Volume 20 - 2018

This study explored the best-operating conditions for a novel electrocoagulation (EC) reactor with the rotating anode for textile wastewater treatment. The influence of operating parameters like inter-electrode distance (IED), current density (CD), temperature, pH, operating time (RT), and rotation speed on the removal efficiency of the contaminant was studied. A comparative study was done using conventional model with static electrodes in two phases under same textile wastewater The findings revealed that the optimal conditions for textile wastewater treatment were attained at RT = 10 min, CD = 4 mA/cm2, rotation speed = 150 rpm, temperature = 25oC, IED = 1cm, and pH = 4.57. The removal efficiencies of colour, biological oxygen demand (BOD), turbidity, chemical oxygen demand (COD), and total suspended solid (TSS) were 98.50%, 95.55%, 96%, 98% and 97.10% within the first 10 min of the reaction. The results of the experiment reveal that the newly designed reactor incorporated with cathode rings and rotated anode impellers provide a superior treatment efficiency within a short reaction time. The novel EC reactor with a rotating anode significantly enhanced textile wastewater treatment compared to the conventional model. The values of adsorption and passivation resistance validated the pollutants removal rate.

Over the last few decades, the evidence on the adverse effects on the health of air pollution has been raised. Mortality is the most important health effect of ambient air pollution. We studied the relation between mortality and criteria pollutant air in Tehran, one of the highly industrialized, densely populated area and most polluted cities of the reign, during 2005-2014. For this purpose, we applied the approach proposed by the World Health Organization using the AirQ 2.2.3 model. Hourly concentrations of pollutants were taken from the Tehran environmental protection agency and Air Quality Control Company. In this model, the attributable proportion of health outcome, the annual number of excess cases of mortality for all causes were estimated. According to results, the number of total mortality caused by exposure to O3, NO2, SO2, PM10, PM2.5 in the past decade was 8042, 15141, 8136, 17776 and 20015 cases, respectively. The number of cumulative total mortality was 53110 cases in ten years. Furthermore, the number of cumulative cardiovascular and respiratory mortality 33887 and 8168 cases was estimated in last decade. A large number of residents of Tehran have died as a result of exposure to air pollutants; therefore for control and management of air pollution, appropriate actions on health and the environment should be performed.

Groundwater is one of the important sources of drinking water In Jijel (northeastern Algeria). Various analyses have shown critical concentrations of lead and cadmium in several groundwater sources used for drinking. The aim of this study is to evaluate the contamination by lead and cadmium of boreholes and hand-dug wells located in the catchment of the Nile River. Therefore, chemical analysis was performed on drinking water samples from eight boreholes; tow hand dug wells and one spring supplying Jijel city in drinking water. The water samples were examined for the presence of cadmium and lead using the SAA- 6200 Atomic Absorption Spectrophotometer (Shimadzu Corporation). The results of this study show high concentrations of lead (ranged from 72.84±0.26 to 458.95±0.55 μg.L-1) and cadmium (ranged from 12.41±0.88 to 33±0.38 μg.L-1) in all water samples. These concentrations far exceeded permissible values according to the WHO are drinking water posing a potential health risk for the public. The water quality in the studied area of Nile River basin must be considered very low.

Presence of antibiotics in the environment specially in aqueous environments is considered a major warning about health and environment. Thus, this study aims the efficiency of coupled process of Activated Carbon (AC) prepared from mango seed+ZnO under UV irradiation as an advanced oxidation process in removing cefazolin antibiotic from aqueous solutions. This experimental study was carried out in a discontinuous reaction chamber with volume of one liter. In this process, the effect of initial pH parameters of the environment (3– 9), initial concentration of cefazolin (20 – 200 mg/L), concentration of modified, photocatalyzer (20 – 100 mg/L) and reaction time (10 – 60 min) were studied. The pilot used consisted of a low pressure mercury lamp with a 55-watt beam radiation power inside the steel chamber. The kinetic of the process was studied based on pseudo first order kinetics. Results showed that the highest removal efficiency of cefazolin antibiotics in the reaction of UV/AC + ZnO, at optimal conditions of pH= 3, contact time of 60 min, initial concentration of 100 mg/L and modified photocatalyzer of 0.1 g/L was equal to 96%. The kinetic model determined for the process followed kinetic model of pseudo- first order kinetics with high correlation of (R2 = 0.99). Results of present study revealed that photocatalyzer process of nanoparticles oxidation on synthetic activated carbon can be effectively used as an advanced oxidation reaction to remove cefazolin and similar pollutants.