Evaluation of a novel integrated membrane biological aerated filter for water reclamation: A practical experience.

The use of treated wastewater in addition to solving the problem of water shortage, can increase soil fertility and reduce the use of chemical fertilizers. We aim to provide a high-quality effluent to feed membrane system, reduce treatment costs and enhance the efficiency of wastewater recycling. All experiments were conducted on a novel integrated membrane biological aerated filter (IMBAF) consisting of a down flow cylindrical biological aerated filter (BAF) filled by silica and a novel sand-coated polystyrene granules (SCP), followed by ultrafiltration (UF) and reverse osmosis (RO) membranes. IMBAF reactor, with 73.6 L volume, was operated for 270 days (in three 90-day stages) with different conditions of returning backwash water. Accordingly, BAF generated high quality water for feeding UF membrane with 94.2%, 68%, 54.4%, 91.2%, and 99.95% of turbidity, 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD), oil and grease (O&G), fecal coliform (FC) removal, respectively. At the end of stage 3, 99.88% of influent was recycled by UF and only 0.12% was disposed of as sludge. The BAF and UF module efficiently promote the quality of water entering RO system. After 75 days of continuous operation, the increase in trans-membrane pressure (TMP) and also decrease in RO membrane permeability were about 14% and 9.4%, respectively, indicating low clogging of the membrane. The use of BAF structure designed in this study increases the wastewater recycling rate, decreases membrane clogging and thereby reduces the costs of concentrate disposal and chemical cleaning.

An overview report on the application of heteropoly acids on supporting materials in the photocatalytic degradation of organic pollutants from aqueous solutions.

Organic pollutants contaminate water resources and the environment when discharged into water streams. Also, the presence of these materials in incompletely treated or untreated wastewater leads to serious environmental hazards. The hydroxyl radicals and holes are regarded as the most oxidant species in the degradation of organic pollutants using the studied composites. The results of this review show that heteropoly acids on supporting materials could be considered as appropriate photocatalysts in the removal of organic pollutant from aqueous solutions.

Assessment of hospitalization and mortality from exposure to PM10 using AirQ modeling in Ilam, Iran.

The aims of this study were to assess the health impact of PM10 on inhabitants and to investigate the trend of PM10 concentrations in Ilam, Iran, from 2012 to 2015. For these aims, daily average concentration of PM10 was obtained from continuous monitoring stations in the study area. Mortality and morbidity due to PM10 were assessed by AirQ software developed by World Health Organization (WHO). Based on the results, the annual mean concentrations of PM10 in all of years were more than WHO guideline and PM10 concentration had a decreasing trend in this study period. Total mortality attributed to PM10 was found to be 49 cases in 2012, 25 in 2013, and 33 in 2014. Hospital admission due to respiratory diseases was the most impact due to PM10. Increase in relative risk (RR) with every 10 µg/m3 increase in PM10 from 2012 to 2015 years for total mortality, respiratory disease hospitalization, and hospital admissions were 0.6, 0.8, and 0.9%, respectively. The results of this study indicated that air pollution is one of the major problems in this urban area and AirQ model as simple tool can help to design preventive and controlling programs in order to reduce human health effects of pollutants.

Application of novel Modified Biological Aerated Filter (MBAF) as a promising post-treatment for water reuse: Modification in configuration and backwashing process.

Biological Aerated Filter (BAF) reactors due to their plentiful biomass, high shockability, high efficiency, good filtration, availability and lack of need for large land areas, are enjoying from great importance in advanced wastewater treatment. Therefore, in this study, Polystyrene Coated by Sand (PCS) was produced as a novel media and its application in a modified down-flow BAF structure for advanced wastewater treatment was assessed in two steps. In step one, the backwash effluent did not return to the system, while in step two backwash effluent returned to increase the water reuse efficiency. The backwash process was also studied through three methods of Top Backwashing (TB), Bottom Backwashing (BB), as well as Top and Bottom Backwashing Simultaneously (TBBS). The results showed that return of backwash effluent had no significant effect on the BAF effluent quality. In the second step similar to the first one with slight differences, the residual average concentrations of TSS, BOD5, and COD at the effluent were about 2.5, 8.2, and 25.5 mg/L, respectively. Additionally, in step two, the mean volume of disposal sludge/volume of treated water (vds/vtw) decreased a large extent to about 0.088%. In other words, the water reuse has increased to more than 99.91%. The backwash time in methods of TB and BB were 65 and 35 min, respectively; however, it decreased in TBBS methods to 25 min. The concentrations of most effluent parameters in this system are in concordance with the 2012 EPA Agriculture Standards, even for irrigation of Non-processed agricultural crops and livestock water consumption.

