Advanced microbial fuel cell for waste water treatment—a review

Environmental Science and Pollution Research - Petroleum, coal, and natural gas reservoir were depleting continuously due to an increase in industrialization, which enforced study to identify...     

A pathway toward future sustainability: Assessing the influence of innovation shocks on CO2 emissions in developing economies

Environment, Development and Sustainability - The prior empirical research focuses on examining only the procyclical impact of innovation on carbon emissions (CO2e), in the majority of cases, for...     

BiVO4-Cu2O/CuO双光电极自偏压光电催化降解苯酚研究

基于费米能级差,构建了以BiVO_4为光阳极,Cu_2O/CuO为光阴极的双光电极可见光响应光催化燃料电池体系,研究了该体系在不同氧化剂的辅助作用下光电催化降解苯酚的效率与动力学.结果表明,向该体系中投加H_2O_2可以显著促进苯酚的降解,且反应过程光电流稳定,铜溶出量低.详细探究了H_2O_2初始浓度、pH对降解的影响,结果表明在H_2O_2投加量为5 mmol·L~(-1),初始pH为3.5条件下利于苯酚降解,5 mg·L~(-1)的苯酚可在120 min内完全去除.顺磁共振和猝灭实验表明该体系的主要氧化物种为·OH、·O~-_2和光生空穴.该催化体系实现了苯酚在可见光下的高效催化降解.     

Monitoring the impact of urban effluents on mineral contents of water and sediments of four sites of the river Ravi, Lahore

We assessed the impact of urban effluents on the concentrations of selected minerals (Cd, Cr, Cu, Fe, Pb, Zn, Mn, Ni, and Hg) in river Ravi before and after its passage through Lahore city. Water and sediment samples were collected from three lowly to highly polluted downstream sites (Shahdera (B), Sunder (C), and Balloki (D)) alongside the least polluted upstream site (Siphon (A)) during high and low river flow seasons. All the mineral concentrations increased up to site C but stabilized at site D, showing some recovery as compared to the third sampling site. The trend of mean mineral concentration was significantly higher during the low than the high flow season at all the sites. The mean Hg concentrations approached 0.14 and 0.12 mg/l at site A which increased (%) up to 107 and 25 % at site B, 1,700 and 1,317 % at site C, and 1,185 and 1,177 % at site D during low and high river flows, respectively. All mineral concentrations were much higher in the sediment than the water samples. Mean Cd (917 %), Cr (461 %), Cu (300 %), Fe (254 %), Pb (179 %), Zn (170 %), Mn (723 %), Ni (853 %), and Hg (1,699 %) concentrations were higher in riverbed sediments sampled from site C in comparison with the sample collected at site A during low flow season. The domestic and industrial discharges from Lahore city have created undesirable water qualities during the low river flow season. As majority of the mineral levels in the river Ravi were higher than the permissible and safe levels, this is of immediate concern for riverine fish consumers and the users of water for recreation and even irrigation. The use of these waters may pose health risks, and therefore, urgent intervention strategies are needed to minimize river water pollution and its impact on fish-consuming communities of this study area and beyond.     

Monitoring of growth and physiological activities of biofilm during succession on polystyrene from activated sludge under aerobic and anaerobic conditions

The present research work monitored the successive biofilm development and its catabolic role in the degradation of polystyrene (PS). PS material was artificially colonized with biofilm by incubating it with activated sludge under aerobic and anaerobic conditions. Biofilm formation was monitored by gravimetric weight analysis, spectrophotometric absorbance technique, heterotrophic plate count, and scanning electron microscopy under aerobic and anaerobic conditions. The wet weight (1.59 and 1.17 g) and dry weight (0.41 and 0.08 g) of a biofilm showed a significant constant increase under aerobic and anaerobic conditions, respectively, from first till 9 weeks of incubation. Plate count of the selected bacteria (Escherichia coli, Salmonella typhimurium, Shigella dysenteriae, Pseudomonas aeruginosa) considerably declined (90–99 %) in the biofilm after seventh and fifth weeks of incubation under aerobic and anaerobic conditions, respectively, indicating a positive shift from pathogenic to beneficial microbial community. While most probable number index of fecal coliforms and E. coli in the sludge showed more reduction (98 and 99 %) under aerobic as compare to anaerobic conditions (86 and 91 %) after 9 weeks of biofilm formation on PS cubes. Correspondingly, the decreasing levels of chemical oxygen demand and biochemical oxygen demand (up to 73 %) showed signs of sludge digestion. Scanning electron microscope coupled with energy dispersive X-ray spectroscope revealed nature of PS media containing high carbon content. However, biofilm development proved to be involved in the biochemical transformation of the PS medium as indicated by Fourier transform infrared spectroscopy.     

