Showing 5 results for Wastewater Treatment
S. A. Ghasemi , Sh. Danesh,
Volume 16, Issue 61 (10-2012)
Abstract
In this research, the quality of the effluent from the City of Mashhad wastewater treatment plants was evaluated based on Ayers and Westcot irrigation water quality guideline, and the potential impacts of these effluents on soil and plants were assessed. For this purpose, the effluent from each of the three existing wastewater treatment plants was sampled on a regular basis, for a period of one year, and their parameters of importance in regard to the agricultural use such as pH, electrical conductivity (EC), concentrations of Sodium, Calcium, Magnesium, Chloride, Boron, Nitrate (NO3-N), bicarbonate and heavy metals were measured. Based on the obtained results, the agricultural use of the effluents from the wastewater treatment plants has severe restriction in regard to the bicarbonate concentrations (8-12.1 meq/L). Also, in view points of parameters such as EC (1250-1874 µS/cm), Sodium (5.8-8.7 as SAR), Chloride (3.2-6.5 meq/L) and adj RNa (7.8-11.7), the effluents were categorized in the class of waters with low to moderate restrictions. However, the measured values of pH (7.3-8), Boron (0.2-0.8 mg/L), Nitrate Nitrogen (0.5-4.2 mg/L) and heavy metals did not indicate any restrictions for agricultural use. From the results of this research, it can be concluded that the use of effluent as irrigation water requires careful planning, monitoring and management strategies.
J. Abedi Koupai, S. S. Eslamian, M. Khaleghi,
Volume 16, Issue 62 (3-2013)
Abstract
Crisis of quality and quantity of water resources is one of the most important problems in arid and semi-arid areas such as Iran. Wastewater treatment and reuse as a potential source of water can not only compensate for the water scarcity but also can prevent the hazardous pollutants from entering the groundwater and surface water resources. There are various methods to improve water quality, among which method of filtration is an effective and efficient method to remove elements. The most important issue for filter system is the selection of adsorbent materials. In this work, the tire chips were used as adsorbent. Column adsorption tests in a pilot system were conducted in two distinct steps using two types of water, including salt water and industrial effluents. Each test was conducted as a factorial experiment with three factors based on a completely randomized design with three replications. Three factors were studied including particle size (2-5 mm and 3-5 cm), filter thickness (10, 30 and 50 cm) and sorbent contact time with solution. The results showed that adsorption rate increased by increasing the thickness of the filter and sorbent contact time with solution. The best performance of reducing the salinity was observed in the treatment with 50 centimeter thickness and 24 contact hours. The salinity of this treatment was reduced by 20.3 percent (in the test with salt water) and 11.2 percent (in the test with industrial effluents). This filter reduced the heavy metals of lead, zinc and manganese up to 99, 72.1 and 41.4 percent, respectively. Also, the performance of millimeter and centimeter particles did not show a significant difference. Generally, the tire chips showed a proper performance to improve the water quality especially for industrial wastewater.
A. Lotfi, M. Mamaghninejad,
Volume 23, Issue 4 (12-2019)
Abstract
Constructed wetland as a purification system plays an important role in water and wastewater treatment and so many research studies have been conducted to examine their efficiency for wastewater treatment. The aim of this study was to evaluate the efficiency of constructed wetland for Arak wastewater treatment plant. In this research, the efficiency of three horizontal subsurface constructed wetlands built with 3*12 meters in dimensions and 1 meter in depth was examined. In these constructed wetlands, two plants including Common reed (Phragmites australis) and Cattails (Typha latifolia) were planted and one unit was left unplanted. TSS, COD, BOD and TC parameters were measured in the 2 week samples and the results were analyzed by SPSS and Excel. The results showed that the type of vegetation had no significant influence on the organic matter removal in the subsurface constructed wetlands; however, the removal efficiencies in the planted constructed wetlands were more than those in the unplanted control one. The TSS, COD, BOD, FC and TC removal efficiency in the constructed wetlands changes was 79%, 60.7%, 45.6%, 86.1% and 90.1%, respectively, for Common reed wetland and 77%, 61.4%, 59.8%, 92.4% and 93.1%, respectively, for Cattails wetland; thee were 69%, 44.5%, 43%, 83.6% and 88.8% for the unplanted wetland, respectively. The results of this research also showed that the organic matter removal was dependent on the influent organics nature and biodegradability. The organic concentration in the wetland effluents met the Iranian regulation limits for different reuse applications, showing the constructed wetland could be a suitable technology for wastewater treatment in Iran.
