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Improvement studies on emission and combustion characteristics of DICI engine fuelled with colloidal emulsion of diesel distillate of plastic oil, TiO2 nanoparticles and water Full text
2018
Karisathan Sundararajan, Narayanan | Ammal, AnandRamachandran Bhagavathi
Experimentation was conducted on a single cylinder CI engine using processed colloidal emulsions of TiO₂ nanoparticle-water-diesel distillate of crude plastic diesel oil as test fuel. The test fuel was prepared with plastic diesel oil as the principal constituent by a novel blending technique with an aim to improve the working characteristics. The results obtained by the test fuel from the experiments were compared with that of commercial petro-diesel (CPD) fuel for same engine operating parameters. Plastic oil produced from high density polyethylene plastic waste by pyrolysis was subjected to fractional distillation for separating plastic diesel oil (PDO) that contains diesel range hydrocarbons. The blending process showed a little improvement in the field of fuel oil-water-nanometal oxide colloidal emulsion preparation due to the influence of surfactant in electrostatic stabilization, dielectric potential, and pH of the colloidal medium on the absolute value of zeta potential, a measure of colloidal stability. The engine tests with nano-emulsions of PDO showed an increase in ignition delay (23.43%), and decrease in EGT (6.05%), BSNOₓ (7.13%), and BSCO (28.96%) relative to PDO at rated load. Combustion curve profiles, percentage distribution of compounds, and physical and chemical properties of test fuels ascertains these results. The combustion acceleration at diffused combustion phase was evidenced in TiO₂ emulsion fuels under study.
Show more [+] Less [-]Dissipation of antibiotics in three different agricultural soils after repeated application of biosolids Full text
2018
Yang, Lu | Wu, Longhua | Liu, Wuxing | Huang, Yujuan | Luo, Yongming | Christie, Peter
Application of biosolids to agricultural soils is one of the pathways by which antibiotics can be introduced into agricultural ecosystems. A pot experiment was conducted with repeated soil amendment with biosolids to examine the concentrations of four classes of antibiotics (tetracyclines, sulfonamides, fluoroquinolones, and macrolides) and their dissipation in three different soil types in wheat-rice rotations. Antibiotics accumulate in the soils after repeated application of biosolids. Fluoroquinolones showed stronger accumulation and persistence in the test soils than the other three classes of antibiotics. The maximum residual antibiotic concentration was that of norfloxacin at 155 ± 16 μg kg⁻¹ in the Typic Hapli-Stagnic Anthrosols (paddy soil). Predicted half-lives were up to 3.69 years, a much longer period than that between biosolid applications (twice each year on average). Antibiotic accumulation followed the rough order fluoroquinolones > tetracyclines > macrolides > sulfonamides, and the sulfonamides were seldom encountered. When biosolid application was suspended, the dissipation rate accelerated. Antibiotic dissipation was slightly slower when biosolids with high heavy metal concentrations were applied and microbial degradation may have been the main mechanism of dissipation. Norfloxacin persistence was positively correlated with its soil adsorption capacity. Cation exchange capacity and soil organic matter content may have vital roles in the soil adsorption of fluoroquinolones. Because of their persistence, the fluoroquinolones must be taken into account in the planning of biosolid applications in agricultural practice.
Show more [+] Less [-]Residue dynamics and risk assessment of Luna Experience® (fluopyram + tebuconazole) and chlorpyrifos on French beans (Phaseolus vulgaris L.) Full text
2018
Katna, Sapna | Dubey, Jatiender Kumar | Patyal, Surender Kumar | Devi, Nisha | Chauhan, Avinash | Sharma, Ajay
The persistence of chlorpyrifos, fluopyram, and tebuconazole was estimated in green pods, matured seeds, and soil of French beans using dispersive QuEChERS. Three foliar applications each of chlorpyrifos and a combination fungicide fluopyram + tebuconazole (Luna experience, 400 SC) were applied at 600 and 125 + 125 as a standard dose and 1200 and 250 + 250 g a.i. ha⁻¹ as a double dose, respectively, were applied at an interval of 10 days and treated pods were picked up at regular intervals. Dried mature seeds and soil were also monitored at harvest. The initial deposits of chlorpyrifos on bean pods were 3.083 and 6.017 mg kg⁻¹ with a half-life of 1.86 and 2.29 days, at respective doses. Foliar application of a combi product Luna experience yielded 3.396 and 5.772 mg kg⁻¹ residues of fluopyram and 3.613 and 5.887 mg kg⁻¹ of tebuconazole in green pods at standard and double dose with almost same half-lives of 3.4 and 3.8–3.9 days. Residues declined below the limit of quantitation (LOQ) of 0.05 mg kg⁻¹ in green beans after 15 and 25 days after the application of double dose of chlorpyrifos and Luna experience, respectively. However, the residues in dry bean seeds and soil reached below the LOQ of 0.05 mg kg⁻¹ at the time of harvest. A pre-harvest interval of 5, 10, and 7 days has been proposed for chlorpyrifos, fluopyram, and tebuconazole, respectively, in beans. HQ < 1 and TMDI < MPI in all test chemicals. Hence, it was concluded that a waiting period of 5 days for chlorpyrifos and 7–10 days in Luna experience will be safer to consumers. This data generated will be useful for regulatory agency for fixing MRLs.
