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Exploring the correlations between antibiotics and antibiotic resistance genes in the wastewater treatment plants of hospitals in Xinjiang, China Full text
2016
Li, Chao | Lu, Jianjiang | Liu, Jiang | Zhang, Genlin | Tong, Yanbing | Ma, Na
Various antibiotics have been extensively used to treating infectious diseases in hospitals. In this study, the abundance and diversity of antibiotics and antibiotic resistance genes (ARGs) were observed in the wastewater samples from five hospitals in Xinjiang, China. The total concentrations of tetracyclines, sulphonamides, and quinolones in hospital influents ranged from 363.4 to 753.3 ng/L, 285.5 to 634.9 ng/L, and 1355.8 to 1922.4 ng/L, respectively. However, the removal efficiency of tetracyclines, sulphonamides, and quinolones in wastewater treatment processes ranged from 72.4 to 79.3 %, 36.0 to 52.2 %, and 45.1 to 55.4 %, respectively. The contamination levels of the selected ARGs varied in all wastewater samples. The highest relative concentrations of sul1, sul2, tetQ, and qnrS were significantly higher than those of other ARGs in this study. Significant positive correlations between the relative abundance of partial ARGs and concentrations of certain antibiotics were observed in hospital wastewaters. Results show that integrons played an important role in disseminating and distributing ARGs in microorganism systems. Furthermore, strong correlations were observed between tetQ, sulphonamide resistance genes (except sulA) and intI1. This study aimed to determine the contamination levels of antibiotics and ARGs and analyze the relationships among ARGs, and antibiotics and integron genes in hospital wastewaters.
Show more [+] Less [-]Occurrence of illicit drugs and selected pharmaceuticals in Slovak municipal wastewater Full text
2016
Bodík, Igor | Mackuľak, Tomáš | Fáberová, Milota | Ivanová, Lucia
We analyzed illicit drugs and their metabolites and pharmaceuticals in wastewater from 15 selected wastewater treatment plants (WWTPs) in Slovakia. Our results indicate that methamphetamine is one of the most commonly used illegal drugs in all the regions of Slovakia monitored in this study. Compared with the international results, the Slovak cities of Dunajská Streda (479 mg/day/1000inh) and Trnava (354 mg/day/1000inh) are among the cities with the largest numbers of methamphetamine users in Europe. These results indicate an increase in the incidence of drugs in big cities and in the satellite cities (Trnava and Dunajská Streda) near Bratislava. These results also confirm the police statistics about production and use of illicit drugs in Slovakia. The highest specific loads of cocaine were found in Bratislava (112 mg/day/1000inh), followed by Petržalka (74 mg/day/1000inh). Compared with other European cities, Bratislava and the other Slovak cities in this study have a relatively low number of COC consumers. The ecstasy load in wastewater from larger cities also significantly increased over the weekend and during music festivals. The highest 2-year mean concentrations of THC-COOH, a cannabis biomarker, were observed in the sewage from BA-Petržalka and BA-Central (191 and 171 ng/L, respectively). A first complex monitoring of pharmaceuticals in all therapeutic groups was also realized in selected Slovak WWTPs. Occurrence of wide spectrum of pharmaceuticals with very high concentrations as well as consumptions were observed mainly in small Slovak cities. Considering all 120 monitored pharmaceuticals, Valsartan had the highest concentrations: 6000 ng/L, on average.
Show more [+] Less [-]Properties of biochars from conventional and alternative feedstocks and their suitability for metal immobilization in industrial soil Full text
2016
Gusiatin, Zygmunt Mariusz | Kurkowski, Radosław | Brym, Szczepan | Wiśniewski, Dariusz
In contaminated soils, excessive concentrations of metals and their high mobility pose a serious environmental risk. A suitable soil amendment can minimize the negative effect of metals in soil. This study investigated the effect of different biochars on metal (Cu, Pb, Zn) immobilization in industrial soil. Biochars produced at 300 and 600 °C from conventional (MS, maize silage; WP, wooden pellets) and alternative (SC, sewage sludge compost; DR, digestate residue) feedstocks were used as soil amendments at a dosage of 10 % (w/w). The type of feedstock and pyrolysis temperature affected the properties of the biochars and their ability to immobilize metal in soil. Compared to production at 300 °C, all biochars produced at 600 °C had higher pH (6.2–10.7), content of ash (7.2–69.0 %) and fixed carbon (21.1–56.7 %), but lower content of volatile matter (9.7–37.2 %). All biochars except DR biochar had lower dissolved organic carbon (DOC) content (1.4–2.3 g C/L) when made at 600 °C. Only MS and SC biochars had higher cation exchange capacity (25.2 and 44.7 cmol/kg, respectively) after charring at 600 °C. All biochars contained low concentrations of Cd, Cu, Ni, Pb and Zn; Cd was volatilized to the greatest extent during pyrolysis. Based on FTIR analysis and molar ratios of H/C and O/C, biochars had a greater degree of carbonization and aromaticity after charring at 600 °C. The efficiency of the biochars in metal immobilization depended mainly on their pH, ash content, and concentration of DOC. SC and DR biochars were more effective for Cu and Zn immobilization than MS and WP biochars, which makes them attractive options for large-scale soil amendment.
