Nitrated phenols in fog

Five nitrated phenols and some of their possible photochemical precursors as phenol, cresol and nitrate were identified in fog water from northeastern Bavaria. The concentrations in a rural and an urban area are presented, and the relationships observed between several of the compounds are discussed in terms of gas phase formation mechanisms. The levels of the nitrated phenols (5–300 nmoleℓ⁻¹) and phenol (<10–1000 nmoleℓ⁻¹) in fog were higher than the concentrations reported for rain.     

Simultaneous determination of brominated phenols in soils

Brominated phenols （BPs）, a widely used group of emerging flame retardants, are important environmental contaminants and exhibit endocrine disrupting potential. Method for simultaneous determination of tetrabromobisphenol A （TBBPA）, tribromophenol （TBP）, dibromophenols （DBPs） and monobromophenols （MBPs） in soils using gas chromatography-mass spectrometry analysis （GC/MS） was successfully developed. Cleanup methods for soil extracts including several solid-phase extraction cartridges and different elution solvents were compared and optimized. Florisil cartridge with dichloromethane as the elution reagent was selected for sample cleanup owing to its high and reproducible recoveries of the target analytes in soils. Derivatization conditions were tested and the optimal conditions were obtained with 20 μL silylation reagent at room temperature. The chromatographic separation was optimized with different columns and DB-XLB column was selected for its excellent separation of the analytes. The limits of detection for the target compounds were from 0.04 to 0.19 ng/g. Mean recoveries of the compounds from spiked soils exceeded 84% with a good reproducibility, excepting that the recovery of 2-bromophenol was relatively poor （lower than 55%） due to its instability. The developed method was applied to the determination of the BPs in the soils collected from e-waste sites. The contents of BPs in the soils were at ng/g levels with TBBPA and TBP the most frequently detected. To our knowledge, this is the first report for the simultaneous determination of TBBPA, TBP, DBPs and MBPs in soils.     

锰矿砂对取代酚的光氧化作用研究

研究了不同条件下锰矿砂对４种取代酚的光氧化作用。结果表明，ｐＨ＝３．１０±０．０４时，苯酚、对氯苯酚、对氨基酚及对苯二酚均能被锰矿砂光催化氧化。低ｐＨ值，适当的苯酚初始浓度及适当的锰矿砂浓度有利于锰矿砂对取代酚的氧化；离子强度和溶解氧浓度不影响反应速度。对其可能的机理及取代基效应进行了讨论。     

Degradation of chlorinated phenols by nanoscale zero-valent iron

Chlorophenols (CPs), as important contaminants in groundwater, are toxic and difficult to biodegrade. Recently nanoscale zero-valent iron received a great deal of attention because of its excellent performance in treating recalcitrant compounds. In this study, nanoscale zero-valent iron particles were prepared using chemical reduction, and the reductive transformations of three kinds of chlorinated phenols (2-CP, 3-CP, and 4-CP) by nanoscale zero-valent iron under different conditions were investigated. The transformation process of the CPs was shown to be dechlorination first, then cleavage of the benzene ring. The removal efficiency of the CPs varied as follows: 2-CP > 3-CP > 4-CP. The reactivity of CPs was associated with their energy of lowest unoccupied molecular orbit (E _LUMO). With the increase in initial concentrations of CPs, removal efficiency decreased a little. But the quantities of CPs reduced increased evidently. Temperature had influence on not only the removal efficiency, but also the transformation pathway. At higher temperatures, dechlorination occurred prior to benzene ring cleavage. At lower temperatures, however, the oxidation product was formed more easily. __________ Translated from China Environmental Science, 2006, 26(6): 698–702 [译自: 中国环境科学]     

QSBR study of substituted phenols and benzoic acids

The biodegradability of 30 substituted phenols and benzoic acids was determined by BOD technique.The molecular weight (MW), heat of formation(Hf)and the energy of the highest occupied molecular orbital(EHOMO)of the studied compounds were calculated by the quantum chemical method MOPAC6.0-AM1.The quantitative structure-biodegradability relationshiops(QSBRs)were developed by the linear regression method and neural network approach,respectively.It has been shown that the neural network method is able to provide a superior fit to the training set data and test set data and produce a lower prediction error than the linear regression method.     

苯酚类化合物光解量子产率与结构性质的定量关系

采用量子化学PM3算法计算得到的苯酚类化合物的量子化学参数,应用偏最小二乘(PLS)算法,建立了能预测苯酚类化合物光解量子产率(Y)的定量结构-性质关系(QSPR)模型.影响苯酚类化合物光解量子产率的主要因素是分子最高占据轨道能(Ehomo)和分子生成热(HOF),logY值随着Ehomo的增大而增大,随着HOF的增大而减小.分子的电负性和(Ehomo-Ehomo)2对logY值也有一定的影响,电负性和(Ehomo-Ehomo)²较小的分子,其logY值也较大.     

