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Analysis of spatial planning documents and strategic environmental assessment reports with regard to hazards of major industrial accidents: a case study involving six Polish cities 全文
2020
Markiewicz, Maria Teresa
In the event of an accident in an industrial plant, the damage caused by it can be enormous. There may be environmental contamination in a large area. Injured persons may be both employees of the plant staying on its premises and local residents. The control of major accidents is realised by implementing the procedures regarding: safety analysis, emergency and operational planning, effective land-use planning (LUP), strategic environmental assessment (SEA), environmental impact assessment (EIA) and public consultation. The paper presents findings of a case study aiming to analyse selected spatial planning documents prepared at the municipality and SEA reports accompanying them, with regard to hazards of major industrial accidents in six Polish cities. In addition, changes of relevant Polish legislation taking place from 1995 till now are explained referring to European Union (EU) law. This article is the very first to present the situation concerning LUP around hazardous plants in Poland based on such extensive data. The assessment shows that the way of recording the major accident hazards is varied, but legal norms, binding at the time when the documents were drawn up, were met in each of the analysed documents. Changes of relevant Poland legislation were not the only reason for differences in the ways of recording the hazards of major industrial accidents in these documents. The case study has revealed that relevant Polish regulations can be still improved. The results of the study have useful implications for the control of major accidents, spatial policy-making and environmental management.
显示更多 [+] 显示较少 [-]Emission profiling of CI engine fueled with neem and wintergreen oil blend with hexanol and octanol manifold injection 全文
2020
Swaminathan, Siluvaimuthu | Subramanian, Thiyagarajan | Martin, Leenus Jesu | Beddhannan, Nagalingam
The present work details the effects of injection of higher order alcohols, namely hexanol (Hex) and octanol (Oct) as secondary fuels in a CI engine. The last decade has seen an exponential increase in the carbon emission chief of which have been contributed by fossil fuels. Vegetable oils provide a viable alternative to the current scenario as they can be synthesized easily from nature and can be readily adapted for use in CI engines. Neem oil (NO) is non-edible and widely available and hence taken as a base fuel for this research. The poor properties of neem oil were improved by the addition of novel low viscous biofuel, namely wintergreen oil (WGO). During the course of this research work, a blend containing a mixture of 50% of neat neem oil and 50% of wintergreen oil (NO50-WGO50) was optimized based on trial tests and taken as pilot fuel while Hex and Oct were injected along with intake air as secondary fuels. The alcohols were injected into the engine successively in the 10%, 20%, and 30% (by mass) ratios. Experiments were conducted in a single-cylinder CI engine fabricating 5.2-kW power at a constant speed of 1500 rpm at varying load conditions. It is observed that inferior performance of NO led to more smoke, HC, and CO in comparison to diesel at all the loads and these are improved with NO50-WGO50 blend. Nevertheless, a minor increase in NOx emission was perceived with the blend. Addition of higher order alcohol promoted reduction of both NOx and smoke emission without affecting performance. Among the various combinations, NO50-WGO50 + Hex30 and Oct30 reduced NOx emission by 12% and 9.5% and smoke emission by 13% and 19% respectively. These results are on par with the diesel performance and emission characteristics.
显示更多 [+] 显示较少 [-]Influence of particle size distribution on anaerobic degradation of phenol and analysis of methanogenic microbial community 全文
2020
Wang, Jing | Wu, Benteng | Sierra, Julian Muñoz | He, Chunhua | Hu, Zhenhu | Wang, Wei
Sludge morphology considerably affects the mechanism underlying microbial anaerobic degradation of phenol. Here, we assessed the phenol degradation rate, specific methanogenic activity, electron transport activity, coenzyme F₄₂₀ concentration, and microbial community structure of five phenol-degrading sludge of varying particle sizes (i.e., < 20, 20–50, 50–100, 100–200, and > 200 μm). The results indicated an increase in phenol degradation rate and microbial community structure that distinctly correlated with an increase in sludge particle size. Although the sludge with the smallest particle size (< 20 μm) showed the lowest phenol degradation rate (9.3 mg COD·gVSS⁻¹ day⁻¹), its methanogenic activity with propionic acid, butyric acid, and H₂/CO₂ as substrates was the best, and the concentration of coenzyme F₄₂₀ was the highest. The small particle size sludge did not contain abundant syntrophic bacteria or hydrogenotrophic methanogens, but contained abundant acetoclastic methanogens. Moreover, the floc sizes of the different sludge varied in important phenol-degrading bacteria and archaea, which may dominate the synergistic mechanism. This study provides a new perspective on the role of sludge floc size on the anaerobic digestion of phenol.
