光电催化降解10-壬基酚聚氧乙烯醚

采用溶胶-凝胶法制备TiO₂薄膜光电极,以该电极为工作电极,铂丝作对电极,饱和甘汞电极为参比电极,对10-壬基酚聚氧乙烯醚的光电催化降解进行了研究.结果表明,该电极具有n型半导体的特征行为.在外加偏压为+0.6V,pH值为5,H₂O₂浓度为30mg/L的条件下对初始浓度为50mg/L的10-壬基酚聚氧乙烯醚溶液光照4h,降解率达53.26%.讨论了氧的存在、外加偏压、pH值等因素对光电催化反应的影响.     

潜流人工湿地去除毒死蜱、双酚A、4-壬基酚

为研究潜流人工湿地对毒死蜱、BPA及4-NP的去除效果,选取宽叶香蒲、芦苇、花叶香蒲及小香蒲4种湿地植物,通过SPE-HPLC测定进出水中3种污染物的浓度,计算4种植物潜流人工湿地对3种污染物的去除效率。结果表明,水力停留时间3 d,4组植物对毒死蜱、BPA和4-NP去除率均高于60%,各植物组对毒死蜱和4-NP的去除效果之间无显著性差异,宽叶香蒲对BPA的去除率为82.66%,显著高于其余3种植物组62.96%~69.63%。在静态条件下,毒死蜱、BPA和4-NP在模拟系统内降解过程符合一级降解动力学方程,降解方程分别为:c=124.63exp(-t/25.393)+3.7618 1,c=316.61exp(-t/34.955)+0.56475 2,c=168.91exp(-t/17.061)+12.133 3(c,剩余浓度,μg/L;t,停留时间,h),半衰期分别为18、21和11 h。     

Photochemical degradation of nonylphenol in aqueous solution：The impact of pH and hydroxyl radical promoters

The degradation of nonylphenol (NP) in aqueous solution with UV, H₂O₂/UV, and Fenton/photo-Fenton processes was studied. The efficacy of direct and hydrogen peroxide photolysis proved to be dependent on the pH value. The addition of H₂O₂ to UV treatment improved NP degradation. The application of UV photolysis and the H₂O₂/UV system at pH 7 resulted in low pseudo first-order rate constants at 10^-4 sec^-1. In the experiments at elevated pH values the pseudo-first order rate constants increased to 10^-3 sec^-1. The efficacy of the Fenton process was lower in comparison with UV and hydrogen peroxide photolysis. The addition of UV irradiation to the H₂O₂/Fe²⁺ system substantially improved NP degradation efficacy. In terms of performance, the photo-Fenton process was similar to the H₂O₂/UV process. The most favourable process for complete nonylphenol degradation considering both operational cost and treatment efficacy was H₂O₂/UV at pH 11 and 250 mol/L H₂O₂.     

壬基酚与壬基酚聚氧乙烯醚对多刺裸腹溞的复合毒性效应

为了探讨壬基酚聚氧乙烯醚（NP10EO）与其降解产物壬基酚（NP）对多刺裸腹溞的复合毒性效应,在实验室条件下研究了NP和NP10EO单一暴露对多刺裸腹溞的急性毒性和亚慢性毒性,以及两者混合暴露对多刺裸腹溞的联合毒性效应。结果表明：NP和NP10EO两种物质单一暴露对多刺裸腹溞的24 h LC50分别为0.154和3.37 mg.L-1,48 h LC50分别为0.065和2.11 mg.L-1。联合毒性实验中,定义0.5×LC50（NP）＋0.5×LC50（NP10EO）为一个毒性单位（1TU）。NP和NP10EO混合暴露后对多刺裸腹溞的24 h和48 h的LC50分别是0.646TU和0.291TU,联合毒性强度明显高于两种物质单一暴露时的毒性强度。在持续混合暴露条件下,多刺裸腹溞的首次生殖时间延迟、母体体长和初生幼体体长严重缩短、首次生殖数量大幅减少。说明NP和NP10EO对多刺裸腹溞的复合毒性表现出明显的协同效应。     

水溶液中壬基酚聚氧乙烯醚的UV/H2O2矿化试验

采用UV/H2O2催化氧化工艺进行水中壬基酚聚氧乙烯醚(NP-10)的降解和矿化试验,考察了H2O2投加量、溶液初始pH值、UV功率和反应温度对NP-10矿化效率的影响,并采用GC-MS对降解过程中间产物进行初步分析。结果表明:UV/H2O2体系能有效降解水溶液中的NP-10,在NP-10初始质量浓度为100.0mg/L、UV功率为45W、H2O2投加量为10.0mmol/L、溶液初始pH值为3.0、反应温度为25℃的条件下,20min时NP-10的去除率可达98.0%以上,240min时TOC去除率可达98.3%;NP-10的矿化过程符合拟一级动力学,矿化速率常数随光强和H2O2投加量的增加而增加,较低的pH值和较高的反应温度有助于NP-10的矿化;降解中间产物主要是酚类化合物;随着反应时间的增加,NP-10及其降解中间产物可以被完全矿化成CO2和H2O。     