Show more [+] Less [-]Application of gas diffusion biocathode in microbial electrosynthesis from carbon dioxide Full text
2016
Bajracharya, Suman | Vanbroekhoven, Karolien | Buisman, Cees J.N. | Pant, Deepak | Strik, David P. B. T. B.
Microbial catalysis of carbon dioxide (CO₂) reduction to multi-carbon compounds at the cathode is a highly attractive application of microbial electrosynthesis (MES). The microbes reduce CO₂ by either taking the electrons or reducing the equivalents produced at the cathode. While using gaseous CO₂ as the carbon source, the biological reduction process depends on the dissolution and mass transfer of CO₂ in the electrolyte. In order to deal with this issue, a gas diffusion electrode (GDE) was investigated by feeding CO₂ through the GDE into the MES reactor for its reduction at the biocathode. A combination of the catalyst layer (porous activated carbon and Teflon binder) and the hydrophobic gas diffusion layer (GDL) creates a three-phase interface at the electrode. So, CO₂ and reducing equivalents will be available to the biocatalyst on the cathode surface. An enriched inoculum consisting of acetogenic bacteria, prepared from an anaerobic sludge, was used as a biocatalyst. The cathode potential was maintained at −1.1 V vs Ag/AgCl to facilitate direct and/or hydrogen-mediated CO₂ reduction. Bioelectrochemical CO₂ reduction mainly produced acetate but also extended the products to ethanol and butyrate. Average acetate production rates of 32 and 61 mg/L/day, respectively, with 20 and 80 % CO₂ gas mixture feed were achieved with 10 cm² of GDE. The maximum acetate production rate remained 238 mg/L/day for 20 % CO₂ gas mixture. In conclusion, a gas diffusion biocathode supported bioelectrochemical CO₂ reduction with enhanced mass transfer rate at continuous supply of gaseous CO₂. Graphical abstract ᅟ
Show more [+] Less [-]Exploratory study on the presence of GM oilseed rape near German oil mills Full text
2016
Franzaring, J. | Wedlich, K. | Fangmeier, A. | Eckert, S. | Zipperle, J. | Krah-Jentgens, I. | Hünig, C. | Züghart, W.
Seed losses from imported oilseed rape (OSR) and the genetically modified (GM) admixtures therein may potentially lead to the establishment of transgenic plants and their hybridization with wild crucifers. The post-market environmental monitoring (PMEM) must therefore also address problems related to seed spillages of GM OSR. Since detailed information on imported commodity flows, GM contents, means of transport, downstream users and efficient containment of GM OSR was lacking, we performed a field study in the vicinity of large oil mills and seed processing industries at the harbours along the river Rhine. One hundred thirty-six composite samples taken from one to 20 plants per site were collected near roads, railways and waterways. Individuals or large groups of feral OSR plants were detected in all of the nine study areas, but only one plant out of 1918 tested was confirmed to be transgenic (GT73). The results suggest that a spread of herbicide tolerant GM OSR has not occurred to date. In order to confirm the absence of GM feral OSR and potentially adverse effects of GM plants in the future, we recommend monitoring feral OSR on a routine basis. We present an approach for the sampling and testing of feral OSR that is based on floristic mapping and rapid tests for the determination of herbicide tolerances.
