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Diazinon, an organophosphate pesticide, induces oxidative stress and genotoxicity in cells deriving from large intestine Полный текст
2016
Boussabbeh, Manel | Ben Salem, Intidhar | Hamdi, Mohamed | Ben Fradj, Salsabil | Abid-Essefi, Salwa | Bacha, Hassen
Diazinon (DZ) (O,O-diethyl-O-[2-isopropyl-6-methyl-4-pyrimidinyl]phosphorothioate) is an organophosphate pesticide which is extensively used to control household insects and fruit and vegetable crops. The exposure to this pesticide has been linked to the development of the serious problem in several experimental animals. The contamination of food by DZ may increase its danger to humans. The aim of this study was to investigate the toxic effect of DZ on intestine using an in vitro model (HCT116). Therefore, we evaluated the cell viability, elucidated the generation of free radicals, measured the mitochondrial membrane potential, and valued DNA fragmentation. Our results showed that DZ is cytotoxic to HCT116. It causes oxidative damage through the generation of free radicals and induces lipid peroxidation and DNA fragmentation. We also demonstrated that such effects can be responsible for DZ-induced apoptosis.
Показать больше [+] Меньше [-]A review on bisphenol A occurrences, health effects and treatment process via membrane technology for drinking water Полный текст
2016
Muhamad, Mimi Suliza | Salim, Mohd Razman | Lau, Woei Jye | Yusop, Zulkifli
Massive utilization of bisphenol A (BPA) in the industrial production of polycarbonate plastics has led to the occurrence of this compound (at μg/L to ng/L level) in the water treatment plant. Nowadays, the presence of BPA in drinking water sources is a major concern among society because BPA is one of the endocrine disruption compounds (EDCs) that can cause hazard to human health even at extremely low concentration level. Parallel to these issues, membrane technology has emerged as the most feasible treatment process to eliminate this recalcitrant contaminant via physical separation mechanism. This paper reviews the occurrences and effects of BPA toward living organisms as well as the application of membrane technology for their removal in water treatment plant. The potential applications of using polymeric membranes for BPA removal are also discussed. Literature revealed that modifying membrane surface using blending approach is the simple yet effective method to improve membrane properties with respect to BPA removal without compromising water permeability. The regeneration process helps in maintaining the performances of membrane at desired level. The application of large-scale membrane process in treatment plant shows the feasibility of the technology for removing BPA and possible future prospect in water treatment process.
Показать больше [+] Меньше [-]Enhanced nutrient removal from municipal wastewater assisted by mixotrophic microalgal cultivation using glycerol Полный текст
2016
Gupta, Prabuddha L. | Choi, Hee Jeong | Lee, Seung-Mok
In a present study, nutrient removal from municipal wastewater by Chlorella vulgaris and Nannochloropsis oculata was investigated by using mixotrophic cultivation with glycerol (0 to 5 g/L). Performance parameters were assessed by estimating the removal of total nitrogen, total phosphorus, chemical oxygen demand (COD), biomass growth, chlorophyll content, lipid yield, and fatty acids. With the addition of 2 g/L glycerol, a maximum biomass productivity of 56 mg/L/day was achieved in the mixotrophic culture of C. vulgaris within 12 days. The mixotrophic culture showed a 30-fold increase in biomass productivity compared to the wastewater without any glycerol. However, the highest total nitrogen removal (80.62 %), total phosphate removal (60.72 %), and COD removal (96.3 %) was observed in the N. oculata culture supplemented with 3, 5, and 1 g/L glycerol, respectively. These results suggest that mixotrophic cultivation using glycerol offers great potential in the production of renewable biomass, waste water treatment, and consequent production of high-value microalgal oil. Graphical Abstract Simultaneous biomass production and nutrient removal using microalgae cultivated in wastewater supplemented with glycerol
Показать больше [+] Меньше [-]Characterizing the compositional variation of dissolved organic matter over hydrophobicity and polarity using fluorescence spectra combined with principal component analysis and two-dimensional correlation technique Полный текст
2016
Su, Ben-Sheng | Qu, Zhen | He, Xiao-Song | Song, Ying-Hao | Jia, Li-Min
Dissolved organic matter (DOM) obtained from three leachates with different landfill ages was fractionated, and its compositional variation based on hydrophobicity and polarity was characterized by synchronous fluorescence spectra combined with principal component analysis (PCA) and two-dimensional correlation technique. The results showed that the bulk DOM and its fractions were comprised of tryosine-, tryptophan-, fulvic-, and humic-like substances. Tyrosine-like matter was dominant in the young leachate DOM and its fractions, while tryptophan-, fulvic-, and humic-like substances were the main components in the intermediate and old leachate DOMs and their fractions. Tryosine-, tryptophan-, fulvic-, and humic-like substances varied concurrently with the hydrophobicity and polarity. However, the change ratio of these substances was different for the three leachates. Tyrosine-like matter, humic-like materials, and fulvic-like substances were the most sensitive to the hydrophobicity and polarity in the young, intermediate, and old leachates, respectively. Such an integrated approach jointly enhances the characterization of the hydrophobicity- and polarity-dependent DOM fractions and provides a promising way to elucidate the environmental behaviors of different DOM species.