Biotransformation of nonylphenol ethoxylates during sewage treatment under anaerobic and aerobic conditions

Biotransformation of nonylphenol ethoxylates (NPEOs) during continuous anaerobic sewage treatment was compared with the aerobic treatment of sewage spiked with 23 μmol/L technical NPEOs over a period of 90 d. Immediate degradation of NPEOs was observed under both anaerobic and aerobic conditions, indicating that the enzymes and bacteria required for NPEO degradation existed abundantly in both aerobic and anaerobic sludge. Both treatments achieved high removal (＞92%) of the spiked NPEO9 mixture.Liquid chromatography-mass spectrometry (LC-MS) analysis showed that short-chain NPEOs (NPEO1-NPEO3) accumulated in anaerobic (2.01-2.56 μmol/L) and aerobic (1.62-2.03 μmol/L) effluents, with nonylphenol (NP) (0.24-0.31 μmol/L) as another group of metabolites in the anaerobic effluent, and nonylphenoxy carboxylates (NPECs) (2.79-3.30 μmol/L) in the aerobic effluent. Significant accumulation of NP in the anaerobic sludge and NPEO1-3 in the sludge of two reactors was observed. These results indicated that it was difficult to control these harmful metabolites in the conventional treatment processes. Denaturing gradient gel electrophoresis profiles of sludge samples support the speculation that the NPEO degradation bacteria might be the dominant indigenous species.     

夏季长江口及其临近海域不同环境介质中壬基酚的分布特征

2006年6月对长江口及其临近海域不同介质中壬基酚的浓度分布进行了初步研究.结果表明,壬基酚在表层水、悬浮物和表层沉积物中的浓度分别为14.09～173.09 ng/L,7.35～72.02 ng/L及(0.73～11.45) ×10-9 dw.表层水体中壬基酚浓度高值区位于长江冲淡水主轴线上,表层沉积物中壬基酚浓度高值区位于长江口东南泥质区和浙江近岸泥质区,长江冲淡水和悬浮物是研究区域壬基酚的主要来源.壬基酚的浓度分布受到水动力条件、悬沙输送方向、微生物活性等环境因素的共同影响.与世界其它河口地区相比较,研究水域水体中壬基酚浓度已达到中等污染水平.     

壬基酚和短链壬基酚聚氧乙烯醚在土壤中的降解研究

研究了壬基酚(NP)类内分泌干扰物在土壤体系和添加污水处理厂剩余污泥的土壤体系中的降解行为.结果表明,NP、壬基酚单氧乙烯醚(NPEO1)、壬基酚二氧乙烯醚(NPEO2)在土壤中的降解遵循一级动力学方程,其降解速率随温度升高而升高.30℃时,初始浓度分别为100、50和100 mg·kg-1的NP、NPEO1和NPEO2可在45 d内完全降解.相同条件下,土壤中NP的降解速率大于NPEO1和NPEO2.体系中添加污泥促进了NPEO1和NPEO2的降解,同时抑制了NP的降解.     

北黄海辽宁近岸水环境中壬基酚污染状况调查及生态风险评估

利用固相萃取气质连用(SPE-GC/MS)法对1月辽宁近岸19个站位水体中壬基酚污染状况进行了调查,结果显示水体中壬基酚浓度为15.13～762.73 ng/L,整体呈现出近岸高于远海,西部海域高于东部的特点,高值区多出现在河流入海口或港口附近.与国内外相关报道比较,调查海域壬基酚处于中等污染水平.以风险熵(RQ)为标准对壬基酚的污染状况的初步评估表明,调查海域壬基酚风险熵为0.05～2.25,某些站位熵值高于阈值,可能造成一定的风险,需要采取相应措施减少污染.     

US/FeEDTA/H2O2协同降解壬基酚聚氧乙烯醚废水研究

采用US/FeEDTA/H2O2体系协同降解壬基酚聚氧乙烯醚废水.探讨了初始pH值、H2O2质量浓度、FeEDTA质量浓度、超声波功率以及壬基酚聚氧乙烯醚的初始质量浓度对壬基酚聚氧乙烯醚降解效果的影响及FeEDTA/H2O2和超声波之间的协同效应.结果表明,US/FeEDTA/H2O2体系降解壬基酚聚氧乙烯醚废水时产生较强的协同作用,而不是简单的几何叠加.US/FeEDTA/H2O2体系对壬基酚聚氧乙烯醚的去除率比超声波与FeEDTA/H2O2体系的几何叠加的去除率高出约60%.在pH=9、H2O2质量浓度250 kg/L、FeEDTA质量浓度100 mg/L、超声波功率600 W的条件下,对初始质量浓度为100 mg/L的壬基酚聚氧乙烯醚溶液降解2 h,其去除率在99%以上.