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RISS 인기검색어
- 검색키워드
- 저자 : Mokhlesur Rahman, M. (검색결과 30 건)
- 무료
- 기관 내 무료
- 유료
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Remediation of Water Contaminated with Herbicide Oxadiazon Using Fenton Reagent
Rahman, Md. Mokhlesur,Kim, Jang-Eok The Korean Society for Applied Biological Chemistr 2010 Applied Biological Chemistry (Appl Biol Chem) Vol.53 No.4
The remediation of water contaminated with herbicide oxadiazon was investigated by applying modified Fenton reagent ($Fe^{3+}/H_2O_2$) at unadjusted pH. Experimental conditions in various reactions allowed for the disappearance of oxadiazon. When using Fenton reagent, the maximum degradation rate was obtained under exposure to UV irradiation as compared to dark condition in which the concentrations of ferric ion and hydrogen peroxide were 3 and 100 mM, respectively. After 5 h of photocatalytic treatment with Fenton reagent, 98.4% of the oxadiazon was degraded. The high degradation rate of this herbicide was achieved by hydroxyl radicals ($OH^{\cdot}$), which were generated by the photocatalytic treatment. UV irradiation accelerated the degradation of oxadiazon in the water system in the presence of Fenton reagent. In addition, the disappearance of oxadiazon was enhanced due to the increased concentrations of ferric ion and/or hydrogen peroxide. For the photo-Fenton reaction, one metabolite (m/z 310) was able to be identified using the GC-MS technique due to dechlorination of oxadiazon. Conclusively, a remediation strategy using Fenton reagent could be applied to degrade oxadiazon from contaminated water.
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Removal Efficiency of the Herbicide Oxadiazon in Treatment Processes for Drinking Water
Mokhlesur, Rahman,Kim, Tae-Hwa,Kwon, Gi-Seok,Yang, Jae-E.,Park, Man,Kim, Jang-Eok The Korean Society for Applied Biological Chemistr 2009 Applied Biological Chemistry (Appl Biol Chem) Vol.52 No.3
A comparative study was performed to evaluate the removal efficiency of herbicide, oxadiazon as an organic contaminant in treatment processes for drinking water. In this investigation, three major treatment processes such as chlorination, ozonation and activated carbon treatment were applied separately to water system. The level of oxadiazon gradually decreased to 28%, when chloride as a disinfectant was applied to the water supply. Activated carbon treatments showed that this herbicide was removed efficiently from the aqueous solution. The results indicated that the performance of powdered activated carbon was more effective than granular activated carbon in terms of adsorption. The adsorption isotherms exhibited an excellent agreement with the experimental data and they were also well represented by the Langmuir and Freundlich equations, indicating the higher adsorption capacity for activated carbons. During ozone treatment, 50% of oxadiazon was removed but this removal was enhanced by the presence of hydrogen peroxide. The association of ozonation with chloride and activated carbon treatments was considered to be the best-tested treatment for drinking water production. Therefore, if oxadiazon enters into the water ecosystem as an organic contaminant, it could be removed effectively by the drinking water treatment processes.
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Rahman, Md. Mokhlesur,Hoque, Syed Munerul,Jesmin, Sabina,Rahman, Md. Siddiqur,Kim, Jang-Eok The Korean Society of Environmental Agriculture 2005 한국환경농학회지 Vol.24 No.2
Groundwater sampled from 24 tube wells of three districts namely Sherpur, Gaibandha and Naogaon in Bangladesh was appraised for their water quality for irrigation and agro-based industrial usage. All waters under test were slightly alkaline to alkaline (pH = 7.2 to 8.4) in nature and were not problematic for crop production. As total dissolved solid (TDS), all groundwater samples were classified as fresh water (TDS<1,000 mg/L) in quality. Electrical conductivity (EC) and sodium adsorption ratio (SAR) values reflected that waters under test were under medium salinity (C2), high salinity (C3) and also low alkalinity (S1) hazard classes expressed as C2S1 and C3S1. As regards to EC and soluble sodium percentage (SSP), groundwater samples were graded as good and permissible in category based on soil properties and crop growth. All water samples were free from residual sodium carbonate (RSC) and belonged to suitable in category. Water samples were under soft moderately hard, hard and very hard classes. Manganese, bicarbonate and nitrate ions were considered as major pollutants in some water samples and might pose threat in soil ecosystem for long-term irrigation. For most of the agro-based industrial usage, Fe and Cl were considered as troublesome ions. On the basis of TDS and hardness, groundwater samples were not suitable for specific industry. Some water samples were found suitable for specific industry but none of these waters were suitable for all industries. The relationship between water quality parameters and major ions was established. The correlation between major ionic constituents like Ca, Mg, K, Na, $HCO_3$ and Cl differed significantly. Dominant synergistic relationships were observed between EC-TDS, SAR-SSP, EC-Hardness, TDS-Hardness and RSC-Hardness.
