Shahin Ghafari - Academia.edu (original) (raw)

Papers by Shahin Ghafari

Research paper thumbnail of Mass transfer Evaluation on POME grown MicrobialGranules in an up flow anaerobic sludge fixed filmbioreactor

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Research paper thumbnail of Coagulation process for semi-aerobic leachate treatment using poly-aluminum chloride

Page 1. 1 Coagulation Process for Semi-Aerobic Leachate Treatment Using Poly-Aluminum Chloride Sh... more Page 1. 1 Coagulation Process for Semi-Aerobic Leachate Treatment Using Poly-Aluminum Chloride Shahin Ghafari, Hamidi Abdul Aziz, Mohamed Hasnain Isa School of Civil Engineering, Universiti Sains Malaysia, Engineering ...

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Research paper thumbnail of Parviz Mohammadi, Shaliza Ibrahim , Mohamad Suffian Mohamad Annuar, Shahin Ghafari, S. Vikineswary. 2012. Influences of environmental and operational factors on dark fermentative hydrogen production from wastes: a review. CLEAN-Soil, Air, Water 40(11): 1297-1305

CLEAN - Soil Air Water

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Research paper thumbnail of Control of pH during water denitrification in an upflow bio-electrochemical reactor (UBER) using a pumparound system

Separation and Purification Technology, 2010

In this study a new reactor design is proposed to control the pH during the bio-electrochemical d... more In this study a new reactor design is proposed to control the pH during the bio-electrochemical denitrification process. A previously developed UBER was modified by including a pumparound system. With the pumparound system a portion of the treated water is continuously ...

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Research paper thumbnail of Effect of carbon dioxide and bicarbonate as inorganic carbon sources on growth and adaptation of autohydrogenotrophic denitrifying bacteria

Journal of Hazardous Materials, 2009

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Research paper thumbnail of Optimization of coagulation-flocculation treatment on paper-recycling wastewater: Application of response surface methodology

Journal of Environmental Science and Health, Part A, 2013

The application of coagulation-flocculation (CF) process for treating the paper-recycling wastewa... more The application of coagulation-flocculation (CF) process for treating the paper-recycling wastewater in jar-test experiment was employed. The purpose of the study was aimed to examine the efficiency of alum and poly aluminum chloride (PACl) in combination with a cationic polyacrylamide (C-PAM) in removal of chemical oxygen demand (COD) and turbidity from paper-recycling wastewater. Optimization of CF process were performed by varying independent parameters (coagulants dosage, flocculants dosage, initial COD and pH) using a central composite design (CCD) under response surface methodology (RSM). Maximum set required 4.5 as pH, 40 mg/L coagulants dosage and 4.5 mg/L flocculants dosage at which gave 92% reduction of turbidity, 97% of COD removal and SVI 80 mL/g. The best coagulant and flocculants were alum and chemfloc 3876 at dose of 41 and 7.52 mg/L, respectively, correspondingly at pH of 6.85. These conditions gave 91.30% COD and 95.82% turbidity removals and 12 mL/g SVI.

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Research paper thumbnail of Improvement of autohydrogenotrophic nitrite reduction rate through optimization of pH and sodium bicarbonate dose in batch experiments

Journal of Bioscience and Bioengineering, 2009

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Research paper thumbnail of Nitrate remediation in a novel upflow bio-electrochemical reactor (UBER) using palm shell activated carbon as cathode material

Electrochimica Acta, 2009

This study investigated the biological denitrification method which is a treatment method able to... more This study investigated the biological denitrification method which is a treatment method able to reduce inorganic nitrate compounds to harmless nitrogen gas. Autohydrogenotrophic denitrifying bacteria were used in this study to prevent any problematic outcomes associated with ...

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Research paper thumbnail of The use of poly-aluminum chloride and alum for the treatment of partially stabilized leachate: A comparative study

Desalination, 2010

... The use of poly-aluminum chloride and alum for the treatment of partially stabilized leachate... more ... The use of poly-aluminum chloride and alum for the treatment of partially stabilized leachate: A comparative study. Shahin Ghafari a , Hamidi Abdul Aziz b , Corresponding Author Contact Information , E-mail The Corresponding Author and Mohammed JK Bashir b. ...

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Research paper thumbnail of Bio-electrochemical removal of nitrate from water and wastewater—A review

Bioresource Technology, 2008

Nitrates in different water and wastewater streams raised concerns due to severe impacts on human... more Nitrates in different water and wastewater streams raised concerns due to severe impacts on human and animal health. Diverse methods are reported to remove nitrate from water streams which almost fail to entirely treat nitrate, except biological denitrification which is capable of reducing inorganic nitrate compounds to harmless nitrogen gas. Review of numerous studies in biological denitrification of nitrate containing water resources, aquaculture wastewaters and industrial wastewater confirmed the potential of this method and its flexibility towards the remediation of different concentrations of nitrate. The denitrifiers could be fed with organic and inorganic substrates which have different performances and subsequent advantages or disadvantages. Review of heterotrophic and autotrophic denitrifications with different food and energy sources concluded that autotrophic denitrifiers are more effective in denitrification. Autotrophs utilize carbon dioxide and hydrogen as the source of carbon substrate and electron donors, respectively. The application of this method in bio-electro reactors (BERs) has many advantages and is promising. However, this method is not so well established and documented. BERs provide proper environment for simultaneous hydrogen production on cathodes and appropriate consumption by immobilized autotrophs on these cathodes. This survey covers various designs and aspects of BERs and their performances.

