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711.
Environmental Chemistry Letters - Aflatoxin M1 contamination in milk and dairy products is a major issue worldwide. Aflatoxin is a carcinogen that enters into the milk through animals feed. Here,...  相似文献   
712.
The main aim of this paper was to identify job stressors, gender responses and association of psychosocial work stressors with prevalence of work related musculoskeletal disorders (MSDs) among foundry workers. The data were obtained with ergonomics checklist using Likert scale. The results of this study showed a high prevalence of MSDs among workers. The male workers were more prone to pain in neck while the female workers were more prone to MSDs in upper back and shoulders. Correlation analysis showed significant relationship of dimensions of work aspects with pain and discomfort. It proved that the work-related MSDs are the results of interaction of multiple stressors associated with work and work environment, and other personal factors. ANOVA indicated that the perception of work aspects as stressors differed significantly between male and female workers.  相似文献   
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714.
The air pollution due to anthropogenic activities seriously affected human life, vegetation, and heritage as well. The vegetation cover in and around the city mitigates the air pollution by acting as a sink for pollution. An attempt was made to evaluate biochemical changes occurred in four selected plant species, namely Azadirachta indica, Mangifera indica, Delonix regia, and Cassia fistula of residential, commercial, and industrial areas of Nagpur city in India. It was observed that the correlated values of air pollutants and plant leaves characteristics alter foliar biochemical features (i.e., chlorophyll and ascorbic acid content, pH and relative water content) of plants due to air pollution. The changes in air pollution tolerance index of plants was also estimated which revealed that these plants can be used as a biomarker of air pollution.  相似文献   
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The effect of different Lystek biosolids doses on the anaerobic digestability of thickened waste activated sludge (TWAS) was evaluated in a lab- and full-scale anaerobic digester. The overall findings of this study emphasize the beneficial impact of Lystek addition to the lab- and full-scale anaerobic digesters in terms of enhanced biogas production and increased volatile suspended solids reduction (VSSR) efficiency. Lystek added at 4% by volume to TWAS increased the methane yield from 0.22 to 0.26 L CH4/g VSSadded at an solids retention time (SRT) of 10 days, and from 0.27 to 0.29 L CH4/g VSSadded at an SRT of 15 days. Furthermore, the VSSRs of 37% and 47% were observed for the TWAS, and the TWAS with 4% Lystek, while at an SRT of 15 days, the observed VSSR were 49% and 58%, respectively. The lab-scale study showed that the influence of Lystek addition on methane yield and solids destruction efficiencies was more pronounced at the shorter SRT, 20% enhancement (SRT of 10 d) vs. 9% enhancement (SRT of 15 d) for methane yield, and 27% (SRT of 10 d) vs. 22% (SRT of 15 d) for VSS destruction efficiency improvement. Furthermore, addition of 4% of Lystek to the feed of the full-scale anaerobic digester at St. Marys wastewater treatment plant (WWTP) resulted in a 50% increase in the average specific methanogenic activity and 23% increase in methane yield of the biochemical methane potential tests after eight months. The results showed that Lystek degradation kinetics were 40% faster than the TWAS, as reflected by first order kinetic coefficients of 0.053 d?1 and 0.073 d?1 for TWAS and Lystek at an SRT of 10 days.  相似文献   
718.
Biowastes are becoming potential feedstocks for direct utilization or conversion to solid, liquid and gaseous fuels via various thermochemical routes. In this regard, jute dust which is a major agro-industrial waste in jute mills was pyrolysed in a fixed-bed reactor with an aim to study the product distribution and their characterization and to identify the optimum condition for bio-oil yield. The investigated process variables were temperature (400–700 °C), heating rate (10 and 40 °C/min) and nitrogen gas flow rate (50–250 ml/min). The yield of bio-oil is found to be maximum at 500 °C with a heating rate of 40 °C/min. However, further increase in temperature leads to decrease in bio-oil yield. Chemical compositions of the bio-oils were investigated using chromatographic and spectroscopic techniques such as 1H NMR, FTIR and GC–MS. The heating value of the bio-oil is 26.71 MJ/kg. The study shows that jute dust have potential for conversion to bio-oil through the process of pyrolysis to supplement the petro-derived liquid fuel for heating and transportation applications after upgrading. The biochar produced as a co-product of jute dust pyrolysis can be a potential soil amendment with multiple benefits including increased soil fertility and C-sequestration.  相似文献   
719.
Removal of nutrients like nitrogen and phosphorus from wastewater can be accomplished by precipitating these as the mineral struvite (NH4MgPO4. 6H2O). Predicting struvite precipitation potential, yield, and purity is important for designers and operators of reactors for struvite precipitation. In this paper, a mathematical model of this precipitation process is developed using physicochemical equilibrium expressions, mass balance equations for nitrogen, phosphorous and magnesium, and charge balance. The model was simulated to explicitly solve for equilibrium concentrations of eighteen species that included dissolved (three), ionic (ten), and solid (five) species for a given set of initial concentrations of ammonium–nitrogen, magnesium and phosphate–phosphorus, and pH. The model simulations were validated against literature experimental data, which used synthetic as well as actual wastewater, and data from our experiments. The model satisfactorily predicted most data. Struvite fraction in the precipitate ranged from 27% to 100%. The purity of struvite in the precipitate and the pH that maximizes struvite fraction was dependent on the initial concentrations of ammonium, magnesium, and phosphate. Optimum pH and struvite fraction was, respectively, 8.5 and 29.3% for an equimolar mixture of ammonia, magnesium, and phosphate and 9.8 and 98.3% for 10:1.7:3.4 mM ratio. Struvite fraction in the precipitate increased as magnesium became limiting or as ammonia to phosphate ratio increased and magnesium to phosphate ratio decreased. Since the struvite component is only a fraction of the total solids, it is erroneous to report the total precipitate produced as being struvite as is conventionally done.  相似文献   
720.
对棉杆热解渣分别进行物理、化学及物理化学综合活化,并以它们为载体,分别负载锰铈的氧化物获得催化剂,探讨它们用于低温选择性催化还原的脱硝性能。同时对3种催化剂进行BET、NH3-TPD、H2-TPR和XRD表征研究。结果表明,经过物理化学综合法活化后所得催化剂的比表面积最大,可达到1 614 m2/g,且其微孔中孔分布最为丰富;NH3-TPD表征结果说明化学活化法所得催化剂对NH3吸附效果最佳,其次为物理化学综合活化法所得的催化剂;H2-TPR表征结果可知经化学活化法所得催化剂氧化还原性最好,其次为物理化学综合活化法所得的催化剂;脱硝试验结果可知物理化学综合活化法所得到的催化剂在低温条件下SCR活性最佳,并对结果进行了分析。  相似文献   
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