探讨水中挥发酚的环境监测方法

水环境污染问题以已经成为了当前全球关注的重点话题,酚类物质是水体污染中常见污染物,对水体中酚类物质的监测,依靠的衡量指标就是水中挥发酚的含量,其能够在一定程度上代表水中酚类物质的含量,因此,对水中挥发酚的监测是水环境监测中一项重要的内容.本文就主要针对水中挥发酚的环境监测方法进行简单的探讨.     

水体中锰离子对酚类有机物的光化学降解的影响

通过对不同锰离子浓度下三种酚在三种不同介质中的光降解情况的研究,来确定水体中的锰离子对酚类有机物的光化学降解的影响。实验结果表明,在不同条件下,不同浓度的锰离子对实验中所选的三种酚的影响有所不同。对邻硝基苯酚的光降解几乎不产生影响,对对甲基苯酚的光降解起到抑制作用,而对2,4-二硝基苯酚的光降解则起到促进作用。     

土壤中酚类化合物降解菌筛选及应用

以苏州某化工场地污染土壤为菌源,以目标污染物为唯一碳源,通过连续培养、分离纯化筛选出高效酚类化合物降解菌。利用16S rDNA基因测序、构建基因树等分子生物学技术手段确定菌株种属,并研究了菌株对酚类化合物耐受性和降解效果。结果表明:以4-甲基苯酚(4-MP)和4-氯-3-甲基苯酚(4-C-3-MP)为唯一碳源筛选出了2株菌,分别为嗜麦芽窄食单胞菌(NM)和香茅醇假单胞菌(NCM)。菌株NM对4-MP耐受性良好,4-MP浓度为400 mg/L时仍能生长繁殖;菌株NCM对4-C-3-MP耐受性较差,4-C-3-MP浓度≥200 mg/L时,菌株NCM受到完全抑制,停止生长。菌株NM不能降解土壤中苯酚,对4-MP和4-C-3-MP去除效果良好,第20天时去除率分别达到43%和22%;菌株NCM对土壤中苯酚、4-MP和4-C-3-MP均有降解效果,第20天时苯酚、4-MP和4-C-3-MP去除率分别为20%、26%和28%,较第15天时去除率分别提高了18、3和6个百分点。     

降低地表水中挥发酚空白值的试验研究

本文采用硅镁型吸附剂提纯4-氨基安替比林(4-AAP),通过不同提纯次数测定空白值、绘制校准曲线以及方法验证实验,得出采用硅镁型吸附剂提纯4-AAP 2次后测得的空白吸光值达到实验要求,其灵敏度和准确度高,方法检出限低于标准规定的要求。     

纳米Fe0颗粒对三种单氯酚的降解

采用化学还原法制备了纳米Fe0颗粒,研究了不同条件下纳米Fe0对3种单氯酚(2-CP, 3-CP, 4-CP)的去除作用.结果表明,纳米Fe0对单氯酚具有良好的去除效果,主要降解途径为先脱氯后开环,实现氯酚分子与Fe原子间的电子转移,达到还原脱氯的效果.3种单氯酚的脱氯难易程度为2-CP＞3-CP＞4-CP,脱氯反应活性与其分子最低空轨道能量(ELUMO)有关.随着氯酚初始浓度的增大,其相对去除率略有降低, 但绝对降解量有较大提高.温度不仅影响脱氯速率,而且影响氯酚去除的途径,温度较高时,氯酚先脱氯后开环;温度低时,较易产生氧化产物.     

我国24个典型饮用水源地中14种酚类化合物浓度分布特征

研究了14种酚类化合物在我国五大流域(黄河、海河、辽河、长江、淮河)24个典型饮用水源地水源水中的浓度水平.结果显示:14种酚类化合物在我国饮用水源地中的浓度在nd～213 ng·L-1范围内,浓度均值在2.44～31.2 ng·L-1范围内,浓度中位数在nd～40.0 ng·L-1范围内.14种酚类化合物中,硝基苯酚类化合物浓度最高,浓度中位数为37.9 ng·L-1,浓度平均值为27.4 ng·L-1.其次为苯酚、五氯酚、二氯苯酚(2,4-二氯苯酚和2,6-二氯苯酚)和三氯苯酚(2,4,6-三氯苯酚和2,4,5-三氯苯酚);四氯苯酚(2,3,5,6-四氯苯酚、2,3,4,6-四氯苯酚、2,3,4,5-四氯苯酚)和烷基苯酚(邻甲基苯酚、间甲基苯酚和对甲基苯酚)浓度较低.通过商值法对14种酚类化合物进行生态风险评价后发现,14种酚类化合物的风险商均远小于1,表明其对我国饮用水源地的生态风险较低.对8种已报道健康参考剂量或致癌斜率因子的酚类化合物进行健康风险评价,结果显示,7种酚类化合物的最大非致癌风险在10-6到10-4范围内,2,4,6-三氯酚和五氯酚的致癌风险在10-6量级以下,表明其健康危害较弱.     

