An Online Calculating Model for Leachate Production in Mazandaran’s Waste Landfills; (Case Study: Babol Municipal Waste Landfill)

Leachate production and management is a challenging environmental issue in municipal landfills and depots in Iran. Leachate contains toxic materials, heavy metals, and organic and microbial pollutants on a significant scale. Its uncontrolled entrance into the surface, groundwater, and soils can also substantially inverse impacts on human health and natural habitats. In Mazandaran province, during the last decades, depots and landfilling of municipal and industrial waste have led to environmental degradation in its eco-sensitive natural zones and brought a series of health, social, and security challenges to the region. Due to the region's high precipitation rate and landfills with no cover, these places practically convert into an extensive resource for leachate production. To diminish the environmental impacts, a lot of work has been done in recent years to develop a sort of leakage gathering system and treatment plants in these landfills, based primarily on an overall estimation. In this study, a calculating computer model has been developed for leakage production based on regional climate conditions and the characteristics of municipal waste. This model is different from the HELP model, which is commonly used for sanitary landfills and is specifically developed for the waste depots of the Mazandaran province. In this model, hydrological methods, which are based on the water balance in the landfill sites, were used for the calculation. The developed model was uploaded as an online service for public use. By referring to the internet address provided, the developed model in the landfill part and the leachate section, the amount of produced leachate for the landfill site of Mazandaran province can be calculated. Also, the leachate volume of the Babol Anjilsi landfill has been calculated as a case study. As a result of this study, the lowest and highest amount of the production leachate for hot and dry months of the year (June and July) and for wet and rainy months (October) was about 63.39 and 260.07 cubic meters per day, respectively

Study on Olive Oil Wastewater Treatment: Nanotechnology Impact

The olive mill wastewater (OMW) is generated from olive oil extraction in olive mills. It contains a very high organic load and considerable quantities of phytotoxicity compounds. Comprehensive articles with different methods have been published about the treatment of OMW. This paper reviews the recent reports on the variety methods of OMW treatment. Biological process, containing aerobic pre-treatment by using different cultures and anaerobic co-digestion with other sewage and also added external nutrient with optimum ratio attracted much attention in the treatment of OMW. However, advanced oxidation process (AOP) due to the high oxidation potential which causes destruction of organic pollutants, toxic and chlorinated compounds have been considered. Furthermore, membrane technologies consist of microfiltration, ultrafiltration and especially nanofiltrationin wastewater treatment are growing in recent years. They offer high efficiency and mediocre investments owing to novel membrane materials, membrane design technics, module figures and improvement of the skills. In addition, fouling reduces the membrane performances in time, which is a main problem of cost efficiency

Evaluation of Bio-Membrane System Efficiency Optimized With Nanotechnology for Treatment of Pulp and Paper Industry Wastewater

Background & Aims: The membrane adsorption bioreactor (MABR) process is the integration of biological treatment and membrane technology. Accordingly, in this study, an MABR was employed for the pulp and paper industry wastewater treatment. Materials and Methods: The purchased powdered activated carbon (PAC) was added to the system as an adsorbent which improved the flux of the membrane. Results: Based on the obtained results, the organic compounds were successfully removed by the average removal of 62% and 86% without and with an adsorbent, respectively. Moreover, the activated sludge was prepared from the Babol-Toyoor Slaughterhouse wastewater treatment, and adding the PAC to the activated sludge led to the better performance of the MABR system by providing a proper condition for microorganism growth. Monitoring the mixed liquid suspended solids during the process demonstrated that increasing mixed liquor suspended solids (MLSS) increased the contaminant removal rate. Conclusion: Overall, the presence of PAC could prevent microorganisms from accumulating on the membrane surface

Exploring the application of the hybrid nano-bioreactor technology based on the developed polyethersulfone mixed-matrix membrane for industrial effluent treatment

Due to the high concentration of various contaminants in the paper mill effluent, it must undergo an efficient treatment process before being discharged to the environment or being reused in the production cycle. In the present study, the submerged membrane adsorption bioreactor (SMABR) system was used for the treatment of the paper mill effluent. The modified polyethersulfone PES/MoS2 membrane was fabricated by incorporating exfoliated MoS2 nanosheets prepared in the laboratory, into the PES matrix. This membrane along with the powdered activated carbon (PAC) were utilized in the SMABR system for the paper mill effluent treatment. After the acclimation of the sludge with the target effluent, the optimum values of food to microorganism (F/M), hydraulic retention time (HRT), and adsorbent dosage were determined separately to be 0.451, 18 h, and 3 g/L by considering the maximum values of chemical oxygen demand (COD) removal and mixed liquor suspended solid MLSS concentration in each stage. In the final stage, the MBR and SMABR systems (using the pristine and modified membranes, separately) were prepared to separately investigate the effect of the presence of the PAC adsorbent and modified membrane, on the output parameters. In all systems, the values of pH and dissolved oxygen (DO) were maintained in the normal range (pH: 6.2–6.7, DO>2) to provide favorable conditions for the growth of microorganisms. Most importantly, best performance in this study was related to the SMABR system consisting the PES/MoS2 membrane and PAC adsorbent, with the highest values of COD removal (96%), MLSS concentration (15620 mg/L), and membrane permeation flux (110 L/m2.h). It is worth mentioning that the functionalized membrane exhibited better hydrophilicity compared with the pristine membrane, resulting in high water permeation flux, which is in accordance with the performance results

