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281.
Sorption of nonpolar (phenanthrene and butylate) and polar (atrazine and diuron) organic chemicals to oil-contaminated soil was examined to investigate oil effects on sorption of organic chemicals and to derive oil–water distribution coefficients (Koil). The resulting oil-contaminated soil–water distribution coefficients (Kd) for phenanthrene demonstrated sorption-enhancing effects at both lower and higher oil concentrations (Coil) but sorption-reducing (competitive) effects at intermediate Coil (approximately 1 g kg−1). Rationalization of the different dominant effects was attempted in terms of the relative aliphatic carbon content which determines the accessibility of the aromatic cores to phenanthrene. Little or no competitive effect occurred for butylate because its sorption was dominated by partitioning. For atrazine and diuron, the changes in Kd at Coil above approximately 1 g kg−1 were negligible, indicating that the presently investigated oil has little or no effect on the two tested compounds even though the polarity of the oil is much less than soil organic matter (SOM). Therefore, specific interactions with the active groups (aromatic and polar domains) are dominantly responsible for the sorption of polar sorbates, and thus their sorption is controlled by available sorption sites. This study showed that the oil has the potential to be a dominant sorptive phase for nonpolar pollutants when compared to SOM, but hardly so for polar compounds. The results may aid in a better understanding of the role of the aliphatic and aromatic domains in sorption of nonpolar and polar organic pollutants. 相似文献
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稻草制浆黑液生物+混凝处理试验 总被引:4,自引:0,他引:4
通过对稻草制浆黑液厌氧、好氧、混凝处理组合工艺的试验研究,探索该工艺的可行性,考察了不同温度、不同有机负荷下,该类废水的生物处理效果以及后续混凝效果。结果表明:中温35℃是厌氧阶段最佳处理温度,好氧阶段不同负荷条件下,CODCr去除率基本相同;经厌氧-好氧处理,黑液CODCr和木质素去除率分别为80%和30%,色度去除不明显;混凝阶段CODCr和木质素去除率分别为70%和90%,色度去除率达90%以上,出水达到国家标准。 相似文献
284.
蒽醌染料中间体溴氨酸降解酶的特性 总被引:5,自引:0,他引:5
从污染地分离筛选出的菌株BX26对蒽醌染料中间体溴氨酸有显著的降解脱色作用,降解过程受降解酶的控制,试验结果表明,降解酶为溴氨酸诱导的胞外酶,该酶在温度高于50℃处理后失活,盐度对该酶失活有影响,盐度高于1%会显著降低该酶活力,酶对溴氨酸的催化脱色要有氧参加,氮气气氛中酶活受抑制。 相似文献
285.
对强夯施工的现场进行了近距离的测量 ,得到了最大地动位移值随距离的变化特征 ,其衰减规律较好地符合负幂函数衰减规律 ,水平径向与垂直向的衰减指数分别为 1 495 3,0 4714。 相似文献
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研究了不同分析方法、去浊度手段和预处理方式对地表水总磷测定的影响。结果表明:钼酸铵分光光度法在跨界水体联合监测中较连续流动分析法、氯化亚锡还原光度法、孔雀绿-磷钼杂多酸分光光度法更为适用;在水样没有色度的情况下,采用浊度-色度补偿法和离心法都能有效消除浊度干扰,相对误差±10%;预处理方式的不同是导致各监测单位测定结果可比性差的最关键因素。 相似文献
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Ning Zhang Hong Li You Zhou Wei Hu Zhixiang Zhang 《Environmental monitoring and assessment》2014,186(3):1377-1384
Two independent field trials were performed in Guangdong and Hubei, China in 2011 to investigate the dissipation and residue levels of triforine in strawberry and soil. A fast and simple method using gas chromatography with electron capture detector was developed and validated to determine triforine levels in strawberry and soil. The average recovery of triforine in strawberry ranged from 87.46 to 104.32 % with a relative standard deviation (RSD) of 0.72 to 4.54 %; that in soil ranged from 83.82 to 103.01 % with an RSD of 3.89 to 4.36 %. The limit of quantification of the proposed method was 0.01 mg/kg for both strawberry and soil. The results suggest that the triforine dissipation curves followed the first-order kinetic. The half-lives of triforine in strawberry from Guangdong and Hubei were 3.58 and 4.42 days, respectively; those in soil were 3.53 and 4.10 days, respectively. The terminal residues of triforine in strawberry ranged from 0.032 to 0.264 mg/kg at preharvest intervals of 0.5, 1, and 3 days. These values are lower than the maximum residue limit of 1 mg/kg in strawberry set by the Codex Alimentarius Commission. 相似文献