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Presence of veterinary antibiotics in livestock manure in two Southeastern Europe countries, Albania and Kosovo
2020
Topi, Dritan | Spahiu, Jeton
Nowadays, veterinary drug application has become an integral practice in livestock farming. Veterinary antibiotics (VAs) are administered onto animals for therapeutic use; meanwhile, in some countries, they are used for growth promotion. To indicate the level of VAs use in livestock breeding in two countries, Albania and Kosovo, their presence was studied in the animal manure. In total, 38 manure samples, 22 from Kosovo and 16 samples from Albania, belonging to cattle, pig, and poultry, were collected and investigated for the presence of VAs. Seven VAs and 2 metabolites, from the groups of sulfonamides and tetracyclines, were identified by ultra-high pressure liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). The detected antibiotics were sulfadiazine (SDZ), sulfathiazole (STZ), sulfamethazine (SMZ), oxytetracycline (OTC), tetracycline (TC), chlortetracycline (TC), and doxycycline (DOY). VAs were detected in 27% and 31.2% of the manure samples, from Kosovo and Albania, respectively, and the levels ranged from 0.04 to 10.1 mg kg⁻¹. VAs were widely detected (100%) in poultry manure from Kosovo, as well as poultry manure from Albania. The contamination rate ranged from pig manure (25%) to cow manure (66.6%). Sulfonamides were the most commonly detected VAs with maximum concentration of sulfadiazine (10.1 mg kg⁻¹) in poultry manure. Tetracyclines were most widely detected in poultry manure, as well as other animal manures. When it comes to the comparison between the two countries, VAs residues are more frequent per analyzed sample and higher in concentrations in the manure samples from Albania. Therefore, an environmental impact of VAs on both countries may be expected. These results indicate that VAs may enter the local ecosystem through manure application to agriculture and potentially may bring ecological risks.
Show more [+] Less [-]Ni(II) Adsorption on Biochars Produced from Different Types of Biomass
2020
Mourgela, Rafaila-Nikola | Regkouzas, Panagiotis | Pellera, Frantseska-Maria | Diamadopoulos, Evan
The objective of this study was to demonstrate biochar’s effectiveness on Ni(II) removal from aqueous solutions by adsorption on three different biochars. Three different waste feedstocks, namely sewage sludge, exhausted olive pomace and the organic fraction of municipal solid waste, were used to produce biochar through pyrolysis at 300 °C, under inert conditions. The obtained biochars were characterized regarding their main properties and then evaluated as potential Ni(II) adsorbents. All investigated materials showed high adsorption efficiency in the range of 78–97%, with the biochar derived from SS exhibiting the best results, possibly because of its higher cation exchange capacity. Ni(II) removal rates were higher when the adsorption experiments were conducted at natural pH, while the removal efficiency under adjusted pH (acidic or alkaline) was slightly lower. The pseudo-second-order kinetic model adequately described the adsorption kinetics depicting high correlation coefficients, while the Freundlich adsorption isotherm model was successful in simulating equilibrium of adsorption.
Show more [+] Less [-]The relationship between corporate social responsibility, environmental investments and financial performance: evidence from manufacturing companies
2020
Shabbir, Malik Shahzad | Wisdom, Okere
The primary objective of this research is to ascertain the relationship between corporate social responsibility, environmental investments and financial performance in Nigerian manufacturing firms. The hypotheses are tested on internal environmental investments and external environmental investments on firm’s financial performance. It further determines if there is a significant difference between the profitability of environmentally conscious and environmentally non-conscious firms in Nigeria. Descriptive analysis is used to explain the variables applied and panel regression analysis is used to find out if there exists a relationship between internal environmental investments (employee benefits, staff training cost), external environmental investments (donations) and firm’s financial performance. The results indicate a positive and significant relationship exists between internal environmental investments and firm’s financial performance. It is also found a positive but insignificant relationship between external environmental investments and firm’s financial performance. Furthermore, paired sample t tests are used to reveal that there was a significant difference between the profitability of environmentally conscious and environmentally non-conscious firms. The finding of this study explains that firms with higher environmental investments have a higher profitability level than environmentally non-conscious firms.