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Research paper thumbnail of A kinetic study of autohydrogenotrophic denitrification at the optimum pH and sodium bicarbonate dose

Bioresource Technology, 2010

In this study the kinetics of autohydrogenotrophic denitrification was studied under optimum solu... more In this study the kinetics of autohydrogenotrophic denitrification was studied under optimum solution pH and bicarbonate concentration. The optimal pH and bicarbonate concentration were firstly obtained using a design of experiment (DOE) methodology. For this purpose a total of 11 experiments were carried out. Sodium bicarbonate concentrations ranging of 20-2000 mg/L and pH values from 6.5 to 8.5 were used in the optimization runs. It was found that the pH has a more pronounced effect on the denitrification process as compared to the bicarbonate dose. The developed quadratic model predicted the optimum conditions at pH 8 and 1100 mg NaHCO(3)/L. Using these optimal conditions, the kinetics of denitrification for nitrate and nitrite degradation were investigated in separate experiments. Both processes were found to follow a zero order kinetic model. The ultimate specific degradation rates for nitrate and nitrite remediation were 29.60 mg NO(3)(-)-N/g MLVSS/L and 34.85 mg NO(3)(-)-N/g MLVSS/L respectively, when hydrogen was supplied every 0.5h.

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Research paper thumbnail of Development of nitrate elimination by autohydrogenotrophic bacteria in bio-electrochemical reactors – A review

Biochemical Engineering Journal, 2012

ABSTRACT

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Research paper thumbnail of Application of response surface methodology (RSM) for optimization of ammoniacal nitrogen removal from semi-aerobic landfill leachate using ion exchange resin

Desalination, 2010

Disposal of untreated landfill leachate can be a source of hazard to receiving waters. Hence, tre... more Disposal of untreated landfill leachate can be a source of hazard to receiving waters. Hence, treatment of landfill leachate is considered environmentally essential. In this study, optimization of ammoniacal nitrogen (NH 3 –N) removal from Malaysian semi-aerobic landfill ...

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Research paper thumbnail of Mass transfer Evaluation on POME grown MicrobialGranules in an up flow anaerobic sludge fixed filmbioreactor

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Coagulation process for semi-aerobic leachate treatment using poly-aluminum chloride

Page 1. 1 Coagulation Process for Semi-Aerobic Leachate Treatment Using Poly-Aluminum Chloride Sh... more Page 1. 1 Coagulation Process for Semi-Aerobic Leachate Treatment Using Poly-Aluminum Chloride Shahin Ghafari, Hamidi Abdul Aziz, Mohamed Hasnain Isa School of Civil Engineering, Universiti Sains Malaysia, Engineering ...

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Research paper thumbnail of Parviz Mohammadi, Shaliza Ibrahim , Mohamad Suffian Mohamad Annuar, Shahin Ghafari, S. Vikineswary. 2012. Influences of environmental and operational factors on dark fermentative hydrogen production from wastes: a review. CLEAN-Soil, Air, Water 40(11): 1297-1305

CLEAN - Soil Air Water

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Research paper thumbnail of Control of pH during water denitrification in an upflow bio-electrochemical reactor (UBER) using a pumparound system

Separation and Purification Technology, 2010

In this study a new reactor design is proposed to control the pH during the bio-electrochemical d... more In this study a new reactor design is proposed to control the pH during the bio-electrochemical denitrification process. A previously developed UBER was modified by including a pumparound system. With the pumparound system a portion of the treated water is continuously ...

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Research paper thumbnail of Effect of carbon dioxide and bicarbonate as inorganic carbon sources on growth and adaptation of autohydrogenotrophic denitrifying bacteria

Journal of Hazardous Materials, 2009

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Optimization of coagulation-flocculation treatment on paper-recycling wastewater: Application of response surface methodology

Journal of Environmental Science and Health, Part A, 2013

The application of coagulation-flocculation (CF) process for treating the paper-recycling wastewa... more The application of coagulation-flocculation (CF) process for treating the paper-recycling wastewater in jar-test experiment was employed. The purpose of the study was aimed to examine the efficiency of alum and poly aluminum chloride (PACl) in combination with a cationic polyacrylamide (C-PAM) in removal of chemical oxygen demand (COD) and turbidity from paper-recycling wastewater. Optimization of CF process were performed by varying independent parameters (coagulants dosage, flocculants dosage, initial COD and pH) using a central composite design (CCD) under response surface methodology (RSM). Maximum set required 4.5 as pH, 40 mg/L coagulants dosage and 4.5 mg/L flocculants dosage at which gave 92% reduction of turbidity, 97% of COD removal and SVI 80 mL/g. The best coagulant and flocculants were alum and chemfloc 3876 at dose of 41 and 7.52 mg/L, respectively, correspondingly at pH of 6.85. These conditions gave 91.30% COD and 95.82% turbidity removals and 12 mL/g SVI.

