Sharif Digital Repository

In the present study, the ACF-TiO2 catalyst was synthesised and used as a catalyst for the destruction of toxic cyanide in both synthetic and real industrial wastewaters. The ACF-TiO2 catalyst was found to be micro-porous with the BET surface area of 163 m2/g. The effect of different operational parameters such as catalyst concentration, cyanide concentration, operation time, and ozone concentration were target parameters in the present study. The findings show that 500 mg/L of catalyst is the optimum value for the photocatalytical process to completely oxidise 25 mg/L of cyanide within 10 min. While it was found that 300 mg/L of catalyst in the presence of 200 mg/h ozone is enough to remove... 

Rotating dissolved air flotation (RDAF) has been utilized for several decades in paper-recycling wastewater treatment; however, it has rarely been addressed in the literature, which makes research into this system challenging and complicated. However, in this work, a full-scale industrial wastewater treatment system for a paper-recycling mill in Mazandaran province, Iran, was evaluated. Experiments indicated that under the same wastewater and chemical conditions, there are differences in the removal efficiencies. This finding was investigated by conducting simulation in ANSYS CFX R18.0 and experimentation simultaneously. Thus, the main purpose of this research was to optimize the operation... 

Discharging unconventional water sources having a high content of inorganic compounds is extremely destructive to the environment. In this research, four novel semi-open-air and closed-air configurations of brine-recycle humidification-dehumidification (BRHDH) systems with zero liquid discharge (ZLD) approach are presented to treat unconventional waters cost-effectively. Bubble-column humidifiers and dehumidifiers are used to have a low initial expenditure, and system multi-staging is implemented to reduce the operating expense of the configurations. The configurations are evaluated for high saline brine treatment using comprehensive energy, exergy, exergoeconomic, and exergoenvironmental... 

The nanofibers prepared by electrospinning process have high potential for the removal of toxic matters from wastewaters. In the present study, the titanium dioxide and titanium dioxide/zinc oxide (TiO2/ZnO) nanofibers prepared by electrospinning technique were coated on the sewage sludge carbon (SSC) surface for adsorption of Ni(II), Cu(II), and COD from aqueous solutions and industrial wastewaters of Iran. The synthesized adsorbents were characterized using XRD, SEM and EDX analysis. The effect of adsorbent type, pH, adsorbent dosage, contact time and initial concentrations of Ni(II), Cu(II) and COD on the adsorption capacity of synthesized SSC/TiO2 and SSC/TiO2/ZnO nanofibrous adsorbents... 

Various technological methods are available for industrial wastewater treatment (WWT), ranging from conventional to advanced treatment processes. It is therefore a complex exercise to select the most appropriate technology to treat the industrial wastewater in a particular situation. Many criteria can be considered in the decision-making process; therefore, multicriteria decision-making methods are especially appropriate for solving this problem. In this paper, we aim to select the most appropriate municipal WWT technology for agricultural usages. We propose a new hybrid methodology based on the best–worst method (BWM) and the behavioral technique for order of preference by similarity to the... 

Rotating dissolved air flotation (RDAF) has been utilized for several decades in paper-recycling wastewater treatment; however, it has rarely been addressed in the literature, which makes research into this system challenging and complicated. However, in this work, a full-scale industrial wastewater treatment system for a paper-recycling mill in Mazandaran province, Iran, was evaluated. Experiments indicated that under the same wastewater and chemical conditions, there are differences in the removal efficiencies. This finding was investigated by conducting simulation in ANSYS CFX R18.0 and experimentation simultaneously. Thus, the main purpose of this research was to optimize the operation... 

In this study, two new composite membranes with antifouling and anti-biofouling properties were prepared through the modification of commercial polyamide (PA) discs using combination of in-situ polymerization of polyacrylic acid (PAA) and grafting of two synthesized bi-plasmonic Au-Ag and Ag-Au photocatalysts. The synthesis and characterization of the photocatalysts in batch mode were discussed in details as primary studies. Two intense 405-nm and 532-nm lasers for Ag-Au and Au-Ag photocatalysts, respectively and a solar-simulated xenon lamp for both photocatalysts were applied for photodegradation studies and the results were compared. In addition, the effect of other parameters such as... 

