Characteristics and formation mechanism of regional haze episodes in the Pearl River Delta of China

To investigate the characteristics and the specific mechanism of continuous haze,comprehensive measurements were conducted from 15 October to 19 November in the Atmospheric Environment Monitoring Super-Station in Heshan of Guangdong province.Five haze episodes occurred in October and November 2014 in the Pearl River Delta(PRD)region. The meteorological parameters, gas data, chemical compositions, and optical parameters of the aerosols were obtained. Among these events, the second haze episode,with the highest concentration of PM2.5 of 187.51 μg/m~3, was the most severe. NO~3-was always higher than SO_4~(2-), which indicated that motor vehicles played an important role in the haze, even though the oxidation rate from SO_2 to SO_4~(2-)was faster than that of NOXto NO_3~-. The difference between the hourly averages of Na+and K+during the haze episode and clean days was small, implying that straw combustion and sea salt had no significant effect on the occurrence of haze, and the backward trajectories of the air masses also conformed with this result. The air pollutants were difficult to disperse because of the significant decrease in the planetary boundary layer(PBL) height. Relative humidity played a crucial role in the formation of haze by leading to hygroscopic growth of the diameter of aerosols.     

Anaerobic treatment of source-separated domestic bio-wastes with an improved upflow solid reactor at a short HRT

Anaerobic treatment is the core technology for resource and energy recovery from source-separated domestic bio-wastes. The higher efficiency of an improved upflow solid reactor(IUSR) designed in this study was demonstrated in the treatment of concentrated black water and kitchen waste. The highest methane production of 48 L/person/day was achieved at the hydraulic retention time(HRT) of 7 days, while the other measures of performance at the HRT of 8.3 days were better than at the HRT of 7 or 10 days, achieving a methane production of 43 L/person/day, removal of total chemical oxygen demand(TCOD)of 89%, removal of soluble chemical oxygen demand(SCOD) of 92%, and conversion of chemical oxygen demand(COD) to methane of 71%. It is not recommended to decrease HRT lower than 7 days due to the instability of the initial period. The concentrations of volatile fatty acids(VFAs) in the IUSR were less than 10 mg/L, indicating that the anaerobic process was stable. Sludge bed development showed that sludge bed with high microbial activity was formed in the bottom and that the precipitation zone of effluents formed should preferably occupy 30% of the height of the IUSR. The effluents of the IUSR could be used for irrigation in agriculture in combination with a settling tank accompanied by disinfection to remove solids and pathogens.     

Treatment of coking wastewater by a novel electric assisted micro-electrolysis filter

A newly designed electric assisted micro-electrolysis filter(E-ME) was developed to investigate its degradation efficiency for coking wastewater and correlated characteristics. The performance of the E-ME system was compared with separate electrolysis(SE) and micro-electrolysis(ME) systems. The results showed a prominent synergistic effect on COD removal in E-ME systems. Gas chromatography/mass spectrometry(GC–MS) analysis confirmed that the applied electric field enhanced the degradation of phenolic compounds.Meanwhile, more biodegradable oxygen-bearing compounds were detected. SEM images of granular activated carbon(GAC) showed that inactivation and blocking were inhibited during the E-ME process. The effects of applied voltage and initial p H in E-ME systems were also studied. The best voltage value was 1 V, but synergistic effects existed even with lower applied voltage. E-ME systems exhibited some p H buffering capacity and attained the best efficiency in neutral media, which means that there is no need to adjust p H prior to or during the treatment process. Therefore, E-ME systems were confirmed as a promising technology for treatment of coking wastewater and other refractory wastewater.     

