Biochemical and histopathological ultrastructural changes caused by ZnO nanoparticles in mice

Five week-old mice were divided into a vehicle control group, and groups exposed to ZnO nanoparticles at low (0.5 g/kg), middle (1 g/kg), high (3 g/kg), and exceptionally high-dose (5 g/kg). After the first, second, third, and fourth weeks’ of exposure, blood biochemistry, histopathology, and electron microscopic ultrastructural changes in liver, kidney and spleen were investigated. Increased alkaline phosphatase activities were observed in all treated mice being statistically significant at higher dose. No changes were observed in the serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, creatinine, blood urea nitrogen, and lipid levels. During the first and second weeks of the treatment, effects on the cytoarchitecture of liver, kidney, and spleen were not perceived while during the third and fouth weeks of treatment sporadic mild effects were seen. Ultrastructural electron microscopic changes in liver, kidney, and spleen were not observed for the low-dose group on the first, second, third, and fourth weeks, suggesting that exposure to ZnO nanoparticles at low dose is safe. Long-term (i.e., more than 28 days) exposure to the exceptionally high-dose resulted in sporadic changes in nuclear chromatin condensation, irregular nuclear membrane, polymorphic mitochondria, mitochondrial swelling, and vacuolation. ZnO nanoparticles could be well tolerated and no death occurred in any group of treated mice.     

Indigenous knowledge about climate change and sustainability of nomadic livelihoods: understanding adaptability coping strategies

Environment, Development and Sustainability - Indigenous knowledge about climate change that makes adaptability necessary by coping strategies leads to the sustainability of nomadic livelihoods....     

Synthesis of vinasse-dolomite nanocomposite biochar via a novel developed functionalization method to recover phosphate as a potential fertilizer substitute

• Nanocomposites were prepared by adding dolomite to vinasse at different ratio. • Textural and morphological features of adsorbents were studied in detail. • CCD based RSM was used for investigation of P ion removal by nanocomposite. • The q_m based on Langmuir model for modified vinasse biochar was 178.57 mg/g. • P loaded nanocomposite improved plant growth and could be utilized as P-fertilizer. The effectiveness of phosphate (P) removal from aqueous solutions was investigated by novel low-cost biochars synthesized from vinasse and functionalized with calcined dolomite. The vinasse-derived biochar, synthesized via pyrolysis at different temperatures, showed easy preparation and a large surface area. The novel vinasse biochar nanocomposites were prepared by adding dolomite to the vinasse biochars with different weight percentages (10, 20 and 30%). The characteristics of the prepared materials were identified for further understanding of the inherent adsorption mechanism between P ions and vinasse biochars. Vinasse-dolomite nanocomposite was very effective in the adsorption of P species from aqueous media. The effect of the operational factors on Vinasse-dolomite nanocomposite was explored by applying response surface methodology (RSM). According to RSM results, the optimum condition was achieved to be contact time 90 (min), 250 (mg/L) of P concentration and pH 7. Thermodynamic isotherm and kinetic studies were applied on experimental data to understand the adsorption behavior. The Vinasse-dolomite nanocomposite revealed preferential P species adsorption in the presence of co-existing anions. The P species could be recovered by 1.0 M HCl where the efficiency was not affected up to the fifth cycle. The P-loaded Vinasse-dolomite nanocomposite was successfully tested on a plant; it significantly improved its growth and proved its potency as a P-based fertilizer substitute.     

Performance of activated carbon coated graphite bipolar electrodes on capacitive deionization method for salinity reduction

• Graphite bipolar electrodes act as an appropriate bed for the CDI process. • Activated carbon Coating improves the application of the electrodes. • CDI is an environmentally friendly method to apply for brackish water. • Initial concentration is the most important parameter in the CDI method. • CDI process in a batch-mode setup needs more development. This research investigates a capacitive deionization method for salinity reduction in a batch reactor as a new approach for desalination. Reductions of cost and energy compared with conventional desalination methods are the significant advantages of this approach. In this research, experiments were performed with a pair of graphite bipolar electrodes that were coated with a one-gram activated carbon solution. After completing preliminary tests, the impacts of four parameters on electrical conductivity reduction, including (1) the initial concentration of feed solution, (2) the duration of the tests, (3) the applied voltage, and (4) the pH of the solution, were examined. The results show that the maximum efficiency of electrical conductivity reduction in this laboratory-scale reactor is about 55%. Furthermore, the effects of the initial concentration of feed solution are more significant than the other parameters. Thus, using the capacitive deionization method for water desalination with low and moderate salt concentrations (i.e., brackish water) is proposed as an affordable method. Compared with conventional desalination methods, capacitive deionization is not only more efficient but also potentially more environmentally friendly.     