Show more [+] Less [-]Preliminary evaluation of BioFire FilmArray® Gastrointestinal Panel for the detection of noroviruses and other enteric viruses from wastewater and shellfish Full text
2018
Gyawali, Pradip | Croucher, Dawn | Hewitt, Joanne
The BioFire FilmArray® Gastrointestinal Panel was evaluated for the rapid detection of adenovirus, astrovirus, norovirus, rotavirus and sapovirus from influent and effluent wastewater and shellfish. The multiplex BioFire FilmArray® Gastrointestinal Panel compared well to singleplex qPCR/RT-qPCR methods for the detection of adenovirus, astrovirus, rotavirus and sapovirus from influent and effluent wastewater samples. However, the BioFire FilmArray® Gastrointestinal Panel showed poor performance for the detection of norovirus, significantly underestimating its presence in wastewater and shellfish samples when compared with the singleplex norovirus GI and GII RT-qPCR assays. Therefore, improvement on detection efficiency for norovirus from environmental and food samples is necessary before using results from the FilmArray® Gastrointestinal Panel to assess associated public health risks.
Show more [+] Less [-]Low temperature effects on nitrification and nitrifier community structure in V-ASP for decentralized wastewater treatment and its improvement by bio-augmentation Full text
2018
Yuan, Jiajia | Dong, Wenyi | Sun, Feiyun | Zhao, Ke
The vegetation-activated sludge process (V-ASP) has been proved to be an environment-friendly decentralized wastewater treatment system with extra esthetic function and less footprint. However, the effects of low temperature on the treatment performance of V-ASP and related improvement methods are rarely investigated, up to now. In this work, the effect of low temperature on nitrification in V-ASP was comprehensively investigated from overall nitrification performance, substrate utilization kinetics, functional enzymatic activities, and microbial community structure shift by comparison with conventional ASP. Bio-augmentation methods in terms of single-time nitrifier-enriched biomass dosage were employed to improve nitrification efficiency in bench- and full-scale systems. The experiment results demonstrated that the NH₄⁺–N removal efficiency in V-ASP system decreased when the operational temperature decreased from 30 to 15 °C, and the decreasing extent was rather smaller compared to ASP, as well as ammonium and nitrite oxidation rates and enzymatic activities, which indicated the V-ASP system possesses high resistance to low temperature. With direct dosage of 1.6 mg nitrifier/gSS sludge, the nitrification efficiency in V-ASP was enhanced dramatically from below 50% to above 90%, implying that bio-augmentation was effective for V-ASP whose enzymatic activities and microbial communities were both also improved. The feasibility and effectiveness of bio-augmentation was further confirmed in a full-scale V-ASP system after a long-term experiment which is instructive for the practical application.
Show more [+] Less [-]Associations between total mercury and methyl mercury exposure and cardiovascular risk factors in US adolescents Full text
2018
Zhang, Yuxi | Xu, Cheng | Fu, Zhi | Shu, Yaqin | Zhang, Jie | Lu, Changgui | Mo, Xuming
Low levels of chronic heavy metal exposure are associated with a range of adverse health effects. However, whether total blood mercury (Hg) and methyl mercury (MeHg) exposure affect risk factors for cardiovascular disease (CVD) in adolescents remains unclear. The associations between CVD risk factors and total blood Hg and MeHg in adolescents were evaluated using data from the National Health and Nutrition Examination Survey (NHANES), 2011–2012. Data for 1129 adolescents (age 12–19 years) who participated in the US NHANES 2011–2012 were analyzed. A multivariate linear regression was performed to investigate the associations between CVD risk factors and blood Hg and MeHg concentrations. We identified a strong positive association between blood Hg and MeHg and total cholesterol in adolescents in adjusted model. No associations with other CVD risk factors were found in the overall population. In the gender-stratified generalized linear models, girls with the highest MeHg levels demonstrated a 4.22% (95% CI 0.80%, 7.76%) greater increase in serum total cholesterol (P for trend = 0.029) when compared with girls with the lowest MeHg levels. Our findings suggest that blood MeHg may be positively associated with total cholesterol in adolescent girls. More research is needed to verify this association and to elucidate its underlying mechanisms.
