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Removal of Cu2+ by biochars derived from green macroalgae 全文
2016
Kim, Beom-Sik | Lee, Hyung Won | Park, Sung Hoon | Baek, Kitae | Jeon, Jong-Ki | Cho, Hye-jŏng | Jung, Sang-Chul | Kim, Sang Chai | Park, Young-Kwon
The by-product char of the fast pyrolysis of a green macroalga Enteromorpha compressa was used to remove copper from an aqueous solution. The surface area and the amount of cation exchange capacity (CEC) were increased by steam activation, resulting in enhanced adsorption capacity. Although chemical activation using a KOH solution increased the pore volume and surface area dramatically, it decreased the adsorption capacity because of activating in the KOH solution and washing decreased CEC. Ion exchange between the Cu ions and cations (Na⁺, K⁺, Ca²⁺, and Mg²⁺) as well as adsorption onto the functional groups on the char surface appeared to be important mechanisms for the removal of Cu. A pseudo-second-order kinetic model and Langmuir isotherm model could interpret the kinetics and equilibrium of the Cu adsorption on the E. compressa char. The maximum amount of Cu adsorption on the char was 137 mg g⁻¹.
显示更多 [+] 显示较少 [-]Homogeneous static magnetic field of different orientation induces biological changes in subacutely exposed mice 全文
2016
Milovanovich, Ivan D. | Ćirković, Saša | De Luka, Silvio R. | Djordjevich, Drago M. | Ilić, Andjelija Ž | Popović, Tamara | Arsić, Aleksandra | Obradović, Danilo D. | Oprić, Dejan | Ristić-Djurović, Jasna L. | Trbović, Aleksa M.
It has been shown that static magnetic field (SMF) of moderate intensity produces considerable impact on biological systems. SMF can be homogeneous or inhomogeneous. In many studies, inhomogeneous SMF was employed. Aware that inhomogeneous SMF could result in experimental variability, we investigated the influence of a vertical homogeneous SMF of different orientation. Male Swiss-Webster 9- to 10-week-old mice were subacutely exposed to upward- and downward-oriented SMF of 128 mT generated by a cyclotron for 1 h/day during a 5-day period. We found that SMF affected various organs and that these effects were, to some degree, dependent on SMF orientation. Both upward- and downward-oriented SMF caused a reduction in the amount of total white blood cells (WBC) and lymphocytes in serum, a decrease of granulocytes in the spleen, kidney inflammation, and an increase in the amount of high-density lipoprotein (HDL). In addition, upward-oriented SMF caused brain edema and increased spleen cellularity. In contrast, downward-oriented SMF induced liver inflammation and a decrease in the amount of serum granulocytes. These effects might represent a specific redistribution of pro-inflammatory cells in blood and among various organs. It appears that homogeneous SMF of 128 mT affected specific organs in the body, rather than simultaneously and equally influencing the entire body system.
显示更多 [+] 显示较少 [-]Extracellular polymeric substances (EPS) and surface properties of activated sludges: effect of organic carbon sources 全文
2016
Geyik, Ayse Gul | Kılıç, Başak | Çeçen, Ferhan
The study aims to clarify how the type of organic substrate in a wastewater affects the production and composition of extracellular polymeric substances (EPS) and hydrophobicity and surface charge of activated sludges. For this purpose, three activated sludge reactors were operated in parallel with feeds composed of the organics (i) peptone, glucose, and acetate and (ii) peptone and (iii) glucose. EPS extracted from sludges were fractionated into very loosely bound, loosely bound, and tightly bound fractions and analyzed for protein and polysaccharide. Also, molecular weight distribution of proteins was determined by using high-pressure size exclusion chromatography (HPSEC). Regardless of the type of organic substrate, in each sludge, tightly bound EPS (TB-EPS) prevailed. The type of organic substrate affected the relative proportion of protein and polysaccharide and had an impact on hydrophobicity and surface charge. The sludge fed with peptone was distinctly more hydrophobic and had a lower negative surface charge than others. HPSEC fingerprints revealed that the variety and size of proteins were dependent on the type of feed. HPSEC also pointed to a shift of high molecular weight (MW) proteins from TB-EPS to others. In addition, results of a parallel study examining the inhibitory effect of Ag⁺ on three sludges were interpreted along with feed composition, EPS, and surface measurements. The response of each sludge to toxic Ag⁺ ion seemed to change with the type of feed.