显示更多 [+] 显示较少 [-]Biological responses at the interface of Ti-doped diamond-like carbon surfaces for indoor environment application 全文
2020
Bouabibsa, Imane | Alhussein, Akram | Lamri, Salim | Sanchette, Frederic | Rtimi, Sami
Diamond-like carbon (DLC) and titanium-doped DLC coatings were prepared by hybrid PECVD/direct current magnetron sputtering (DCMS). In this study, we show that the operating conditions of titanium-doped DLC coatings used for implants in surgical devices significantly modify their surface properties and consequently their interaction with cells. The coatings showed uniform distribution on the substrate and their biocompatibility was tested by way of rat calvaria osteoblasts. Doping DLC with Ti changed the roughness and wettability of the film interface. The autoclaving of the samples led to the surface oxidation and the formation of TiO₂ on the top-most layers of Ti-doped DLC. This was quantitatively assessed by X-ray photoelectron spectroscopy (XPS) and revealed the presence of Ti³⁺ and Ti⁴⁺ species in redox reactions during their interactions with cells. By XPS analysis, the oxidative carbonaceous species C=O and O=C–C were detected during the bacterial inactivation. Reactive oxygen species (ROS) were identified on the sputtered samples and the ⦁OH radical was identified as the most important oxidative radical intermediate leading to bacterial disinfection. The position of the intra-gap of the oxidized C species is suggested within the TiO₂ bandgap.
显示更多 [+] 显示较少 [-]A novel thermophilic anaerobic granular sludge membrane distillation bioreactor for wastewater reclamation 全文
2020
Duong, Chinh Cong | Chen, Shiao-Shing | Lê, Huy Quang | Chang, Hau-Ming | Nguyen, Nguyen Cong | Cao, Dan Thanh Ngoc | Chien, I-Chieh
Membrane distillation (MD) has a high heat requirement. Integrating MD with thermophilic bioreactors could remedy this problem. A laboratory-scale thermophilic anaerobic granular sludge membrane distillation bioreactor (ThAGS-MDBR) was used to treat wastewater with a high organic loading rate (OLR). Waste heat from ThAGS was used directly for the MD process to reduce energy consumption. The result demonstrated that the ThAGS-MDBR system achieved a high-efficiency removal of chemical oxygen demand (more 99.5%) and NH₄⁺-N (96.4%). Furthermore, the highest methane production from the proposed system was 332 mL/g CODᵣₑₘₒᵥₑd at OLR of 16 kg COD/m³/day. Specifically, an aggregate of densely packed diverse microbial communities in anaerobic granular sludge was the main mechanism for the enhancement of bioreactor tolerance with environmental changes. High-quality distillate water from ThAGS-MDBR was reclaimed in one step with total organic carbon less than 1.7 mg/L and electrical conductivity less than 120 μS/cm. Furthermore, the result of the DNA extraction kit recorded that Methanosaeta thermophila was a critical archaea for high COD removal and bioreactor stability.
