Photoelectrocatalytic systems for simultaneous energy recovery and wastewater treatment: a review

Environmental Chemistry Letters - The rising energy conflicts and environmental pollution are calling for the rapid development of advanced techniques such as photoelectrocatalysis to...     

Measuring the bias of technical change of industrial energy and environment productivity in China: a global DEA-Malmquist productivity approach

Environmental Science and Pollution Research - Thanks to the booming industry, China has made a huge economic achievement during the past several decades. However, it is suffering severe...     

运用BDD电极优化废水中氨氮的直接电化学检测方法

针对高氨氮条件下离子选择电极稳定性差的问题,筛选了3种市售硼掺杂金刚石(BDD)电极,以探究直接电化学检测氨氮的可行性.采用极化曲线法测试了3种BDD电极的析氧、析氢和析氯电位,以获得最佳电势窗口.采用循环伏安法研究了氨氮在3种BDD电极上的氧化还原行为,在1.6 V处发现了明显的氨氮氧化峰,可为氨氮直接检测提供定性依...     

太湖水体散射特性及其与悬浮物浓度关系模型

水体散射特性与水环境参数如悬浮颗粒及其浓度密切相关.利用Wetlabs公司研制的水体固有光学特性测量系统,于2006-10～2006-11对太湖水体的散射系数和后向散射系数进行了测量.在对水体散射特性分析的基础上,建立了太湖水体颗粒物后向散射系数的光谱模型.此外,利用后向散射率计算水体折射系数,根据折射系数的变化范围,将水中颗粒物的主导因子分为3种类型：①浮游植物主导;②无机颗粒物主导;③两者共同主导.在对散射系数与无机悬浮物、有机悬浮物、总悬浮物浓度相关性分析的基础上,针对颗粒物主导因子的不同,分别建立了散射系数与无机悬浮物浓度的乘幂关系模型.     

水泥对垃圾焚烧飞灰中重金属的固化研究

采用水泥固化法处理垃圾焚烧飞灰,研究了飞灰与水泥质量比、养护时间、添加剂和化学预处理对垃圾焚烧飞灰固化块中重金属Zn、Pb、Cu、Cd、Cr浸出的影响.结果表明,当飞灰与水泥质量比为3:4,养护时间为11d的条件下,以砂浆塑化剂为添加剂,固化块Pb、Cu、Cd和Cr的浸出浓度分别降低了72.4％、70.6％、60.0％...     

彗星试验检测地下水有机污染物的遗传毒性效应

应用人外周血淋巴细胞和小鼠淋巴细胞彗星试验,对长治市5个样点的地下水有机浓集物进行了遗传毒性研究。结果表明,各水样中有机浓集物在3个染毒剂量50,200,800 m L·管-1条件下均可对人外周血淋巴细胞和小鼠淋巴细胞DNA产生不同程度的遗传损伤,并且随着浓度的升高,DNA损伤程度明显增加,各实验组与溶剂对照组相比有P<0.05或P<0.01显著差异。研究表明,上述2种淋巴细胞彗星试验可有效地检测地下水体有机污染物的遗传毒性。     

Experimental investigation on convection heat transfer characteristics of flat plate under environmental wind condition

By establishing wind tunnel and employing electrical heating method, the heat transfer characteristics of flat plate were investigated under environmental wind condition. Both the uniform and linear heat flux boundary conditions were adopted for comparison purpose. Besides, the impacts of heat flux q_wm, tilt angle α and wind incidence angle θ on heat transfer were explored in cases of windward and leeward facing positions. The local convection heat transfer coefficient h_cx and average convection Nusselt number Nu_cm were obtained. The results show that, when α is small, there are two maximum values of h_cx under linear heat flux boundary condition. As for Nu_cm, differences between the two boundary conditions seem indistinctive. At windward orientation, Nu_cm is not sensitive to α. While for leeward orientation, Nu_cm has a rapid decline progress with the increasing α, which indicates the tilt angle α is an important parameter to affect the heat transfer of plate. Finally, new correlations of Nu_cm have been developed, which were proven effective in engineering applications.     