Show more [+] Less [-]Impact of arsenic(V) on testicular oxidative stress and sperm functional attributes in Swiss albino mice Full text
2016
Guvvala, Pushpa Rani | Sellappan, Selvaraju | Parameswaraiah, Ravindra Janivara
The arsenic (As) is a multi system effector including reproduction. The present study examined the association of graded doses of As(V) on testicular microenvironment and sperm function in mice. Thirty-six adult male mice were randomly assigned to six groups (n = 6). Group A served as control without test chemical. The groups B, C, D, E, and F were administered graded doses of 10, 25, 50, 100, and 200 ppm As(V), respectively, through drinking water for 40 days. A dose-dependant significant (P < 0.05) decrements were observed in epididymal sperm kinematic attributes (progressive motility, rapid, fast progressive, VCL, VSL, VAP, LIN, STR, WOB and TYPE A (STR >80 %, ALH 2.5 μm) by CASA), viability, plasma membrane functional integrity, and mitochondrial membrane potential which were associated with insignificant decrease in serum testosterone levels. The histoarchitectural studies of testes showed progressive loss of spermatozoa concentration in the seminiferous tubules as the As(V) dose increased. The mice exposed to As(V) had an increase in the As accumulation, protein carbonylation, and lipid peroxidation levels associated with alterations in SOD, CAT, and GST activities in the testes. In conclusion, higher doses of As(V) (more than 50 ppm) were found to be testicular toxicants which impaired semen quality by inducing oxidative stress in the testicular microenvironment.
Show more [+] Less [-]Alleviating effects of exogenous NO on tomato seedlings under combined Cu and Cd stress Full text
2016
Wang, Yi-jun | Dong, Yu-Xiu | Wang, Juan | Cui, Xiu-min
To investigate the effect of NO on the different origin and regulation of oxidative stress of Cu and/or Cd, tomato seedlings were treated with Cu, Cd, or Cu + Cd in a nutrient solution culture system. The main effect of Cu²⁺ was a significant reduction in root activity and nitrate reductase (NR) activity, which was similar to that under 50 μM Cd treatment, but promoted Cu accumulation. The supply of Cu under Cd treatment decreased Cd concentration, while not altered Cu concentration by contrast with Cu treatment, which is suggestive of a replacement of Cu²⁺ with Cd²⁺ and effective decrease in the boiotoxicity of 50 μM Cd²⁺ to tomato seedlings. However, NO alleviated the restriction to NR activity significantly and made the biomass of tomato seedlings recover under Cd treatment, and also increased root activity under Cu and Cu + Cd treatment. Exogenous NO markedly reduced the absorption and transportation of Cu but did not obviously change the translocation of Cd to the aboveground parts under Cu + Cd treatment. Both metals induced lipid peroxidation via the decreasing activation of antioxidant enzymes. The antioxidant enzyme system worked differently under Cu, Cd, or Cu + Cd stress. The activities of peroxidase (POD) and catalase (CAT) were higher under single Cd stress than under the control. Meanwhile, Cu + Cd treatment decreased the activities of POD, superoxide dismutase (SOD), and ascorbic acid peroxidase (APX). Exogenous NO increased POD and SOD activities in the leaves and roots, and CAT activity in the roots under combined Cu and Cd stress. These results suggest that a different response and regulation mechanism that involves exogenous NO is present in tomato seedlings under Cu and Cd stress.
Show more [+] Less [-]Residue decline and risk assessment of fluopyram + tebuconazole (400SC) in/on onion (Allium cepa) Full text
2016
Patel, Badal V. | Chawla, Suchi | Gor, Hetal | Upadhyay, Payal | Parmar, Kaushik D. | Patel, Anil R. | Shah, Paresh G.