Efficiency of Polymeric Membrane Graphene Oxide-TiO2 for Removal of Azo Dye

Achieving the desired standard of drinking water quality has been one of the concerns across water treatment plants in the developing countries. Processes such as grid chamber, coagulation, sedimentation, clarification, filtration, and disinfection are typically used in water purification plants. Among these methods, unit filtration which employs polymers is one of the new technologies. There have been many studies about the use of semiconductive TiO2 with graphene oxide (GO) on the base of different polymeric membranes for the removal of azo dyes, especially methylene blue (MB). Polymeric GO-TiO2 membranes have high photocatalytic, antifouling property and permeate the flux removal of organic pollutants. The aim of this study was to investigate the characteristics of different polymeric membranes such as anionic perfluorinated polymer (Nafion), cellulose acetate, polycarbonate (PC), polysulfone fluoride (PSF), and polyvinylidene fluoride (PVDF). The result of this study showed that the GO-TiO2 membrane can be used in the field of water treatment and will be used for the removal of polycyclic aromatic hydrocarbons (PAHs) from wastewater

Dynamically coated photocatalytic zeolite–TiO2 membrane for oil-in-water emulsion separation

This paper evaluated the effectiveness of polyester (PS)/poly(vinyl alcohol) (PVA) dynamic membrane (DM) incorporating photocatalytic zeolite/TiO2 for oil-in-water (O/W) emulsion separation. The photocatalytic zeolite/TiO2 was established onto the membrane surface via self-forming and pre-coating method with the aims of reducing membrane fouling during O/W emulsion treatment. The results obtained showed that the pre-coated composite DM could decrease support membrane fouling by improving flux recovery rate by 5.8%, while the use of the self-forming composite DM exhibited lower flux recovery rate after three filtration cycles in O/W emulsion treatment. The results were confirmed by cleaning and oil removal efficiency. The cleaning efficiency of composite DM was further enhanced by substitution of deionized water with sodium dodecyl sulfate as a cleaning agent in the treatment of O/W emulsion. Using sodium dodecyl sulfate, the pre-coated composite DM showed higher flux recovery rate (81%) than the self-forming composite DM. In addition, the photocatalytic effects of zeolite/TiO2 on the DM with respect to flux recovery rate and oil rejection under UV light source were investigated. It was found that by combining cleaning process and UV irradiation, the fouling of DM was further decreased, recording high flux recovery rate (up to 83.6%) without compromising oil rejection rate (85.3%)

Study of Adsorption of H2 and CO2 on Distorted Structure of MOF-5 Framework; A Comprehensive DFT Study

To investigate the adsorption property of H2 and CO2 on the organic ligand of C-MOF-5 (H2BDC) and T-MOF-5 (ZnO-doped H2BDC (ZnO-H2BDC)), Density functional theory (DFT) method was performed. First, the adsorption of ZnO on H2BDC resulted in examining binding energies, the charge transfer, density of states, dipole moments and adsorption geometries were investigated. The binding properties have been calculated and investigated theoretically for ZnO-doped H2BDC in terms of binding energies, band structures, Mulliken charges, and density of states (DOSs). According to obtained results, the H2BDC was strongly doped with ZnO. H2 and CO2 adsorption capacities for ZnO-doped H2BDC are significantly enhanced while there are low adsorption capacities for H2BDC. According to results, at least in the organic ligand of the MOF-5, the highest and lowest adsorption of CO2 (or H2) is attributed to the T-MOF-5 and C-MOF-5 respectively. Our calculations reveal that ZnO-doped H2BDC system (T-MOF-5) has much higher adsorption energy and higher net charge transfer value than pristine H2BDC (C-MOF-5). Also by changing in structure from cubic to tetragonal, the main site for H2 and CO2 adsorption was changed

Impacts of zeolite nanoparticles on substrate properties of thin film nanocomposite membranes for engineered osmosis

In this work, microporous substrates modified by zeolite nanoparticles were prepared and used for composite membrane making with the aim of reducing internal concentration polarization (ICP) effect of membranes during engineered osmosis applications. Nanocomposite substrates were fabricated via phase inversion technique by embedding nanostructured zeolite (clinoptilolite) in the range of 0–0.6 wt% into matrix of polyethersulfone (PES) substrate. Of all the substrates prepared, the PES0.4 substrate (with 0.4 wt% zeolite) exhibited unique characteristics, i.e., increased surface porosity, lower structural parameter (S) (from 0.78 to 0.48 mm), and enhanced water flux. The thin film nanocomposite (TFN) membrane made of this optimized substrate was also reported to exhibit higher water flux compared to the control composite membrane during forward osmosis (FO) and pressure-retarded osmosis (PRO) test, without compromising reverse solute flux. The water flux of such TFN membrane was 43% higher than the control TFC membrane (1.93 L/m2 h bar) with salt rejection recorded at 94.7%. An increment in water flux is ascribed to the reduction in structural parameter, leading to reduced ICP effect