显示更多 [+] 显示较少 [-]Chemical characteristics of rainwater in the tropical rainforest region in northwestern Borneo 全文
2020
Valappil, Ninu Krishnan Modon | Viswanathan, Prasanna Mohan | Hamza, Vijith
A comprehensive study of the chemical composition of rainwater was carried out from October 2016 to September 2017 in the equatorial tropical rainforest region of northwestern Borneo. Monthly cumulative rainwater samples were collected from different locations in the Limbang River Basin (LRB) and were later categorized into seasonal samples representing northeast monsoon (NEM), southwest monsoon (SWM), and inter-monsoon (IM) periods. Physical parameters (pH, EC, TDS, DO, and turbidity), major ions (HCO₃⁻, Cl⁻, Ca²⁺, Mg²⁺, Na⁺, and K⁺) and trace metals (Co, Ni, Cd, Fe, Mn, Pb, Zn, and Cu) were analyzed from collected rainwater samples. Rainwater is slightly alkaline with mean pH higher than 5.8. Chloride and bicarbonate are the most abundant ions, and the concentration of major ions in seasonal rainwater has shown slight variation which follows a descending order of HCO₃⁻> Cl⁻> Na⁺ > Ca²⁺ > Mg²⁺ > K⁺ in NEM and Cl⁻ > HCO₃⁻ > Na⁺ > Ca²⁺ > K⁺ > Mg²⁺ in SWM and Cl⁻ > HCO₃⁻ > Na⁺ > Ca²⁺ > Mg²⁺ > K⁺ in IM period. Trace metals such as Fe and Ni have shown dominance in seasonal rainwater samples, and all the metals have shown variation in concentration in different seasons. Variation in chemical characteristic of seasonal rainwater samples identified through piper diagram indicates dominance of Ca²⁺-Mg²⁺-HCO₃⁻ and mixed Ca²⁺-Mg²⁺-Cl⁻ facies during NEM, SWM, and IM periods. Statistical analysis of the results through two-way ANOVA and Pearson’s correlation also indicates significant variation in physico-chemical characteristics. This suggests a variation in contributing sources during the monsoon seasons. Factor analysis confirmed the source variation by explaining the total variance of 79.80%, 90.72%, and 90.52% with three factor components in NEM, SWM, and IM rainwater samples with different loading of parameters. Enrichment factor analysis revealed a combined contribution of marine and crustal sources except K⁺ which was solely from crustal sources. Sample analysis of backward air mass trajectory supports all these findings by explaining seasonal variation in the source of pollutants reaching the study area. Overall, the results show that the chemical composition of seasonal rainwater samples in LRB was significantly influenced by natural as well as anthropogenic processes. These include (long-range and local) industrial activities, fossil fuel combustion, forest burning, transportation activities including road transport and shipping activities, and land-derived soil dust along with chemical constituents carried by seasonal wind.
显示更多 [+] 显示较少 [-]Decomplexation of Cu(II)/Ni(II)-EDTA by ozone-oxidation process 全文
2020
Xu, Suyun | Yan, Ning | Cui, Minghao | Liu, Hongbo
In this study, ozone-oxidation was used to treat synthetic chemical plating solution containing Cu(II)/Ni(II)-EDTA solution to realize the purpose of decomplexation. The effects of solution pH, initial concentration of Cu(II)/Ni(II)-EDTA, the molar ratio of EDTA to Cu(II)/Ni(II), and the coexistence of Cu(II)/Ni(II) on their removal efficiencies were investigated. The degradation of EDTA-Cu(II) and EDTA-Ni(II) were mainly attributed to OH oxidation, and the removal rates of Cu(II)/Ni(II) depend on the complete decomplexation. The removal rates of Cu(II) and Ni(II) was affected by the pH of solution, and the optimal pH was found to be 7–9; nevertheless, their removal rates can still be up to 90% even in acidic pHs of 3~5. When the molar ratio of EDTA to Cu(II)/Ni(II) increased from 1:1 to 3:1, the kinetics of metal ion removal rate declined from 0.0788 and 0.1139 min⁻¹ to 0.0250 and 0.0271 min⁻¹. The synergistic effect was found in the Cu(II)/Ni(II) blended system due to the higher catalytic capability and the lower complexation affinity toward EDTA for Ni(II). In summary, ozone oxidation can be considered as an effective technology to realize the complete decomplexation of Cu(II)/Ni(II)-EDTA that contained in chemical plating industry wastewater. Graphical Abstract
显示更多 [+] 显示较少 [-]Protective effects of dietary mannan oligosaccharide on heat stress–induced hepatic damage in broilers 全文
2020
Chen, Yueping | Cheng, Yefei | Wen, Zhao | Zhou, Yanmin
Heat stress is a major concern in broiler’s production, which can damage liver of broilers. This study investigated the protective effects of mannan oligosaccharide (MOS) on heat stress–induced hepatic injury in broilers. A total of 144 day-old male chicks were allocated into three treatment groups. Broilers raised under normal ambient temperature were fed a basal diet (control group), and broilers under heat stress (32–33 °C for 8 h daily) were given the basal diet supplemented without MOS (heat stress group) or with 1 g/kg MOS (MOS group) for 42 days. Compared with the control group, heat stress reduced liver weight, whereas increased aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities in the serum. It also reduced glutathione peroxidase (GSH-Px) activity in the serum and liver, GSH content, and superoxide dismutase (SOD) activity in the liver, but increased malondialdehyde (MDA) concentration in the serum and liver. Dietary MOS decreased serum ALT activity in heat-stressed broilers. MOS inclusion also decreased serum MDA content, but elevated hepatic GSH-Px and SOD activities, with MDA content and GSH-Px activity still being different from the control group, and SOD activity being similar to the control group. Heat stress increased concentrations of tumor necrosis factor α (TNF-α) in the serum and liver, interleukin-1β (IL-1β) in the liver, and mRNA abundances of HSP70, TLR4, MyD88, TNF-α, and IL-1β in the liver of broilers. Serum TNF-α content and mRNA abundances of hepatic TLR4 and TNF-α in MOS group were lower than the heat stress group, whereas these indexes were still higher than the control group. Our results indicated that dietary MOS ameliorated hepatic damage in heat-stressed broilers through alleviation of oxidative stress and inflammation.
