Background: Composting process is a feasible biological treatment for the recycling of municipal solid wastes as a soil amendment. The principal requirement of compost for it to be safely used in soil is a high degree of stability or maturity, which implies stable organic matter content as well as the absence of phytotoxic compounds and plant or animal pathogens. Objectives: At the present study, the maturity and stability of composted municipal solid wastes at a biocompost plant was evaluated. Materials and Methods: For the assessment of compost maturity, important parameters including temperature, moisture content, pH, electrical conductivity, carbon-to-nitrogen (C/N) ratio, microbial parameters including Salmonella, total and fecal coliforms were measured during the composting process (80 days). In addition, phytotoxicity as seed germination index and heavy metals concentration (Zn, Cu, Cr, Ni, Cd and Pb) was determined at the end of the composting time. Results:The results showed that the C/N ratio decreased during the composting process (reached to 15.6) due to the loss of carbon and the increase in nitrogen content per unit material; also, the NH 4 + /NO 3 ratio decreased with increase in the time of composting and reached

Background: Dust exposure at quarry mines is inevitable and can result in poor air quality. This research aimed to assess pulmonary symptoms and lung functions of dust-exposed workers at an iron-ore mine in eastern Iran. Methods: An environmental cross-sectional study sampled 174 dust-exposed mine workers and 93 unexposed administrative employees as the reference group. A standardized questionnaire on respiratory symptoms was completed in accordance with recommendations of the American Thoracic Society(ATS). Calibrated spirometer measured Pulmonary Function Tests (PFTs). Data were analyzed via SPSS-21, integrating independent samples t-test, Chi-square and linear or logistic-regression models. Results: There was no significant variation between dust-exposed and reference groups in terms of age, weight, height, work experience and the number of smokers (P>0.05). Mean levels of exposure to inhalable and respirable mineral-dust were 15.09±2.34 and 3.45±2.57 mg/m3 respectively. Pulmonary capacities of dust-exposed group were considerably decreased as compared to others (Forced Vital Capacity [FVC] 86.55±13.77 vs. 105.05±21.5; Forced Expiratory Volume in 1 second [FEV1] 88.06±16.8 vs. 105.81±21.55; FEV1/FVC 103.03±18.17 vs. 93.3±12.49; and Peak Expiratory Flow [PEF] 89.82±22.58 vs. 98.09±20.60) (P<0.001); with a higher prevalence of cough (P=0.041), wheezing (P=0.032), and dyspnea (P=0.035) among formers. Age along with exposure to respirable-dust significantly reduced FVC, FEV1 and FEV1/FVC. Cigarette consumption attenuated FVC and FEV1 on an average of 5 to 9 units. Conclusion: Controlled occupational dust-exposure is a definitive pre-requisite to reduce respiratory problems among quarry workers, with an explicit consideration towards mineral- mine workers. Modifiable accomplices like smoking and non-compliance of PPEs usage should be amicably resolved.

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Among toxic heavy metals, cadmium is one of the most dangerous for human health. Since cadmium is a well-known toxic metal, industrial effluents and wastewaters rich in cadmium must be treated prior to their disposal. Present study deals with the evaluation of biosorptive removal of cadmium by Trichoderma fungus. The effect of different important parameters such as initial pH, cadmium concentration, contact time, stirring rate, and temperature on cadmium sorption was investigated. Cadmium biosorption capacity and its removal efficiency increased along with the increase of pH of the solution, and maximum biosorption of cadmium(II) ions were observed at pH 6. Biosorption kinetics data were fitted using pseudo-first-order and pseudo-second-order models. It was found that the kinetics data fitted well the pseudo-first-order during the initial 120 min of biosorption, and when the biosorption time was 120 min, the experimental data fitted very well with the pseudosecond-order kinetics reaction. Thermodynamic parameters such as standard Gibbs free energy (ΔG˚), standard enthalpy (ΔH˚), and standard entropy (ΔS˚) were evaluated. The results confirmed that biosorption of cadmium(II) ions by Trichoderma fungus was spontaneous and endothermic nature.