显示更多 [+] 显示较少 [-]The spatiotemporal distribution of dissolved carbon in the main stems and their tributaries along the lower reaches of Heilongjiang River Basin, Northeast China 全文
2016
Wang, Lili | Song, Changchun | Guo, Yuedong
The Heilongjiang River Basin in the eastern Siberia, one of the largest river basins draining to the North Pacific Ocean, is a border river between China, Mongolia, and Russia. In this study, we examined the spatial and seasonal variability in dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and dissolved total carbon (DTC) concentrations along lower reaches of Heilongjiang River Basin, China. Water samples were collected monthly along the mouths of main rivers (Heilongjiang River, Wusuli River, and Songhua River) and their ten tributary waters for 2 years. The DOC concentrations of waters ranged from 1.74 to 16.64 mg/L, with a mean value of 8.90 ± 0.27 mg/L (n = 165). Notably, mean DIC concentrations were 9.08 ± 0.31 mg/L, accounting for 13.26∼83.27 % of DTC. DIC concentrations increased significantly after the Heilongjiang River passed through Northeast China, while DOC concentrations decreased. Over 50 % of DIC concentrations were decreased during exports from groundwater to rice fields and from rice fields to ditches. Water dissolved carbon showed large spatial and temporal variations during the 2-year measurement, suggesting that more frequently samplings were required. Carbon (DIC + DOC) loads from the Heilongjiang River to the Sea of Okhotsk were estimated to be 3.26 Tg C/year in this study, accounting for 0.64 % of the global water dissolved carbon flux. DIC export contributed an average of 51.84 % of the estimated carbon load in the Heilongjiang River, acting as an important carbon component during riverine transport. Our study could provide some guides on agricultural water management and contribute to more accurately estimate global carbon budgets.
显示更多 [+] 显示较少 [-]People with diabetes, respiratory, liver or mental disorders, higher urinary antimony, bisphenol A, or pesticides had higher food insecurity: USA NHANES, 2005–2006 全文
2016
Shiue, Ivy
This study was aimed to examine the prevalence of food insecurity and what social, health, and environmental characteristics could constitute such situation in a national and population-based setting. Data was retrieved from the National Health and Nutrition Examination Survey, 2005–2006. Information on demographics, lifestyle factors, self-reported ever medical conditions in the past and self-reported food security conditions in the last 12 months calculated on the household level was obtained by household interview. Bloods and urines (subsample) were collected at the interview as well. Only adults aged 20 years and above (n = 4979) were included for statistical analysis in the present study. Chi-square test, t test, and survey-weighted logistic regression modeling were performed. Three thousand eight hundred thirty-four (77.9 %) people were with full food security, 466 (9.5 %) people were with marginal food security and 624 (12.7 %) people were with low or very low food security. Being younger, having higher ratios of family income to poverty thresholds (due to low level of education or lack of financial support), having prior asthma, arthritis, chronic bronchitis, depression, diabetes, eczema, emphysema or liver problems, having higher levels of serum cotinine, urinary antimony, bisphenol A, pesticides, or having lower levels of urinary Benzophenone-3 were associated with food insecurity. In addition to socioeconomic and smoking conditions, evidence on people with several prior health conditions and being exposed to environmental chemicals and food insecurity is further provided. Future social, health and environmental policy, and programs protecting people from food insecurity by considering both health and environmental factors mentioned above would be suggested.
