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Vulnerability assessment of areas allocated for municipal solid waste disposal systems: a case study of sanitary landfill and incineration 全文
2019
Ngamsang, Thittaya | Yuttitham, Monthira
This study was conducted to assess the vulnerability of areas allocated for sanitary landfill in Nakhon Ratchasima and for incineration in Phuket, Thailand, and to investigate the factors contributing to their vulnerability. Analysis was conducted to develop a vulnerability index using a composite index approach and the Intergovernmental Panel on Climate Change (IPCC) framework approach, while correlation and t tests were applied to identify the relationships and differences between the two systems. Additionally, vulnerability indices were developed using the IPCC vulnerability definition. The results suggested that the vulnerability of the areas allocated for sanitary landfill and incineration were not significantly different. The factor that had the greatest impact on the vulnerability of the sanitary landfill was nuisance, while sub-component correlation analysis revealed that cadmium in groundwater was significantly negatively correlated with vulnerability (r = − 0.958, p < 0.05). Furthermore, the factor that had the greatest effect on vulnerability from incineration was leachate. Similarly, correlation analysis suggested that the chemical oxygen demand in leachate and solid waste residues was significantly positively correlated with vulnerability (r = 0.981, 0.975 respectively, p < .05). It is hoped that these findings can be used to establish measures for preventing environmental problems, as well as to prioritize and identify issues that need to be resolved urgently, and to help policy makers select appropriate systems for different regions of Thailand.
显示更多 [+] 显示较少 [-]Ginkgo biloba attenuates aluminum lactate-induced neurotoxicity in reproductive senescent female rats: behavioral, biochemical, and histopathological study 全文
2019
Verma, Sonia | Ranawat, Pavitra | Sharma, Neha | Nehru, Bimla
Extensive use of aluminum (Al) in industry, cooking utensils, and wrapping or freezing the food items, due to its cheapness and abundance in the environment, has become a major concern. Growing evidence supports that environmental pollutant Al promotes the aggregation of amyloid beta (Aβ) in the brain, which is the main pathological marker of Alzheimer’s disease (AD). Further, AD- and Al-induced neurotoxic effects are more common among women following reproductive senescence due to decline in estrogen. Though clinically Ginkgo biloba extract (GBE) has been exploited as a memory enhancer, its role in Al-induced neurotoxicity in reproductive senescent female rats needs to be evaluated. Animals were exposed to intraperitoneal dose (10 mg/kg b.wt) of Al and oral dose (100 mg/kg b.wt.) of GBE daily for 6 weeks. A significant decline in the Al-induced Aβ aggregates was observed in hippocampal and cortical regions of the brain with GBE supplementation, as confirmed by thioflavin (ThT) and Congo red staining. GBE administration significantly decreased the reactive oxygen species, lipid peroxidation, nitric oxide, and citrulline levels in comparison to Al-treated rats. On the contrary, a significant increase in the reduced glutathione, GSH/GSSG ratio as well as in the activities of antioxidant enzymes was observed with GBE administration. Based on the above results, GBE prevented the neuronal loss in the hippocampus and cortex, hence caused significant improvement in the learning and memory of the animals in terms of AChE activity, serotonin levels, Morris water maze, and active and passive avoidance tests. In conclusion, GBE has alleviated the behavioral, biochemical, and histopathological alterations due to Al toxicity in rats. However, molecular studies are going on to better understand the mechanism of GBE protection against the environmental toxicant Al exposure. Graphical abstract .
