[en] The quantity and quality of leachate generated in a landfill are very important when it comes to waste management. Sanitary landfill is still being considered as most common element for waste management. Leachate is generated in both fluctuating quantity and quality during landfilling. To eliminate the adverse effects arising from leachate and meet standards for discharge into the environment, the authorities have forced to use suitable and effective methods and technologies for leachate treatment. “Here we review (1) comprehensive information on landfill leachate (LFL) in terms of quantity, quality, and treatment methods mostly used in Iran. (2) In the present review, the treatment methods have been classified into four categories: (a) physical, (b) physicochemical, (c) biological, and (d) combined biological and physicochemical and their advantages, drawbacks, and efficiency are discussed”. Given the presence of bio-recalcitrant and refractory elements in leachate and also strict standards enacted for protection the environment, application physicochemical, as a pretreatment and biological technology seems to be a complementary option for landfill leachate treatment in Iran. However, unfortunately there are no valid information in view both points of valorization and characteristics, therefore, it can fascinate researchers to pay attention these critical parameters in LFL treatment and waste management.

[en] Highlights: • Effect of various factors and mechanisms of sorption process have been analyzed. • Ultrasound-assisted magnetic adsorption system is effective for DNP removal. • Best efficiency and adsorption capacity were equal to 89.93% and 425.58 mg/g. • MGO could keep its performance to at least the 10th cycle. • Adsorption isotherms, thermodynamics, kinetics and reusability were studied. 2,4-Dinitrophenol (DNP) was listed as a priority pollutant; accordingly, DNP-contaminated effluent must be treated before discharging to the receiving resources. In the present study, the hybrid ultrasound-assisted GO-Fe₃O₄ system was employed to decontaminate DNP solution. Ultrasound irradiation makes the mass transfer of adsorbate improved and Fe₃O₄ enables GO separation from liquid phase under external magnetic field. The as-synthesized GO-Fe₃O₄ composite was characterized by SEM, TEM, XRD, FTIR, BET and VSM. A response surface methodology based central composite design (RSM-CCD) was used to estimate and optimize of various variables on DNP removal percentage. Under optimal conditions (pH: 4.45, adsorbent dose: 0.178 g/L, ultrasound frequency: 40.02 kHz and DNP concentration: 50.10 mg/L, maximum adsorption capacity was calculated to be 425.58 mg/g for the ultrasound system, higher than the simple system 309.40 mg/g, indicating the importance of synergistic effect between the ultrasound waves and the adsorption process. The ultrasound-assisted adsorption system showed the better agreement with the Langmuir isotherm (R² > 0.997), while the results of the stirring system were more consistent with the Freundlich model (R² > 0.991). The experimental results indicated that the pseudo-second-order kinetic model well fitted by experiment data and rate constant was calculated to be 0.000148 min⁻¹ and 0.000002 min⁻¹ under ultrasound and silent systems, respectively. The rate of desorption under ultrasound was more favorable and reuse of the adsorbent in both systems after 10th consecutive cycles reduced by about 22%. Thermodynamic calculations also confirmed the endothermicity and spontaneity of both systems. Electrostatic attraction, hydrogen bonding, and π -π interactions played key roles during the adsorption of DNP onto the MGO. In conclusion, the outcomes of this study provide valuable information of the ultrasound-assisted GO-Fe₃O₄ system for practical applications.

[en] Asbestos, as with other pollutants in the air, has adverse effects on the health of human beings and animals. Today, the relationship between presence of asbestos fibers in the air breathed by humans and developing serious diseases such as lung cancer (asbestosis) and mesothelioma has been proven. This study was designed and conducted within the time period of August 2017 and June 2018 to determine the concentration of asbestos fiber in the ambient air of Shahryar City and to evaluate their health effects for the general population of the city. For this purpose, samples were taken from four points, and overall 32 air samples were taken along the year. The samples were then analyzed by the phase contrast microscopy (PCM) method. Also, to investigate the type of asbestos and for more accurate counting of fibers, SEM analysis was utilized. Finally, based on the EPA IRIS method, the health effects resulting from asbestos risks were also evaluated. The results of this study indicated that the mean annual concentration of asbestos fiber in the ambient air of Shahryar City was obtained as 0.0019 f/ml PCM and 0.0072 f/ml SEM. Furthermore, the most polluted point was S1 point (0.0119 –0.0026 f/ml, PCM), while the lowest concentration was related to S4 point (0.001 f/ml PCM–0.0021 f/ml SEM). The mean annual risk resulting from airborne asbestos fiber in the ambient air of Shahryar City for all samples was obtained as 1.72 × 10⁻⁶ to 2.2 × 10⁻⁴, which was higher than the recommended risk range in some points.

[en] 

Background

Application of the point-of-use water treatment (POU-WT) systems has consistently increased during the last decade in Iran. In this study, the qualitative performances of reverse osmosis-based POU devices in selected cities of Iran were investigated.