A comparative study on capability of different tree species in accumulating heavy metals from soil and ambient air.

Heavy metals (HMs) in the urban environment can be bio-accumulated by plant tissues. The aim of this study was to compare fourteen different tree species in terms of their capability to accumulate four airborne and soilborne HMs including; zinc (Zn), copper (Cu), lead (Pb), and cadmium (Cd). Samplings were performed during spring, summer, and fall seasons. To compare bioaccumulation ability, bio-concentration factor (BCF), comprehensive bio-concentration index (CBCI), and metal accumulation index (MAI) were applied. Species with the highest accumulation for single metal which shown using BCF did not have the highest CBCI and MAI. Based on CBCI and MAI, Pinus eldarica (7.74), Wistaria sinensis (8.82), Morus alba (8.7), and Nigral morus (27.15) had the highest bioaccumulation capacity of HMs, respectively. Therefore, these species can be used for phytoextraction of HMs pollution and green and buffer zone in the urban.

Cardiovascular, respiratory, and total mortality ascribed to PM10 and PM2.5 exposure in Isfahan, Iran.

BACKGROUND: Air pollution is an important environmental issue due to its proven serious impacts on human health. The aim of this study was to estimate the attribution of particulate matter with an aerodynamic diameters of ≤ 2.5 and 10 (PM2.5 and PM10) in the prevalence of cardiovascular and respiratory diseases and premature deaths in Isfahan in 2013-2014. MATERIALS AND METHODS: This descriptive, ecological study was conducted to assess health impacts of PM2.5 and PM10 on the population using Air Q2.2.3 software, suggested by the World Health Organization (WHO). RESULTS: The results showed that the annual mean, winter mean, summer mean, and the 98 percentile of PM10 concentration in Isfahan were 108, 100, 116, and 264 µg/m3, respectively. The number of deaths per year related to PM2.5 was 670 and that for PM10 was 713 cases. The number of annual deaths due to cardiovascular and respiratory diseases attributed to PM10 was 316 and 68 cases, respectively. CONCLUSION: The results of this study revealed that about 44.3% of total annual death due to cardiovascular diseases and 9.55% of that due to respiratory diseases were attributed to PM10 exposure. In the other word, residents were exposed to PM2.5 and PM10 concentrations higher than the WHO guidelines which caused a notable increase in the rate of mortality.

Cutaneous leishmaniasis prevalence and morbidity based on environmental factors in Ilam, Iran: Spatial analysis and land use regression models.

The aim of this study was to investigate the impact of the environmental factors on cutaneous leishmaniasis (CL) prevalence and morbidity in Ilam province, western Iran, as a known endemic area for this disease. Accurate locations of 3237 CL patients diagnosed from 2013 to 2015, their demographic information, and data of 17 potentially predictive environmental variables (PPEVs) were prepared to be used in Geographic Information System (GIS) and Land-Use Regression (LUR) analysis. The prevalence, risk, and predictive risk maps were provided using Inverse Distance Weighting (IDW) model in GIS software. Regression analysis was used to determine how environmental variables affect on CL prevalence. All maps and regression models were developed based on the annual and three-year average of the CL prevalence. The results showed that there was statistically significant relationship (P value≤0.05) between CL prevalence and 11 (64%) PPEVs which were elevation, population, rainfall, temperature, urban land use, poorland, dry farming, inceptisol and aridisol soils, and forest and irrigated lands. The highest probability of the CL prevalence was predicted in the west of the study area and frontier with Iraq. An inverse relationship was found between CL prevalence and environmental factors, including elevation, covering soil, rainfall, agricultural irrigation, and elevation while this relation was positive for temperature, urban land use, and population density. Environmental factors were found to be an important predictive variables for CL prevalence and should be considered in management strategies for CL control.