毕业论文

打赏
当前位置: 毕业论文 > 化学论文 >

不同条件下污泥中壬基酚短链壬基酚聚氧乙烯醚及有机质降解的影响研究

时间:2019-01-10 09:55来源:毕业论文
通过对比各条件下3种污染物的降解程度,污泥中NP和NP1EO在空白好氧条件下的降解效果最好。NP2EO在空白好氧条件下,经过50 d的发酵也能很有效地降解且降解速率明显高于厌氧条件下的污

不同条件下污泥中壬基酚、短链壬基酚聚氧乙烯醚及有机质降解的影响研究摘要:城市生活污水处理厂处理污水后会产生大量的污泥,而这些污泥中存在着许多难以降解的类似于NP、NP1EO和NP2EO这样的污染物,所以必须要选择一种降解效率高、速度快、污染少的降解途径。本实验在污泥中加入酵素剂和空白实验做对比;以及在有氧和无氧条件下作对比,将二氯甲烷和甲醇按9:1的比例作为提取剂,用高效液相色谱法测定污泥中NP、NP1EO和NP2EO的含量,并比较测得的数据,选择最佳的降解方法。另外,以邻菲罗啉作为指示剂,用重铬酸钾法滴定,测得污泥中有机质的含量。结论:通过对比各条件下3种污染物的降解程度,污泥中NP和NP1EO在空白好氧条件下的降解效果最好。NP2EO在空白好氧条件下,经过50 d的发酵也能很有效地降解且降解速率明显高于厌氧条件下的污泥,而是否添加酵素剂对这些污染物的降解影响并不大。32501
毕业论文关键词:酵素剂、污泥、壬基酚、短链壬基酚聚氧乙烯醚、降解、高效液相色谱法
Research on degradation of nonylphenol, short-chain nonylphenol polyeothoxylates and organic matter in sludge under different conditions
Abstract: Large amount of sludge was produced in the municipal waste-water treatment plant after the deposing of sewage. However, lots of refractory pollutants like nonylphenol (NP) , nonylphenol monoethoxylate (NP1EO) and nonylphenol diethoxylate (NP2EO) were adsorpted in sludge, so a high-efficient, high-speed and less-polluted solution should be chosen to degrade them. The experiment was designed to make a contrast under the four conditions: two of the four were added some enzyme agents to the sludge, but one with oxygen and the other without oxygen; the left two were blank experiments (one with oxygen). First,methylene chloride and methyl alcohol were used as exacting agents by the proportion of 9:1, and the content of NP, NP1EO and NP2EO in sludge was determined with high performance liquid chromatography (HPLC). Then the results were compared and the best degradation method was achieved. In addition, the progress of monitoring organic matter in sludge with potassium dichromate method by taking phenanthroline monohydrate for indicator was finished. Conclusion: By comparing the degrees of the three pollutants under different conditions, NP and NP1EO degraded more under the conditions with oxygen and no enzyme agents. Besides, a good degradation result of NP2EO was obtained after the sludge fermented for 50 days under the conditions with oxygen and no enzyme agents, and its efficiency was much better than the opposite one, while whether adding enzyme agents or not nearly had no effect to the degradation of these pollutants. 源自$六l维,论:文w网)加7位QQ3249^114 www.lwfree.cn
Keywords: enzyme agents; sludge; nonylphenol; short-chain nonylphenol  polyeothoxylates; degradation; high performance liquid chromatography
 前言  
壬基酚聚氧乙烯醚(NPEOs)是一类人工合成的化学物质,自1940年开始在商业上使用,到1980年其使用量已迅速增长。NPEOs的使用范围广泛,在纺织业、塑料业、化肥工艺、农药、医药、造纸业等各个领域都有所涉及,而且这些行业所使用的NPEOs中有60%左右会经废水排放进入污水处理厂,最后累积在污水处理厂排出的污泥中[1],这些污泥如果得不到有效的处理将会在环境中迁移,对人类造成极大的危害。
一般认为NPEOs在污水处理厂(STPs)中的降解途径主要是乙氧基链的逐步缩短,生成短链的产物如壬基酚一乙氧基醚(NP1EO)和壬基酚二乙氧基醚(NP2EO)以及最终产物壬基酚(NP)[2]。NP是一种呈无色或淡黄色,略带苯酚气味,被称为“精子杀手”的拟雌激素类物质[3],能够引起水中生物像鱼类和螺类这样的雄性个体的雌性化发育。同时这些物质还会对生物体的神经系统和免疫系统等机能产生不良作用。另外壬基酚还具有三致效应[4]、持久性和生物蓄积性,一旦进入环境,便以食物链的形式逐级放大,对生物和人类都存在着严重的危害[5]。 不同条件下污泥中壬基酚短链壬基酚聚氧乙烯醚及有机质降解的影响研究:http://www.lwfree.cn/huaxue/20190110/29139.html
------分隔线----------------------------
推荐内容