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Research paper thumbnail of Improvement of autohydrogenotrophic nitrite reduction rate through optimization of pH and sodium bicarbonate dose in batch experiments

Journal of Bioscience and Bioengineering, 2009

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Nitrate remediation in a novel upflow bio-electrochemical reactor (UBER) using palm shell activated carbon as cathode material

Electrochimica Acta, 2009

This study investigated the biological denitrification method which is a treatment method able to... more This study investigated the biological denitrification method which is a treatment method able to reduce inorganic nitrate compounds to harmless nitrogen gas. Autohydrogenotrophic denitrifying bacteria were used in this study to prevent any problematic outcomes associated with ...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The use of poly-aluminum chloride and alum for the treatment of partially stabilized leachate: A comparative study

Desalination, 2010

... The use of poly-aluminum chloride and alum for the treatment of partially stabilized leachate... more ... The use of poly-aluminum chloride and alum for the treatment of partially stabilized leachate: A comparative study. Shahin Ghafari a , Hamidi Abdul Aziz b , Corresponding Author Contact Information , E-mail The Corresponding Author and Mohammed JK Bashir b. ...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Bio-electrochemical removal of nitrate from water and wastewater—A review

Bioresource Technology, 2008

Nitrates in different water and wastewater streams raised concerns due to severe impacts on human... more Nitrates in different water and wastewater streams raised concerns due to severe impacts on human and animal health. Diverse methods are reported to remove nitrate from water streams which almost fail to entirely treat nitrate, except biological denitrification which is capable of reducing inorganic nitrate compounds to harmless nitrogen gas. Review of numerous studies in biological denitrification of nitrate containing water resources, aquaculture wastewaters and industrial wastewater confirmed the potential of this method and its flexibility towards the remediation of different concentrations of nitrate. The denitrifiers could be fed with organic and inorganic substrates which have different performances and subsequent advantages or disadvantages. Review of heterotrophic and autotrophic denitrifications with different food and energy sources concluded that autotrophic denitrifiers are more effective in denitrification. Autotrophs utilize carbon dioxide and hydrogen as the source of carbon substrate and electron donors, respectively. The application of this method in bio-electro reactors (BERs) has many advantages and is promising. However, this method is not so well established and documented. BERs provide proper environment for simultaneous hydrogen production on cathodes and appropriate consumption by immobilized autotrophs on these cathodes. This survey covers various designs and aspects of BERs and their performances.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A kinetic study of autohydrogenotrophic denitrification at the optimum pH and sodium bicarbonate dose

Bioresource Technology, 2010

In this study the kinetics of autohydrogenotrophic denitrification was studied under optimum solu... more In this study the kinetics of autohydrogenotrophic denitrification was studied under optimum solution pH and bicarbonate concentration. The optimal pH and bicarbonate concentration were firstly obtained using a design of experiment (DOE) methodology. For this purpose a total of 11 experiments were carried out. Sodium bicarbonate concentrations ranging of 20-2000 mg/L and pH values from 6.5 to 8.5 were used in the optimization runs. It was found that the pH has a more pronounced effect on the denitrification process as compared to the bicarbonate dose. The developed quadratic model predicted the optimum conditions at pH 8 and 1100 mg NaHCO(3)/L. Using these optimal conditions, the kinetics of denitrification for nitrate and nitrite degradation were investigated in separate experiments. Both processes were found to follow a zero order kinetic model. The ultimate specific degradation rates for nitrate and nitrite remediation were 29.60 mg NO(3)(-)-N/g MLVSS/L and 34.85 mg NO(3)(-)-N/g MLVSS/L respectively, when hydrogen was supplied every 0.5h.

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Research paper thumbnail of Development of nitrate elimination by autohydrogenotrophic bacteria in bio-electrochemical reactors – A review

Biochemical Engineering Journal, 2012

ABSTRACT

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Research paper thumbnail of Application of response surface methodology (RSM) for optimization of ammoniacal nitrogen removal from semi-aerobic landfill leachate using ion exchange resin

Desalination, 2010

Disposal of untreated landfill leachate can be a source of hazard to receiving waters. Hence, tre... more Disposal of untreated landfill leachate can be a source of hazard to receiving waters. Hence, treatment of landfill leachate is considered environmentally essential. In this study, optimization of ammoniacal nitrogen (NH 3 –N) removal from Malaysian semi-aerobic landfill ...

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