Show more [+] Less [-]Graywater treatment technologies and reuse of reclaimed water for toilet flushing
2020
Ren, Xueli | Zhang, Yanyan | Chen, Hongbin
The reuse of wastewater is one effective approach to solving the problem of water resource scarcity. However, deterioration in the quality of reused water, such as increased odor and bacterial growth, restricts its reuse. The objectives of this study were to characterize graywater (GW) treatment technology and to verify the suitability of the reclaimed water for toilet flushing. A membrane bioreactor (MBR) and biological aerated filter (BAF) were used to treat GW in a 1-year laboratory-scale experiment. The optimal operational conditions of the MBR and BAF were as follows: hydraulic retention time = 2–3 h, dissolved oxygen = 4–7 mg/L, mixed liquor suspended solids = 3500–4500 mg/L, and contact reaction time = 1.96–5.89 h, dissolved oxygen = 3–5 mg/L, backwash cycle time = 24–48 h, respectively. The MBR treatment resulted in reductions in COD, NH₃-N, and turbidity of 60–90%, 80–90%, and 95–99%, respectively, whereas those of BAF treatment were 50–90%, 50–90%, and 80–90%, respectively. The BOD₅ values of MBR and BAF effluent were 1.2–4.5 mg/L and 2.5–7 mg/L, respectively. GW treated by both MBR and BAF met the standard for reusing water for toilet flushing. The effluent from MBR, BAF, and BAF + ultrafiltration treatment and purified mixed wastewater was used to simulate toilet flushing at 28 °C, with the addition of 5 mg/L NaClO to the reused water. The residual chlorine levels were 1.5, 0.6, 0.9, and 0.5 mg/L, respectively, after 15 days. No bacteria were detected in any of the reclaimed water after 15 days. The water quality of the effluent of MBR-treated GW was better than that of the mixed wastewater. The results show that it is viable to use GW purified by MBR for toilet flushing. This study provides a scientific basis for the popularization and application of reclaimed water for toilet flushing.
Show more [+] Less [-]Concentrations, Speciation, and Bioavailability of Heavy Metals in Street Dust as well as Relationships with Physiochemcal Properties: A Case Study of Jinan City in East China
2020
Dong, Shuzhen | Zhang, Shengwei | Wang, Lijun | Ma, Ge | Lu, Xinwei | Li, Xiaoping
A total of 77 street dust samples were collected from Jinan City in East China and were analyzed for the concentrations, speciation, bioavailability, and influencing factors of ten heavy metals. The results showed that the average concentrations of Ba, Co, Cr, Cu, Cd, Mn, Ni, Pb, Zn, and V in the street dust were 642.77, 8.24, 114.09, 87.71, 1.08, 517.04, 30.29, 80.32, 497.84, and 51.76 mg/kg, and the concentrations of Ba, Cr, Cu, Cd, Ni, Pb, and Zn exceeded the local soil element background values. In the street dust, Ba, Co, Cr, Mn, Ni, and V were mainly in the residual; Cu and Pb were controlled by the oxidizable; Cd mainly existed in the acid extractable; and Zn was dominated by the reducible. According to the ratios of the acid extractable to the sum of four forms, Cd (39.85%) presented a high environmental risk; Mn and Zn (24.29% and 27.78%) exhibited a medium risk; and V, Cu, Pb, Ba, Co, Ni, and Cr had no environmental risk. The order of mobility or potential risk of heavy metals was Cd (85.8%) > Zn (77.1%) > Cu (64.3%) > Pb (62.0%) > Mn (51.7%) > Ba (38.9%) > Co (31.2%) > Ni (30.1%) > V (25.8%) > Cr (23.1%), suggesting that Cd, Zn, Cu, Pb, and Mn presented relatively high movability and risk. The bioavailability order of heavy metals was Cd (82.7%) > Zn (63.6%) > Mn (40.4%) > Ni (20.4%) > Pb (11.7%) > Cu (11.1%) > V (7.8%) > Cr (3.7%) in the gastric phase and Cu (24.6%) > Cd (19.9%) > Mn (16.2%) > Ni (6.6%) > Pb (5.7%) > Zn (4.4%) > Cr (3.0%) > V (2.3%) in intestinal phase, implying that Cd, Zn, Mn, and Cu were highly bioavailable in the gastrointestinal environment, which coincided with the risk of speciation. The speciation of heavy metals in street dust had certain correlations with their bioavailability. The physiochemical properties of street dust had significant effects on the concentrations, speciation, and bioavailability of heavy metals in street dust. The simple, fast, and nondestructive magnetic measurements could be used as indicators of the concentrations, speciation, and bioavailability of heavy metals in street dust.