显示更多 [+] 显示较少 [-]Enhanced Bioremediation of Heavy Metal Contaminated Landfill Soil Using Filamentous Fungi Consortia: a Demonstration of Bioaugmentation Potential 全文
2019
Hassan, Auwalu | Pariatamby, Agamuthu | Ahmed, Aziz | Auta, Helen Shnada | Hamid, Fauziah Shahul
This study aimed to determine the mycoremediative capacity of filamentous fungi consortia in landfill heavy metal contaminated soil. Streak plate method was utilized for the isolation of fungi from the landfill soil. Isolates were identified using morphological and molecular techniques. Heavy metal tolerance of the fungi was determined using radial growth diameter technique. Twelve species of landfill indigenous fungi were used for the bioremediation process. Two categories of fungi consortia namely highly tolerant fungi (Perenniporia subtephropora, Daldinia starbaeckii, Phanerochaete concrescens, Cerrena aurantiopora, Fusarium equiseti, Polyporales sp., Aspergillus niger, Aspergillus fumigatus, and Trametes versicolor) and moderately tolerant fungi (Paecilomyces lilacinus, Antrodia serialis, and Penicillium cataractum) were used to amend the contaminated soil; meanwhile, the unamended soil served as control. Maximum tolerance index of 1.0 was reported in Cr-, Cu-, and Fe-amended PDA medium. Meanwhile, the maximum heavy metal bioremoval efficiencies were for highly tolerant fungal consortium treated soil and were recorded as As (62%) > Mn (59%) > Cu (49%) > Cr (42%) > Fe (38%). Likewise, the maximum metal removal rate constant (K) and the half-lives (t₁/₂) were 0.0097/day 71 days, 0.0088/day 79 days, 0.0067/day 103 days, 0.0054/day 128 days, and 0.0048/day 144 days for As, Mn, Cu, Cr, and Fe, respectively, which were all for soil treated with consortium of highly tolerant fungi (P. subtephropora, D. starbaeckii, P. concrescens, C. aurantiopora, F. equiseti, Polyporales sp., A. niger, A. fumigatus, and T. versicolor). Spectra analysis revealed a clear distinction in the functional groups between the fungal treated and the untreated soils. Peaks at 874 ± 2 cm⁻¹ and 1425 ± 2 cm⁻¹ were only found in fungi amended soil. Physicochemical parameters mainly pH and redox potential played a key role in the bioremediation process, and bioaccumulation was believed to be the favored mechanism for the metal bioremoval. The data are suitable for assessing the contribution of bioaugmentation with consortia of fungi. It is equally important for assessing the synergistic effect of fungi on the reduction of extractable heavy metals in contaminated soil.
显示更多 [+] 显示较少 [-]Industrial environmental efficiency assessment for China’s western regions by using a SBM-based DEA 全文
2019
Guo, Si-Dai | Li, Hang | Zhao, Rui | Zhou, Xiao
This study employed a data envelopment analysis (DEA) by using slacks-based measure (SBM) with undesirable outputs to assess the industrial environmental efficiency of western China during the period of 2001–2015. The Malmquist index was further used to examine the changes in the industrial environmental efficiency of the analyzed region. The result showed that western China presented a low industrial environmental efficiency throughout the period of 2001–2015. Chongqing City was the only province that exhibited strong economic and environmental coordination. The level of technical development was identified as a key determinant of industrial environmental efficiency. This study provided policy implications on emissions reduction and the improvement of industrial efficiency. Limitations of the approach were provided to lay foundation for future studies.
显示更多 [+] 显示较少 [-]How does intensification influence the operational and environmental performance of photo-Fenton processes at acidic and circumneutral pH 全文
2019
Salazar, Luis Miguel | Grisales, Claudia Mildred | Garcia, Dorian Prato
This study evaluates the technical, economical, and environmental impact of sodium persulfate (Na₂S₂O₈) as an enhancing agent in a photo-Fenton process within a solar-pond type reactor (SPR). Photo-Fenton (PF) and photo-Fenton intensified with the addition of persulfate (PFPS) processes decolorize 97% the azo dye direct blue 71 (DB71) and allow producing a highly biodegradable effluent. Intensification with persulfate allowed reducing treatment time in 33% (from 120 to 80 min) and the consumption of chemical auxiliaries needed for pH adjustment. Energy, reagents, and chemical auxiliaries are still and environmental hotspot for PF and PFPS; however, it is worth mentioning that their environmental footprint is lower than that observed for compound parabolic concentrator (CPC)-type reactors. A life-cycle assessment (LCA) confirms that H₂O₂, NaOH, and energy consumption are the variables with the highest impact from an environmental standpoint. The use of persulfate reduced the relative impact in 1.2 to 12% in 12 of the 18 environmental categories studied using the ReCiPe method. The PFPS process emits 1.23 kg CO₂ (CO₂-Eqv/m³ treated water). On the other hand, the PF process emits 1.28 kg CO₂ (CO₂-Eqv/m³ treated water). Process intensification, chemometric techniques, and the use of SPRs minimize the impact of some barriers (reagent and energy consumption, technical complexity of reactors, pressure drops, dirt on the reflecting surfaces, fragility of reactor materials), limiting the application of advanced oxidation systems at an industrial level, and decrease treatment cost as well as potential environmental impacts associated with energy and reagents consumption. Treatment costs for PF processes (US$0.78/m³) and PFPS processes (US$0.63/m³) were 20 times lower than those reported for photo-Fenton processes in CPC-type reactors.