显示更多 [+] 显示较少 [-]Evaluation of geno-toxicity of methyl parathion and chlorpyrifos to human liver carcinoma cell line (HepG2) 全文
2016
Patnaik, Rajashree | Padhy, Rabindra Nath
Insecticides and their residues are known to cause several types of ailments in human body. An attempt had been made to assess digitally the geno-toxicity of methyl parathion (MP) and chlorpyrifos (CP) to in vitro-grown HepG2 cell line, with Hoechst 33342 staining, comet, and micronucleus assays. Additionally, “acridine orange/ethidium bromide” (AO/EB) staining was done for the determination of insecticide-induced cytotoxicity, in corollary. Hoechst 33342 staining of cells revealed a decrease in live cell counts at 8–40 mg/L MP and 15–70 mg/L CP. Moreover, nuclear fragmentations in ranges 8 to 40 mg/L MP and 15 to 70 mg/L CP were recorded dependant on individual doses, increasingly with concomitant increases in comet tail length values. DNA fragmentation index measured in comet assays was 94.3 ± 0.57 at 40 mg/L MP and 93.3 ± 2.08 at 70 mg/L CP. Average micronuclei number was 59.0 ± 2.00 at 40 mg/L MP and 62.6 ± 1.52 at 70 mg/L CP, per 1000 cell nuclei, in micronucleus assay. Minimum inhibitory concentration (MIC) values with AO/EB staining for monitoring cytotoxicity were 4 and 10 mg/L for MP and CP, respectively. Lethal concentration₅₀ (LC₅₀) values were 20.89 mg/L MP and 79.43 mg/L CP in AO/EB staining, for cytotoxicity with probit analyses. It was concluded that MP was comparatively more geno-toxic than CP to HepG2 cell. It was discernible that at lower levels of each insecticide, geno-toxicity was recorded in comparison to cytotoxicity.
显示更多 [+] 显示较少 [-]The implementation of data reconciliation for evaluating a full-scale petrochemical wastewater treatment plant 全文
2016
Behnami, Ali | Shakerkhatibi, Mohammad | Dehghanzadeh, Reza | Benis, Khaled Zoroufchi | Derafshi, Siavash | Fatehifar, Esmaeil
Data reconciliation and mass balance analysis were conducted for the first time to improve the data obtained from a petrochemical wastewater treatment plant (WWTP), and the results were applied to evaluate the performance of the plant. Daily average values for 209 days from the inlet and outlet of the plant obtained from WWTP documentation center along with the results of four sampling runs in this work were used for data reconciliation and performance evaluation of the plant. Results showed that standard deviation and relative errors in the balanced data of each measurement decreased, especially for the process wastewater from 24.5 to 8.6 % for flow and 24.5 to 1.5 % for chemical oxygen demand (COD). The errors of measured data were −137 m³/day (−4.41 %) and 281 kg/day (7.92 %) for flow and COD, respectively. According to the balanced data, the removal rates of COD and 5-day biological oxygen demand (BOD₅) through the aeration unit were equal to 37 and 46 %, respectively. In addition, the COD and BOD₅ concentrations were reduced by about 61.9 % (2137 kg/day) and 78.1 % (1976 kg/day), respectively, prior to the biological process. At the same time, the removal rates of benzene, toluene, and styrene were 56, 38, and 69 %, respectively. The results revealed that about 40 % of influent benzene (75.5 kg/day) is emitted to the ambient air at the overhead of the equalization basin. It can be concluded that the volatilization of organic compounds is the basic mechanism for the removal of volatile organic compounds (VOCs) and it corresponds to the main part of total COD removal from the WWTP.
显示更多 [+] 显示较少 [-]Metal toxicokinetics and metal-driven damage to the gut of the ground beetle Pterostichus oblongopunctatus 全文
2016
Bednarska, Agnieszka J. | Laskowski, Ryszard | Pyza, Elżbieta | Semik, Danuta | Świątek, Zuzanna | Woźnicka, Olga
Toxicokinetics makes up the background for predicting concentrations of chemicals in organisms and, thus, ecological risk assessment. However, physiological and toxicological mechanisms behind toxicokinetics of particular chemicals are purely understood. The commonly used one-compartment model has been challenged recently, showing that in the case of metals it does not describe the pattern observed in terrestrial invertebrates exposed to highly contaminated food. We hypothesised that the main mechanism shaping toxicokinetics of metals in invertebrates at high exposure concentrations in food is the cellular damage to the gut epithelial cells. Gut damage should result in decreased metal assimilation rate, while shedding the dead cells - in increased elimination rate. We performed a typical toxicokinetic experiment, feeding the ground beetles Pterostichus oblongopunctatus food contaminated with Cd, Ni or Zn at 40 mM kg⁻¹ for 28 days, followed by a depuration period of 14 days on uncontaminated food. The male beetles were sampled throughout the experiment for body metal concentrations and histopathological examinations of the midgut. All metals exhibited a complex pattern of internal concentrations over time, with an initial rapid increase followed by a decrease and fluctuating concentrations during further metal exposure. Histopathological studies showed massive damage to the midgut epithelium, with marked differences between the metals. Cd appeared the most toxic and caused immediate midgut cell degeneration. The effects of Ni were more gradual and pronounced after at least 1 week of exposure. Zn also caused extensive degeneration in the gut epithelium but its effects were the weakest among the studied metals.