Show more [+] Less [-]Removal of Trichloroethylene by Sulfide-Modified Nanoscale Zerovalent Iron Coated with Different Stabilizers in Aqueous Solution
2020
Ning, Qin | Dong, Haoran | Li, Long | Wang, Yaoyao | Wang, Bin
In this study, the dispersion stability and reactivity of sulfide-modified nanoscale zerovalent iron (SNZVI) coated with different surface stabilizers (i.e., starch, sodium dodecylbenzene sulfonate (SDBS), or carboxymethyl cellulose (CMC)) were investigated. All the three types of surface stabilizers could enhance the dispersion stability of SNZVI but exerted differing influences on the reactivity toward trichloroethylene (TCE) removal. The coating of starch on SNZVI markedly improved TCE removal, which was positively correlated with the enhanced dispersion stability (i.e., more active surface sites). However, although the SDBS and CMC could enhance the dispersion stability of SNZVI, they resulted in an inhibition in TCE removal, especially for CMC. It was presumed that the coated SDBS/CMC on the surface of SNZVI occupied the active surface sites for TCE removal. Besides, the effect of groundwater geochemistry (i.e., pH, Ca²⁺, and humic acid (HA)) was examined. The increasing pH from 5 to 9 led to a slight decrease for all stabilized SNZVI particles. The presence of Ca²⁺ or HA exerted distinct influence on the TCE removal by the three stabilized SNZVI. The Ca²⁺/HA exerted an insignificant effect on the reactivity of CMC-SNZVI but markedly decreased the reactivity of starch-SNZVI and SDBS-SNZVI. The varying effects of Ca²⁺/HA should be due to their distinct interactions with different types of stabilizers on the surface of SNZVI.
Show more [+] Less [-]Review: Efficiently performing periodic elements with modern adsorption technologies for arsenic removal
2020
Uddin, Md Jamal | Jeong, Yeon-Koo
Arsenic (As) toxicity is a global phenomenon, and it is continuously threatening human life. Arsenic remains in the Earth’s crust in the forms of rocks and minerals, which can be released into water. In addition, anthropogenic activity also contributes to increase of As concentration in water. Arsenic-contaminated water is used as a raw water for drinking water treatment plants in many parts of the world especially Bangladesh and India. Based on extensive literature study, adsorption is the superior method of arsenic removal from water and Fe is the most researched periodic element in different adsorbent. Oxides and hydroxides of Fe-based adsorbents have been reported to have excellent adsorptive capacity to reduce As concentration to below recommended level. In addition, Fe-based adsorbents were found less expensive and not to have any toxicity after treatment. Most of the available commercial adsorbents were also found to be Fe based. Nanoparticles of Fe-, Ti-, Cu-, and Zr-based adsorbents have been found superior As removal capacity. Mixed element-based adsorbents (Fe-Mn, Fe-Ti, Fe-Cu, Fe-Zr, Fe-Cu-Y, Fe-Mg, etc.) removed As efficiently from water. Oxidation of AsO₃³⁻ to AsO₄³⁻and adsorption of oxidized As on the mixed element-based adsorbent occurred by different adsorbents. Metal organic frameworks have also been confirmed as good performance adsorbents for As but had a limited application due to nano-crystallinity. However, using porous materials having extended surface area as carrier for nano-sized adsorbents could alleviate the separation problem of the used adsorbent after treatment and displayed outstanding removal performances.
