Journal of Advances in Environmental Health Research
Volume:3 Issue: 3, Summer 2015

Moving bed biofilm reactor (MBBR) is a process in which attached growth is utilized for wastewater treatment. This process does not require sludge recycling or backwash. Activated sludge processes can be promoted to an MBBR by adding media to an aeration tank. Rapid sand filter is a physical method for the removal of total suspended solids (TSS) in advanced wastewater treatment. The purpose of this study was the evaluation of effluent reuse feasibility of MBBR and rapid sand filter in agricultural irrigation. Results showed TSS, biochemical oxygen demand (BOD5), and chemical oxygen demand (COD) concentrations in effluent were 10, 7.7, and 85.75 mg/l, respectively. Removal efficiency of TSS, BOD5, and COD was 98%, 98.8%, and 94.6%, respectively. Furthermore, the value of chemical parameters was less than the standard limitations. Average removal efficiency of total coliform, fecal coliform, and nematode was 100%. Total dissolved solids (TDS) and electrical conductivity (EC) in effluent were 960.5 mg/l and 1200.63 μs/cm, respectively. The Wilcox diagram showed that effluent was in the C3-S1 class, which means effluent quality was appropriate for irrigation. The results showed that effluent quality was completely compatible with the national standards in agricultural irrigation.

Degradation of humic substances in water is important due to its adverse effects on the environment and human health. The aim of this study was modeling and investigating the degradation of humic substances in water using immobilized ZnO as a catalyst. ZnO nanoparticles were synthesized through simple coprecipitation (CPT) method and immobilized on glass plates. The immobilized ZnO nanocatalyst was characterized through scanning electron microscopy (SEM) and X-ray diffraction (XRD). Response surface methodology (RSM) and central composite design (CCD) were used to create an experimental design for humic degradation and color removal efficiency. The most important parameters including initial concentration, pH, and contact time were optimized. The optimum conditions were initial concentration of 7.68 mg/l, pH of 4.42, and contact time of about 125.6 minutes. Under optimal conditions, maximum humic substances and color removal of about 100 and 82.37% were obtained, respectively. These results illustrate that an immobilized form of ZnO can be used as an efficient nanocatalyst for effective degradation of humic substances in water.

Exogenous estrogens or pollutants with estrogen-like activity can induce vitellogenin (VTG) synthesis in male and juvenile fish, making this protein a useful indicator of chemicals that mimic estrogenic activity. The purpose of this study was to investigate the impact of municipal wastewater on blood biochemical parameters of common carp (Cyprinus carpio). Under experimental conditions, biomarkers such as sex steroid levels, alkali-labile phosphate levels, cholesterol and triglycerides, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) were assessed in immature fish exposed to municipal wastewaters collected from a sewage canal in Behbahan, Khuzestan Province, Iran. No significant changes were found in testosterone levels on day 21; however, estradiol, alkali-labile phosphate, triglycerides, cholesterol, and LDL-cholesterol significantly increased in the fish exposed to municipal wastewater compared with the control group. A significant decrease in HDL-cholesterol levels was observed in the fish exposed to municipal wastewater at the end of the experiment. In conclusion, the results of the present study indicated that sewage effluent of Behbahan may contain endocrine disrupters and exposure to sublethal concentrations of municipal wastewater may cause dysfunction in reproductive health indicators of common carp.

One of the parameters responsible for decreased water quality in a distribution system is temperature changes. This study was conducted to examine the effect of temperature on pH, turbidity, and residual chlorine in Sanandaj, Iran, Water Distribution System. The required water samples were taken from 85 stations during April to October 2014. Sampling was carried out over 6 months and twice per month. The average amount of residual chlorine measured at these stations was 0.58 and 0.52 mg/l, and turbidity was 0.86 and 0.98 nephelometric turbidity unit (NTU) in winter and spring, respectively. The temperature did not have any effect on pH, the amount of pH in winter and spring were 7.56 and 7.57, respectively. The results showed significant differences in the concentration of residual chlorine and turbidity of Sanandaj Water Distribution Network between winter and spring (P ≤ 0.01). Thus, the concentration of residual chlorine and turbidity varies in warm and cold seasons. However, no significant difference was observed in pH (P ≥ 0.01). The research results indicated that temperature does not have any effect on the qualitative parameters measured in the study area.