Показать больше [+] Меньше [-]Structural benefits of bisphenol S and its analogs resulting in their high sorption on carbon nanotubes and graphite Полный текст
2016
Guo, Huiying | Li, Hao | Liang, Ni | Chen, Fangyuan | Liao, Shaohua | Zhang, Di | Wu, Min | Pan, Bo
Bisphenol S (BPS), a new bisphenol analog, is considered to be a potential replacement for bisphenol A (BPA), which has gained concern because of its potentially adverse health impacts. Therefore, studies are needed to investigate the environmental fate and risks of this compound. In this study, the adsorption of BPS and four structural analogs on multi-walled carbon nanotubes (MWCNTs) and graphite (GP) were investigated. When solid-phase concentrations were normalized by the surface areas, oxygen-containing functional groups on the absorbents showed a positive impact on phenol sorption but inhibited the sorption of chemicals with two benzene rings. Among BPS analogs, diphenyl sulfone showed the lowest sorption when hydrophobic effects were ruled out. Chemicals with a butterfly structure, formed between the two benzene rings, showed consistently high sorption on MWCNTs, independent of the substituted electron-donating or accepting functional groups. This study emphasizes the importance of chemical conformation on organic, contaminant sorption on engineered, carbonaceous materials.
Показать больше [+] Меньше [-]Simultaneous GC-MS determination of seven phthalates in total and migrated portions of paper cups Полный текст
2016
Park, Yu Na | Choi, Min Sun | Rehman, Shaheed Ur | Gye, Myung Chan | Yoo, Hye Hyun
Phthalate acid esters are widely used as plasticizers to impart plastic flexibility in various industrial applications. In this study, the content of seven phthalates, dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), di-(2-ethylhexyl) adipate (DEHA), di-2-ethylhexyl phthalate (DEHP), di-n-octyl phthalate (DNOP), di-isononyl phthalate (DINP), and di-isodecyl phthalate (DIDP) were determined in paper cups using gas chromatography–mass spectrometry (GC-MS). In addition, the potential migration of these seven phthalates from paper cups into various food stimulants under different conditions was evaluated. The levels of DBP, DEHA, DEHP, and DNOP were in the ranges of 0.07–3.14, 0.16–42.69, 0.45–58.56, and 0.3–2.4 mg/kg, respectively. Meanwhile, BBP, DINP, and DIDP were not detected in most of the tested samples. In the migration test, DEHA was released to 50 % ethanol and n-heptane in a time-dependent manner and the maximum migration levels were 65.62 ± 3.61 and 95.56 ± 19.76 μg/L, respectively. The release of other phthalates was very low or negligible. These results demonstrated that paper cups are not a significant source of phthalate exposure; however, DEHA could be released from paper cups into alcoholic beverages or oily liquid beverages in the human diet.
Показать больше [+] Меньше [-]Comparison and mechanism of photocatalytic activities of N-ZnO and N-ZrO2 for the degradation of rhodamine 6G Полный текст
2016
Sudrajat, Hanggara | Babel, Sandhya
N-doped ZnO (N-ZnO) and N-doped ZrO₂ (N-ZrO₂) are synthesized by novel, simple thermal decomposition methods. The catalysts are evaluated for the degradation of rhodamine 6G (R6G) under visible and UV light. N-ZnO exhibits higher dye degradation under both visible and UV light compared to N-ZrO₂ due to possessing higher specific surface area, lower crystalline size, and lower band gap. However, it is less reusable than N-ZrO₂ and its photocatalytic activity is also deteriorated at low pH. At the same intensity of 3.5 W/m², UVC light is shown to be a better UV source for N-ZnO, while UVA light is more suitable for N-ZrO₂. At pH 7 with initial dye concentration of 10 mg/L, catalyst concentration of 1 g/L, and UVC light, 94.3 % of R6G is degraded by N-ZnO within 2 h. Using UVA light under identical experimental conditions, 93.5 % degradation of R6G is obtained by N-ZrO₂. Moreover, the type of light source is found to determine the reactive species produced in the R6G degradation by N-ZnO and N-ZrO₂. Less oxidative reactive species such as superoxide radical and singlet oxygen play a major role in the degradation of R6G under visible light. On the contrary, highly oxidative hydroxyl radicals are predominant under UVC light. Based on the kinetic study, the adsorption of R6G on the catalyst surface is found to be the controlling step.