SnO2薄膜光波导传感元件检测二甲苯蒸气

利用SnO2薄膜光波导传感元件,研究了检测二甲苯蒸气的新方法.采用溶胶-凝胶法制备了SnO2薄膜/锡掺杂玻璃光波导元件,将该元件固定在光波导气体检测系统,对挥发性有机物蒸气进行检测.实验结果表明,室温下该敏感元件对二甲苯蒸气有较高的选择性响应.对于体积分数为2.5×10-7的二甲苯蒸气,响应和恢复时间分别为5s和36s.该元件具有响应快、可逆性好、灵敏度高等特点.     

Development of a novel mathematical model using a group contribution method for prediction of ionic liquid toxicities

A new mathematical model has been developed that expresses the toxicities (EC₅₀ values) of a wide variety of ionic liquids (ILs) towards the freshwater flea Daphnia magna by means of a quantitative structure-activity relationship (QSAR). The data were analyzed using summed contributions from the cations, their alkyl substituents and anions. The model employed multiple linear regression analysis with polynomial model using the MATLAB software. The model predicted IL toxicities with R² = 0.974 and standard error of estimate of 0.028. This model affords a practical, cost-effective and convenient alternative to experimental ecotoxicological assessment of many ILs.     

Spatial distribution and source apportionment of PCBs in sediments around İzmit industrial complexes, Turkey

The spatial distribution, degree of pollution and major sources of PCBs were evaluated in surficial sediments within the heavily urbanized and industrialized ?zmit Bay and its main freshwater inputs. ΣPCB concentrations range from 2.90 to 85.4ngg(-1) in marine sediments and from ND to 47.7ngg(-1) in freshwater sediments. Results suggest that high concentrations of ΣPCBs were localized around a chlor-alkali plant and an industry that handles bulk liquid, dry and drummed chemicals, and petroleum products in the Bay. Using a chemical mass balance receptor model (CMB), major sources of PCBs in the region were investigated. The CMB model identified Aroclor 1254 and 1260 to be the major PCB sources in marine sediments and the less chlorinated Aroclor 1248 and 1242 as the major PCB sources in freshwater sediments. The potential sources for the PCBs were briefly discussed in terms of their use in various industrial applications.     

Oil-Induced environmental Kuznets curve in organization of petroleum exporting countries (OPEC)

This study investigates the environmental Kuznets curve (EKC) hypothesis in 10 of the Organization of Petroleum Exporting Countries (OPEC). To realize the study’s aims a time series model is built based on the period 1977–2008, utilizing the ecological footprint as an environmental indicator and income, labour, capital, oil consumption and oil price as economic indicators. Employing the Autoregressive Distributed Lag (ARDL) approach, by comparing the short and long-run income elasticities, the EKC hypothesis is present in six OPEC countries namely Algeria, Iraq, Venezuela, Nigeria, Qatar and Kuwait. Moreover, the Toda–Yamamoto–Dolado–Lütkepohl (TYDL) causality tests outcome show that, after oil consumption, the most significant factors in increasing ecological footprint are labor and capital. This implies the relocation of pollution intensive industries to almost all of the OPEC countries. However, oil prices reduce environmental damage by its negative effect on the ecological footprint. From the outcome of this study it is important for the investigated countries to reduce their consumption of fossil fuel energy since it represents an important source of pollution. This can be achieved by allocating more labor and capital in projects and investments on renewable energy, energy efficiency and energy saving.     

Potential recyclable materials derived from riverine litter at log boom Sungai Batu in Kuala Lumpur

Journal of Material Cycles and Waste Management - Monitoring the riverine litter was essential for the aesthetical value and reducing the negative impacts toward the human health, environment and...