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Abiotic Degradation Degradation of the Herbicide Oxadiazon in Water
Rahman Md. Mokhlesur,Park, Jong-Woo,Park, Man,Rhee In-Koo,Kim, Jang-Eok The Korean Society for Applied Biological Chemistr 2006 Journal of Applied Biological Chemistry (J. Appl. Vol.49 No.4
The performance of abiotic degradation of oxadiazon was investigated by applying zerovalent iron(ZVI), potassium permanganate($KMnO_4$) and titanium dioxide($TiO_2$) in the contaminated water. Experimental conditions allowed the disappearance of oxadiazon in the abiotic system. The degradation of this herbicide was monitored in buffer solutions having pH 3, 5 and 7 in the presence of iron powder in which the maximum degradation rate was achieved at acidic condition(pH 3) by 2% of ZVI treatment. The oxidative degradation of oxadiazon was observed in aqueous solution by $KMnO_4$ at pH 3, 7 and 10 in which the highest disappearance rate was found at neutral pH when treated with 2% of $KMnO_4$. The catalytic degradation of oxadiazon in $TiO_2$ suspension was obtained under dark and UV irradiation conditions. UV irradiation enhanced the degradation of oxadiazon in aquatic system in the presence of $TiO_2$. Conclusively, the remediation strategy using these abiotic reagents could be applied to remove oxadiazon from the contaminated water.
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Assessing Metallic Toxicity of Wastewater for Irrigation in Some Industrial Areas of Bangladesh
( Mokhlesur Rahman ),( Abu Sayem Jiku ),( Jang Eok Kim ) 한국환경농학회 2011 한국환경농학회지 Vol.30 No.2
BACKGROUND: Wastewaters were collected from 25 sites of two industrial areas of Mymensingh and Gazipur in Bangladesh to assess metallic toxicity of wastewater for irrigation usage. METHODS AND RESULTS: The analyzed wastewaters were slightly alkaline to alkaline in nature and were problematic for irrigation except 3 samples. As per TDS values, 9 samples were rated as fresh water and the rest 16 were classified as brackish water. EC and SAR reflected that all samples were medium salinity (C2), high salinity (C3), very high salinity (C4) and low alkalinity (S1) hazard classes expressed as C2S1, C3S1 and C4S1. Wastewaters of different industries were graded as excellent, good, permissible and doubtful for irrigation purpose as per SSP. According to hardness (HT), wastewater were under moderately hard, hard and very hard classes. Cd, Cr and Cu ions were treated as toxicant for irrigating soils and crops. Zn was problematic for long-term irrigation. The concentrations of Pb, Fe and Na were far below the toxic levels. Synergistic relationships were observed between pH-EC, pH-TDS, EC-TDS, SAR-SSP and SSP-hardness. CONCLUSION(s): If wastewater is applied for irrigation due to the fresh water shortage, it can contaminate soil due to some toxic metal ions.