Mutual detoxification of mercury and selenium in unicellular Tetrahymena

Selenium(Se) is commonly recognized as a protective element with an antagonistic effect against mercury(Hg) toxicity. However, the mechanisms of this Hg–Se antagonism are complex and remain controversial. To gain insight into the Hg–Se antagonism, a type of unicellular eukaryotic protozoa(Tetrahymena malaccensis, T. malaccensis) was selected and individually or jointly exposed to two Hg and three Se species. We found that Se species showed different toxic effects on the proliferation of T. malaccensis with the toxicity following the order:selenite(Se(IV)) selenomethionine(SeMeth) selenate(Se(VI)). The Hg–Se antagonism in Tetrahymena was observed because the joint toxicity significantly decreased under co-exposure to highly toxic dosages of Hg and Se versus individual toxicity. Unlike Se(IV) and Se(VI), non-toxic dosage of SeM eth significantly decreased the Hg toxicity, revealing the influence of the Se species and dosages on the Hg–Se antagonism. Unexpectedly, inorganic divalent Hg(Hg~(2+)) and monomethylmercury(MeHg) also displayed detoxification towards extremely highly toxic dosages of Se, although their detoxifying efficiency was discrepant. These results suggested mutual Hg–Se detoxification in T. malaccensis, which was highly dependent on the dosages and species of both elements. As compared to other species, SeM eth and MeHg promoted the Hg–Se joint effects to a higher degree. Additionally, the Hg contents decreased for all the Hg–Se co-exposed groups, revealing a sequestering effect of Se towards Hg in T. malaccensis.     

大气污染环境下传统康复技能培训在精准扶贫中的应用性探索

在大气污染环境下,传统的康复技能培训能带动地方区域性经济发展,实现精准扶贫,为了定量分析大气污染环境下传统康复技能培训和地区性经济增长关系,提高精准扶贫力度,提出一种基于模糊评价决策的传统康复技能培训经济促进性效益评估模型,并应用在精准扶贫中。构建大气污染环境下传统康复技能培训的经济促进性增长约束变量,结合FMOLS和DOLS方法进行传统康复技能培训在精准扶贫中的促进性指标参量分析,建立精准扶贫的资金回报动态规划模型,采用模糊决策评价决策方法实现康复技能培训的效益评估。     

电化学方法用于酸性红B模拟废水脱色试验研究

本文研究了两种电极材料 (SnO2 Ti和RuO2 Ti)对酸性红B模拟废水的脱色效果 ,考察了不同 pH、电流密度(j)及外加电解质 (Na2 SO4/NaCl)对处理过程的影响。结果表明 ,两种电极材料都能对酸性红B染料废水进行有效脱色 ,主要是Cl-在电解过程中的间接氧化作用 ,同时也包括电极表面的直接氧化作用。     

电磁防护技术和防护装备

电磁辐射(EMI)污染已被公认为大气污染、水质污染、噪音污染之外的第四大公害，电视广播发射塔、雷达站、通信发射台、变电站、高压电线，还有电脑、手机、微波炉、电磁灶，甚至我们乘坐的地铁列车等等都能制造电磁辐射污染。它无色、无味、无形，可以穿透包括人体在内的多种物质，人体如果长期暴露在超过安全的辐射剂量下，细胞就会被大面积杀伤或杀死，从而引发多种疾病。     

微生物法处理含铬(Ⅵ)废水的研究

采用硫酸盐还原菌处理含铬(Ⅵ)废水，研究了其去除铬(Ⅵ)的最适宜工艺条件。实验表明，该菌的适用范围广，处理含铬废水的能力强。在菌液与废液体积比为1．0：1、铬(Ⅵ)质量浓度为150mg／L条件下处理36h，铬(Ⅵ)去除率达99．9％。     

冷原子荧光法测定水中痕量汞的改进

对冷原子荧光法测定地表水及工业废水中汞的分析处理方法提出改进措施，改进的方法准，快，简，省，符合监测规范要求。     

水温及污泥龄对生物处理系统运行的影响

水温和污泥龄对硝化作用有着重要的影响；水温和污泥龄对污泥增长量也起着主导性作用。指出水温对难降解程度有重大影响。