Show more [+] Less [-]Nickel, vanadium, and lead as indicators of sediment contamination of marina, refinery, and shipyard areas Full text
2018
Pereira, ThayaneLúcia | Wallner-Kersanach, Mônica | Costa, LuizaDy Fonseca | Costa, DanielPereira | Baisch, Paulo Roberto Martins
Metallic elements found in the aquatic environment may originate in areas where petroleum is refined and vessels are maintained and repaired. This study aims to assess contamination caused by nickel (Ni), lead (Pb), and vanadium (V) in sediment of the Lagoa dos Patos estuary (RS, Brazil) and to evaluate them as indicators of areas under the influence of petroleum products and antifouling paints. Surface sediments were collected in summer and in winter in areas of marinas, shipyards, refinery, and a control station. High Pb and V concentrations in shipyards and at the Yacht Club showed that some organisms may be affected by toxicity. High Pb results of the index of geoaccumulation (Igeo) were found at the Yacht Club and shipyards. Al, Ni, and V had similar distribution in the sediment in both seasons. Ni and V had high relation in winter at the Yacht Club and at the Santos Shipyard, thus suggesting that these elements come mainly from petroleum products. The same happened to the relations between Pb and V, as well as Pb and Ni at the Santos Shipyard. These elements are employed as useful tools as indicators to identify places with moderate to high localized anthropogenic inputs of petroleum derivatives and antifouling paints.
Show more [+] Less [-]Photochemical oxidation of di-n-butyl phthalate in atmospheric hydrometeors by hydroxyl radicals from nitrous acid Full text
2018
Lei, Yu | Zhu, Chengzhu | Lu, Jun | Zhu, Yongchao | Zhang, Qiuyue | Chen, Tianhu | Xiong, Hongbin
The photochemical oxidation of di-n-butyl phthalate (DBP) by •OH radicals from nitrous acid (HONO) in atmospheric hydrometeors was explored by two techniques, steady-state irradiation, and laser flash photolysis (LFP). The effects of atmospheric liquid parameters on DBP transformation were systematically evaluated, showing that DBP does not react with HONO directly and •OH-initiated reactions are crucial steps for consumption and transformation of DBP. Two reaction channels are operative: •OH addition and hydrogen atom abstraction. The overall rate constant for the reaction of DBP with •OH is 5.7 × 10⁹ M⁻¹ s⁻¹, and its specific rate constant for addition is 3.7 × 10⁹ M⁻¹ s⁻¹ determined by using laser flash photolysis technique. Comparing the individual reaction rate constant for aromatic ring addition with the total rate constant, the majority of the •OH radicals (about 65%) attack the aromatic ring. The major transformation products were identified by GC-MS, and the trends of their yields derived from both ring addition and H-abstraction with time are discussed. These results provide important insights into the photochemical transformation of DBP in atmospheric hydrometeors and contribute to atmospheric aerosol chemistry.
Show more [+] Less [-]Perception and practices of tobacco smoking among medical students in the Nile Delta, Egypt Full text
2018
Kabbash, Ibrahim Ali | Sarsik, Sameh Magdy | Kabbash, Mahmoud Ibrahim | Hagar, Aya Abdul-Rahman | Othman, Nahlah Mohammad | Ismail, Mohammad Fahmy | Elazoul, Mohammad Rasmy | Salem, Salem Mohammed
This study was conducted to identify medical students’ perception and practices towards tobacco smoking, as well as to identify factors affecting their adoption to smoking habit, among medical students in the Nile Delta. From December 2014 to February 2015, a questionnaire-based cross-sectional study was conducted at the four faculties of medicine in the Nile Delta. A total of 1715 students were targeted from the 2nd to 6th academic years to represent different levels of knowledge, awareness, and the influence of medical education on their attitude towards smoking. 5.6 and 1.2% of the students reported being smokers and ex-smokers, respectively, with a higher prevalence among 6th-year students, 40% of them reported to be involved with substance abuse. In general, medical students had positive antismoking attitude. The prevalence of smoking among medicine students was not high. However, there is a need to address smoking cessation programs during their study.
Show more [+] Less [-]Study on the pollution status and control measures for the livestock and poultry breeding industry in northeastern China Full text
2018
Wang, Hanxi | Xu, Jianling | Liu, Xuejun | Sheng, Lianxi | Zhang, Di | Li, Longwei | Wang, Aixia
Livestock and poultry breeding industry is one of the main economic pillars of northeastern China. However, the amount of pollutants produced is much higher than that in other parts of China. Through a questionnaire survey, indoor experiment, and outdoor experiment, it was found that the resource utilization rate of livestock and poultry manure in the northeastern region is low, with the pollution of livestock and poultry breeding mainly including air and water pollution. The alarm level of cultivated land and manure is II. While the livestock and poultry breeding is relatively concentrated area, its level is higher than grade II. Based on the pollution status of small farms, biogas can be produced through fermentation, along with the preparation of organic fertilizer, to completely utilize the manure and straw, while obtaining higher economic value, and effectively controlling the pollution from livestock and poultry breeding.
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