One of the parameters responsible for decreased water quality in a distribution system is temperature changes. This study was conducted to examine the effect of temperature on pH, turbidity, and residual chlorine in Sanandaj, Iran, Water Distribution System. The required water samples were taken from 85 stations during April to October 2014. Sampling was carried out over 6 months and twice per month. The average amount of residual chlorine measured at these stations was 0.58 and 0.52 mg/l, and turbidity was 0.86 and 0.98 nephelometric turbidity unit (NTU) in winter and spring, respectively. The temperature did not have any effect on pH, the amount of pH in winter and spring were 7.56 and 7.57, respectively. The results showed significant differences in the concentration of residual chlorine and turbidity of Sanandaj Water Distribution Network between winter and spring (P ≤ 0.01). Thus, the concentration of residual chlorine and turbidity varies in warm and cold seasons. However, no significant difference was observed in pH (P ≥ 0.01). The research results indicated that temperature does not have any effect on the qualitative parameters measured in the study area.

Due to the present water shortage and environmental problems associated with industrial effluent, investigation of novel treatment technologies is an essential approach. Being a highly toxic chemical of asphyxiating characteristics, cyanide is seen as a major environmental pollutant in a wide range of industrial effluents. The present study aimed to address the adsorption and photocatalytic degradation of cyanide using activated fly ash and TiO2/UV. To investigate the removal efficiency of cyanide, two sets of experiments were designed. First, cyanide was absorbed by activated fly ash and degraded via a photocatalytic process, individually. Second, simultaneous adsorption and degradation was examined. The removal efficiency of cyanide by modified fly ash (MFA), TiO2/UV, and their combination (MFA-TiO2/UV) was 76.1%, 81%, and 86.6%, respectively. Optimal conditions for the combination of activated fly ash AFA-TiO2/UV were contact time of 6 hours, temperature of 100 °C, and AFA: TiO2 ratio (w/w) of 1:1. Under these conditions, a maximum removal rate of 92.4% was obtained when 1.2 g of MFA/TiO2 was used with a pH value of 3 in the presence of UV light. Based on the results of cyanide removal, it can be concluded that the combination of adsorption and photocatalytic degradation with MFA-TiO2/UV can be utilized to improve the removal of cyanide from wastewater.

Phenol and its derivatives are pollutant compounds that are present in the wastewater of many industries. The objective of this study was to investigate the photocatalytic degradation of phenol in water containing various concentrations of sodium chloride. A laboratory study was conducted to evaluate the performance of UV/ZnO process on the efficiency of phenol removal from saline water with ZnO nanoparticles fixed on glass using UVC radiation. The effects of pH, contact time, sodium chloride concentrations, and the initial concentration of phenol on the photocatalytic removal of phenol were studied. The photocatalytic degradation of phenol showed suitable efficiency under the absence of sodium chloride (100% phenol removal at a concentration of 5 mg/l and during 120 minutes). However, the removal efficiency decreased in the presence of a concentration of 30 g/l of sodium chloride (92.4%). Additionally, phenol photocatalytic degradation efficiency decreased as a result of an increase in the initial concentration of phenol and the efficiency increased as a result of a decrease in pH (pH = 3). The results obtained from this study indicated that ZnO nanoparticles or ultraviolet rays alone cannot remove phenol fully and have a much lower efficiency in comparison with the photocatalytic degradation of phenol. Thus, the photocatalytic degradation process (UV/ZnO) is an effective method of removing phenol from saline water solutions.