Source apportionment of PM2.5 and visibility in Jinan, China

Atmospheric extinction is impacted by the chemical composition of particles. To better understand the chemical composition of PM_2.5 (particles with diameters of less than 2.5 μm) and its relationship with extinction, one-month sampling campaigns were carried out in four different seasons from 2013 to 2014 in Jinan, China. The seasonal average concentrations of PM_2.5 were 120.9 (autumn), 156.6 (winter), 102.5 (spring), and 111.8 μg/m³ (summer). The reconstructed PM_2.5 chemical composition showed that sulfate, nitrate, chlorine salt, organic matter (OM), mineral dust, elemental carbon (EC) and others accounted for 25%, 14%, 2%, 24%, 22%, 3% and 10%, respectively. The relationship between the chemical composition of PM_2.5 and visibility was reconstructed by the IMPROVE method, and ammonium sulfate, ammonium nitrate, OM and EC dominated the visibility. Seven main sources were resolved for PM_2.5, including secondary particles, coal combustion, biomass burning, industry, motor vehicle exhaust, soil dust and cooking, which accounted for 37%, 21%, 13%, 13%, 12%, 3% and 1%, respectively. The contributions of different sources to visibility were similar to those to PM_2.5. With increasing severity of air pollution, the contributions of secondary particles and coal combustion increased, while the contribution of motor vehicle exhaust decreased. The results showed that coal combustion and biomass burning were still the main sources of air pollution in Jinan.     

Release characteristics and control of hydrogen sulfide during thermal drying of municipal wastewater sludge

Journal of Material Cycles and Waste Management - Hydrogen sulfide (H2S) is the most predominant malodorous gas released during the thermal drying of municipal wastewater sludge. Experiment using a...     

Recycling of biogenic hydroxyapatite (HAP) for cleaning of lead from wastewater: performance and mechanism

Environmental Science and Pollution Research - In China, the utilization and recycling of chicken waste have become a significant environmental issue. In this study, we investigate the efficacy of...     

Electroreduction of hexavalent chromium using a porous titanium flow-through electrode and intelligent prediction based on a back propagation neural network

● Titanium-based flow-through electrode achieved high Cr(VI) reduction efficiency. ● Flow-through pattern enhanced the mass transfer and reduced cathodic polarization. ● BPNN predicted the optimal electroreduction conditions of flow-through cell. Flow-through electrodes have been demonstrated to be effective for electroreduction of Cr(VI), but shortcomings are tedious preparation and short lifetimes. Herein, porous titanium available in the market was studied as a flow-through electrode for Cr(VI) electroreduction. In addition, the intelligent prediction of electrolytic performance based on a back propagation neural network (BPNN) was developed. Voltametric studies revealed that Cr(VI) electroreduction was a diffusion-controlled process. Use of the flow-through mode achieved a high limiting diffusion current as a result of enhanced mass transfer and favorable kinetics. Electroreduction of Cr(VI) in the flow-through system was 1.95 times higher than in a parallel-plate electrode system. When the influent (initial pH 2.0 and 106 mg/L Cr(VI)) was treated at 5.0 V and a flux of 51 L/(h·m²), a reduction efficiency of ~99.9% was obtained without cyclic electrolysis process. Sulfate served as the supporting electrolyte and pH regulator, as reactive CrSO₇²⁻ species were formed as a result of feeding HSO₄⁻. Cr(III) was confirmed as the final product due to the sequential three-electron transport or disproportionation of the intermediate. The developed BPNN model achieved good prediction accuracy with respect to Cr(VI) electroreduction with a high correlation coefficient (R² = 0.943). Additionally, the electroreduction efficiencies for various operating inputs were predicted based on the BPNN model, which demonstrates the evolutionary role of intelligent systems in future electrochemical technologies.     

Visualization and analysis of mapping knowledge domain of oxidation studies of sulfide ores

Environmental Science and Pollution Research - The oxidation of sulfide ores is a common phenomenon. To better understand the current development and status of oxidation studies of sulfide ores...     

Occurrence and change of estrogenic activity in the process of drinking water treatment and distribution

From 2010 to 2012, the Yangtze River and Hanjiang River (Wuhan section) were monitored for estrogenic activities during various water level periods. Using a recombinant yeast estrogen screen (YES) assay, 54 water samples were evaluated over the course of nine sampling campaigns. The mean 17β-estradiol equivalent (EEQ) value of raw water from the Yangtze River was 0–5.20 ng/L; and the EEQ level from the Hanjiang River was 0–3.22 ng/L. In Wuhan, drinking water treatment plants (DWTPs) using conventional treatments reduced estrogenic activities by more than 89 %. In general, water samples collected during the level period showed weaker estrogenic activities compared to those collected during the dry period. The samples collected in 2010 showed the strongest estrogenic activities of the 3-year period. The lack of correlations between estrogenic activities and selected common water quality parameters showed that estrogenic activity cannot be tied to common water quality parameters.     

包头市生态重要性评价

本文从生物多样性维持与保护、土壤保持、水源涵养、防风固沙四方面进行包头市生态重要性评价,得出包头市生态重要性等级变化趋势,以期为划分包头市生态功能区划以及城市科学发展提供理论依据。     

上海乔木林分碳储量比较分析研究

基于全国第七次（2004年-2009年）森林资源清样调查资料,并参考上海市2011年森林植被遥感数据,运用线性相关和双曲线相关的换算因子连续函数法,对上海8种主要乔木林分碳储量进行估算,并分析了不同龄组和地域分布的乔木林分碳储量。结果表明,两种方法的估值差别较大,但均是樟树、幼龄林和市区乔木林分碳储量贡献比较大。     

能源富集城市的可持续发展探讨——以甘肃庆阳为例

能源富集城市是指该市的能源储藏量丰富,能源工业的收入是该市的主要经济支柱。能源富集城市在享受能源开采利用带来巨大的收益同时,也在饱受着能源开采利用带来巨大的恶果。本文以庆阳市为例．首先分析了庆阳市发展过程中存在的问题,其次借鉴成功转型的能源城市案例,对庆阳市成功转型,走上可持续发展道路提出了相关的对策建议。