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Adsorption and desorption cycles of reactive blue BF-5G dye in a bone char fixed-bed column Full text
2019
Maeda, Celso Hissao | Araki, Carina Akemi | Moretti, Artur Lemes | de Barros, Maria Angélica Simões Dornellas | Arroyo, Pedro Augusto
In the textile industry, the amount of dye unfixed in fabrics is discarded with wastewaters. Effluents of this nature can be treated efficiently by adsorption on activated bone char, but the reuse of adsorbent is necessary for the technique to be economically feasible. Therefore, the objective of this work was to study the process of desorption of BF-5G blue dye from a bone char fixed-bed column. Solutions of sodium chloride, acetic acid and ethyl alcohol were tested as regenerating agents. Due to the hydrophobicity effect of organic solvent molecules, the highest desorption capacity was observed for ethyl alcohol solution, and the fixed bed was reused after six cycles of adsorption. The other solutions did not promote significant desorption. The results showed that adsorption of the dye involved irreversible interactions between adsorbate molecules and bone char. However, the use of acetic acid solution resulted in the neutralisation of some of the adsorbent surface charges, allowing the fixed bed to operate for a longer time in the second cycle than in the first.
Show more [+] Less [-]The impact of carbon emission and forest activities on health outcomes: empirical evidence from China Full text
2019
Farooq, Muhammad Umar | Shahzad, Umer | Sarwar, Suleman | ZaiJun, Li
The higher economic growth of China intensifies the consumption of fossil fuel, such as coal and oil, for electricity generation, transportation etc., which is responsible for environmental degradation through the emissions of carbon, sulfur, and nitrogen etc. The objectives of this study are to investigate the impact of greenhouse gas emission on health issues and provide the effective solution to overcome health-related issues, caused by carbon, sulfur, and nitrogen emission. For this purpose, we propose that higher afforestation activities can help to mitigate the carbon emission and can help to reduce the health diseases. The findings of quantile regressions reported that an increase in carbon emission causes significantly higher health issues. On the contrary, afforestation activities reported a negative coefficient, suggesting that growth of forests can be useful measure in control of health issues. The findings of the current study can be utilized in policy making and to explore the nexus between greenhouse gas emission, afforestation, and health issues.
Show more [+] Less [-]Treatment of synthetic wastewater and cheese whey by the anaerobic dynamic membrane bioreactor Full text
2019
Paçal, Müge | Semerci, Neslihan | Çallı, Barış
The aim of this study was to develop a laboratory-scale anaerobic dynamic membrane bioreactor (AnDMBR) for the treatment of high-strength synthetic and real cheese whey wastewater. We determined the appropriate pore size for a convenient type of support material (nylon mesh) to optimize cake layer formation. The performance of the AnDMBRs was measured in terms of chemical oxygen demand (COD) and solids removal efficiencies. During high-strength synthetic wastewater treatment, the 70-μm pore size AnDMBR achieved COD removal efficiencies of 78% and 96% with COD loading rates of 4.03 and 2.34 kg m⁻³ day⁻¹, respectively, while the 10-μm pore size AnDMBR achieved 66% and 92% COD removal efficiencies at COD loading rates of 5.02 and 3.16 kg m⁻³ day⁻¹. The 10 μm pore size AnDMBR was operated in two periods: first period and second period (before and after physical cleaning) during high-strength synthetic wastewater treatment. The 10-μm pore size AnDMBR removed 83% and 88% of suspended solids during period 1 and period 2, respectively. Furthermore, using a pore size of 10 μm retained 72% of solids (973 mg L⁻¹) in the reactor outlet. The 10-μm pore size AnDMBR performed better than the 70-μm pore size AnDMBR in terms of cake layer formation. The 10-μm pore size AnDMBR was used to treat real cheese whey wastewater, resulting in COD removal efficiencies ranging from 59% (4.32 kg m⁻³ day⁻¹) to 97% (5.22 kg m⁻³ day⁻¹). In addition, 85% of suspended solids were removed from real cheese whey wastewater after treatment. The results show that dynamic membrane technology using a pore size of 10 μm can be used to treat real industrial wastewater.
