大气环境影响预测模式应用的几个问题

将当前大气环境影响预测模式应用中，对颗粒污染物地面浓度模式修正，气态污染物地面最大浓度模式选用和求长方法，静风条件下地面浓度模式及其参数选择等方面容易出现疏忽或失误的问题提出了来讨论，并提出了正确的应用方法。     

环保经济发展趋势判断与方式改进研究

近几年,环保经济成为中国经济社会可持续发展的必然趋势和内在要求。但由于中国环保经济起步晚,在发展过程中逐渐显露出许多问题,阻碍了环保经济发展步伐,因此针对这些问题,对其进行了改进,以期实现环境与经济和谐发展。为充分发挥环保经济优势,对其发展趋势进行了判断,并分析发展过程中出现的问题,针对这些问题,对其进行改进。然后利用熵值法对某市在实施方法改进后的环保经济发展情况进行实证研究,结果表明:在实施方法改进后,某市的环保经济发展水平得到了极大的提高,方法改进具有一定的成效。     

府河武汉段水环境问题及污染防治对策研究

对府河武汉段流域水质及主要水污染源污染负荷进行分析和核算,结果表明:2015年府河武汉段城镇生活是最主要污染源,其COD和NH_3-N入河量分别为16 552吨和4 779.87吨,占各类污染源总入河总量的58.46%和78.31%;COD、NH_3-N和TP排放量已超过承载力,为了满足水质目标要求,需分别削减排放量988.59吨、2 930.82吨和201.05吨。针对府河武汉段的水体污染特征和存在问题,提出了治理城镇生活污染、防治农业农村污染、开展流域综合整治、推进流域联防联控等相应防治对策。     

Transient species in the ozonolysis of tetramethylethene

The reaction of alkenes with ozone has great effect on atmospheric oxidation, its transient species can produce OH radicals and contribute to the formation of secondary organic aerosols (SOA). In the present study, the reaction of tetramethylethene (TME) with ozone was investigated using self-assembled low temperature matrix isolation system. The TME and ozone were co-deposited on a salt plate at 15 K, and then slowly warmed up the plate. The first transient species primary ozonide (POZ) was detected, indicating that the reaction followed Criegee mechanism. Then POZ began to decompose at 180 K. However, secondary ozonide (SOZ) was not observed according to Criegee mechanism. Probably, Criegee Intermediate (CI) did not react with inert carbonyl of acetone, but with remaining TME formed tetra-methyl epoxide (EPO).     

Brilliant red X-3B uptake by a novel polycyclodextrin-modified magnetic cationic hydrogel: Performance, kinetics and mechanism

A novel polycyclodextrin-modified magnetic cationic hydrogel (PCD-MCH) was developed and its performance, kinetics and mechanism for the removal of reactive brilliant red X-3B (X-3B) were studied. The results showed that the zeta-potential of PCD-MCH was 32.8 to 16.7 mV at pH 3.0–10.5. The maximum X-3B adsorption capacity of PCD-MCH was 2792.3 mg/g. The adsorption kinetics could be well-described by the Weber–Morris model and the homogeneous surface diffusion model (HSDM). Diffusion stages corresponding to surface or film diffusion, intra-particle or wide mesopore diffusion, and narrow mesopore/micropore diffusion occurred at 0–120, 120–480 and 480–1200 min, respectively. The latter two diffusion stages were rate-controlling for X-3B adsorption kinetics. At the initial X-3B concentration of 600 mg/L, the diffusion coefficient (D_s) and external mass transfer coefficient in the liquid phase (k_F) were 3 × 10^?11 cm²/min and 4.68 × 10^?6 cm/min, respectively. X-3B approaching the center of PCD-MCH particles could be observed at 360 min. At the end of the third diffusion stage, the C_p at q/q_e = 0 was 45.20 mg/L, which was close to the homogeneous C_p value of 46 mg/L along the radius of PCD-MCH particles. At pH 3.0–10.0, PCD-MCH showed stable X-3B adsorption capacities. After five regeneration-reuse cycles, the residual adsorption capacity of regenerated PCD-MCH was higher than 892.7 mg/g. The corresponding adsorption mechanism was identified as involving electrostatic interactions, cyclodextrin cavities and hydrogen bonds, of which cyclodextrin cavities showed prominent capture performance towards dye molecules through the formation of inclusion complexes.     

Fast screening compositions of PM2.5 by ATR-FTIR: Comparison with results from IC andOC/EC analyzers

Chemical speciation of fine particles or PM_(2.5) collected on filters is still a costly and timeconsuming task. In this study, filter-based PM_(2.5) samples were collected during November–December 2013 at four sites in Guangzhou, and the major components were fast screened(~7 min per filter sample) by Attenuated Total Reflectance(ATR)-Fourier Transform Infrared Spectroscopic(FTIR) in comparison with that measured by Organic carbon/Element carbon(OC/EC) analyzer and Ion Chromatography(IC). The concentrations of nitrate, ammonium, sulfate,primary organic carbon(POC) and secondary organic carbon(SOC) measured by OC/EC and IC analyzers were better correlated with their infrared absorption peak heights at 1320 cm~(-1) for nitrate, 1435, 3045 and 3215 cm~(-1) for ammonium, 615 cm~(-1) for sulfate, 690, 760 and 890 cm~(-1) for POC and 1640 and 1660 cm~(-1) for SOC respectively, during polluted days(PM_(2.5) 75 μg/m~3) than during clean days(PM_(2.5)≤ 75 μg/m~3). With the evolution of a haze episode during our field campaign, the concentrations of the major PM_(2.5) components displayed consistent variations with their infrared absorption peak heights, suggesting ATR-FTIR could be a fast and useful technique to characterize filter-based PM_(2.5) compositions particularly during pollution events although cautions should be taken when PM_(2.5) levels are low. Notably, elevated PM_(2.5) mass concentrations occurred with enhanced ratios of [NO_(-3)]/[SO_4~(2-)] and [NH~(+4)]/[SO_4~(2-)], implying that nitrogenous components play vital roles in the PM_(2.5) pollution events in the study region.     