Characterisation of an extracellular polysaccharide produced by Bacillus mucilaginosus MY6-2 and its application in metal biosorption

A novel extracellular bioflocculant from Bacillus mucilaginosus MY6-2 was obtained by alcohol precipitation, dialysis and lyophilisation. The chemical analysis indicated that the bioflocculant was mainly composed of extracellular polysaccharide (named EPS MY6-2). Monosacchride composition result analysed by Gas chromatography indicated that EPS MY6-2 was mainly composed of Man, Glc, Gal, GlcA and GalA. The result of flocculating characteristics indicated that pH, EPS dosage and cation supplement had evident effect on flocculating activity of EPS MY6-2. The biosorption of iron ions from aqueous solution was tested with respect to pH, initial metal ion concentration and EPS dosage. The optimum biosorption conditions were as follows: pH 5.0, initial ion concentration from 200 to 800 mg/L and EPS dosage of 60 mg/L ion solution. The adsorption rates are maintained above 95% under these conditions. The adsorption data provided an excellent fit to both Langmuir and Freundlich isotherms, implying that the binding of the iron ions took place as a monolayer on the surface of the EPS.     

Trends in on-road vehicle emissions and ambient air quality in Atlanta,Georgia, USA,from the late 1990s through 2009

On-road vehicle emissions of carbon monoxide (CO), nitrogen oxides (NO_x), and volatile organic compounds (VOCs) during 1995–2009 in the Atlanta Metropolitan Statistical Area were estimated using the Motor Vehicle Emission Simulator (MOVES) model and data from the National Emissions Inventories and the State of Georgia. Statistically significant downward trends (computed using the nonparametric Theil-Sen method) in annual on-road CO, NO_x, and VOC emissions of 6.1%, 3.3%, and 6.0% per year, respectively, are noted during the 1995–2009 period despite an increase in total vehicle distance traveled. The CO and NO_x emission trends are correlated with statistically significant downward trends in ambient air concentrations of CO and NO_x in Atlanta ranging from 8.0% to 11.8% per year and from 5.8% to 8.7% per year, respectively, during similar time periods. Weather-adjusted summertime ozone concentrations in Atlanta exhibited a statistically significant declining trend of 2.3% per year during 2001–2009. Although this trend coexists with the declining trends in on-road NO_x, VOC, and CO emissions, identifying the cause of the downward trend in ozone is complicated by reductions in multiple precursors from different source sectors.

Implications:Large reductions in on-road vehicle emissions of CO and NO_x in Atlanta from the late 1990s to 2009, despite an increase in total vehicle distance traveled, contributed to a significant improvement in air quality through decreases in ambient air concentrations of CO and NO_x during this time period. Emissions reductions in motor vehicles and other source sectors resulted in these improvements and the observed declining trend in ozone concentrations over the past decade. Although these historical trends cannot be extrapolated to the future because pollutant concentration contributions due to on-road vehicle emissions will likely become an increasingly smaller fraction of the atmospheric total, they provide an indication of the benefits of past control measures.     

塔式自然通风好氧堆肥反应器的开发与应用

针对现有堆肥反应器处理效率低、运行和维护成本较高及堆肥效率不稳定等问题,开发了塔式自然通风好氧堆肥反应器。从物料和热量平衡、通风量优化等方面对反应器进行研究。反应器主要包括反应器主体、通风管、物料承托筛板和温度监控系统等,具有运行及维护简单、能源耗费低等优点。在通风高度为3 m,初始物料投加量5.65 kg(干重比︰粪便/锯末=1∶2.5),含水率约60%时,对人粪便进行好氧堆肥实验。结果表明,堆体温度最高至62℃,并且在50℃以上高温保持5 d;TOC和COD均呈持续下降趋势,降解率分别为64.14%和56.45%;种子发芽指数为113.64%,完全达到腐熟标准。