Methods

This applied- descriptive study was conducted in three cities of Tehran, Rasht, and Ahvaz in 2016 (selected based on the level of POU devices sale index in three phases). After choosing the most popular five brands of six stages POU devices, 360 water sampling zones and POU consumer households of the selected cities were measured. Also, the awareness of the consumers about POU-WT systems selection and performance was investigated through a designed questionnaire.

Results

The qualitative parameters in the three cities were acceptable (p < 0.05) for tap water (except for EC in Ahvaz), the output water were as follows: pH = 6.05–7.5, EC = 49.8–58.2 μs/cm, TOC = 0.01–0.23 mg/L and Nitrate = 0.52–4.5 mg/LNO₃ (lower or within the range of regulatory limits), Total Hardness = 33–41.5 mg/L and Fluoride = 0.01–0.23 mg/L (which were lower than the admissible limit, with p < 0.05), HPC values were in the range of 543–676 CFU/mL, which exceeded the regulatory level. Results of ANOVA analysis showed significant differences between the selected cities. The results of the questionnaire survey showed that the dissatisfaction of tap water quality and health-related concerns were the two main reasons for household POU-WT systems; awareness levels of 64% of these households about the performances of their POU systems were weak. Also, social media were mostly used by POU-WT users for brand selected.

Conclusion

Based on the results of the tap-water quality application of POU-WT systems are not recommended in Tehran and Rasht, and regarding the outputs of these systems, side effects of softened water, lack of Fluoride and a remarkable increase of the number of bacteria should be considered. In Ahvaz, application of POU-WT systems can decrease the health-related problems and it is necessary to increase the access to read POU-WT efficiency information for the consumers.

[en] Although the number of cholera infection decreased universally, climate change can potentially affect both incidence and prevalence rates of disease in endemic regions. There is considerable consistent evidence, explaining the associations between cholera and climatic variables. However, it is essentially required to compare and interpret these relationships globally. The aim of the present study was to carry out a systematic review in order to identify and appraise the literature concerning the relationship between nonanthropogenic climatic variabilities such as extreme weather- and ocean-related variables and cholera infection rates. The systematic literature review of studies was conducted by using determined search terms via four major electronic databases (PubMed, Web of Science, Embase, and Scopus) according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach. This search focused on published articles in English-language up to December 31, 2018. A total of 43 full-text studies that met our criteria have been identified and included in our analysis. The reviewed studies demonstrated that cholera incidence is highly attributed to climatic variables, especially rainfall, temperature, sea surface temperature (SST) and El Niño Southern Oscillation (ENSO). The association between cholera incidence and climatic variables has been investigated by a variety of data analysis methodologies, most commonly time series analysis, generalized linear model (GLM), regression analysis, and spatial/GIS. The results of this study assist the policy-makers who provide the efforts for planning and prevention actions in the face of changing global climatic variables.

[en] Highlights: • Most prescribed antibiotics in Iran were found in two rivers as well as the influent and effluent. • There was a large variation in antibiotic removal from negative removal to 100% in WWTPs. • Negative removal was observed for macrolides. • A significant difference between antibiotics concentration in effluents and rivers were observed. • The target antibiotics were not detected in any of the analyzed ground, source and treated water samples. The presence of most prescribed antibiotic compounds from four therapeutic classes (β-lactam, cephalosporins, macrolides, fluoroquinolones) were studied at two full-scale WWTPs, two rivers, thirteen groundwater resources, and five water treatment plants in Tehran. Analytical methodology was based on high performance liquid chromatography/tandem mass spectrometry after solid-phase extraction. Samples were collected at 33 sample locations on three sampling periods over four months from June to August 2016. None of the target antibiotics were detected in groundwater resources and water treatment plants, while seven out of nine target antibiotics were analyzed in two studied river waters as well as the influent and effluent of wastewater treatment plants at concentrations ranging from < LOQ to 926.32 ng/L. Ciprofloxacin predominated in all analyzed influent (552.6–796.2 ng/L) and effluent (127–248.7 ng/L) samples of WWTP A, whereas cephalosporins including cephalexin (523.3–977.7 ng/L) and cefixime (278.65 to 422.1 ng/L) were the most abundant detected antibiotics in the influent and effluent of WWTP B. Aqueous phase removal efficiencies were assessed and ranged from 339.83% to 100% for the seven detected antibiotics. “Negative removals” were observed for erythromycin, azithromycin, and cefixime due to the deconjugation of conjugated metabolites via biological transformation in the studied WWTPs. From a statistical point of view, significant differences (p < 0.05) were observed in the concentrations of cefixime, cephalexin, azithromycin, and erythromycin in the effluent of both studied WWTPs. Ciprofloxacin and cephalexin were the most abundant detected antibiotics in the two studied river waters. Statistical results revealed that there were significant differences in the concentrations of ciprofloxacin, azithromycin, and erythromycin (p < 0.05) in Firozabad ditch (receiving WWTP effluent) and Kan River (non-receiving WWTP effluent) which demonstrated that WWTPs discharges could be an important source of antibiotics being released in water bodies.