Using zero liquid discharge systems is one of the efficient methods to reduce the negative environmental impact of the brines of the desalination systems and also to recycle the industrial wastewaters for reuse. Due to the simple fabrication process, low maintenance cost, intensive to inlet water quality, and the ability to use renewable and low-grade-heat, modified humidification-dehumidification systems may be a proper choice for the zero liquid discharge applications. Thus, in the present study, the energy, exergy, exergoeconomic, and exergoenvironmental assessment of three advanced brine recycle humidification-dehumidification systems for zero liquid discharge operation are... 

In the present study, the ACF-TiO2 catalyst was synthesised and used as a catalyst for the destruction of toxic cyanide in both synthetic and real industrial wastewaters. The ACF-TiO2 catalyst was found to be micro-porous with the BET surface area of 163 m2/g. The effect of different operational parameters such as catalyst concentration, cyanide concentration, operation time, and ozone concentration were target parameters in the present study. The findings show that 500 mg/L of catalyst is the optimum value for the photocatalytical process to completely oxidise 25 mg/L of cyanide within 10 min. While it was found that 300 mg/L of catalyst in the presence of 200 mg/h ozone is enough to remove... 

The nanofibers prepared by electrospinning process have high potential for the removal of toxic matters from wastewaters. In the present study, the titanium dioxide and titanium dioxide/zinc oxide (TiO2/ZnO) nanofibers prepared by electrospinning technique were coated on the sewage sludge carbon (SSC) surface for adsorption of Ni(II), Cu(II), and COD from aqueous solutions and industrial wastewaters of Iran. The synthesized adsorbents were characterized using XRD, SEM and EDX analysis. The effect of adsorbent type, pH, adsorbent dosage, contact time and initial concentrations of Ni(II), Cu(II) and COD on the adsorption capacity of synthesized SSC/TiO2 and SSC/TiO2/ZnO nanofibrous adsorbents... 

In this study, magnetic nanoparticles (MNPs) modified with poly amidoamine (PAMAM) dendrimers - by adding methyl acrylate and ethylenediamine continuously till 10th generation- which further anchored to benzaldehyde ligand through polymeric bonding and studied as a novel method for synthesizing a nano sorbent for removing naphthalene (NAP) from aqueous environments. Synthesized nanopolymer was characterized by Fourier transform infrared spectroscopy (FTIR), Field-Emission Scanning Electron Microscopy (FE-SEM) equipped with EDS, X-ray Diffraction (XRD), Vibrating Sample Magnetometry (VSM), thermal gravimetric analysis (TGA). Based on the obtained analysis results synthesized average... 

In this work, the adsorption of benzoic acid (BA) over metal organic framework of chromium-benzenedicarboxylates (MIL-101) is reported for the first time. The influences of pH, contact time, initial concentration, and temperature of BA solution on the adsorption behavior were investigated. The Langmuir adsorption isotherm was adequate to represent the experimental data (R2 > 0.99) and the adsorption kinetics was well-represented by a pseudo-second order kinetic model (R2 > 0.96). The zeta potential of MIL-101 decreased with increasing pH confirming the importance of electrostatic interactions between MIL-101 and BA as well as the importance of the large pore volume (1.32 m3/g) and large... 

High molecular mass of naphthalene make it non-biodegradable and the biological methods for treated the pollutant are much time consuming. In this paper, two methods of ozonation and aeration are used to remove naphthalene. Because of the industrial wastewater has a great range of pH, in this study different concentrations of soluble naphthalene are placed in variable pH conditions, different contact times and changes in amount of aeration and ozonation. ANOVA results indicated a significant difference between two methods. The average removal of naphthalene by use of ozonation is 55 % and 37 % for aeration. As results, the best conditions that naphthalene are removed is in acidic environment... 

