mohamad javad zoqi

In response to the increasing color pollution in industrial wastewaters and the need for effective treatment methods, this research investigates the application of the Fenton and microwave-enhanced Fenton processes for color removal. The aim of this study is to compare the effectiveness of these two processes and to identify the optimal conditions for the maximum removal of color pollutants. This study evaluates the efficiency of the Fenton and microwave-enhanced Fenton processes in dye removal from wastewater. To examine the impact of parameters such as pH, dye concentration, Fe2+, and H2O2 on the efficiency of removing the Reactive Red 198 dye and COD, these variables were altered during the experiments. The mechanism of dye molecule removal was analyzed through UV-Vis spectroscopy. The optimal conditions for the microwave-enhanced Fenton process included an initial dye concentration of 300 mg/l, a pH of 3.5, an Fe2+ concentration of 20 mg/l, and an H2O2 concentration of 100 mg/l. Under these conditions, a COD reduction of up to 85% and dye removal of over 98% were observed. The findings suggest that the microwave-enhanced Fenton process can effectively reduce color pollutants and improve the quality of industrial wastewater. This method offers high reaction speed and remarkable efficiency under various treatment conditions, making it a suitable solution for treating wastewater with high dye loads.

The escalating challenge of industrial dye pollution in wastewater necessitates the exploration of effective treatment methodologies. This study introduces a novel approach combining microwave irradiation with the Fenton oxidation process, showcasing a significant leap in the removal of Reactive Yellow 145 pollutants. By systematically manipulating variables such as Reactive Yellow 145 concentration, catalyst presence, and reaction environment pH, the investigation reveals a substantial increase in the degradation efficiency of complex dye molecules. The synergy between microwave energy and chemical oxidants under optimal conditions results in a remarkable reduction of both color and chemical oxygen demand (COD) levels, with the process achieving over 95% dye elimination and 82% COD reduction within 7 minutes. The analysis of UV-Vis spectroscopy before and after treatment showed that the microwave-enhanced Fenton process efficiently decomposed dye molecules, with a notably faster decomposition rate observed for azo and hydrazine groups compared to aromatic structures. This study not only underlines the potential of microwave-assisted Fenton processes in addressing persistent wastewater contaminants but also sets the groundwork for future research in scalable, environmentally friendly wastewater treatment solutions.

Heavy metals are found in high concentrations in industrial wastewater and cause damage to humans and other organisms by entering to water, soil and food chain. Stabilization and solidification is a common process in the treatment of sludge containing heavy metals. In this study, solidification/stabilization of ceramic tile industry sludge was investigated using cement and additives like water, lime, microsilica and ordinary clay.

In this study, by designing the tests by response surface methodology, the effect of different additives on compressive strength and metals concentration after pollution leakage test was investigated. So, hazardousness of wastes after stabilization and solidification and the samples tolerance against the environmental loads was evaluated.

Results showed the highest value compressive strength in high amounts of cement. Decreasing the amount of waste and replacing more lime, clay and microsilica, the compressive strength was increased. In optimal mode, by 5.77% lime, 8.69% clay, 4.35% microsilica and 51.84% cement, the maximum compressive strength was achieved about 116 kg/cm2. The minimum concentration of Cr was 0.0782 mg/L and resulted from 11.23% lime, 21.31% clay, 10.65% microsilica and 27.46% cement. Minimum Pb concentration (0.0043 mg/L) was obtained in 11.23% lime, 21.31% clay, 4.35% microsilica and 33.76% cement.

The more efficiency on compressive strength is related to cement. In addition, applying the lime, clay, microsilica and cement concluded the effective reduction of Cr and Pb concentration in leaching the stabilized samples.

