Saeed Dehestaniathar; Shahram Sadeghi; Ebrahim Mohammadi; Esmaeil Ghahramani; Maryam Safay
Abstract
Background and Objectives: Constructed wetlands and conventional treatment methods have a same duty in wastewater treatment، but they have different methods and mechanisms. The aim of this study was to investigate the removal of phenol from synthetic wastewater using horizontal sub-surface flow constructed ...
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Background and Objectives: Constructed wetlands and conventional treatment methods have a same duty in wastewater treatment، but they have different methods and mechanisms. The aim of this study was to investigate the removal of phenol from synthetic wastewater using horizontal sub-surface flow constructed wetland and the aeration and hydraulic retention time effects on phenol removal efficiency. Materials and methods: This study was an interventional study that was carried out on a laboratory scale in horizontal sub-surface flow constructed wetland. In order to determine the effect of aeration on the efficiency of phenol removal,، one reactor was aerated and another one was non-aerated. Pumice was used as a media. The wetlands were planted by Phragmatis australis. Results: The results showed that phenol degradation in both aerated and non-aerated wetland was influenced by organic loading rate and hydraulic retention time. It was also found that the removal of phenol was completely accomplished in both aerated and non-aerated wetlands. This is while the phenol removal rate is higher in aerated wetland,، and in order to achieve the same results,، the hydraulic retention time in non-aerated reactor should be about twice as high as the aerated one. Conclusion: : Horizontal sub-surface flow constructed wetland has a high efficiency in phenol removal. Therefore, if the conditions of operation especially hydraulic retention time are optimized، it can be applied as an effective system for phenol removal from wastewater.
hossein kamani; ayat hossein panahi; Somayeh Talebi; mohamad havangi
Abstract
Background and Objectives: Phenol is one of most common organic pollutants in aqueous environments. Phenol presence in the environment can make some health problems such as carcinogenesis, abnormality of heartbeat, etc for humans and poisonous problems for other organisms. Therefore, this pollutant must ...
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Background and Objectives: Phenol is one of most common organic pollutants in aqueous environments. Phenol presence in the environment can make some health problems such as carcinogenesis, abnormality of heartbeat, etc for humans and poisonous problems for other organisms. Therefore, this pollutant must be removed from polluted effluents to prevent water pollution. Using nanoparticles in adsorption processes is considered as an effective method for contaminants removal. The aim of this study was to investigate the efficiency of magnesium oxide nanoparticles in phenol removal from aqueous solutions. Materials and Methods:In this research, nanoparticles of magnesium oxide were used with size of 43 nm. After the preparation of phenol stock solution, effects of pH،(3- 5- 7- 9- 11)، contact time(10,30, 60, 90, and 120 min)، MgO dosage(20, 40, 60, 80 and 100 mg/L) and initial concentration of phenol (25, 50, 75 and 100 mg/l) Were investigated. Results: Results indicated that the removal efficiency increased with increasing pH, contact time, MgO dosage to a certain range and decreasing initial concentration. Such that the maximum efficiency was equal to 81% in the pH of about 11, initial concentration of 50 mg/L, MgO dosage of 80 mg/l and contact time of 60 min. It was found that adsorption kinetics and equilibrium data follow a pseudo-second-order kinetics model and a Langmuir isotherm model respectively. Conclusion: This study showed that the magnesium oxide nanoparticles have the ability to remove the phenol and can be used effectively in removing phenol from aqueous solution
ghorban asgari; Javad Faradmal; Abdolmotaleb Seid-mohammadi; Halime Almasi; somaye akbari
Abstract
Background and objective: Industrialization has led not only to an increase in water demand, but also to an increase in water pollution due to the discharge of polluted industrial wastewaters with high salt content, and the organic compounds such as phenol into the water bodies. This ...
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Background and objective: Industrialization has led not only to an increase in water demand, but also to an increase in water pollution due to the discharge of polluted industrial wastewaters with high salt content, and the organic compounds such as phenol into the water bodies. This study aimed to investigate the efficiency of electrocuagulation and electro-Fenton processes in phenol removal from saline wastewater using Taguchi exprimental design method. Material and methods: This experimental study was performed in a reactor (1 liter) with synthetic phenolic saline wastewater. In this study for electrocoagulation process, the effects of five operation parameters on phenol removal efficiency including reaction time (20-80 min), electrolyte (1-4%), pH (3-5-7-9), initial phenol concentration (500-1000-1500-250 mg/L) and current density (4-16 mA/cm2) were investigated in four levels by Taguchi L16 orthogonal array. Also for electro-Fenton process, the effects of six operation parameters on removal efficiency in five levels including reaction time (20-80 min), electrolyte (0-4%), pH (2-3-4-6-8), initial phenol concentration (250-500-1000-1500-2000), current density ( 0-16mA/cm2) and hydrogen peroxide (50-300mg/L) were evaluated by Taguchi L25 orthogonal array. The concentration of phenol was determined according to the estandard method in spectrophotometric wavelength of 500 nm. Results: Experimental data showed that the optimum phenol elimination condition in electrocuagulation process was initial phenol concentration of 250 mg/L, pH = 5, electrolyt = 3%, curent density of 8 mA/cm2 and reaction time of 60 min. The most influential factor in removal efficiency was the initial concentration (63.2%), and the lowest effect belonged to the electrolyt (4.2%). The optimum phenol removal condition for electro-Fenton process was initial concentration of 250 mg/L, pH:3, electrolyt:2%, hydrogen peroxide:150 mg/L, current density of 8 mA/cm2 and 20 mine contact time. The most influential factor in elimination efficiency was the curent density (29.12%), and the lowest influence on response variable belonged to the reaction time (3.08%). Conclusion: This study showed the electro-Fenton process was effective in the removal of phenolthat can be used as an appropriate process in wastewater treatment.