A method was validated for estimating fluopyram and tebuconazole in onion on LC-MS/MS using dispersive QuEChERS. Three sprays of a combination fungicide fluopyram + tebuconazole (Luna experience, 400 SC) were applied @ 75 + 75 and 150 + 150 g a.i. ha⁻¹ at an interval of 10 days on onion using Knapsack sprayer. First spray was made at bulb setting stage. Spring onion samples were drawn at 0 (1 h), 1, 3, 5, 7, 10, 15, and 20 days and matured onion bulb at harvest (52 days) after the last spray. Soil samples were also drawn at harvest. Foliar application of the combination product resulted in 1.14 and 2.86 mg kg⁻¹ fluopyram residues on spring onion at standard and double dose, respectively, one hour after the last application. The levels of fluopyram residues gradually declined and recorded 0.25 and 0.58 mg kg⁻¹ on 20th day of application with half-lives of 8.8 and 9.1 days at standard and double dose, respectively. For tebuconazole, the corresponding residues observed after 1 h (0 day) of application were 0.92 and 2.29 mg kg⁻¹. The levels declined gradually to 0.12 and 0.33 mg kg⁻¹ on 20th days with half-life of 6.7 to 7.7 days at standard and double dose, respectively. Here, we are proposing a pre-harvest interval of 7 day for fluopyram and tebuconazole in spring onion when applied at 75 + 75 g a.i. ha⁻¹ (400 SC). Risk assessment was done by calculating hazard quotient and by comparing theoretical maximum residue intake (TMRI) with maximum permissible intake (MPI). In all the cases, results of the study showed that HQ (Hazard Quotient) ≤1 and TMDI < MPI. Hence, the use of this combination product can be recommended with pre harvest interval of 7 days. The data can be used in establishing MRLs (maximum residue limits) for spring onion after considering multilocation trials.
Show more [+] Less [-]Influence of shifting cultivation practices on soil–plant–beetle interactions Full text
2016
Ibrahim, Kalibulla Syed | Momin, Marcy D. | Lalrotluanga, R. | Rosangliana, David | Ghatak, Souvik | Zothansanga, R. | Kumar, Nachimuthu Senthil | Gurusubramanian, Guruswami
Shifting cultivation (jhum) is a major land use practice in Mizoram. It was considered as an eco-friendly and efficient method when the cycle duration was long (15–30 years), but it poses the problem of land degradation and threat to ecology when shortened (4–5 years) due to increased intensification of farming systems. Studying beetle community structure is very helpful in understanding how shifting cultivation affects the biodiversity features compared to natural forest system. The present study examines the beetle species diversity and estimates the effects of shifting cultivation practices on the beetle assemblages in relation to change in tree species composition and soil nutrients. Scarabaeidae and Carabidae were observed to be the dominant families in the land use systems studied. Shifting cultivation practice significantly (P < 0.05) affected the beetle and tree species diversity as well as the soil nutrients as shown by univariate (one-way analysis of variance (ANOVA), correlation and regression, diversity indices) and multivariate (cluster analysis, principal component analysis (PCA), detrended correspondence analysis (DCA), canonical variate analysis (CVA), permutational multivariate analysis of variance (PERMANOVA), permutational multivariate analysis of dispersion (PERMDISP)) statistical analyses. Besides changing the tree species composition and affecting the soil fertility, shifting cultivation provides less suitable habitat conditions for the beetle species. Bioindicator analysis categorized the beetle species into forest specialists, anthropogenic specialists (shifting cultivation habitat specialist), and habitat generalists. Molecular analysis of bioindicator beetle species was done using mitochondrial cytochrome oxidase subunit I (COI) marker to validate the beetle species and describe genetic variation among them in relation to heterogeneity, transition/transversion bias, codon usage bias, evolutionary distance, and substitution pattern. The present study revealed the fact that shifting cultivation practice significantly affects the beetle species in terms of biodiversity pattern as well as evolutionary features. Spatiotemporal assessment of soil–plant–beetle interactions in shifting cultivation system and their influence in land degradation and ecology will be helpful in making biodiversity conservation decisions in the near future.
Show more [+] Less [-]Multi-component adsorption of copper, nickel and zinc from aqueous solutions onto activated carbon prepared from date stones Full text
2016
Bouhamed, F. | Elouear, Z. | Bouzid, J. | Ouddane, B.
The removal of Cu²⁺, Ni²⁺, and Zn²⁺ ions from their multi-component aqueous mixture by sorption on activated carbon prepared from date stones was investigated. In the batch tests, experimental parameters were studied, including solution pH, contact time, initial metal ions concentration, and temperature. Adsorption efficiency of the heavy metals was pH-dependent and the maximum adsorption was found to occur at around 5.5 for Cu, Zn, and Ni. The maximum sorption capacities calculated by applying the Langmuir isotherm were 18.68 mg/g for Cu, 16.12 mg/g for Ni, and 12.19 mg/g for Zn. The competitive adsorption studies showed that the adsorption affinity order of the three heavy metals was Cu²⁺ > Ni²⁺ > Zn²⁺. The test results using real wastewater indicated that the prepared activated carbon could be used as a cheap adsorbent for the removal of heavy metals in aqueous solutions.
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