显示更多 [+] 显示较少 [-]Defence responses in rice plants in prior and simultaneous applications of Cladosporium sp. during leaf blast suppression 全文
2016
Chaibub, Amanda Abdallah | de Carvalho, Jacqueline Campos Borba | de Sousa Silva, Carlos | Collevatti, Rosane Garcia | Gonçalves, Fábio José | de Carvalho Barros Côrtes, Márcio Vinícius | de Filippi, Marta Cristina Corsi | de Faria, Fabrícia Paula | Lopes, Douglas Christian Borges | de Araújo, Leila Garcês
An alternative method to control rice blast (Magnaporthe oryzae) is to include biological agent in the disease management strategy. The objective of this study was to assess the leaf blast-suppressing effects of rice phylloplane fungi. One Cladosporium sp. phylloplane fungus was shown to possess biocontrolling traits based on its morphological characteristics and an analysis of its 18S ribosomal DNA. Experiments aimed at determining the optimal time to apply the bioagent and the mechanisms involved in its rice blast-suppressing activities were performed under controlled greenhouse conditions. We used foliar spraying to apply the Cladosporium sp. 48 h prior to applying the pathogen, and we found that this increased the enzymatic activity. Furthermore, in vitro tests performed using isolate C24 showed that it possessed the ability to secrete endoxylanases and endoglucanases. When Cladosporium sp. was applied either prior to or simultaneous with the pathogen, we observed a significant increase in defence enzyme activity, and rice blast was suppressed by 84.0 and 78.6 %, respectively. However, some enzymes showed higher activity at 24 h while others did so at 48 h after the challenge inoculation. Cladosporium sp. is a biological agent that is capable of suppressing rice leaf blast by activating biochemical defence mechanisms in rice plants. It is highly adapted to natural field conditions and should be included in further studies aimed at developing strategies to support ecologically sustainable disease management and reduce environmental pollution by the judicious use of fungicidal sprays.
显示更多 [+] 显示较少 [-]Regulatory effects of dioxin-like and non-dioxin-like PCBs and other AhR ligands on the antioxidant enzymes paraoxonase 1/2/3 全文
2016
Shen, Hua | Robertson, Larry W. | Ludewig, Gabriele
Paraoxonase 1 (PON1), an antioxidant enzyme, is believed to play a critical role in many diseases, including cancer. PCBs are widespread environmental contaminants known to induce oxidative stress and cancer and to produce changes in gene expression of various pro-oxidant and antioxidant enzymes. Thus, it appeared of interest to explore whether PCBs may modulate the activity and/or gene expression of PON1 as well. In this study, we compared the effects of dioxin-like and non-dioxin-like PCBs and of various aryl hydrocarbon receptor (AhR) ligands on PON1 regulation and activity in male and female Sprague-Dawley rats. Our results demonstrate that (i) the non-dioxin-like PCB154, PCB155, and PCB184 significantly reduced liver and serum PON1 activities, but only in male rats; (ii) the non-dioxin-like PCB153, the most abundant PCB in many matrices, did not affect PON1 messenger RNA (mRNA) level in the liver but significantly decreased serum PON1 activity in male rats; (iii) PCB126, an AhR ligand and dioxin-like PCB, increased both PON1 activities and gene expression; and (iv) even though three tested AhR ligands induced CYP1A in several tissues to a similar extent, they displayed differential effects on the three PONs and AhR, i.e., PCB126 was an efficacious inducer of PON1, PON2, PON3, and AhR in the liver, while 3-methylcholantrene induced liver AhR and lung PON3, and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the most potent AhR agonist, increased only PON3 in the lung, at the doses and exposure times used in these studies. These results show that PCBs may have an effect on the antioxidant protection by paraoxonases in exposed populations and that regulation of gene expression through AhR is highly diverse.
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