Assessment of temporal and spatial water quality in international Gomishan Lagoon,Iran, using multivariate analysis

Coastal lagoon ecosystems are vulnerable to eutrophication, which leads to the accumulation of nutrients from the surrounding watershed over the long term. However, there is a lack of information about methods that could accurate quantify this problem in rapidly developed countries. Therefore, various statistical methods such as cluster analysis (CA), principal component analysis (PCA), partial least square (PLS), principal component regression (PCR), and ordinary least squares regression (OLS) were used in this study to estimate total organic matter content in sediments (TOM) using other parameters such as temperature, dissolved oxygen (DO), pH, electrical conductivity (EC), nitrite (NO₂), nitrate (NO₃), biological oxygen demand (BOD), phosphate (PO₄), total phosphorus (TP), salinity, and water depth along a 3-km transect in the Gomishan Lagoon (Iran). Results indicated that nutrient concentration and the dissolved oxygen gradient were the most significant parameters in the lagoon water quality heterogeneity. Additionally, anoxia at the bottom of the lagoon in sediments and re-suspension of the sediments were the main factors affecting internal nutrient loading. To validate the models, R², RMSECV, and RPDCV were used. The PLS model was stronger than the other models. Also, classification analysis of the Gomishan Lagoon identified two hydrological zones: (i) a North Zone characterized by higher water exchange, higher dissolved oxygen and lower salinity and nutrients, and (ii) a Central and South Zone with high residence time, higher nutrient concentrations, lower dissolved oxygen, and higher salinity. A recommendation for the management of coastal lagoons, specifically the Gomishan Lagoon, to decrease or eliminate nutrient loadings is discussed and should be transferred to policy makers, the scientific community, and local inhabitants.     

Association of textile industry effluent with mutagenicity and its toxic health implications upon acute and sub-chronic exposure

Complex industrial discharges pose certain risks to the ecosystem. This study was aimed at identifying acute and sub-chronic toxicological effects of the textile industry wastewater. The textile wastewater was evaluated for the metals and organic pollutants by atomic absorption spectrophotometer and GC-MS respectively. In vitro genotoxicity and mutagenicity were assessed by Comet assay in peripheral lymphocytes isolated from Ovis aries and Ames test in Salmonella typhimurium strains TA-100 and 102 respectively. Physiological and behavioral changes along with systemic toxicity were determined in Rattus norvegicus albinus following acute and sub-chronic exposure. High amount of heavy metals such as Cr, Pb, Hg, As, and Cd were detected in textile wastewater. Organic pollutants such as 25-deacetoxy cucurbitacin-b, E-14-Hexadecenal, 11-Tricosene, and phthalates were also found. In vitro genotoxicity assessment in lymphocytes showed statistically significant DNA damaging potential of textile wastewater. Textile wastewater also showed significantly higher (p? 0.05) mutagenic potential in Salmonella TA-100 and TA-102 strains than sodium azide and 2-amino anthracycline. Acute exposure of textile wastewater to Rattus norvegicus was associated with several physiological changes and behavioral symptoms. Sub-chronic exposure of textile wastewater in Rattus norvegicus instigated the degeneration and necrosis of epithelial cells in renal tubules, hydropic degeneration and necrosis of hepatocytes, peri-bronchiolar infiltration and emphysema of the alveoli, and the degradation of myocardial cells. This study concludes that the textile wastewater may cause genotoxicity and mutagenicity, result in physiological and behavioral changes upon acute exposure, and inflict various pathological lesions upon sub-chronic exposure.     

Alum-based sludge (AbS) recycling for turbidity removal in drinking water treatment: an insight into statistical,technical, and health-related standpoints

This study aimed to evaluate the feasibility of recycling alum-based sludge (AbS) generated from drinking water treatment facility for turbidity removal. A response surface methodology (RSM)-based modeling and factor analysis were first implemented for assessing the optimal conditions of four independent factors, such as initial turbidity concentration, humic acid (HA) concentration, pH, and AbS dose on the water turbidity removal via the use of AbS as a coagulant agent. The optimum values of the four main variables were determined as initial turbidity concentration?=?59.65 NTU, pH?=?5.56, AbS dose?=?19.71 g/L, and HA concentration?=?12.28 mg/L, and at the optimum conditions, the percentage of turbidity removal was obtained as 94.81 (±?1.01)% for real water. At the optimum conditions of AbS usage as a coagulant for real water samples, monitoring of water quality parameters of the process indicated no health-related concerns in terms of hardness (all types), alkalinity, pH, residual aluminum, and even bacteriological (fecal and total coliforms) contamination. The results indicated a potential for AbS recycling in the treatment plant as a coagulant agent, although some requirements should be fulfilled before full-scale application.     

