Environment
Elaheh faghihnasiri; Farhad Qaderi; S. Mustapha Rahmaninezhad
Articles in Press, Accepted Manuscript, Available Online from 30 January 2024
Abstract
Industrial processes are among human activities that cause the production of a large volume of wastewater containing organic pollutants such as phenol and its derivatives. Soil remediation is crucial for enhancing environmental quality for both humans and other living organisms. This study investigated ...
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Industrial processes are among human activities that cause the production of a large volume of wastewater containing organic pollutants such as phenol and its derivatives. Soil remediation is crucial for enhancing environmental quality for both humans and other living organisms. This study investigated the use of an electro-peroxone system to remove environmental pollutants from soil. In conjunction with ozonation, the study employed electrochemically generated hydrogen peroxide using a carbon electrode, addressing concerns about transportation and storage. Experiments were structured using response surface methodology (RSM) with three variables: ozone dosages ranging from 4 to 8 l/hr, initial pollutant concentrations from 20 to 50 mg/kg, and treatment durations between 7 and 14 days. The effectiveness of phenol removal from soil was assessed by applying a consistent voltage of 2 V/cm to the soil samples in all experiments. Results revealed a negative correlation between initial pollutant concentration and ozone consumption and a positive correlation between treatment duration and pollutant removal efficiency. Optimal removal efficiency occurred with a 14-day treatment duration, an 8 l/hr ozone dosage, and a 20 mg/kg initial pollutant concentration. The electro-peroxone system's application indicates its potential as a sustainable, eco-friendly, and cost-effective approach to soil remediation for pollution.
Environment
H. Tamadon Ghareghie; M. Yazdi; D. Yousefi Kebria; H. Aminirad
Abstract
Soil contamination is considered a controversial issue in most countries. Nowadays, it is important to clearly understand how pollutants influence the soil from different sources. Today, hydrocarbons are one of the most important sources of soil contaminants, which is considered as a fundamental issue ...
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Soil contamination is considered a controversial issue in most countries. Nowadays, it is important to clearly understand how pollutants influence the soil from different sources. Today, hydrocarbons are one of the most important sources of soil contaminants, which is considered as a fundamental issue at the global level. The current study aims to analyze and model the effect of simultaneous parameters (time and concentration) of phenols and naphthalene with different percentages (10, 15, 20 and 25%) together with the amount of bentonite in fine-grained sandy soil. The designed experiments made use of response surface methodology (RSM) and Design-Expert software to carry out a computer-based simulation. According to the proposed model, the amount of bentonite is most affected by the permeability of the soil. The obtained results also showed that the permeability significantly decreases in the light of increasing the percentage of phenol and naphthalene coupled with the amount of bentonite and the age of contamination. On average, an 80% reduction of permeability was observed in contaminated soil, which was found in the soil contaminated with naphthalene. According to the results of the synergistic effects of time, the considerable impacts of both the percentage of hydrocarbon pollutants and the amount of bentonite on the reduction of permeability are quite evident.
D. Yousefi Kebria; S. Mokhtarpour
Abstract
Aromatic hydrocarbons are toxic pollutants that enter into environment through various industries. These pollutants are carcinogenic and cause genetic mutations. There are various solutions, including biological methods, extraction, and electrocoagulation. This research aims to synthesize the nano zero-valent ...
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Aromatic hydrocarbons are toxic pollutants that enter into environment through various industries. These pollutants are carcinogenic and cause genetic mutations. There are various solutions, including biological methods, extraction, and electrocoagulation. This research aims to synthesize the nano zero-valent iron (nZVI) from the ferrous waste and granules of nZVI by the chemical combination of nZVI with polyvinyl alcohol (PVA). The performance of these two adsorbents was evaluated to degradation of phenol from an aqueous solution. The physical properties of the synthesized nanoparticles were determined using SEM analysis. Effect of pH, contact time, contaminant concentration, and adsorbent dosage on the removal efficiency were studied. The results showed that the maximum removal efficiency of phenol by nZVI and GnZVI was 78, 57.83 %, respectively, at the condition of pH 3, 60 minutes initial concentration of 8 ppm and adsorbent dosage of 2.5 g. The removal efficiency of phenol in acidic conditions and laboratory temperature by adsorption of nZVI is higher than GnZVI with a difference in removal efficiency of approximately 20 %. Equilibrium isotherms were analyzed by Langmuir and Freundlich equations and it was observed that these experiments followed Freundlich model.
T. Salehi; D. Yousefi Kebria
Abstract
The present study focused on the synergistic effects bioremediation of phenol in aqueous solution using combination of anaerobic mixed culture and Granular Activated Carbon (GAC) as a biological GAC (BGAC). Meanwhile, the effect of contact time and various phenol concentrations on adsorption and ...
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The present study focused on the synergistic effects bioremediation of phenol in aqueous solution using combination of anaerobic mixed culture and Granular Activated Carbon (GAC) as a biological GAC (BGAC). Meanwhile, the effect of contact time and various phenol concentrations on adsorption and biosorption process investigated. The phenol concentration was analyzed using UV/Vis spectrophotometer. The morphology and structure of two adsorbents (GAC and BGAC) were characterized by FESEM and BET specific surface area analysis. The batch experiments using mixed bacterial culture, isolated from wood and paper factory wastewater, were adapted to high concentrations of phenol and employed in order to evaluate the tolerance and biosorption capability of microorganisms for phenol biodegradation. The synergetic effect of phenol removal using combination of GAC with an anaerobic biofilm indicated that the removal efficiency for concentration of 700, 800, and 1000 mg/l at initial stages increased to 4, 10, and 12%, respectively and while by increment of the retention time did not shown significant impact on the removal efficiency. These results conducted both desorption of adsorbates due to biotransformation in the aqueous solution and direct assimilation of adsorbates on GAC by the microorganism’s biofilm. The adsorption data were fitted with pseudo-first-order and pseudo-second-order models and it was found that the pseudo-second-order model explains the adsorption kinetics more efficiently. The compatibility of the Freundlich and Langmuir adsorption models to equilibrium data were investigated. In fact, the Langmuir isotherm was found to be the best fitting isotherm.
S. Nasrollahpour; D. Yousefi Kebria; M. Ghavami
Abstract
Phenol and its metabolites are among the hazardous organic compounds, due to their carcinogenicity, toxicity, long term persistence in the environment. The purposes of this study are the synthesis of organoclay as an adsorbent with high physicochemical stability, environmental compatibility and its application ...
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Phenol and its metabolites are among the hazardous organic compounds, due to their carcinogenicity, toxicity, long term persistence in the environment. The purposes of this study are the synthesis of organoclay as an adsorbent with high physicochemical stability, environmental compatibility and its application for remediation of aqueous solutions contaminated with phenol. In this research, organoclay was synthesized by the combination of sodium bentonite and Cetyl Trimethyl Ammonium Bromide (CTAB) surfactant with three different Cation Exchange Capacities (CECs). As well as, adsorption capacity of synthesized organoclay was determined during reuse until saturation. The results revealed that the removal efficiencies of phenol at concentrations of 100, 1000, 2000, and 3000 mg/L were 68, 84, 82, and 80%, respectively. In general, the use of organoclay can be an alternative to the complex and expensive systems for the removal of phenol from aqueous solutions with respect to its simplicity, high performance, and cost-effectiveness.
