固相微萃取-气相色谱-质谱法测定地毯中总挥发性有机化合物

建立了一种固相微萃取与气相色谱质谱联用测定地毯中总挥发性有机化合物的方法,该方法简便快速,重现性好,分析结果同小型环境平衡舱法测定的结果比较吻合。     

Biodegradation of azo dyes by genetically engineered azoreductase

A azoreductase gene with 537 bp was obtained by PCR amplification from Rhodobacter sphaeroides ASI. 1737. The enzyme,with a molecular weight of 18.7 kD, was efficiently expressed in Escherichia coli and its biodegradation characteristics for azo dyes were investigated. Furthermore, the reaction kinetics and mechanism of azo dyes catalyzed by the genetically engineered azoreductase were studied in detail. The presence of a hydrazo-intermediate was identified, which provided a convincing evidence for the assumption that azo dyes were degraded via an incomplete reduction stage.     

2020年成都市典型臭氧污染过程特征及敏感性

2020年4月24日至5月6日成都市臭氧(O3)和细颗粒物(PM2.5)复合污染过程期间,在成都市城区开展大气臭氧及其前体物(NO,、VOCs)和气象参数观测实验,基于观测数据采用OBM模型对市区臭氧敏感性和主控因子进行识别,并采用PMF模型对关键VOCs物种进行来源解析.结果表明,臭氧超标日各污染物浓度均有所上升,VOCs物种中芳香烃和含氧(氮)化合物上升幅度较大;成都市城区O3超标天对应的臭氧处于显著VOCs控制区,芳香烃和烯烃对O3生成最为敏感,且存在削减NOx的不利效应;结合VOCs来源解析,城区VOCs主要来源:移动源(22.4％)、餐饮及生物质燃烧源(21.8％)、工业源(15.1％)和溶剂使用源(9.3％),臭氧超标天溶剂使用源、餐饮及生物质类燃烧源贡献率明显上升.成都市城区春季应以VOCs减排为重点,并加大芳香烃和烯烃相关源控制力度.     

服务于安全

巴固工贸(上海)有限公司位于上海市外主桥保税区港澳路389号,是一家由法国巴固集团与上海外高桥保税区新发展有限公司,于1996年2月合资建立了加工贸易企业,公司的注册资金为150万美元。主要加工、经营个人劳动保护产品,是中国境内唯一的中外合资专营劳动保护用品的公司。 作为外方投资方的法国巴固集团创立于1975年,经历了近30年的开拓、发展,法国巴固集团已确立了全球PPE行业的龙头地位,成为全球最大的个人保护用品的生产供应商之一,产品达3000余种。集团在法国本土、欧洲及美洲都设有分支机构;销售和服务网络分布于全球每个角落,年销售额达10亿美元。     

工作量变化的生产性噪声测定及综合评价

通过对样板钳工噪声的测定及分析,探索工作量不确定的非稳态,间断噪声的表达方式,方法：调查样板钳工的主要品怕源及年工时,测定相应噪 的日等效连续A声级,根据能量平衡原理计算年等效连续A声组（简称LeqA,Y),进行主要噪声的频谱分析,结果：该工种的主要品声源是平铁,切割,锉磨,其LeqA,d分别是95．7,98．2,90．4;计算LeqA,y为92．1,切割,锉磨属高频噪声,结论：LeqA,y是工作量不确定的非稳态噪声简单,实用的综合评价指标。     

Mechanism of calcium mitigating membrane fouling in submerged membrane bioreactors

Two parallel membrane bioreactors (MBRs) were operated under different calcium dosages (168.5, 27 mg/L) to gain a better understanding of the mechanism of retarding membrane fouling by adding calcium. The results showed that the particle size of sludge flocs increased and the particle size distribution tended to be narrow at the optimum dosage (168.5 mg/L). Calcium was effective in decreasing loosely bound extracellular polymeric substances (LB-EPS) in microbial flocs and soluble microbial products (SMP) in the supernatant at the dosage of 168.5 mg/L by strengthening the neutralization and bridging of EPS with flocs. Furthermore, the amount of COD_S and COD_C decreased in both the mixed liquor and the fouling cake layer on the membrane surface. In order to compare the filtration characteristics of cake layers from the MBRs with the two calcium dosages, the specific cake resistance and the compressibility coefficient were measured. The specific cake resistance from the MBR with optimum dosage (168.5 mg/L) was distinctly lower than that with low dosage (27 mg/L). The compressibility coefficient of the cake layers under two dosages were respectively attained as 0.65, 0.91. Scanning electron microscopy (SEM) and three-dimensional confocal scanning laser microscope analysis (CLSM) images were utilized to observe the gel layer directly.     

汽车制造行业企业自行监测关键问题剖析及对策研究

为摸清汽车制造行业企业自行监测开展情况,利用实地勘察和资料查阅的方式对济南市28家样本企业自行监测活动开展情况进行研究.结果表明,样本企业中71％无组织监测频次不足,82％未开展周围环境质量监测,42.9％排放标准执行错误,11％监测指标表征错误,100％自动监测无效数据未修约直接公示,42.9％自动监测运维记录不完善...     

浅谈VOCs燃烧法处理技术及发展

近年来随着大气污染治理的力度不断加强,PM2.5、PM10、SO₂、NO₂等多项污染物治理效果显著,但我国VOCs排放总量却呈上升趋势。文章首先对挥发性有机物(VOCs)进行的来源和危害进行简要介绍;其次对VOCs易混淆的几点概念进行阐述;最后对大气中VOCs燃烧法处理技术进行深入分析,期望为基层有关工作者及涉VOCs燃烧法处理企业提供部分参考价值。