Show more [+] Less [-]Speciation and accumulation pattern of heavy metals from soil to rice at different growth stages in farmland of southwestern China
2020
Zhang, Zhenming | Wu, Xianliang | Wu, Qiusheng | Huang, Xianfei | Zhang, Jiachun | Fang, Hui
Paddy rice, one of the most important food crops in Southeast Asia, is considered a main source of human exposure to heavy metal contamination because it efficiently accumulates heavy metals. In the present study, of Japonica rice grains, straw, roots, leaves, and husks and rhizosphere paddy soils (0–20 cm and 20–40 cm depth) were collected from Zunyi in northern Guizhou Province, China. The forms of heavy metals, including Cr, Cd, Pb, Cu, and Zn, in the two soil profiles were investigated using Tessier’s five-stage sequential extraction procedure. There was no heavy metal pollution in the study area based on the evaluation of the geo-accumulation index and the potential ecological risk index. Accumulation varied from one area to another, and the highest metal accumulation was found in the order of root > stems > leaves. The bioaccumulation factor (BCF) results revealed that during the grain-filling stage, the rice had high BCF values (> 1) for Cd and Zn. The target hazard quotient (THQ) of ingestion peaked for Cd and reached its minimum level for Zn in not only in adults but also in children. The THQ was ranked as Cd > Cu > Pb > Cr > Zn for both adults and children. The hazard index values for adults and children for the five heavy metals were 1.81 × 10⁻³ and 1.55 × 10⁻³, respectively, indicating that these metals have little effect on the human body. The lifetime carcinogenic risk values for local adults and children were 4.28 × 10⁻⁵ and 5.92 × 10⁻⁵, respectively, both of which were within the tolerable to acceptable risk range. In summary, obvious hazards for local adults and children were not observed in this study. Considering the total amount and chemical forms of Cd, it is necessary to notify the appropriate departments about the possible rice contamination caused by Cd in the soil.
Show more [+] Less [-]Research on the technology of detection and risk assessment of fire areas in gangue hills
2020
Wang, Haiyan | Tan, Bo | Zhang, Xuedong
Coal gangue hills are prone to spontaneous combustion, thereby polluting the environment of mining areas such as the soil, groundwater, and atmosphere, and the frequent occurrence of gangue hill collapses, landslides, explosions, and other accidents can even endanger the lives and property of residents. To realize the safety management of coal gangue spontaneous combustion and evaluate its present risks, this paper selects the Dongzhou Kiln gangue hill in Zuoyun County, Datong City, China, as the research object to conduct a risk assessment study. The Dongzhou gangue hill fire area is relatively large, with a total area of 183,039 m². Smoke emission commonly occurs at the site, and the surface temperature reaches 50 °C, while the CO concentration exceeds 10⁻³. A radon detection scheme for concealed fire zones verified with borehole temperature measurements is applied. The high-temperature area is delineated with relevant data obtained by infrared thermal imaging, radon concentration, and borehole temperature detection technologies, and a coal gangue spontaneous combustion risk assessment method is established, while the gas toxicity and explosion risks of the construction area and fire trends are analyzed. The research results indicate that there are 6 likely high-temperature regions in the test area, 4 high-toxicity areas in the drilling construction area, 1 area with a high explosion risk, and 3 areas with a high risk of spontaneous combustion. Among these areas, platform 2 is a high-risk area and needs to be carefully considered. The construction of the entire area is at high risk, including toxicity, gas explosion, and spontaneous combustion risks, and measures must be implemented to reduce the overall risk.
Show more [+] Less [-]How does “the Belt and Road” and the Sino-US trade conflict affect global and Chinese CO2 emissions?
2020
Fan, Jing-Li | Dong, Yangyang | Zhang, Xian
In the context of the rapid development of the Belt and Road (B&R) Initiative, the continuous transfer of Sino-US trade to the B&R countries is an important means to mitigate the threat of Sino-US trade, and the environmental impact of this transfer should be considered, so as to provide a scientific basis for China’s policy formulation about achieving this possible trade transfer with minimized environmental impacts. This study proposes a multiregional input-output model and analyzes the impact on carbon dioxide (CO₂) emissions of transferring the Sino-US trade to the B&R countries for two types of scenarios. The results show the following: (1) A transfer of either the import trade or the export trade increases global and Chinese CO₂ emissions by 81.76 Mt and 24.84 Mt, respectively. When both the import trade and export trade are transferred, the increases in CO₂ emissions are only 0.22% and 0.26%, respectively. (2) Globally, the changes in international trade-embodied CO₂ emissions are responsible for most of the global emission changes, especially the CO₂ emissions exported from Russia, India, and many Southeast Asian countries to China. (3) Different from the impact on global emissions, the increases in Chinese domestic production-based CO₂ emissions influence China’s total CO₂ emissions. Due to the imported CO₂ emissions, the consumption-based CO₂ emissions are affected to a greater degree and increase by 70.30 Mt, accounting for only 0.86% of the CO₂ emissions in 2015. Finally, some policy implications are proposed.
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