Activity

NH

CL is a very beneficial for modifying the structure and morphology of carbon aerogel, and the dynamic behavior of the column with respect inlet benzene concentration can be explained by Yan-Nelson model.

NH4CL is a very beneficial for modifying the structure and morphology of carbon aerogel, and the dynamic behavior of the column with respect inlet benzene concentration can be explained by Yan-Nelson model.The lower concentration of arsenic in the groundwater is serious health concerns of the people who are continuously taking from their drinking water. In this study, synthetic arsenic-contaminated water was prepared in the laboratory with varying concentrations of arsenic (100 to 1000 μg/L) and treated by nanosize adsorbent (copper oxide nanoparticles (CuO NPs)). The colloidal and powder form of CuO NPs were synthesized in the laboratory by the hydrothermal technique on a large scale and their shape and size were confirmed by XRD, FTIR, FESEM, and HRTEM analysis. It was found 30 ± 2 nm as size and spherical shape. The equilibrium adsorption of As (III) occurred at 90 min of contact time, pH 7.5, and 4 g/L adsorbent dosage. The maximum percent removal of As (III) was reached to 97.8, 94.6, 91.5, and 88.4% at an initial arsenic concentration of 100, 200, 500, and 1000 μg/L, respectively. The adsorption of As (III) followed pseudo-second-order kinetic and Freundlich isotherm model. Moreover, the overall cost of the synthesized CuO NPs (including material, operational, manpower, and transport cost with other overhead charges) was Rs. 281.832 g-1, which is lesser than the market price (Rs. 500.018 g-1). Hence, the optimized adsorption design would help for the efficient removal of As (III) from aqueous medium.

Bioaerosols play an important role in incidence of infections in indoor and outdoor air of hospitals. Microorganisms

human beings and they are found everywhere in the environment, including different wards of a hospital. So, quantitative and qualitative analysis of microorganisms is highly important in hospital air. The aim of this study was to evaluate the diversity and density of bacteria and fungi in the air of Shohadaye Mehrab Hospital in Yazd City, Iran.

Sampling was performed using a single-stage pump (Quick Take30) at a flow rate of 28.3l per minute for five minutes. As a result, 288 indoor and outdoor hospital air samples were collected. Numbers and types of bacterial and fungal colonies were identified using colony morphology, gram staining, and standard microbial tests. Chi-square test, PCA and linear mixed model were run by SPSS version 24.0 for data analysis.

The highest bacterial contaminations were found in the burns ward (294CFU/m

), operating theater (147CFU/m

), and emergency depar a susceptible site for opportunistic microorganisms, even low concentration of fungi/bacteria in air can be considered as a risk factor that facilitates transmission of the infectious agents in the hospital. Therefore, control measures should be taken to reduce the infection hazard in health staff and patients. These measures include ensuring effective ventilation, cleaning and decontaminating surfaces and equipment, restricting the personnel and patient companions’ movement across the wards.Measurement and prediction of wastewater quality parameters are crucial for evaluating the risk to the receiving waters. This study presents new methods for the identification of outlier data and smoothing as an effective pre-processing technique prito to modelling. This new data processing method uses a combination of the autoregressive integrated moving average (ARIMA) model and -the adaptive neuro fuzzy inference system with fuzzy C-means clustering (FCM) (ANFIS-FCM). These new pre-processing methodsare compared to previously employed non-linear approaches for modelling of wastewater influent/effluent 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD) and total suspended solids (TSS). Linear modelling of each parameter, 242 linear models, were investigated, and a linear model for each parameter was selected. The results of the non-linear models led to an acceptable prediction for qualitative parameters so that the high coefficient of determination (R 2 ) was observed for the influent and effluent BOD and TSS, respectively. The range of the R 2 for all models was recorded as 0.8-0.87 and 0.83-0.89, respectively. By a combination of the linear and non-linear mothods a hybrid model was introduced. The proposed hybrid model for the influent BOD with the highest correlation between the observed and predicted values, and limited scattering was identified as the optimal model (R2 = 0.95). The use of hybrid models to predict wastewater quality parameters improved the performance and efficiency of the models. In addition, a comparison of the hybrid model with the recently developed models in the literature indicates that the developed ARIMA-ANFIS-FCM outperformed other models.The aim of this study was to evaluate the efficiency of photocatalytic ozonation process using graphene-dioxide titanium nanocomposite in removing Pentachlorophenol (PCP) from aqueous solutions. selleck chemicals llc In this study, nanocomposites with graphene to TiO2(G/T) ratios of 110 and 120 were synthesized by hydrothermal method, and its characteristics were assessed using various analyses, SEM, XRD, FTIR, TEM, BET and TGA. In this process, the effects of parameters including O3 concentration (0.25-1.25 mg/L), nanocomposite concentration (50-500 mg/L), initial PCP concentration (10-100 mg/L), and time (10-60 min), were studied. The results showed that PCP removal efficiency was increased by decreasing solute concentration. Increasing nanocomposite dose to 100 mg/L was led to an increase in efficiency (99.1%), but then a decreasing trend was observed. Increasing the concentration of ozone, up to specific value, also enhanced the efficiency but then had a negative effect on process efficiency. Furthermore, the optimum ratio of the catalyst was determined to be 120. The highest efficiency of the process for initial pentachlorophenol concentration of 100 mg/L was obtained 98.82% in optimum conditions (catalyst dose of 100 mg/L and 60 min). It is concluded that the photocatalytic ozonation process using graphene-dioxide titanium nanocomposite had the highest efficiency in removal and mineralization of PCP.