Urinary metabolomic profiling in rats exposed to dietary di(2-ethylhexyl) phthalate (DEHP) using ultra-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS)

Di(2-ethylhexyl) phthalate (DEHP) is an omnipresent environmental chemical with widespread nonoccupational human exposure through multiple ways. Although considerable efforts have been invested to investigate mechanisms of DEHP toxicity, the key metabolic biomarkers of DEHP toxicity remain to be identified. The aim of this study was to assess the urinary metabonomics of dietary DEHP in rats using the technique of ultra-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS). Fourteen female Wistar rats were divided into two groups and given increasing dietary doses of DEHP for 30 consecutive days. The urinary metabolite profile was studied using ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) enabled clusters to be clearly separated. Eleven principal urinary metabolites were identified as contributing to the clusters. The clusters in the positive electrospray ionization (ESI) mode were xanthurenic acid, kynurenic acid, nonate, N6-methyladenosine, and L-isoleucyl-L-proline. The clusters in the negative ESI mode were hippuric acid, tetrahydrocortisol, citric acid, phenylpropionylglycine, cPA(18:2(9Z, 12Z)/0:0), and LysoPC(14:1(9Z)). The urinary metabonomic changes indicated that exposure to dietary DEHP can affect energy-related metabolism, liver and renal function, fatty acid metabolism, and cause DNA damage in rats. The findings of this study on the urinary metabolites and metabolic pathways of DEHP may form the basis for future studies on the mechanisms of toxicity of this commonly found environmental chemical.     

Cancer risk from gaseous carbonyl compounds in indoor environment generated from household coal combustion in Xuanwei,China

Airborne carbonyls were characterized from emitted indoor coal combustion. Samples were collected in Xuanwei (Yunnan Province), a region in China with a high rate of lung cancer. Eleven of 19 types of samples (58%) demonstrated formaldehyde concentrations higher than the World Health Organization exposure limit (a 30-min average of 100 μg m^?3). Different positive significant correlations between glyoxal/methylglyoxal and formaldehyde/acetaldehyde concentrations were observed, suggesting possible different characteristics in emissions between two pairs of carbonyl compounds. A sample in the highest inhalation risk shows 29.2 times higher risk than the lowest sample, suggesting different coal sampling locations could contribute to the variation of inhalation risk. Inhabitants in Xuanwei also tend to spend more time cooking and more days per year indoors than the national average. The calculated cancer risk ranged from 2.2–63 × 10^?5, which shows 13 types of samples at high-risk level. Cumulative effect in combination with different carbonyls could have contributed to the additive actual inhalation cancer risk. There is a need to explicitly address the health effects of environmentally relevant doses, considering life-long exposure in indoor dwellings.     

RPB-O3/H2O2法处理硝基苯模拟废水

在超重力场中,研究了硝基苯模拟废水的臭氧/双氧水(O3/H2O2)法处理效果,考察了超重力因子β、H2O2浓度、初始p H、液体流量及处理时间等因素对硝基苯去除率的影响。结果表明,硝基苯去除率随超重力因子β和处理时间的增加而增大,而随H2O2浓度、初始p H和液体流量的增加呈先增大后降低的趋势。当硝基苯初始浓度300 mg/L,工艺条件β=80、p H=10.0、臭氧质量浓度约为40 mg/L、H2O2浓度为4.9 mmol/L、液体流量为120 L/h时,循环处理35 min硝基苯去除率可达96.7%。处理时间60 min后,废水中硝基苯含量1.4 mg/L,COD为39 mg/L,达国家一级排放标准(GB 8978-1996)。在此条件下,硝基苯的降解过程符合准一级反应动力学。     

城市大气环境治理成本核算及其总量、结构分析——以西安市为例

基于单位成本分析模型对2000—2009年西安市大气环境治理的价值量进行了系统核算,并从总量与结构两方面对核算结果进行了深入和全面的分析。结果表明,从西安市历年大气环境的实际治理成本(除2002、2006、2009年)来看,该市在大气环境治理方面的投资基本上逐年增加,但是增加幅度较小,而大气环境虚拟治理成本在一般年份(除2002、2006、2009年)总体上呈现先增加后减小的变化趋势。可见,西安市为改变环境污染状况,不断增加大气环境治理方面的投资,但在初期治理资金缺口仍在增加,而随着投资的持续增加,许多大气环境治理设施的建立与作用的发挥,大气环境污染状况逐渐减轻,治理资金缺口开始变小;在核算年份中,西安市工业大气环境污染治理的重点主要放在了烟尘方面,城镇生活SO2虚拟治理成本在生活废气总虚拟治理成本中所占比例最高。最后,针对发现问题,对该市今后大气环境治理工作的方向和措施给出了建议。     

Enhanced electrokinetic remediation of lead-contaminated soil by complexing agents and approaching anodes