Saeid Soltani Margani, Jahangir Abedi Koupai, Manouchehr Heidarpour, Seyed Alireza Gohari,
Volume 30, Issue 1 (3-2026)
Abstract
This research focuses on evaluating the efficiency of constructed wetlands in treating municipal wastewater using two plants: vetiver (Chrysopogon zizanioides) and common reed (Phragmites australis). Given the increasing pollution of water resources and water scarcity in Iran, the application of nature-based solutions (NBS), particularly constructed wetlands, is a crucial approach for effective wastewater management and treatment. This study concentrates on the wastewater from the treatment plant of Isfahan University of Technology and, over a period of six months, assesses the impact of four different treatments in a completely randomized design: 1) wetland planted with vetiver (V), 2) wetland planted with reed (N), 3) control wetland without plants (B), and 4) control wetland without plants but with a supporting substrate (P), on chemical parameters of wastewater and plants. The measured parameters include BOD₅, COD, nitrate, and phosphate. Results indicated the highest levels of BOD₅ and COD in the control treatments (without plants) and a significant reduction in these parameters in the treatments planted with vetiver and reed. The best removal performance for these two parameters was observed in the sixth month at a hydraulic retention time of 30 days, with reductions of 67% and 65% for BOD₅ and 85% and 84% for COD in the vetiver and reed treatments, respectively. In the sixth month, at a retention time of 15 days, nitrate levels decreased by 25% and 34% in the vetiver and reed treatments, respectively, and by 39% and 59% at 30 days retention time. These differences were statistically significant at the 5% level for both retention time and plant type. Phosphate reductions in the sixth month at 15-day retention were 65% and 81% in vetiver and reed treatments, respectively, and at 30 days, 82% and 87%, with these decreases being statistically significant for both retention times and plant types at the 5% level. Retention time results showed that the reduction of BOD₅ and COD is directly related to retention time, with longer retention times yielding higher removal percentages. Regarding nitrogen and phosphorus, the reed demonstrated the highest performance, effectively reducing these pollutants. The total nitrogen uptake in the shoots and roots of the reed after 30 days was 33.4 and 22.51 mg/kg dry plant matter, respectively, indicating the high capacity of the reed for nitrogen absorption from wastewater. This study demonstrates that planting vetiver and reed can serve as sustainable solutions for improving water quality and effective water resource management in Iran
Noroullah Mirghaffari, Mohsen Soleimani, Azita Tayebi,
Volume 30, Issue 1 (3-2026)
Abstract
As the industry expands and water resources decline, attention has increasingly focused on the treatment and recycling of wastewater generated by various industrial processes. Adsorption using cost-effective and readily available adsorbents is a simple and low-cost method for wastewater treatment in various industrial sectors. In this study, clinoptilolite natural zeolite (CNZ) was employed for the removal of two dye pollutants: cationic methylene blue and disperse red 60. To evaluate the efficiency of CNZ, four variables, pH, contact time, adsorbent dosage, and initial dye concentration, were investigated using response surface methodology. Based on the results obtained from batch experiments, the maximum removal efficiencies of methylene blue and disperse red 60 by CNZ were 98.9% and 78.7%, respectively. These optimal removal percentages were achieved under the following conditions: a contact time of 120 minutes, an initial dye concentration of 50 mg/L, an adsorbent dosage of 20 g/L, and a pH of 10 for methylene blue and a pH of 4 for disperse red 60. The pseudo-second-order kinetic model, with an R² value greater than 0.90, exhibited the best fit for the adsorption of both dyes from aqueous solutions. Furthermore, the extent of dye adsorption exhibited a better correlation with the Langmuir (Disperse Red 60) and the Freundlich (Methylene Blue) adsorption isotherms. Results of column experiments demonstrated that the maximum adsorption capacities for Methylene Blue and Disperse Red 60 were 97.7 and 45.9 mg/g, respectively. The results revealed the high potential of CNZ as a sorbent for cationic dye pollutants from industrial wastewaters.