Show more [+] Less [-]Antibiotics in hospital effluents: occurrence, contribution to urban wastewater, removal in a wastewater treatment plant, and environmental risk assessment Full text
2019
Aydin, Senar | Aydin, Mehmet Emin | Ulvi, Arzu | Kilic, Havva
The study presented the occurrence of antibiotics in 16 different hospital effluents, the removal of antibiotics in urban wastewater treatment plant (WWTP), and the potential ecotoxicological risks of the effluent discharge on the aquatic ecosystem. The total concentration of antibiotics in hospital effluents was ranged from 21.2 ± 0.13 to 4886 ± 3.80 ng/L in summer and from 497 ± 3.66 to 322,735 ± 4.58 ng/L in winter. Azithromycin, clarithromycin, and ciprofloxacin were detected the highest concentrations among the investigated antibiotics. The total antibiotic load to the influent of the WWTP from hospitals was 3.46 g/day in summer and 303.2 g/day in winter. The total antibiotic contribution of hospitals to the influent of the WWTP was determined as 13% in summer and 28% in winter. The remaining 87% in summer and 72% in winter stems from the households. The total antibiotic removal by conventional physical and biological treatment processes was determined as 79% in summer, whereas it decreased to 36% in winter. When the environmental risk assessment was performed, azithromycin and clarithromycin in the effluent from the treatment plant in winter posed a high risk (RQ > 10) for the aquatic organisms (algae and fish) in the receiving environment. According to these results, the removal efficiency of antibiotics at the WWTP is inadequate and plant should be improved to remove antibiotics by advanced treatment processes.
Show more [+] Less [-]Varying concentrations of soil chromium (VI) for the exploration of tolerance thresholds and phytoremediation potential of the oregano (Origanum vulgare) Full text
2019
Levizou, Efi | Zanni, Anna A. | Antoniadis, Vasileios
Varying concentrations of soil Cr(VI) were used in order to explore the tolerance thresholds and phytoremediation potential of Greek oregano (Origanum vulgare), in a pot experiment conducted outdoors. Oregano exhibited a rather exceptional capacity to bioaccumulate Cr in both the aerial part (up to 1200 mg of total Cr kg⁻¹ DM) and the root—reaching 4300 mg kg⁻¹ DM when grown in soil [Cr(VI)] of 150–200 mg kg⁻¹. Plant responses indicated that there was a threshold set at 100 mg Cr(VI) kg⁻¹ in the soil, above which the following results were recorded: (i) a restriction of Cr translocation from below- to above-ground plant part, (ii) a raise of the soil-to-root Cr transfer, and (iii) the Cr(III) evolution from the reduction of Cr(VI) was significantly decelerated in the root and accelerated in the aerial part. Soil [Cr] that surpassed this threshold challenged plant tolerance, resulting in a dose-dependent reduction of growth and antioxidant phenolics pool. Nonetheless, the significant Cr uptake capacity at plant level accounted for the considerably short remediation time (i.e., 29 years at soil [Cr(VI)] of 150 mg kg⁻¹) calculated according to these results. The overall performance of oregano indicated that phytoremediation would be feasible at sites with Cr contamination levels ranging within the above-defined thresholds.