Effects of Compatibilizer and Thermoplastic Starch (TPS) Concentration on Morphological,Rheological, Tensile,Thermal and Moisture Sorption Properties of Plasticized Polylactic Acid/TPS Blends

The blends of polylactic acid plasticized with acetyl tributyl citrate (P-PLA) and thermoplastic wheat starch (TPS) were prepared by a co-rotating twin screw extruder and the effect of maleic anhydride grafted PLA (PLA-g-MA) content as reactive compatibilizer on blends compatibility through morphological, rheological and tensile properties of the blends was investigated. Considerable improvement in properties of P-PLA/TPS (70/30 w/w) blend with incorporating the optimum PLA-g-MA content of 4 phr was achieved as this blend exhibited better morphological and rheological properties with an increase by 158 and 276% in tensile strength and elongation at break, respectively, compared to the uncompatibilized blend. Also the thermal stability and moisture sorption properties of the blends as effected by TPS content were studied. Decreasing in thermal stability and increasing in equilibrium moisture content of the blends were observed with progressively increasing of TPS content. For prediction the moisture sorption behaviour of blends with various TPS contents at different relative humidity, the moisture sorption isotherm data were modeled by GAB (Guggenheim–Anderson–de Boer) model.     

Microbial Degradation of UV-Pretreated Low-Density Polyethylene Films by Novel Polyethylene-Degrading Bacteria Isolated from Plastic-Dump Soil

Eleven effective low-density polyethylene (LDPE)-degrading bacterial strains were isolated and identified from landfill soil containing large amounts of plastic materials. The isolates belonged to 8 genera, and included Pseudomonas (areroginosa and putida), Sphingobacterium (moltivorum), Delftia (tsuruhatansis), Stentrophomonas (humi and maltophilia), Ochrobacterum (oryzeae and humi), Micrococcus (luteus), Acinetobacter (pitti), and Citrobacter (amalonaticus). Abiotic degradation of LDPE films by artificial and natural ultraviolet (UV)-exposure was analyzed by FT-IR spectroscopy. LDPE films treated with UV-radiation were also inoculated with the isolates and biofilm production and LDPE degradation were measured. Surface changes to the LDPE induced by bacterial biofilm formation were visualized by Scanning Electron Microscopy. The most active bacterial isolate, IRN19, was able to degrade polyethylene film by 26.8?±?3.04% gravimetric weight over 4 weeks. Analysis of 16S rRNA sequence of this isolate revealed 96.97% similarity in sequence to Acinetobacter pitti, which has not previously been identified as a polyethylene-degrading bacterium. Also, most the effective biofilm forming isolate, IRN11, displayed the highest cell mass production (6.29?±?0.06 log cfu/cm²) after growth on LDPE films, showed 98.74% similarity to Sphingobacterium moltivourum.     

Devulcanization of Ground Tires by Different Strains of Bacteria: Optimization of Culture Condition by Taguchi Method

Biological devulcanization of ground tires (GTs) was evaluated by eleven different bacteria belonging to the genera Thiobacillus, Gordonia, Nocardia, Amycolaptopsis and Pseudomonas. The GTs were treated by each bacterium in a mineral medium and devulcanization was measured by increasing the sulfate of the medium and decreasing the sulfur of the GTs. The effects of incubation time (10 and 20 days) and the percent of ground tire in the medium (0.5 and 5 w/v %) on desulfurization were investigated. No significant changes were observed after 10 days of incubation. The total sulfur contents of all bio-treated GTs were decreased by 6–21% in 0.5% GTs after 20 days of incubation. While in 5% GTs, the total sulfur contents were mainly decreased using Thiobacillus ferroxidans DSMZ 583 and PTCC 1647 up to 27 and 15%, respectively. SEM photograph further indicated a good coherency interface between the bacteria and the GTs. Subsequently, Taguchi method was applied for the optimization of the culture condition of DSMZ 583. An L12 orthogonal array was performed by which the effects of eleven factors in two levels were evaluated. It was found that the amount and mesh size of GTs are the most important factors in biological devulcanization of ground tires.