显示更多 [+] 显示较少 [-]Assessment of iron-modified calcite/zeolite mixture as a capping material to control sedimentary phosphorus and nitrogen liberation 全文
2020
Zhan, Yanhui | Yu, Yang | Lin, Jianwei | Wu, Xiaolong | Wang, Yan | Zhao, Yuying
Calcite/zeolite mixture (CZ) can be used to construct a capping layer for the simultaneous management of phosphorus (P) and nitrogen (N) liberation from sediments into the overlying water (OVER-water). However, its control efficiency of sedimentary P release still needs to be improved. To address this issue, an iron-modified CZ (Fe-CZ) was synthesized, characterized, and employed as a capping material to simultaneously prevent P and N release from sediments into OVER-water. Batch and microcosm incubation experiments were performed to study the efficiency and mechanism for the control of P and N release from sediments by capping Fe-CZ. Results showed that sediment capping with Fe-CZ resulted in the significant reduction of soluble reactive P (SRP) and ammonium-N (NH₃-N) in OVER-water, with reduction rates of 77.8–99.7% and 54.0–96.7%, respectively. Furthermore, the Fe-CZ capping layer decreased the SRP concentration in the pore water (PORE-water) at depth of 0–30 mm and reduced the concentration of PORE-water NH₃-N at depth of 0–50 mm. Moreover, the Fe-CZ capping layer gave rise to the great decrement of the concentration of the labile P measured by DGT (diffusive gradient in thin films) technology (P-DGT) in the profile of OVER-water and sediment. Additionally, the Fe-CZ capping resulted in the reduction of redox-sensitive P (P-BD) in the 0–50 mm sediment and caused the transformation of P-BD to calcium-bound P (P-HCl) and residual P (P-RES) in the 0–10 mm sediment as well as to P-RES in the 10–20 mm sediment. Results of this work indicate that the Fe-CZ capping has a high potential for the simultaneous management of P and N release from sediments, and the decrease of the contents of sediment P-DGT, sediment P-BD, PORE-water SRP and PORE-water NH₃-N as well as the conversion of mobile P to more stable P in the top sediment should have a significant role in the simultaneous interception of sedimentary P and N liberation into OVER-water by the Fe-CZ capping.
显示更多 [+] 显示较少 [-]Behaviour of waste polypropylene pyrolysis char-based epoxy composite materials 全文
2020
Sogancioglu, Merve | Yel, Esra | Ahmetli, Gulnare
In this study, polypropylene (PP) plastic wastes were pyrolysed. Solid pyrolysis product (char) was used as filler material for the preparation of epoxy composite. 300, 400, 500, 600 and 700 °C were selected as final pyrolysis temperatures. Solid pyrolysis product (char) was analysed by elemental, FTIR, SEM, BET and TGA analysis. The epoxy composite samples were prepared with char obtained from pyrolysis. Mechanical properties of composites were analysed by hardness, tensile strength, elongation at break, electrical conductivity tests to explain the effects of pyrolysis temperature and char doses over composite properties. Thermogravimetric properties of composites were determined by TGA analyses. The water absorption behaviour of composite samples was determined by water adsorption test. Epoxy composite produced from PP char obtained under 300 °C showed the most ideal behaviour.
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