Show more [+] Less [-]Protective effect of cinnamon against acetaminophen-mediated cellular damage and apoptosis in renal tissue Full text
2019
Abdeen, Ahmed | Abdelkader, Afaf | Abdo, Mohamed | Wareth, Gamal | Aboubakr, Mohamed | Aleya, Lotfi | Abdel-Daim, Mohamed
Acetaminophen, APAP, is a common over-the-counter drug with antipyretic-analgesic action. When APAP is used in large doses, it causes hepatotoxicity and nephrotoxicity but safe at therapeutic doses. Cinnamon (Cinnamomum zeylanicum) is extensively used in folk medicine due to its high content of natural antioxidants. The current investigation was planned to study the possible ameliorative effect of cinnamon toward induced APAP-apoptosis and cellular damage in renal cells. Four groups (nine rats each) were used; negative control group administrated distilled water for 15 days; positive control APAP group administrated a single dose of APAP (1 g/kg) orally on the last day; APAP+Cin L (200 mg/kg) and APAP+Cin H (400 mg/kg) aqueous extract of cinnamon orally once a day for 15 days. An hour after the last dose of cinnamon, all rats in the third and fourth group were administrated a single dose of APAP (1 g/kg) orally. GC/MS analysis was performed to identify the plant used in the study. APAP markedly increased serum levels of creatinine, BUN, and glucose and decreased levels of albumin and total protein. In addition, APAP could also exert severe alteration in the kidney histopathology along with upregulation of caspase-3 and PCNA. However, pre-treatment with cinnamon ameliorated the APAP-induced cellular alterations and apoptosis, possibly through its high content of antioxidants.
Show more [+] Less [-]Occurrence and distribution of perfluorooctane sulfonate and perfluorooctanoic acid in three major rivers of Xinjiang, China Full text
2019
Wang, Gehui | Wang, Xiaolong | Xing, Zhenni | Lu, Jianjiang | Chang, Qigang | Tong, Yanbin
Drinking water is a main pathway of human exposure to perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). These two compounds have been identified in environmental waters worldwide, but little is known about their occurrence in Xinjiang. In this study, 155 water samples were obtained from 37 locations across Ulungur River, Manasi River, and Tarim River in Xinjiang, and were assessed by using liquid chromatography tandem-mass spectrometry. PFOS and PFOA were detected in over 50% of the samples with mean concentrations of 3.194 ng/L for PFOS and 3.460 ng/L for PFOA. Spatial and regional distribution differences do exist among the three analyzed rivers. PFOS and PFOA in Manasi River were observed at the highest levels (especially in M10 and M11), but no aggravation occurred from 2014 to 2017. Seasonal variations of PFOS and PFOA concentrations showed that water samples collected during summer were higher than those in other three seasons. The occurrence, levels, and distribution patterns of PFOS and PFOA were investigated in the present study, which provides useful theory and data support for human health risk assessment. The findings of the present study can be considered for controlling these water pollutants in environmental waters.
Show more [+] Less [-]Performance and working mechanism of a novel anaerobic self-flotation reactor for treating wastewater with high suspended solids Full text
2019
Zeng, Zhuo | Zheng, Ping | Zhang, Meng | Abbas, Ghulam
The new design of internal flotation components and the use of biogas were employed to develop a novel anaerobic self-flotation (ASF) reactor. Compared with the upflow anaerobic sludge blanket (UASB) reactor, the removal efficiencies of total chemical oxygen demand (COD) and suspended solids (SS) of the ASF reactor were higher than 90% under high SS concentration and high volumetric organic loading rate (OLR). The biogas flotation, sludge bed retention, and effluent washout accounted for 60%, 30%, and 10% of SS mass, respectively, proving that the biogas flotation was the main mechanism of SS removal in the ASF reactor. Extracellular polymer substance, mainly consisting of polysaccharide (PS) and protein (PN), was found to promote the SS removal by biogas flotation via the scum formation at the ratio of 294.12 g-VS/g-PS and 103.09 g-VS/g-PN. The EPS yield was determined as 2.3 ± 0.6 g-PS/g-COD and 11.5 ± 2.6 g-PN/g-COD at the OLR of 60 kg/(m³ day). The biogas production was revealed to enhance the SS removal by providing flotation driving force and by decreasing the scum density. A model was established to describe the quantitative relationship between flotation scum and OLR. This work would shed light on the high SS wastewater treatment challenge of high-rate anaerobic processes by using biogas flotation.