Sorption behavior of tetracyclines on suspended organic matters originating from swine wastewater

Tetracyclines(TCs) discharged from livestock wastewater have aroused public concerns due to their pharmacological threats to ecosystems and human health. As an important medium in the wastewater, suspended organic matters(SOMs) play vital roles in antibiotics transport and degradation. However, limited information has been reported in the relevant literature. This study investigated TCs sorption behavior on SOM, withdrawn from swine wastewater. High TCs sorption capacities were detected, with the maximum values ranging from 0.337 to 0.679 mg/g. Increasing p H and temperature led to the decline of sorption capacity. Results from three-dimensional excitation–emission matrix fluorescence spectroscopy and Fourier transform infrared spectrometry revealed that amide and carboxyl groups were the main functional groups for TCs adsorption. The interactions between SOM and TCs were clarified as predominated by hydrogen-bonding and cation-exchange in acid conditions, and electrostatic repulsion in neutral or alkaline conditions. Adsorption kinetics modeling was conducted, and a satisfactory fitting was achieved with the Freundlich equation. These results indicated that the adsorption process was a rather complex process, involving a combination of cation-exchange and hydrogen-bonding. The results will provide a better understanding of the capability of SOM for TCs transport and abatement in the wastewater treatment process.     

分子筛在铅污染土壤修复中的应用研究

采用溶液试验,从待选钝化材料中初步筛选出对Pb具有较好钝化效果的钝化材料,运用经典混料设计的试验方法,将优选出的13X分子筛、凹凸棒土、粉煤灰三种钝化材料复配成钝化剂,添加到Pb含量为1 500mg/kg的污染土中,添加量为污染土的20％,并保持土壤的含水率35％,3天后取钝化后土壤,采用(HJ/T 300-2007)(固体废物浸出毒性浸出方法醋酸缓冲溶液法)测其浸出液中的重金属Pb含量,采用Minitab软件对混料设计试验数据进行处理,优选出钝化重金属Pb的最佳钝化剂配方:分子筛25％,凹凸棒土42.6％,粉煤灰32.4％,钝化后浸出液中重金属Pb含量为0.027 1 mg/L,明显低于地表水质量标准的Ⅲ类标准0.05 mg/L.     

Lambda-cyhalothrin disrupts the up-regulation effect of 17β-estradiol on post-synaptic density 95 protein expression via estrogen receptor α-dependent Akt pathway

Lambda-cyhalothrin(LCT),one of the type II pyrethroids,has been widely used throughout the world.The estrogenic effect of LCT to increase cell proliferation has been well established.However,whether the estrogenic effect of LCT will influence neurodevelopment has not been investigated.In addition,17β-Estradiol(E2)plays a crucial role in neurodevelopment and induces an increase in synaptic proteins.The post-synaptic density 95(PSD95)protein,which is involved in the development of the structure and function of new spines and localized with estrogen receptor α(ERα)at the post-synaptic density(PSD),was detected in our study by using hippocampal neuron cell line HT22.We found that LCT up-regulated PSD95 and ERα expression,estrogen receptor(ER)antagonist ICI182,780 and phosphatidylinositol-4;5-bisphosphate 3-kinase(PI3K)inhibitor LY294,002 blocked this effect.In addition,LCT disrupted the promotion effect of E2 on PSD95.To investigate whether the observed changes are caused by ERα-dependent signaling activation,we next detected the effects of LCT on the ERα-mediated PI3K-Protein kinase B(PKB/Akt)-eukaryotic initiation factor(e IF)4E-binding protein 1(4E-BP1)pathway.There existed an activation of Akt and the downstream factor 4E-BP1 after LCT treatment.In addition,LCT could disrupt the activation effect of E2 on the Akt pathway.However,no changes in c AMP response element-binding protein(CREB)activation and PSD95 messenger ribonucleic acid(m RNA)were observed.Our findings demonstrated that LCT could increase the PSD95 protein level via the ERα-dependent Akt pathway,and LCT might disrupt the up-regulation effect of E2 on PSD95 protein expression via this signaling pathway.     

Human bronchial epithelial cell injuries induced by fine particulate matter from sandstorm and non-sandstorm periods: Association with particle constituents

Epidemiological studies have demonstrated the exacerbation of respiratory diseases following sandstorm-derived particulate matter(PM) exposure.The presence of anthropogenic and biological agents on the sandstorm PM and the escalation of PM 2.5 μm(PM2.5)pollution in China have led to serious concerns regarding the health effects of PM2.5during Asian sandstorms.We investigated how changes in PM2.5composition,as the weather transitioned towards a sandstorm,affected human airway epithelial cells.Six PM2.5samples covering two sandstorm events and their respective background and transition periods were collected in Baotou,an industrial city near the Gobi Desert in China.PM samples from all three periods had mild cytotoxicity in human bronchial epithelial cell line BEAS-2B,which was positively correlated with the contents of polycyclic aromatic hydrocarbons and several metals.All PM samples potently increased the release of interleukin-6(IL-6) and interleukin-8(IL-8).Endotoxin in all samples contributed significantly to the IL-6 response,with only a minor effect on IL-8.Cr was positively correlated with both IL-6 and IL-8 release,while Si was only associated with the increase of IL-6.Our study suggests that local agricultural and industrial surroundings in addition to the sandstorm play important roles in the respiratory effects of sandstorm-derived PM.