饮用水源突发挥发酚污染应急处理中试研究

通过为期2个月规模为4m3·h-1的中试试验,考察了常规给水工艺(混凝、沉淀和过滤)对突发挥发酚污染原水的处理情况.重点考察了活性炭吸附、臭氧预氧化和高锰酸钾预氧化等3种应急工艺的除酚效能.结果表明,常规混凝沉淀对挥发酚的去除率低于10%,砂滤在12h内可起到拦截挥发酚的作用,3种应急工艺均可提高挥发酚的去除效果,起到应急的作用.其中活性炭吸附对挥发酚的去除率可达44%;在0.5mg·L-1的投量下高锰酸钾预氧化可达到50%的除酚效率;臭氧预氧化可使沉淀出水挥发酚达标(0.002mg·L-1),挥发酚去除率约99%.     

Mechanisms of granular activated carbon anaerobic fluidized-bed process for treating phenols wastewater

ＩｎｔｒｏｄｕｃｔｉｏｎＢｅｆｏｒｅｔｈｅ 1 980ｓｃｏｎｖｅｎｔｉｏｎａｌｔｒｅａｔｍｅｎｔｐｒｏｃｅｓｓｅｓｏｆｐｈｅｎｏｌｓｗａｓｔｅｗａｔｅｒａｒｅｓｏｌｖｅｎｔｅｘｔｒａｃｔｉｏｎ ,ｐｈｙｓｉｃａｌａｄｓｏｒｐｔｉｏｎ ,ｃｈｅｍｉｃａｌｏｘｉｄａｔｉｏｎａｎｄａｅｒｏｂｉｃｂｉｏｌｏｇｉｃａｌｐｒｏｃｅｓｓ.Ａｍｏｎｇｔｈｅｂｉｏｌｏｇｉｃａｌｕｎｉｔｐｒｏｃｅｓｓｅｓａｃｔｉｖａｔｅｄｓｌｕｄｇｅｐｒｏｃｅｓｓｉｓｍａｉｎｏｎｅ.Ａｆｔｅｒｔｈｅ 1 980ｓａｎａｅｒｏｂｉｃｂｉｏｌｏｇｉｃ…     

矿化垃圾固定床吸附过程和穿透曲线预测

以轴向扩散模型和恒定图式假设为基础,推导出了适用于预测固定床穿透曲线的积分模型.通过动态循环法对苯酚和对氯苯酚在矿化垃圾中的吸附行为进行了研究,采用Freundlich等温吸附方程描述穿透曲线,并得到了便于应用的代数模型.通过不同条件下固定床实验来确认模型,结果证实模型可以很好地描述穿透曲线.同时讨论了操作参数和矿化垃圾特性对穿透曲线的影响,结果表明,较低的进料浓度和进科流量以及内扩散和轴向扩散的影响都会造成实际穿透曲线与预测穿透曲线之间的偏差.     

Investigation of chlorinated phenols sorption mechanisms on different layers of the Danube alluvial sediment

The characteristics of the Danube river alluvial sediment are of great importance in assessing the risk for transport of pollutants to drinking water sources. Characterization of the sediment column layers has shown that the alluvial sediment, sampled near the city of Novi Sad, is a mesoporous sandy material with certain differences in the properties of individual layers. In order to investigate the sorption mechanisms of four chlorinated phenols (CPs) on the alluvial deposit, static sorption experiments were performed at pH 4, 7 and 10. The results of sorption experiments, confirmed by principal components analysis sugest different mechanisms govern the sorption process at different pH conditions. This can be attributed to the molecular characteristics of CPs, geosorbent properties and to variations in the surface charge of the sorbent at different pH conditions.     

用QSAR模型预测苯酚类化合物对发光菌的联合毒性

测定了苯酚与11种取代苯酚对发光菌的单一毒性和毒性单位比为1:4,1:1,4:1二元混合物的联合毒性.采用相加指数法对联合毒性进行了评价,结果表明,苯酚和取代苯酚的二元混合物对发光菌的联合作用以相加作用为主.在此基础上,根据12种苯酚类化合物的单一毒性建立了QSAR方程: -lgEC₅₀=6.158-0.279pKa,对混合物中取代苯酚的毒性进行了预测,预测值与实测值吻合较好.