Metal levels in computer monitor components discarded in the vicinities of electronic workshops

Levels of Pb, Ni, Cr, Cu, Zn, and Cd in the glass screens (GS) and printed wiring boards (PWBs) of obsolete computer monitors (OCMs) were determined by flame atomic absorption spectrophotometry (FAAS) following standard digestion. Metal concentrations (mg kg^?1) in GS were in the following ranges (medians in brackets): Pb ND – 3100 (46), Cd 0.5–2.6 (0.8), Cr ND – 18.7 (3.1), and Zn 8.1–600 (37) and in PWBs (mg kg^?1): Pb 34,600 ± 17,000, Cd 11 ± 9, Cr 59 ± 45, Zn 15,900 ± 7800, Cu79,000 ± 22,600, and Ni 3200 ± 2500. In GS, the levels of the six metals were lower than their total threshold limit concentrations (TTLC), except for Pb with a TTLC of 1000 mg kg^?1 in 10% of the samples. In the PWBs, the TTLC of Pb and Cu (2500 mg kg^?1) was exceeded many fold. For Zn (5000 mg kg^?1) and Ni (2000 mg kg^?1); they were exceeded by 90% and 65%, respectively. For OCMs manufactured in 2001 and later, Pb and Zn levels in GS and Cr, Zn, and Ni in PWBs were significantly reduced.     

Statistical interpolation model for the description of ground pollution due to the TCDD produced in the 1976 chemical accident at seveso in the heavily contaminated zone “A”;

The influence of NTA on chromium genetic activity was studied in the D7 strain of Saccharomyces cerevisiae. At low dose (subgenotoxic) of sodium chromate (CrVI) (5mM), NTA increased the point mutation while at higher dose (25 mM) of chromate in the presence of NTA a decrease of point reverse mutation was observed. Probably NTA affected either the uptake of Cr(VI) favouring the intracellular reduction to Cr(III), or the recombinational repair of DNA breaks induced by chromate oxiding activity.

An increase of point (reverse) mutation was obtained in the experiments with NTA and chromium chloride, suggesting the hypothesis that NTA might interact with Cr(III) forming NTA‐Cr(III) complexes able to permeate cellular membranes and bind to DNA. In addition NTA genetic inactivity was confirmed.     

Background metal levels determination in bivalves – quality assessment of the European Water Framework Directive

Background levels of metals (Ag, Cd, Cu, Cr, Hg, Ni, Pb and Zn) in biomonitors (Mytilus galloprovincialis mussels and Crassostrea gigas oysters), in estuarine waters within the Basque Country (south-east Bay of Biscay) are estimated using non-parametric statistical tools and data are presented graphically, with the aim of being used in assessing the ecological status, within the European Water Framework Directive (WFD). The basis for this study was the statistical analysis of data compiled from monitoring programmes undertaken along the Basque coast, between 1990 and 2008. For this analysis, a heuristic method was adapted and used. Results showed different metal background ranges throughout the year for both mussels and oysters. Values corresponding to the upper limit of the background range (i.e. value of the upper whisker of the box-plot) are proposed as the ‘high/good’ status boundary, according to the WFD.     

Determination of minimum inhibitory concentration and half maximal inhibitory concentration of antibiotics and their degradation products to assess the eco-toxicological potential

Abstract

Numerous studies have been reported on today’s ubiquitous presence of antibiotics in surface waters causing the emergence of multidrug-resistant bacteria. Advanced water treatment procedures aim at the complete prevention and elimination of antibiotics from entering natural water bodies. In this study, photoinduced degradation processes using UVC-irradiation were applied toward selected fluoroquinolone, tetracycline, macrolide, and sulfonamide antibiotics. Photodegradation products were elucidated using high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS). Rate constants and quantum efficiencies were determined for the active substances and their photo-transformation products. As a measure of ecotoxicity, minimum inhibitory and half-maximal inhibitory concentrations were determined against the Gram-negative bacterium Pseudomonas fluorescens and the Gram-positive Bacillus subtilis in a standard assay format. These values were further recorded as a function of UV exposure time. The irradiation time-dependent increase of minimum inhibitory concentration (MIC) values agreed well with the kinetic models. After 10?min of irradiation, the compound solutions ceased to inhibit bacterial cell growth, indicating removal of the pharmaceutical activity. These findings were found in agreement with quantitative structure–activity relationship analysis. The combination of microbiological activity testing, molecular structure analysis, chemical kinetic investigation, and quantitative structure–activity relationship models proved to be able to predict irradiation times and evaluate potential ecotoxicological hazard of the irradiated drugs.     