The effluent of the beverage industry has high amounts of organic compounds, and biological treatment methods are very common in this field. By applying efficient methods to treat the effluent of the beverage industry, it is possible to provide the ground for the consumption of treated effluent in other places. The general purpose of the present study is to evaluate the efficiency of the activated sludge process with extensive aeration and sludge return for wastewater treatment of the beverage industry. The present study lasted for 60 days. After making a laboratory pilot, for evaluation, first the pilot was fed with sugar and then synthetic effluent was prepared and transferred to the pilot. The organic load has increased from 1.03 kgCOD/m3.d to 1.93 kgCOD/m3.d. In this study, the COD parameter was used to measure the effluent pollution of the beverage industry and the working cycle was 24 hours. The results of the mentioned process showed that with the final organic loading at the rate of 1.93 kgCOD/m3.d, the removal efficiency was equal to 90%. By examining the hydraulic retention times of 6, 12, 18 and 24 hours, the highest efficiency in the retention time of 24 hours was obtained and in the research process, the pH was between 7 and 9 and the temperature was in the mesophilic range. Therefore, it can be concluded that the process of activated sludge with extensive aeration and sludge return is effective in treating the effluent of beverage industries with medium organic load.

The most used dyes in textile industries are Azo Group dyes. Azo dyes have complex aromatic compounds, low chemical and biodegradable stability. Due to these properties, treatment of this type of wastewater by conventional methods will not meet environmental standards. The advanced oxidation process has been widely used to treat organic matter from wastewater. In this study, dye purification of azo dye Reactive Red 195 by UV/H2O2 process was investigated. Moreover, the parameters affecting this process have also been determined.

In this study, dye treatment was conducted in the presence of different concentrations of hydrogen peroxide, and at different retention time, temperature and pH values in a continuous photoreactor equipped with UV lamps. Using central composite design and response surface methodology (RSM), effects of various concentrations of hydrogen peroxide, retention time, temperature, and pH on the color and COD removal were studied in the range of 0–2%, 60-240 min, 25-80 oC, and 3-10, respectively.

The results showed that the concentration of hydrogen peroxide and retention time were the most influential parameters on color and COD removal. Color removal significantly enhanced by increasing retention time and H2O2 concentration to 200 min and 1.2%, respectively. pH increase had positive effect on color removal. There were increases in the rate of color and COD removal as the temperature went up to 50 oC. However, temperature of 80 oC negatively impacted AOP process. According to RSM, the optimum factor levels were achieved at 1.28%, 240 min, 49 oC and 10 for concentrations of hydrogen peroxide, reaction time, temperature, and pH, respectively.

According to the result, UV/H2O2 proved to be capable of degrading Reactive Red 195. Almost all the azo dye color destroyed after 209 min while 87.52 % of the COD was removed after 240 min of irradiation.

Solidification/stabilization is an effective technique for reducing the leachability of contaminants in soils. Magnesia phosphate cement and ordinary Portland cement can be used to remediate soils contaminated. In this study, the performance of the solidified/stabilized soil was compared for mixtures composed of magnesia phosphate and ordinary Portland cement.

In this study, the experimental soil were contaminated with 500, 1000 and 5000 mg/kg of lead. Lead-contaminated soils were stabilized by mixing magnesia phosphate and Portland cement in proportions of 25% and 50% by weight. Cement and soil mortars were prepared with water-to-cement ratio 0.5 of distilled water. The performance was assessed using unconfined compressive strength (UCS), toxicity characteristic leaching procedure (TCLP), initial and final setting and X-ray powder diffraction (XRD).

The results showed that use of magnesia phosphate cement instead of Portland cement could significantly reduce the concentration of lead in TCLP leachate, the setting time and increase the buffer capacity and the formation of crystals in samples containing lead. In 28-day samples containing soil with 5000 mg Pb/kg, Pb concentration in TCLP leachate of samples stabilized with 50% and 25% cement had been determined as 0.41 mg/L and 1.15 mg/L for magnesia phosphate cement and 4.92 mg/L and 12.04 mg/L for Portland cement, respectively. However, using this type of cement instead of Portland cement reduces the compressive strength of 7 and 28 days.

The substitution of Portland cement with magnesium phosphate cement for stabilization and solidification of contaminated soil revealed a significant decrease in leachability of heavy metals, setting time, maintenance and equipment cost.