Optimizing process parameters that affect the remediation time and power consumption can improve the treatment efficiency of the electrokinetic remediation as well as determine the cost of a remediation action. Lab-scale electrokinetic remediation of Pb-contaminated soils was investigated for the effect of complexant ethylenediaminetetraacetic acid (EDTA) and acetic acid and approaching anode on the removal efficiency of Pb. When EDTA was added to the catholyte, EDTA dissolved insoluble Pb in soils to form soluble Pb–EDTA complexes, increasing Pb mobility and accordingly removal efficiency. The removal efficiency was enhanced from 47.8 to 61.5 % when the EDTA concentration was increased from 0.1 to 0.2 M, showing that EDTA played an important role in remediation. And the migration rate of Pb was increased to 72.3 % when both EDTA and acetic acid were used in the catholyte. The “approaching anode electrokinetic remediation” process in the presence of both EDTA and acetic acid had a higher Pb-removal efficiency with an average efficiency of 83.8 %. The efficiency of electrokinetic remediation was closely related to Pb speciation. Exchangeable and carbonate-bounded Pb were likely the forms which could be removed. All results indicate that the approaching anode method in the presence of EDTA and acetic acid is an advisable choice for electrokinetic remediation of Pb-contaminated soil.     

TiO2-Cu2O/蒙脱土复合光催化剂的制备与性能

以钠基蒙脱土（MMT）为载体,先采用溶胶-凝胶法将纳米TiO₂引入到MMT层间,再采用化学沉积法将纳米Cu₂O负载在TiO₂/MMT上,制备出TiO₂-Cu₂O/MMT纳米复合光催化剂。采用XRD、SEM、紫外-可见漫反射技术对催化剂进行了表征。以甲基橙为目标污染物,考察了催化剂的光催化性能。表征结果显示：TiO₂与Cu₂O均匀分布在MMT的表面与片层孔隙中;TiO₂-Cu₂O/MMT结合了TiO₂和Cu₂O的特性,拓宽了催化剂的光吸收范围。实验结果表明,在光源为可见光、初始甲基橙质量浓度为20 mg/L、光催化剂加入量为2 g/L的条件下,TiO₂-Cu₂O/MMT纳米复合光催化剂对甲基橙的光催化降解效果明显优于单一负载的Cu₂O/MMT和TiO₂/MMT,大幅提高了催化剂的光催化效率,反应300 min时TiO₂-Cu₂O/MMT对甲基橙溶液的脱色率达到93%。     

Harvesting of Chlorella sp. using hollow fiber ultrafiltration

Introduction

The suitability of the application of ultrafiltration (UF) to harvest Chlorella sp. from the culture medium was examined. We investigated the effects of two improved UF system, forward air?Cwater flushing and backwash with permeate, on the concentration process.

Materials and methods

Backwash with permeate was selected as an optimization of the improved UF system, which was more effective for permeate flux recovery. Moreover, the hollow fiber UF system by adding periodical backwash with permeate was examined for Chlorella sp. harvesting.

Results and discussion

It was found that Chlorella sp. could be concentrated with high recovery in a lab-scale experiment. An overall algal biomass recovery of above 90% was achieved when the volume concentration factor was 10. For an original biomass of 1.3?±?0.05?g/L, 1?min backwash followed by 20?min forward concentrating was more effective, which resulted in a recovery of 94% and a high average flux of 30.3?L/m²/h. In addition, the algal recovery was highly correlated to the volume concentration factor and the initial biomass. A high concentration factor or a high initial biomass resulted in a low biomass recovery.     

Identification and quantitative detection of Legionella spp. in various aquatic environments by real-time PCR assay

In this study, a SYBR green quantitative real-time PCR was developed to quantify and detect the Legionella spp. in various environmental water samples. The water samples were taken from watershed, water treatment plant, and thermal spring area in Taiwan. Legionella was detected in 13.6 % (24/176), and the detection rate for river water, raw drinking water, and thermal spring water was 10, 21.4, and 16.6 %, respectively. Using real-time PCR, concentration of Legionella spp. in detected samples ranged between 9.75?×?10⁴ and 3.47?×?10⁵?cells/L in river water, 6.92?×?10⁴ and 4.29?×?10⁵?cells/L in raw drinking water, and 5.71?×?10⁴ and 2.12?×?10⁶?cells/L for thermal spring water samples. The identified species included Legionella pneumophila (20.8 %), Legionella jordanis (4.2 %), Legionella nautarum (4.2 %), Legionella sp. (4.2 %), and uncultured Legionella sp. (66.6 %). The presence of L. pneumophila in aquatic environments suggested a potential public health threat that must be further examined.     

长江水体溶解有机质与金属离子作用污染分析

将万州区牌楼段的长江水与金属离子混合,通过测定荧光光谱得出,在金属离子质量浓度较低(1.0×10-7 mg/mL)时,长江水中的腐殖质与金属离子发生螯合作用而使荧光强度降低,而在更高浓度时,则由于吸附/解吸作用而使荧光强度增强.三维荧光谱图的测定结果表明,金属离子浓度的大小决定了其与腐殖质的基团反应类型.实验结果表明,...     

试谈企业“安全性评价标准”与创评价的整体意识

安全性评价作为安全管理科学的一种方法,已在机电行业广泛开展,并取得一定成效,但通过实践,发现它仍有不足之处。就进一步完善“安全性评价标准”(下称“标准”)谈述见解,并力求以生产工具本质安全化的观点,编制了“产品设计安全性评价检查表”,试用此法,杜绝事故隐患。