Showing 47 results for Waste
I. Hasanpour, M. Shirvani, M.a. Hajabbasi, M.m. Majidi,
Volume 26, Issue 2 (9-2022)
Abstract
Low organic matter content and alkaline pH of calcareous soils in arid and semi-arid regions are the main reasons for the low nutrient availabilities for plants in these soils. One way to improve the chemical properties and fertility of calcareous soils is the application of organic substances such as biochar produced from pyrolysis of organic wastes. However, biochars have an almost predominant alkaline pH, which exacerbates plant nutrient deficiencies in calcareous soils when used for a long time. Pyrolysis of some organic wastes under controlled temperature conditions can lead to the production of acidic biochar. The effect of acidic biochars on several chemical properties of two calcareous soils in Isfahan province was investigated in the present study. Treatments included two types of biochar (pine cone and rice husk), three levels of biochar addition (one, three, and six percent), two types of soil (a sandy loam (Tiran) and a clay loam (Lavark)), and two incubation periods (one and six months). The results showed that applying biochar could slightly decrease soil pH but raised soil electrical conductivity. In addition, the amount of organic carbon, total nitrogen, and available concentration of manganese in all treatments and the concentrations of available phosphorus, potassium, iron, zinc, and copper in the most of treatments showed a significant increase compared to the control. Amending soil with biochar at a 6% rate caused the most significant changes in the measured parameters in both soil types. In general, the results of this study indicated that acidic biochar produced from pine cones and rice husk can be used as a suitable conditioner to improve the chemical properties and fertility of calcareous soils.
S. Jalinousi, E. Joudaki, A. Moghadassi, M. Mahdieh,
Volume 27, Issue 4 (12-2023)
Abstract
This research presents the application of phytoremediation to remove ammonia from effluent possessing high ammonium content and alkalinity in one of the most complex refineries in Iran. The objective of this research was to find new methods to protect and preserve water resources. At first, the algae distribution was investigated. After purifying the samples, Chlorella Vulgaris was selected as resistant algae in the areas that experienced ammonia shocks. A 10-liter container and an airlift photobioreactor with similar laboratory conditions were developed to control biomass production. Experiments were conducted over 20 days and maximum biomass production occurred in the first 16-17 days. Cell density was expressed as dry cell weight in ammonia concentration from 10 mg/L to 500 mg/L. It was also observed that when the Nitrogen content of the culture medium was less than 50 mg/L, ammonia was completely removed in both methods. At a concentration of 10 mg/L, total ammonia in both methods was removed in the first week. At 50 mg/L to 100 mg/L concentrations, about 94% of ammonia was removed in the glass container and about 95% in the bioreactor. In these concentrations, with high ammonia content, the final cell density, and absorption power were significantly low and this was evident at 500 mg/L. Prevention of water evaporation and biomass settling, better control of some vital parameters including pH, temperature, light, and energy intensity, effective mass and heat transfer, and carbon dioxide concentration led to better efficiency of the airlift photobioreactor. A noteworthy point in this result was the extraordinary performance of Chlorella Vulgaris in removing toxic pollutants such as ammonia and possibly using it in the biological systems of sanitary, refineries, and petrochemicals.
Y. Choopan, H. Arianpour,
Volume 28, Issue 2 (8-2024)
Abstract
Reducing the effects of the misuse of urban wastewater is to use it in agriculture along with the subsurface irrigation system, which effects on the soil also require extensive investigations. Therefore, the present research was performed in a randomized complete block design with two factors of the type of irrigation source (well water W1 and treated urban wastewater W2) and the type of irrigation system (surface S1 and subsurface drip S2) in three replications (R) for a soil depth of 0-40 centimeter during two crop seasons. The results showed that the potassium, sodium, salinity, and sodium absorption ratio were significant at the 1% probability level in the comparison of system type and irrigation source type, whereas the values of pH, calcium, and magnesium were not significant in the comparison of system type and irrigation source type. The lowest value of calcium, magnesium, sodium cations, chlorine, phosphate, and sulfate anions was obtained in the W1S1 treatment. Also, the highest parameters of salinity, calcium, magnesium, phosphate, potassium, and chlorine were observed for the W2S2 treatment. It can be concluded that irrigation with urban wastewater has improved the chemical properties of the soil, and the type of irrigation system has had minor changes.
S.a. Ghaffari Nejad, F. Moshiri, S.m. Mousavi,
Volume 29, Issue 2 (7-2025)
Abstract
This study was conducted to evaluate soil fertility management scenarios including separate use of chemical and organic fertilizers (animal manure and municipal waste compost) and their integrated application on changes in the amount of available nitrogen, phosphorus, and potassium in the soil from November 2017 for four years in six consecutive crops at the Agricultural Research Station of the Soil and Water Research Institute. The results showed a depletion of 14 and 44% of soil available nitrogen and phosphorus, and no depletion of available potassium in the treatment without fertilizer in six consecutive cultivations. Annual consumption of 20 t ha-1 of municipal waste compost and 75% of the recommended nitrogen showed the highest amount of soil-available nitrogen. Unlike phosphorus, the amount of soil available nitrogen in municipal waste compost treatments was significantly higher than in cattle manure. The highest available soil phosphorus was in the treatment with 10 t ha-1 of cattle manure before each crop, and the average available phosphorus in six consecutive cultivations was significantly higher than in the other treatments. The use of 10 t ha-1 of cattle manure and municipal waste compost before each crop resulted in the highest accumulation of potassium in the soil, respectively. The available soil potassium in cattle manure treatments was significantly higher than in municipal waste compost. The results of this experiment indicated the importance of using fertilizers containing nitrogen, phosphorus, and potassium in maintaining soil fertility stability in the long term.
S. Rezaei, M. Heidarpour, A. Aghakhani,
Volume 29, Issue 2 (7-2025)
Abstract
The growing concern for environmental protection and increasing demand for green approaches to address environmental problems have prompted researchers to explore a sustainable and reliable method for treating dyeing wastewater. One of the sustainable and reliable methods is the electrocoagulation process. In this study, a batch electrocoagulation reactor was designed to evaluate the efficiency of this process in treating dyeing wastewater. The effects of two parameters, electrode distance and retention time, on pollutant removal efficiency were investigated. Electrode distances of 2, 5, and 7 cm were tested, and retention times of 10, 15, 20, 25, and 30 minutes were examined. Results indicated that the optimal electrode distance was 5 cm and the optimal retention time was 20 minutes. Under these conditions, the removal efficiency of BOD, COD, TSS, color, and turbidity reached 83%, 85%, 98%, 98%, and 93%, respectively. The results of this research demonstrate the significant potential of the electrocoagulation system for treating dyeing wastewater.
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.
