Degradation of 4-aminophenol by hydrogen peroxide oxidation using enzyme from Serratia marcescens as catalyst

This paper reports on the degradation of 4-aminophenol using hydrogen peroxide as oxidizer and the enzyme from Serratia marcescens AB 90027 as catalyst. The effecting factors during degradation and the degrading mechanism were studied. Also, the location of the enzyme in the cell, which could catalyze the degradation of 4-aminophenol, was analyzed. The results showed that to degrade 50 mL of 4-aminophenol whose concentration was 500 mg/L, the optimal conditions were: volume of H₂O₂ = 3 mL, temperature = 40–60°C and pH = 9–10. In the degradation process, 4-aminophenol was first converted to benzoquinone and NH₃, then organic acids including maleic acid, fumaleic acid, and oxalic acid were formed, and then finally CO₂ and H₂O were generated as final products. The enzyme that could catalyze the degradation of 4-aminophenol was mainly extracellular enzyme. Translated from Environmental Chemistry, 2006, 25(2): 141–144 [译自: 环境化学]     

天平的不等臂性对测试的影响

天平是一种重要的试验室检测仪器,在个体防护用品的检验工作中同样不可或缺,比如防护服的透气量测试、旋转辊筒法对防护鞋外底磨耗量的检测等,都会用到天平。本文主要从产生天平不等臂的原因及不等臂的检测、不等臂的调整等方面,简要论述了天平的正确性对测量的影响。     

某钢铁厂土壤中多环芳烃污染评价与风险评估

在某钢铁厂搬迁后的主厂区设置了191个采样孔,对0~5 m土壤进行分层(5层)采样,分析土壤中多环芳烃化合物(PAHs)浓度,研究了苯并(a)蒽、苯并(b)荧蒽、苯并(a)芘、二苯并(a,h)蒽、茚并(1,2,3-cd)芘5种PAHs浓度的分层变化,采用内梅罗指数(P)对土壤污染程度进行评价,并通过RBCA Version 2.5模型对土壤致癌风险进行评估。结果表明:土壤第1层、第2层和第3层的5种PAHs浓度均值高于DB11/T 811—2011《场地土壤环境风险评价筛选值》中居住用地的筛选值;除第4层苯并(b)荧蒽、苯并(a)芘、二苯并(a,h)蒽和第5层二苯并(a,h)蒽外,其他污染物的平均浓度低于居住用地的筛选值;反映土壤中PAHs污染程度的内梅罗指数自第1层向下逐渐降低,苯并(a)蒽的P从69.75降至1.99,苯并(b)荧蒽的P从84.75降至3.12,苯并(a)芘的P从163.75降至5.68,茚并(1,2,3-cd)芘的P从111.92降至0.91,二苯并(a,h)蒽的P从393.20降至3.21,表明土壤中PAHs污染程度逐渐下降;5种污染物中,苯并(a)芘的单一污染物致癌风险贡献率最高,可达56.11%,暴露途径主要为经口摄入;该厂区须经治理达到要求后方可作为居住用地。     

论"世界遗产"资源开发利用过程中的环境地质因素及其保护问题

现今随着人口剧增、科学技术进步和资源的不断开发利用,人类工程行为和经济活动已经成为巨大的地质营力,使得某些世界级文化遗产、自然遗产保护区的地质环境发生变化,所面临的资源、环境和可持续发展等方面压力极大。作者以周口店北京人遗址的现状为例,仅就“世界遗产”资源开发利用过程中的环境地质因素及其环境保护等具有共性的问题进行探讨。     

絮凝耦合过硫酸钠氧化处理实际含糖废水

含高浓度污染物和色度实际含糖废水的高效处理一直是水处理领域的难点。针对单一絮凝沉淀和过硫酸钠氧化体系的技术局限性,首次构建了絮凝耦合过硫酸钠氧化体系,同步实现了对废水中COD和色度的高效去除,并深入探究了污染物的转化机理。结果表明：在最佳实验条件下,絮凝耦合过硫酸钠氧化体系对实际含糖废水中COD的去除率高达 95.74%,色度去除率高达96%。紫外全波长扫描和GC-MS分析结果表明,絮凝沉淀过程优先去除不含发光基团的大分子聚合物、长链烷烃等有机污染物,含发光基团的大分子有机污染物部分被去除;在后续过硫酸钠氧化过程中,实际废水中含发光基团的大分子有机污染物几乎被彻底去除,小分子有机污染物得到高效去除。本研究可为复杂的实际含糖废水的达标排放提供参考。     