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Remediation of Water Contaminated with Herbicide Oxadiazon Using Fenton Reagent
( Mokhlesur Rahman ),( Jang Eok Kim ) 한국응용생명화학회 2010 Applied Biological Chemistry (Appl Biol Chem) Vol.53 No.4
The remediation of water contaminated with herbicide oxadiazon was investigated by applying modified Fenton reagent (Fe3+/H2O2) at unadjusted pH. Experimental conditions in various reactions allowed for the disappearance of oxadiazon. When using Fenton reagent, the maximum degradation rate was obtained under exposure to UV irradiation as compared to dark condition in which the concentrations of ferric ion and hydrogen peroxide were 3 and 100 mM, respectively. After 5 h of photocatalytic treatment with Fenton reagent, 98.4% of the oxadiazon was degraded. The high degradation rate of this herbicide was achieved by hydroxyl radicals (OH`), which were generated by the photocatalytic treatment. UV irradiation accelerated the degradation of oxadiazon in the water system in the presence of Fenton reagent. In addition, the disappearance of oxadiazon was enhanced due to the increased concentrations of ferric ion and/or hydrogen peroxide. For the photo-Fenton reaction, one metabolite (m/z 310) was able to be identified using the GC-MS technique due to dechlorination of oxadiazon. Conclusively, a remediation strategy using Fenton reagent could be applied to degrade oxadiazon from contaminated water.
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Assessing Metallic Toxicity of Wastewater for Irrigation in Some Industrial Areas of Bangladesh
Rahman, Md. Mokhlesur,Jiku, Md. Abu Sayem,Kim, Jang-Eok The Korean Society of Environmental Agriculture 2011 한국환경농학회지 Vol.30 No.2
BACKGROUND: Wastewaters were collected from 25 sites of two industrial areas of Mymensingh and Gazipur in Bangladesh to assess metallic toxicity of wastewater for irrigation usage. METHODS AND RESULTS: The analyzed wastewaters were slightly alkaline to alkaline in nature and were problematic for irrigation except 3 samples. As per TDS values, 9 samples were rated as fresh water and the rest 16 were classified as brackish water. EC and SAR reflected that all samples were medium salinity (C2), high salinity (C3), very high salinity (C4) and low alkalinity (S1) hazard classes expressed as C2S1, C3S1 and C4S1. Wastewaters of different industries were graded as excellent, good, permissible and doubtful for irrigation purpose as per SSP. According to hardness ($H_T$), wastewater were under moderately hard, hard and very hard classes. Cd, Cr and Cu ions were treated as toxicant for irrigating soils and crops. Zn was problematic for long-term irrigation. The concentrations of Pb, Fe and Na were far below the toxic levels. Synergistic relationships were observed between pH-EC, pH-TDS, EC-TDS, SAR-SSP and SSP-hardness. CONCLUSION(s): If wastewater is applied for irrigation due to the fresh water shortage, it can contaminate soil due to some toxic metal ions.
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Impact of Herbicide Oxadiazon on Microbial Activity and Nitrogen Dynamics in Soil Environment
Rahman, Md. Mokhlesur,Song, Kyung-Sik,Rhee, In-Koo,Kim, Jang-Eok The Korean Society for Applied Biological Chemistr 2005 Journal of Applied Biological Chemistry (J. Appl. Vol.48 No.4
Influence of herbicide oxadiazon on soil microbial activity and nitrogen dynamics was evaluated. Soil samples were treated with oxadiazon at field and tenfold field rates and incubated. Organic amendment was added as an additional substrate for soil microorganisms. Tenfold field rate oxadiazon stimulated substrate-induced respiration (SIR) and dehydrogenase activity (DHA) in amended soil as compared to unamended soil and control treatment. Soil urease activity was not affected by oxadiazon treatment. In both amended and unamended soils, treatment of the herbicide at higher rate had not significant influence on $NH_4$-N and $NO_3$-N concentrations. Higher dose of oxadiazon was degraded in both soils, but dissipation rate in amended soil was higher than unamended soil, with half-lives ($t_{1/2}$) of 23.1 and 138.6 days, respectively. Recommended field rate did not affect microbial activity and nitrogen dynamics in soil ecosystem. Results showed influence of oxadiazon on cycling processes of nitrogen in soil was not significant however its effect on microbial activity was a tendency depending on addition of organic amendment to soil.
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