Показать больше [+] Меньше [-]Bioaccumulation of pathogenic bacteria and amoeba by zebra mussels and their presence in watercourses Полный текст
2016
Mosteo, R. | Goñi, P. | Miguel, N. | Abadías, J. | Valero, P. | Ormad, M. P.
Dreissena polymorpha (the zebra mussel) has been invading freshwater bodies in Europe since the beginning of the nineteenth century. Filter-feeding organisms can accumulate and concentrate both chemical and biological contaminants in their tissues. Therefore, zebra mussels are recognized as indicators of freshwater quality. In this work, the capacity of the zebra mussel to accumulate human pathogenic bacteria and protozoa has been evaluated and the sanitary risk associated with their presence in surface water has also been assessed. The results show a good correlation between the pathogenic bacteria concentration in zebra mussels and in watercourses. Zebra mussels could therefore be used as an indicator of biological contamination. The bacteria (Escherichia coli, Enterococcus spp., Pseudomonas spp., and Salmonella spp.) and parasites (Cryptosporidium oocysts and free-living amoebae) detected in these mussels reflect a potential sanitary risk in water.
Показать больше [+] Меньше [-]Effects of gravel on infiltration, runoff, and sediment yield in landslide deposit slope in Wenchuan earthquake area, China Полный текст
2016
Li, Tianyang | He, Binghui | Chen, Zhanpeng | Zhang, Yi | Liang, Chuan | Wang, Renxin
Amounts of landslide deposits were triggered by the Wenchuan earthquake with magnitude 8.0 on May 12, 2008. The landslide deposits were composed of soil and rock fragments, which play important roles in hydrological and erosion processes in the steep slope of landslide deposits. The mixtures of soil and gravels are common in the top layers of landslide deposits, and its processes are obviously different with the soil without gravels. Based on the data of field investigation, a series of simulated scouring flow experiments with four proportion of gravel (0, 25, 33.3, and 50 %) and three scouring flow rates (4, 8, 12 L/min) under two steep slopes (67.5, 72.7 %) were conducted sequentially to know the effects of proportion of gravel on infiltration capacity, runoff generation, and sediment production in the steep slope of landslide deposit. Results indicated that gravel had promoted or reduced effects on infiltration capacity which could affect further the cumulative runoff volume and cumulative sediment mass increase or decrease. The cumulative infiltration volume in 25 % proportion of gravel was less than those in 0, 33.3, and 50 % proportion of gravel. The cumulative runoff volume was in an order of 25 > 0 > 33.3 > 50 % while cumulative sediment mass ranked as 25 > 33.3 > 0 > 50 % with different proportions of gravel. A significant power relationship was found between scouring time and cumulative runoff volume as well as cumulative sediment mass. The relationship between average soil and water loss rate and proportion of gravel was able to express by quadratic function, with a high degree of reliability. The results have important implications for soil and water conservation and modeling in landslide deposit but also provide useful information for the similar conditions.
Показать больше [+] Меньше [-]Use of mixed solid waste as a soil amendment for saline-sodic soil remediation and oat seedling growth improvement Полный текст
2016
Fan, Yuan | Ge, Tian | Zheng, Yanli | Li, Hua | Cheng, Fangqin
Soil salinization has become a worldwide problem that imposes restrictions on crop production and food quality. This study utilizes a soil column experiment to address the potential of using mixed solid waste (vinegar residue, fly ash, and sewage sludge) as soil amendment to ameliorate saline-sodic soil and enhance crop growth. Mixed solid waste with vinegar residue content ranging from 60-90 %, sewage sludge of 8.7–30 %, and fly ash of 1.3–10 % was added to saline-sodic soil (electrical conductivity (EC₁:₅) = 1.83 dS m⁻¹, sodium adsorption ratio (SAR₁:₅) = 129.3 (mmolc L⁻¹)¹/², pH = 9.73) at rates of 0 (control), 130, 260, and 650 kg ha⁻¹. Results showed that the application of waste amendment significantly reduced SAR, while increasing soil soluble K⁺, Ca²⁺, and Mg²⁺, at a dose of 650 kg ha⁻¹. The wet stability of macro-aggregates (>1 mm) was improved 90.7–133.7 % when the application rate of amendment was greater than 260 kg ha⁻¹. The application of this amendment significantly reduced soil pH. Germination rates and plant heights of oats were improved with the increasing rate of application. There was a positive correlation between the percentage of vinegar residue and the K/Na ratio in the soil solutions and roots. These findings suggest that applying a mixed waste amendment (vinegar residue, fly ash, and sewage sludge) could be a cost-effective method for the reclamation of saline-sodic soil and the improvement of the growth of salt-tolerant plants.
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