广东省土壤硒空间分布及潜在环境风险分析

利用广东省260个土壤剖面数据,开展区域尺度下的土壤总硒（Se）质量分数的空间分布研究。结果表明,研究区内土壤硒含量变异性较强,符合对数正态分布特征,其几何质量分数为0.23 mg·kg-1,高于全国平均水平。表层土壤硒基线质量分数范围为0.13到0.41 mg·kg-1,处于硒缺乏与中等含量水平之间。土壤硒的空间分布格局与区域成土母质密切相关,表现为：高硒质量分数的土壤主要位于石灰岩和砂页岩区域,而低硒质量分数的土壤主要位于紫色页岩和花岗岩地区。土壤硒缺乏可能是影响研究区人体健康的重要问题。此外,研究区由土壤退化和土壤侵蚀引发的流入周边水体的土壤硒每年可高达23 t。     

云南宣威燃煤室内可吸入颗粒物质量浓度变化特征

应用中流量采样器TSP-PM10-PM2.5对我国肺癌高发区宣威地区6个乡村19家农户进行采样,运用滤膜称重法来分析不同燃料类型室内及相应室外的大气颗粒物质量浓度特征.结果显示,各村庄室内、室外PM10质量浓度比值(I/O)变化范围为1.74~2.87,说明室内PM10污染主要由室内污染源引起;做饭时段室内PM10污染比其他时段严重,尽管烟囱可以将大量的污染物排出室外,但室内颗粒物的质量浓度依然较高.室内PM10质量浓度依燃料类型从高到低依次为块煤用户>型煤用户>燃柴用户>用电用户,室内PM2.5质量浓度依燃料类型从高到低表现为块煤用户>燃柴用户>用电用户;块煤、型煤用户的室内PM10的质量浓度平均值(442.49μg/m3、399.14μg/m3)超过国家室内空气质量标准日均值150μg/m3,污染严重;燃柴和用电用户室内PM10的质量浓度平均值(145.50μg/m3、119.91μg/m3)低于国家室内空气质量标准日均值150μg/m3,污染较轻.块煤用户PM2.5质量浓度日均值(132.58μg/m3)超过2012年2月29日环境保护部发布的环境空气质量标准二级标准75μg/m3,而燃柴和用电户PM2.5的质量浓度(55.24μg/m3、65.02μg/m3)均低于环境空气质量标准二级标准75μg/m3,说明块煤用户室内细颗粒污染较重,用电和燃柴用户室内细颗粒物污染相对较轻.     

SHMP分散配制用于环境风险模拟研究的纳米ZnO颗粒溶胶

选择SHMP(六偏磷酸钠)作分散剂,研究超声时间与静置时间对商购纳米ZnO的优化分散效果,以配制出用于环境风险模拟研究中的分散粒径小、效果稳定且浓度较高的纳米ZnO颗粒溶胶. 结果表明,相同条件下加分散剂的体系分散效果好于不加分散剂体系. 最佳优化分散方法:在100 mL超纯水中先加入45 mg SHMP作分散剂,再加入0.5 g的商购纳米ZnO,超声60 min后静置6 d,最终得到的颗粒溶胶平均粒径为(176.5±15)nm (纳米粒度-Zeta电位仪),TEM表征粒径为60～90 nm,Zeta电位为(-64.7±5.64)mV,实测分散浓度为(95.87±4.37)mg/L,其稳定性基本可以维持5 d.      

