润土吸附处理苯胺基乙腈车间生产废水的处理效果相比较,采用铁交联膨润土+H2O2氧化法处理,CODcr及苯胺的去除率分别达了40.6%及92.6%,苯胺含量低于500mg/L,可生化性BOD5/CODcr提高到0.32左右,基本上可满足了后续生化处理进水的要求,论文同时对铁交联-H2O2氧化法处理苯胺基乙腈废水进行了动力学研究。另外,在制备改性膨润土的过程中,本研究分别采用X-射线衍射,红外光谱,电镜扫描比较研究了钠化膨润土,有机膨润土以及铁交联膨润土的结构方面的变化,经过有机化或铁交联后,膨润土的层间距大于钠化膨润土;在红外光谱分析中,有机膨润土以及铁交联膨润土出现了新的特征峰,扫描电镜分析结果进一步说明了膨润土经过改性后,其表面填塞了改性基团,使得改性后的膨润土处理生产废水的性能提高,从而说明膨润土经过改性后结构及性质上的变化是有利于处理苯胺基乙腈生产废水。论文最后,对提纯膨润土、有机膨润土、铁交联膨润土-H2O2、活性炭处理苯胺基乙腈废水的处理效果进行了比较,确定了较优方法,即采用铁交联膨润土+H2O2联合氧化处理苯胺基乙腈废水,并通过对产酸段污泥活性的测定确定了其要求的预处理段出水的最佳pH值范围为6.0~6.5。更多还原

【Abstract】 N-phenylglycinonitrile chemical wastewater is one of the refractory wastewater with high concentration, low biodegradability and high toxicity; the main components are anilines and cyanides which are harmful to organisms at low concentration and classed as hazardous pollutants. Experiments study on the pre-treatment of this wastewater before the biological-treatment was introduced in this paper.Montmorillonite, the primary constituent of bentonite, is an aqueous aluminosilicate clay mineral with expandable layer structure. With its special physical and chemical properties, the bentonite has better effect for wastewater treatment by the course of organic or heavy metal modification, modified bentonite is an effective adsorbent for the removal of organic contaminates and heavy metals from wastewater. Therefore, the application of modified bentonite in wastewater treatment has been emphasized and investigated by environmentalists.First, using Ca-bentonite as raw material, Na-bentonite was prepared by microwave radiation after purification, and the preparation conditions were follows: use NaCl as modified regents, the reagent volume of 50% C2H5OH to the bentonite quality is 7:5（ml/g）and the reaction time is 4min, the experimental results showed that the CEC of Na-bentonite increased to 93mmol/100g after modification from 62.4mmol/100g which is useful to the organic modified and the Fe-pillared modified.Secondely, the organo-bentonite was prepared from Na-bentonite by cation surfactant CTMAB. The preparation conditions were optimized and the ability of organo-bentonite to remove organic compounds in N-pHenylglycinonitrile chemical wastewater was investigated. The experiment results show that the appropriate preparation conditions of organic bentonite were follows: the amount of surfactant is 90CEC, the microwave radiation time is 2min,the reagent volume of H2O2 to the bentonite quality is 6:1（ml/g）; the feasible treating conditions of N-pHenylglycinonitrile chemical wastewater by organo-bentonite were follows: the organo-bentonite concentration is 20g/L, the pH of wastewater is 6.0, the adsorption temperature is 30℃and the adsorption time is 60min. The organo-bentonite has a high ability of adsorption compared to Na-bentonite, the removal rate of CODcr and anilines can reach 23.3%, 54.4% and the BOD5/CODcr increased to 0.11, the adsorption can be well represented by linear isothermal adsorption model and pseudo secondary kinetics model, however, the removal rate only can reach 3.4%and 8% if using the raw bentonite as adsorption regent. However, the organo- bentonite adsorption ability to the N-pHenylglycinonitrile chemical wastewater was rather limited, the removal rate didn’t achieve the ideal degree to meet the requirement of subsequent biochemical treatment.For the wastewater treatment limitation of organo-bentonite, using the Fe-pillared bentonite and H2O2 to treat the N-pHenylglycinonitrile chemical wastewater by oxiditon was tried, and the removal ability was investigated, too. The experimental results showed that the optimal treatment conditions were obtained as follows: pH value is about 4.0, added amount of H2O2 is 6.66g/L, amount of Fe-pillared bentonite added is 20g/L, temperature is 30℃, and treatment time is 60min, he removal rate can reach 23.3%, 54.4% and the BOD5/CODcr increased to 0.11 which meet to the requirement of subsequent biochemical treatment. Comparing to the ogano-bentonite adsorption, the effect of oxidation method by Fe-pillared bentonite and H2O2 had been improved effectively. Simultaneously, the reaction kinetics was studied.Thirdly, the structures of Na-bentonite, organo-bentonite and Fe-pillared bentonite was investigated by XRD, IR and SEM respectively. Studies on X-ray diffraction date （XRD） demonstrated that the interlayer spacing were obviously enlarged through organic modification or Fe-crosslinked modification ; results of infrared spectrum （IR） discovered that some new characteristic peaks appeared, and the basic structure didn’t destroy; SEM indicate that the bentonite surface was packed modified groups via modification, which improved the treatment effect, therefore, the change of structure and properties of bentonite is usful to the treatment effeciecy during modification.Finally, this paper put forward using Fe-pillared bentonite-H₂O₂ to treat N-pHenylglycinonitrile chemical wastewater by comparing the treatment effect of each method, including purified bentonite, Na-bentonite, organo-bentonite and Fe-pillared bentonite-H₂O₂, and determined the optimal pH of the pre-treatment process effluent which is about 6.0～6.5 through testing the sludge activity in hydrolysis-acidification reactor.更多还原