The aim of this research work is to investigate sorption characteristic of acid treated brown algae Sargassum bevanom (acid treated S. bevanom) for the removal of Cr(VI) ions from aqueous solutions. The acid-treated alga was prepared by transferring the S. bevanom into 0.5. M HCl and then stirring the mixture at 300. rpm for 6. h at room temperature. The sorption of Cr(VI) ions by batch method is carried out. The optimum conditions of biosorption were found to be: a biomass dose of 0.7. g in 100. ml of Cr(VI), contact time of 110. min and pH 3, respectively. In optimum condition, removal efficiency was 89.64%. It was found that temperature has a positive effect on the removal efficiency.... 

Dynamic hydrosalinity models are available, but are not used extensively on a large scale soil which receives wastewater from industrial areas, partly because adequate database are expensive to be obtained. Thus, for this reason, there is an urgent need to assess the salt and other pollutant loads collected in wastewater flows into the soil and/ or ground water systems. A conceptual hydrosalinity model was used on two major underlying principals of mass balance and steady state. This model was initially tested on the 4,117 km2 plains west of the Yazd-Ardakan district in the central part of Iran. This model was used at a time when the soil and ground water salinity problem was serious due to... 

Dyestuffs removal from industrial wastewater requires special advanced technologies, since dyes are usually difficult to remove by biological methods. In this study nanofiltration process was used for removal of different dyestuffs from solutions. The rate of dye removal by spiral wound nanofiltration membrane in film thin composite MWCO=90 Dalton, was evaluated for four classes of dyes acidic, disperse, reactive and direct in red and blue dyes medium. Dye absorbance was measured by spectrophotometric method (2120 Standard Method 1998). Effects of feed concentration, pressure and total dissolved solids concentration were also studied. Results showed that increasing dye concentration lead to... 

The aim of this work was to study the treatment of strong beet sugar wastewater by an upflow anaerobic fixed bed (UAFB) at pilot plant scale. Three fixed bed bioreactors (each 60 L) were filled with standard industrial packing, inoculated with anaerobic culture (chicken manure, cow manure, anaerobic sludge digested from domestic wastewater) and operated at 32-34 °C with 20 h hydraulic retention time (HRT) and influent COD ranging between 2000-8000 mg/L. Under these conditions the maximum efficiency of organic content reduction in the reactor ranged from 75% to 93%. The reactor filled with standard pall rings made of polypropylene with an effective surface area of 206 m2/m3 performed best in... 

Temperature and up flow velocity are regarded as the two main parameters significantly affecting microbial ecology and characteristics of UASB systems. The 2.3 m high and 0.25 m2-cross-section UASB pilot used in this study received slaughtery effluent with SCOD in the range of 2000-5000 mg/L. Temperature was varied in the 28-35 °C mesophilic range using an in-line heat exchanger and three up flow velocities studied were 0.3, 0.57, and 1 m/h without any recycling. At least one-week adjustment time was allowed after any change in the conditions. Since granules had been formed previously, the start-up phase lasted for only two weeks and up flow velocity and temperature was maintained at 0.3 m/h... 

Organic loading rate (OLR) is an important parameter significantly affecting microbial ecology and characteristics of UASB systems. In this study, UASB performance was evaluated in a 1000 1 reactor receiving feed from a traditional medium-size slaughterhouse. The initial seed for granules formed earlier was from a mesophilic municipal anaerobic digester sludge with a VSS content of 29gl-1. The temperature of influent was adjusted by an inline thermostat around 33°C. The reactor was started with an OLR of 5kg SCODm-3d-1 with gradual increase to 10kg SCOD m -3d-1 over a 2-week period. Examination of VSS data showed that on the average 89.3±11.3% of bioparticle mass was present at the lower 30%... 

The performance of a rotating biological contactor (RBC) for posttreatment of the slaughterhouse effluent from an upflow anaerobic sludge blanket (UASB) reactor was investigated in this study. The 280-L, six-stage RBC pilot plant was operated at different organic loading rates (OLRs) and biodisk speeds. The overall removal efficiencies for soluble biochemical oxygen demand (SBOD), total biochemical oxygen demand (TBOD), and total chemical oxygen demand (TCOD) decreased with increasing OLRs. Disk rotational speed did not have a significant effect on performance in the range studied. The results showed that satisfactory posttreatment to meet regulatory requirements for agricultural purposes...