Antibiotics are potential pollutants that represent an important environmental problem because of their toxic effects on the food chain and aqueous streams. The goal of this study was determining the efficiency of a horizontal subsurface flow constructed wetland for a pharmaceutical pollutants antibiotic penicillin G. This study used constructed wetland pilot system for removal of penicillin G in artificial wastewater.in this study, the effects of initial concentration of wastewater, hydraulic retention time and reed on the pollutant removal efficiency were investigated. The data was analyzed using the central composite design which is the most commonly used response surface methodology design. 30 Samples of wastewater were taken from the output of constructed wetlands subsurface and tested in laboratory based on the standard reference method for experiments in water and wastewater. The results showed that reed, and retention time, has a direct relationship, and enhance them to increase efficiency. The initial concentration of wastewater is inversely related to removal efficiency. In the constructed wetland, the removal efficiency for 72 hours and different input concentrations was between 94.17% and 73.61%. Based on the study results, it can be stated that subsurface constructed wetland can remove the maximum concentration of hospital wastewater and even double this concentration with efficiency up to 90 percent, and it can be used as a proper treatment system for removal of penicillin G.

Reactive Red 198 is a mono azo dye widely used in the textile industry of Iran. The toxicity of reactive dyes is higher than other dyes and causes disorders such as irritation, cancer and mutation in humans. The overall objective of this study was to determine the efficiency of a Constructed Wetland pilot system with conventional and baffled horizontal subsurface flow to remove reactive red 198.

In order to remove Reactive Red 198, two cells were constructed in parallel with 2 × 0.6 × 0.5 m. In the conventional and baffled cell, native straw of Phragmites australis was used. In the research process, COD concentration and reactive dye concentration were investigated. The effect of retention time and type of plant on the efficiency were also investigated.

The results showed that the maximum removal efficiency of the reactive red dye 198 was obtained at 100 mg/L inlet pollutant concentration and 3.5 days retention time, which was related to the baffled cells. Also, the presence of the baffles in the constructed wetland system increased the removal efficiency. The presence of straw in both cells was directly affected the removal efficiency. The effect of the retention time in the conventional cell was more effective in removal efficiency than the baffled cell. The pollutant inlet concentration was also inversely correlated with the removal efficiency.

According to the results, it can be concluded that the baffled and conventional horizontal subsurface constructed wetland can be used for low concentrations and at low retention time as a well-functioning system in the removal of reactive Red 198.

In the recent years, the use of municipal wastewater for irrigation has attracted the consideration of arid countries. Despite the potential use of municipal wastewater in plants irrigation as sustainable strategy, the environmental impacts need to be investigated. The aim of this study was to evaluate the use of treated wastewater in irrigation crop plants.

The present study was carried out to assess levels of iron, zinc, chrome, copper, manganese and nickel, in plants irrigated with water from different sources. Impact of different irrigation sources on metals uptake by plants were determined using Statistical tests.

According to the results, the type of water source (well water, treated wastewater) had a significant effect at 5% level on the mean concentration of Cu in barley leaves, Cr, Cu and Ni in barley root and Cu and Ni in soil around barley root. In this study, nickel concentration was higher than critical value in the soil around the roots for both plants and both irrigation sources due to the presence of nickel in the ultramafic rocks. Due to the proper performance of Birjand treatment plant stabilization ponds in reducing heavy metals from municipal wastewater, the concentration of most heavy metals in plant and soil in irrigation with treated wastewater was significantly lower than in irrigation with well water. The proximity of farms to heavy-duty vehicles increased the concentration of copper in all the situations studied which were close to the critical range. The concentration of chromium in shoots of plant was lower than other metals.

As a result, the values of heavy metals in different parts of plants were below the acceptable levels as suggested. In comparison to plants, the soil presented higher concentration of all studied metals. However, the regular monitoring of levels of these metals from well water and treated wastewater, in plants and soil is essential to prevent excessive build-up of these metals in the food chain.