显示更多 [+] 显示较少 [-]Nanostructured catalysts applied to degrade atrazine in aqueous phase by heterogeneous photo-Fenton process 全文
2019
Benzaquén, Tamara B. | Barrera, Deicy A. | Carraro, Paola M. | Sapag, Karim | Alfano, Orlando M. | Eimer, Griselda A.
SBA-15 and KIT-6 materials have been synthesized and modified with iron salts by the wet impregnation method with different metal loadings. The different mesostructures obtained were characterized by N₂ adsorption–desorption at 77 K, X-ray diffraction, temperature-programmed reduction, and ultraviolet–visible spectroscopy. These iron-containing mesostructured materials have been successfully tested for the heterogeneous photo-Fenton degradation of aqueous solutions of dangerous herbicides, such as atrazine, using UV–visible light irradiation, at room temperature and close to neutral pH. The results showed that the Fe/SBA-15 (10%) and Fe/KIT-6 (5%) catalysts exhibited the highest activities. However, the Fe/KIT-6 (5%) catalyst with minor Fe loading than Fe/SBA-15 (10%) presented a higher degradation of atrazine (above 98% in a reaction time of 240 min). Therefore, the interconnectivity of the cage-like mesopores had an important influence on the catalytic activity, favoring probably mass-transfer effects. Thus, the high performance of these materials indicates that the heterogeneous via of photo-Fenton process can also be efficiently employed to treat wastewaters containing pollutants such as herbicides, in order to reduce them to simplest and less toxic molecules.
显示更多 [+] 显示较少 [-]Hybrid Carbon Nanochromium Composites Prepared from Chrome-Tanned Leather Shavings for Dye Adsorption 全文
2019
Arcibar-Orozco, Javier A. | Barajas-Elias, Bertha S. | Caballero-Briones, Felipe | Nielsen, Lilja | Rangel-Mendez, Jose R.
Every year, the leather tanning industry produces substantial quantities of residues such as chrome-tanned leather shavings (CTLS), which contain considerable amounts of Cr(III) salts. The residues have no particular value and under natural conditions can transform into toxic Cr(VI) wastes. The objective of the present work is to evaluate the transformation of these residues into carbon adsorbents at low temperatures (< 600 °C), using ZnCl₂ as an activating agent. The pyrolysis temperature and residence times were studied. The materials were characterized and qualified by Acid Black 210 (AB) adsorption. The results indicated that low amounts of chromium oxides (less than 2% of Cr), in the form of 50–200 nm particles, remained after the synthesis procedure. The deposited chromium oxides were present in (II), (III), and (IV) oxidation states. The low preparation temperatures employed prevented further chromium oxidation to Cr(VI). Maximum surface areas of 439 m²/g were obtained. The materials efficiently removed AB (maximum experimental adsorption capacity of 44.4 mg/g) by means of electrostatic interaction caused by the positively charged distribution of the carbons. The adsorption capacity was not affected by temperature, but pH had a mixed effect due to the combination of a shift in surface charge distribution and dye speciation. The results demonstrated that it is possible to obtain a value-added product, i.e., carbons modified with chromium nanoparticles for dye removal, from a hazardous residue of the tanning industry.
显示更多 [+] 显示较少 [-]Effect of Copper Oxide Nanoparticles on the Physiology, Bioactive Molecules, and Transcriptional Changes in Brassica rapa ssp. rapa Seedlings 全文
2019
Chung, Ill-Min | Rekha, Kaliyaperumal | Venkidasamy, Baskar | Thiruvengadam, Muthu
Global deterioration of water, air, and soil quality by the release of toxic chemicals from anthropogenic pollutants is becoming a serious global problem. The extensive use of copper oxide nanoparticles (CuO NPs) can be environmentally hazardous when these NPs enter the atmosphere. The present study aimed to evaluate the role of CuO NPs on plant growth, photosynthetic capacity, and bioactive compounds, as well as their transcriptional level changes in Brassica rapa seedlings. Chlorophyll, carotenoid, and sugar content decreased, while proline and anthocyanins were significantly enhanced in the CuO NP-treated seedlings compared with the untreated controls. Reactive oxygen species (ROS), malondialdehyde (MDA), and hydrogen peroxide (H₂O₂) production were also enhanced in the seedlings exposed to CuO NPs, which could have caused DNA damage that was detected by a DNA laddering assay. The glucosinolate (GSL) and phenolic compound content were significantly increased in CuO NP-treated seedlings compared with that in control seedlings. Transcriptional variation of genes associated with oxidative stress (CAT, POD, and GST), R2R3-type MYB involved in GSL (BrMYB28, BrMYB29, BrMYB34, and BrMYB51), and phenolic compounds (ANS, PAP1, PAL, and FLS) biosynthesis was analyzed using real-time polymerase chain reaction. Significant upregulation of CAT, POD, GST, BrMYB28, BrMYB29, BrMYB34, BrMYB51, ANS, PAP1, PAL, and FLS genes was observed in seedlings exposed to different concentrations of CuO NPs relative to the untreated seedlings. Therefore, we suggest that the use of CuO NPs could stimulate the toxic effects and enhance phytochemicals (i.e., glucosinolates and phenolic compounds) in B. rapa.