2006─2010年环保重点城市主要污染物浓度变化特征

利用2006─2010年全国环保重点城市的空气质量日报数据,分析了大气ρ(SO2)、ρ(NO2)和ρ(PM10)的变化特征. 结果表明:从年际变化看,ρ(SO2)和ρ(PM10)呈下降趋势,ρ(NO2)变化不显著.从季节变化看,ρ(SO2)、ρ(NO2)和ρ(PM10)均呈冬季高、夏季低的特征.从浓度谱分布看,全国大气中ρ(SO2)、ρ(NO2)和ρ(PM10)分别集中在0～0.150、0～0.100和0～0.250 mg/m3范围内,ρ(SO2)和ρ(PM10)谱峰区间逐渐向低浓度范围偏移,高浓度事件逐渐减少,表明SO2和PM10污染得到较明显的控制,而ρ(NO2)谱峰变化不大.从浓度变化看,山西ρ(SO2)、ρ(NO2)和ρ(PM10)下降最明显,年变化率分别为-11.2、-3.6和-14.2 μg/m3;青海ρ(SO2)、山东ρ(NO2)和ρ(PM10)的上升趋势最明显,年变化率分别为4.4、2.7和4.5 μg/m3.      

2017—2019年中国337个城市及重点区域臭氧污染状况分析

分析了2017—2019年中国337城市O_3污染特征,结果表明:2017—2019年全国O_3第20～70百分位浓度逐年增幅相对稳定,第80～95百分位浓度逐年上升速率最快,平均每年升高5.5μg/m~3。全国O_3超标以轻度污染为主,主要集中在5—9月,占全年O_3超标天数的85.3%;"2+26"城市、汾渭平原交界、长三角、苏皖鲁豫交界O_3超标天数占全国63.9%,"2+26"城市O_3污染最为严重,平均每城市超标71 d。2017—2019年O_3单因子超标分别损失全国空气质量优良天数比例为4.5个百分点、4.9个百分点和7.4个百分点,2019年9月O_3单因子超标天数比例为18.8个百分点,单月使全年优良天数减少1.2个百分点。天津、河北、山东、北京、河南、山西、江苏的O_3污染相对较重,天津市发生O_3污染的关键温度为26～34℃,风速为2.0～2.5 m/s,相对湿度为40%～80%,降水明显减少和温度偏高是导致2019年O_3浓度升高的重要气象因素。     

基于含VOCs原辅材料和产污环节实测的印刷行业VOCs排放特征分析

为掌握印刷行业VOCs(挥发性有机化合物)污染特征,进一步科学合理地推进印刷行业VOCs减排,利用“气袋法采样+实验室FID检测”以及便携式非甲烷总烃测试仪对京津冀地区25家典型印刷企业VOCs排放情况进行检测.基于21类含VOCs原辅材料的VOCs含量及时应使用环节废气VOCs浓度的监测结果,得出不同类型原辅材料VOCs含量水平,以及产污环节的VOCs废气浓度水平.结果表明:①油墨VOCs含量范围为0.05%~76.9%,胶印油墨、凹印油墨、柔印油墨和网印油墨符合GB 38507—2020《油墨中可挥发性有机化合物(VOCs)含量的限值》中含量限值的样品数分别占抽检样品总数的98.3%、85.7%、66.7%和100.0%,VOCs含量水平差别较大.②润版液、清洗剂、胶粘剂、光油等原辅材料VOCs含量水平分别为0.4%~45.0%、3.0%~98.7%、0.1%~60.0%、0.1%~50.0%,其中溶剂型样品VOCs含量明显高于水性、UV样品.③从生产过程VOCs产污水平来看,同类工艺的烘干环节VOCs产污浓度普遍高于印刷、清洗、润版等环节;采用溶剂型油墨、胶粘剂、光油的生产工艺VOCs产污浓度(100.0~5 000.0 mg/m3)明显高于其他工艺类型(10.0~500.0 mg/m3);VOCs产污浓度最高的为采用溶剂型油墨的凹版印刷工艺(300.0~5 000.0 mg/m3),其次为采用溶剂型胶粘剂的干式复合工艺(300.0~1 000.0 mg/m3)和采用溶剂型光油的上光工艺(200.0~1 000.0 mg/m3).研究显示,平版胶印、柔印、丝印、复合、上光等工艺均可通过源头替代达到较低的VOCs产污浓度水平(≤50.0 mg/m3),但凹印工艺在采用水性墨替代后VOCs产污浓度水平为50.0~500.0 mg/m3,仍需采取高效的末端处理措施.