石油污染土壤原位生物修复强化技术研究进展

因石油污染物的性质及土壤环境条件限制,石油污染土壤中的石油降解微生物普遍存在数量偏少和活性不足的问题,导致其自然净化能力较低,且速度缓慢。多种原位强化技术可提高石油降解微生物的降解能力,主要包括生物投加法、生物刺激法、生物通风法及微生物燃料电池等。生物投加法主要包括高效微生物、固定化微生物及植物-微生物的投加等方法;生物刺激法主要包括营养物质、生物表面活性剂、共代谢生长基质、电子受体的投加等方法。系统分析了各原位生物修复强化技术的作用机理及研究、应用现状,在此基础上提出了电动-微生物联合修复技术、微生物燃料电池-微生物联合修复技术及固定化材料纳米粒子的应用是原位生物修复强化技术未来的研究方向。     

探究生态环境监测的现状及发展趋势

近年来,我国的生态环境遭到破坏的情况越来越严重,社会各界都开始关注生态环境问题,环境污染问题仅是其中的一部分,最主要的生态文明建设、生态环境和保护问题,以及资源的可持续发展和利用。我国在生态环境的污染和破坏方面的监测水平仍然不够先进。如果仅凭借理化指标和生物指标来进行监测,其监测的有效性不高,在未来,生态监测是环境监测的发展趋势。     

Evaluating the impact of sulfamethoxazole on hydrogen production during dark anaerobic sludge fermentation

● SMX promotes hydrogen production from dark anaerobic sludge fermentation. ● SMX significantly enhances the hydrolysis and acidification processes. ● SMX suppresses the methanogenesis process in order to reduce hydrogen consumption. ● SMX enhances the relative abundance of hydrogen-VFAs producers. ● SMX brings possible environmental risks due to the enrichment of ARGs. The impact of antibiotics on the environmental protection and sludge treatment fields has been widely studied. The recovery of hydrogen from waste activated sludge (WAS) has become an issue of great interest. Nevertheless, few studies have focused on the impact of antibiotics present in WAS on hydrogen production during dark anaerobic fermentation. To explore the mechanisms, sulfamethoxazole (SMX) was chosen as a representative antibiotic to evaluate how SMX influenced hydrogen production during dark anaerobic fermentation of WAS. The results demonstrated SMX promoted hydrogen production. With increasing additions of SMX from 0 to 500 mg/kg TSS, the cumulative hydrogen production elevated from 8.07 ± 0.37 to 11.89 ± 0.19 mL/g VSS. A modified Gompertz model further verified that both the maximum potential of hydrogen production (P_m) and the maximum rate of hydrogen production (R_m) were promoted. SMX did not affected sludge solubilization, but promoted hydrolysis and acidification processes to produce more hydrogen. Moreover, the methanogenesis process was inhibited so that hydrogen consumption was reduced. Microbial community analysis further demonstrated that the introduction of SMX improved the abundance of hydrolysis bacteria and hydrogen-volatile fatty acids (VFAs) producers. SMX synergistically influenced hydrolysis, acidification and acetogenesis to facilitate the hydrogen production.     

畜粪污染处理与利用研究

国内外对于粪便固体物的处理主要采用焚烧法、干燥法和堆肥法等，在粪便污水处理方面主要采用厌氧消化法，它将治污、产气和综合利用相结合，使废物资源化，达到环境效益、经济效益和社会效益相统一。     

济南市不同来源大气颗粒物的特征分析

本文对济南市几个典型来源的大气颗粒物用Ｘ光光电子能谱和电子自共振波谱仪（ＥＳＲ）进行表征,并模型酸雨对这些颗粒物进行了淋洗,分析淋洗液中的金属含量,结果表明：电厂颗粒物中的硫主要以ＳＯ３,ＳＯ＾２－４,ＳＯ２,ＳＯ＾２－３和Ｓ等多种形式存在,钢厂颗粒物中的表面硫主要以ＳＯ＾２－４和Ｓ＾２－的形式存在,炼油厂颗粒表面硫以ＳＯ＾２－４和ＳＯ２的形式存在,但颗粒物内层的硫主要以ＳＯ＾２－４形式存在,而且