Show more [+] Less [-]Monitoring of environmental persistent organic pollutants in hair samples collected from wild terrestrial mammals of Primorsky Krai, Russia Full text
2019
Iatrou, Evangelia I. | Tsygankov, Vasiliy | Seryodkin, Ivan | Tzatzarakis, Manolis N. | Vakonaki, Elena | Barbounis, Emmanouil | Zakharenko, Alexander M. | Chaika, Vladimir V. | Sergievich, Alexander A. | Tsatsakis, Aristidis M. | Golokhvast, Kirill
Persistent organic pollutants (POPs) constitute a wide range of chemicals. Their release into the environment has raised great concern due to their potentially harmful impact in humans and wildlife species. The aim of this current study was to detect selected POPs in hair samples of wild terrestrial mammals from Primorsky Krai, Russia, so as to assess potential environmental exposure. The tested wild species were leopard cat, musk deer, wolf, amur hedgehog, and raccoon dog. The targeted organochlorines were hexachlorobenzene (HCB) and DDTs (opDDE, ppDDE, and opDDD), polychlorinated biphenyl (PCB) congeners (28, 52, 101, 118, 138, 153, and 180), and polycyclic aromatic hydrocarbons (PAHs) (acenaphylene (ACEN), fluorene (FLU), anthracene (ANTH) phenathrene (PHEN), and pyrene (PYR)). The detection of POPs was conducted in hair samples by a one-step hair extraction method, by using a headspace solid-phase microextraction technique (HS-SPME) and analyzed then by GC-MS. The majority of the wild animal hair samples were found positive in all tested pollutants. More specifically, the percentage of positive hair samples for HCB was 93.3% and for DDTs, PCBs, and PAHs, 20.0 to 100.0%, 6.7 to 100.0%, and 75.0 to 100.0%, respectively. DDT, PCB, and PAH detection ranged from 1.26 to 52.06 pg mg⁻¹, 0.73 to 31.34 pg mg⁻¹, and 2.59 to 35.00 pg mg⁻¹, respectively. The highest mean concentration levels of all tested pollutants were found for musk deer (PCBs 12.41 pg mg⁻¹, DDTs 21.87 pg mg⁻¹, PAHs 22.12 pg mg⁻¹) compared to the other wild species. To the best of our knowledge, this is the first study that provides results regarding contamination in different terrestrial mammals by POP exposure. The use of hair as a matrix is proven to be an effective tool for nondestructive biological monitoring of POP contamination in terrestrial ecosystems.
Show more [+] Less [-]A survey of extended-spectrum β-lactamase-producing Enterobacteriaceae in environmental water in Okinawa Prefecture of Japan and relationship with indicator organisms Full text
2019
Miyagi, Kazufumi | Hirai, Itaru
Surveys of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-pE) in stream water and untreated wastewater were carried out in Okinawa Prefecture, Japan. Thirty-six samples of water were collected from 18 streams in Okinawa Prefecture, as well as ten samples of wastewater flowing into four wastewater treatment plants (WWTPs). We investigated bacterial species, Escherichia coli O antigen, ESBL phenotype, ESBL genotype, and pulsed-field gel electrophoresis (PFGE) type of isolates, and total viable count and fecal coliforms as indicator organisms. The relation between indicator organisms and ESBL-pE was also validated using the same samples. A total of 141 ESBL-pE including 107 E. coli, 15 Klebsiella pneumoniae, 2 Proteus mirabilis, and 17 other species was isolated from stream water and wastewater. Of the 141 ESBL-pE, 14.9% and 54.6% were found to be blaCTX-M-15 and blaCTX-M-14-like types, respectively, which have been found in hospital isolates in Okinawa. Two pairs of possibly related patterns according to PFGE criteria were isolated from stream water and wastewater in two districts. When ESBL-pE was significantly isolated, total viable count and fecal coliform boundaries were ≥ 6.0 × 10³ CFU/ml and ≥ 4.3 × 10² most probable number/100 ml, respectively. These results suggested that ESBL-pE isolated from stream water is human derived, and that total viable count and fecal coliforms will be useful as indicators for confirming the spread of ESBL-pE to the environment by means of simple hygiene surveys.
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