显示更多 [+] 显示较少 [-]Ammonia Oxidizers as Biological Health Indicators of Elevated Zn and Cu in Poultry Litter Amended Soil 全文
2019
Mundepi, Abha | Cabrera, Miguel | Norton, Jeanette | Habteselassie, Mussie
Ammonia-oxidixing bacteria (AOB) and archaea (AOA) mediate the first and rate-limiting step of nitrification and are responsive to agricultural management practices. These two attributes make them ideal indicators of biological soil health. We conducted a laboratory incubation study to determine their response to elevated levels of zinc (Zn) and copper (Cu) in poultry litter treated soil at three substrate concentrations: 0 (low), 50 (medium) and 100 (high) mg ammonium ([Formula: see text]-N) kg⁻¹ soil. Nitrification potential (NP) was measured to characterize changes in their function in which 1-octyne was used to separate their contributions. Quantitative polymerase chain reaction was used to measure their abundance by targeting amoA. Increasing Zn from 21 to 250 mg kg⁻¹ resulted in large reductions in AOB (78%) and AOA (85%) abundance at the high [Formula: see text] level over 28 days. Likewise, increasing Cu from 20 to 120 mg kg⁻¹ significantly reduced AOB (92%) and AOA (63%) abundance at the high [Formula: see text] level over 28 days. The relative contribution of AOB to NP was significantly higher than that of AOA in both Zn (~60%) and Cu (~70%) treated soils despite the numerical dominance of AOA over AOB. Overall, results indicate that elevated levels of Zn and Cu depressed AOB and AOA abundance and function and that their effect was dependent on availability of [Formula: see text]. The results also indicated that AOB are functionally more important than AOA under elevated Zn and Cu concentrations and that management practices to improve N use efficiency should focus on AOB under this condition.
显示更多 [+] 显示较少 [-]Trends of electronic waste pollution and its impact on the global environment and ecosystem 全文
2019
Akram, Rida | Andrews, Martina | Shah, Fahad | Hashmi, Muhammad Zaffar | Wahid, Abdul | Kātibī, Muḥammad ʻAdnān | Mubeen, Muhammad | Khan, Naeem | Rehmani, Muhammad Ishaq Asif | Awais, Muhammadd | ʻAbbās, Maẓhar | Shahzad, Khurram | Ahmad, Shakeel | Hammad, Hafiz Mohkum | Nasim, Wajid
Electronic waste (e-waste) is used for all electronic/electrical devices which are no more used. Conventionally, waste management policies are desfighandle the traditional waste. Although e-waste contains toxic materials, however, its management is rarely focused by policy makers; therefore, its negative impact on the global environment, ecosystem, and human health is aggravated. The review outlines the categories of e-waste materials, major pollutants including ferrous/non-ferrous metals, plastics, glass, printed circuit boards, cement, ceramic, and rubber beside, some valuable metals (such as copper, silver, gold, platinum). Toxic elements from e-waste materials, released in the air, water, and soil, include arsenic, cadmium, chromium, mercury, and lead, causing pollution. Although their roles in biological systems are poorly identified, however, they possess significant toxic and carcinogenic potential. It is therefore critical to monitor footprint and device strategies to address e-waste-linked issues from manufacturing, exportation, to ultimate dumping, including technology transmissions for its recycling. This review traces a plausible link among e-waste condition at a worldwide dimension, as far as settlement procedures to keep it secure and carefully monitored when traded. Their fate in the three spheres of the earth, i.e., water, soil, and air, impacts human health. The strategies and regulation to handle e-waste generation at the global level have been discussed. Graphical abstract .
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