Showing 4 results for Water Treatment
Tooran Yarahmadi, Mazyar Peyda, Mehran Mohammadian Fazli, Rizan Rezaeian, Negin Soleimani,
Volume 1, Issue 2 (3-2016)
Abstract
Background: Turbidity removal using inorganic coagulants such as iron and aluminum salts in water treatment processes causes environmental and human health concern. Historically, the use of natural coagulant to purify turbid water has been practiced for a long time. Recent research indicates that Descurainia Sophia seed can be effectively used as a natural coagulant to remove water turbidity.
Method: In this work, turbidity removal efficiency of Descurainia Sophia seed extract was compared with Ferric chloride. Experiments were performed in laboratory scale. The coagulation experiments were done with kaolin as a model soil to produce turbidity in distilled water. The turbidity removal efficiency of Descurainia Sophia seed extract and Ferric chloride were conducted with jar test apparatus. In all experiments, initial turbidity was kept constant 100(NTU). Optimum combination of independent variables was used to compare two different types of coagulants.
Result: The obtained results showed that Ferric chloride could remove 89.75% of the initial turbidity, while in case of Descurainia Sophia this value was 43.13%. The total organic carbon (TOC) analysis of the treated water using seed extract showed an increased concentration of TOC equal to 0.99 mg/L.
Conclusions:This research has shown that Descurainia Sophia seed extract has an acceptable potential in the coagulation/flocculation process to treat turbid water.
Zahra Shamsi, Mohammad Reza Yaftian, Abdol Hossein Parizanganeh, Abbas Ali Zamani,
Volume 3, Issue 1 (12-2017)
Abstract
Background: Water pollution is an important environmental problem, undoubtedly, the presence of toxic heavy metals forms the main source of water contamination. Sorption characteristics of polyurethane foams modified with bis (2-ethylhexyl)phosphoric acid (DEHPA) for the removal of zinc, lead and cadmium ions from contaminated solutions were investigated.
Methods: Operating variables, such as initial pH of the aqueous solution (1-6), ion concentrations (5-100 mg/l), sorbent dosage (1-8 g) and contact time (0-60 min), were studied.
Results: A value of 98 ± 3% of initial amount of studied ions (20 mg/l) was eliminated using 5 g of polyurethane sorbent modified with DEHPA (0.01 M in methanol) at pH 5. The selectivity order for metal ions toward the sorbent is Zn> Pb> Cd. Analysis of the equilibrium sorption data using Langmuir, Freundlich and Temkin models revealed that the Langmuir model was well suited to describe the zinc, lead and cadmium ions sorption. Power function, simple Elovich, pseudo first-order and pseudo second-order kinetics were applied for kinetic study in batch sorption and it was found that experimental data can be suitably described by pseudo second-order model.
Conclusion: Removal of studied metal ions from real samples shows that the modified polyurethane foam is useful for the treatment of polluted waters.
Samaneh Taghilou, Mazyar Peyda, Younes Khosravi, Mohammad Reza Mehrasbi,
Volume 5, Issue 3 (9-2019)
Abstract
Background: Population growth and industrial and agricultural activities have increased the consumption of water, leading to clean water scarcity. Wastewater treatment is an important concern as determining proper sites for wastewater treatment plants (WWTP) largely influences proper operation. The present study aimed to determine an optimized site for WWTP in the rural complexes of Zanjanrood catchment in Zanjan province, Iran.
Methods: The site priority map was generated using the geographical information system (GIS) and analytical hierarchy process (AHP). Locating of the plants was based on various parameters. After map preparation, the weight of each parameter was determined using the AHP approach, and the conversion of the layers was performed using the GIS. The site priority map for each sub-catchment was determined and optimized.
Results: In the criteria pairwise comparison matrix, the distance from the city had the highest value (16%), while the distance from the oil and gas transmission pipelines had the lowest value (1%). The site was located at the lowest elevation compared to the villages in each complex.
Conclusion: According to the results, the AHP followed by the optimization method could pinpoint the optimal sites for the environmental protection of treatment plant construction in rural areas.
Parvin Asadifard, Abbasali Zamani, Farideh Piri, Somayyeh Piri,
Volume 7, Issue 3 (9-2021)
Abstract
Background: In this research, the adsorption efficiency of Cellulose (as a raw compound prepared from trash papers) and Cellulose Nanopolystyrene (CNP) as adsorbents for waste water treatment was investigated. Lead and cadmium ions as the pollutants added to aqueous solutions and a synthetic effluent solution was prepared.
Methods: The effective factors influencing the adsorption process including the pH of aqueous phase and its ionic strength, the adsorbent dose, the duration of adsorbent, and time dependency have been assessed. The removal efficiency was assessed by determination of studied metal ions using a flame atomic absorption spectrometer before and after removal procedure.
Results: It was found that 0.1g of Cellulose as adsorbent removed 96.81%‚ 50.06% of Pb2+and Cd2+ from 45 mL of synthetic effluent solution at pH =5 after 30 min at 27°C, respectively. Moreover, 0.1g of the CNP removed 96.88%‚ 60.41% of Pb2+and Cd2+ from similar above-mentioned conditions. The CNP showed better adsorbent characteristics in the adsorption of Pb2+ and Cd2+ ions than the Cellulose. The Langmuir and Freundlich isotherm models successfully demonstrated the experimental observations for removing Pb2+ and Cd2+ ions by CNP as the adsorbent. The Dubinin-Radushkevich D-R) and Temkin isotherm models were better adapted than other used models for the adsorption procedure.
Conclusion: This research confirms the efficiency of treated Cellulose and Cellulose Nano-polystyrene (CNP) adsorbents from trash papers for eliminating Pb2+ and Cd2+ ions from synthetic effluent solution.
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