M A Hashim

Publications of M A Hashim

• A comparative study of experimental optimization and response surface optimization of Cr removal by emulsion ionic liquid membrane.

  Authors: Rahul Kumar Goyal, N S Jayakumar, M A Hashim

  Journal of hazardous materials. 08/2011; 195:383-90.

  A comparative study on the optimization of process parameters of an emulsion ionic liquid membrane (EILM) by experimental work and response surface methodology (RSM) has been carried out. EILM wasA comparative study on the optimization of process parameters of an emulsion ionic liquid membrane (EILM) by experimental work and response surface methodology (RSM) has been carried out. EILM was prepared by using kerosene as solvent, Span 80 as surfactant, NaOH as internal reagent, a hydrophobic ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM](+)[NTf(2)](-)) as a stabilizer and a second ionic liquid tri-n-octylmethylammonium chloride (TOMAC) as a carrier. The prepared EILM was used to separate and concentrate Cr from wastewaters. The comparison between the experimentally optimized and the RSM optimized values was accomplished by optimizing the following parameters: homogenization speed, carrier concentration, internal phase concentration, agitation speed, treat ratio, internal to membrane phase ratio, surfactant concentration and pH of the feed phase. The comparison showed that all the values were in good agreement except for the internal phase concentration and the treat ratio. It was observed that the stability provided by [BMIM](+)[NTf(2)](-) decreased as the extraction progressed due to its high density. Nevertheless, a good stability could be obtained by the combination of [BMIM](+)[NTf(2)](-) and Span 80 during extraction process.

• Performance evaluation of supported ionic liquid membrane for removal of phenol.

  Authors: S Nosrati, N S Jayakumar, M A Hashim

  Journal of hazardous materials. 07/2011; 192(3):1283-90.

  This work evaluates the performance of ionic liquid in supported liquid membrane (SLM) for the removal of phenol from wastewater. Ionic liquids are organic salts entirely composed of organic cationsThis work evaluates the performance of ionic liquid in supported liquid membrane (SLM) for the removal of phenol from wastewater. Ionic liquids are organic salts entirely composed of organic cations and either organic or inorganic anions. Due to the fact that the vapor pressure of ionic liquid is not detectable and they are sparingly soluble in most conventional solvents, they can be applied in SLM as the organic phase. In this work, 1-n-alkyl-3-methylimidazolium salts, [C(n)MIM](+)[X](-) have been investigated so as to determine an optimal supported ionic liquid membrane. The effect of operational parameters such as pH, stirring speed and the concentration of stripping agent has been studied, and an evaluation of different membrane supports were also carried out. With a minimal amount of the ionic liquid 1-Butyl-3-methylimidazolium hydrogensulfate, 85% phenol removal could be achieved by using polytetrafluoroethylene hydrophobic membrane filter in the SLM.

• Remediation technologies for heavy metal contaminated groundwater.

  Authors: M A Hashim, Soumyadeep Mukhopadhyay, Jaya Narayan Sahu, Bhaskar Sengupta

  Journal of environmental management. 06/2011; 92(10):2355-88.

  The contamination of groundwater by heavy metal, originating either from natural soil sources or from anthropogenic sources is a matter of utmost concern to the public health. Remediation ofThe contamination of groundwater by heavy metal, originating either from natural soil sources or from anthropogenic sources is a matter of utmost concern to the public health. Remediation of contaminated groundwater is of highest priority since billions of people all over the world use it for drinking purpose. In this paper, thirty five approaches for groundwater treatment have been reviewed and classified under three large categories viz chemical, biochemical/biological/biosorption and physico-chemical treatment processes. Comparison tables have been provided at the end of each process for a better understanding of each category. Selection of a suitable technology for contamination remediation at a particular site is one of the most challenging job due to extremely complex soil chemistry and aquifer characteristics and no thumb-rule can be suggested regarding this issue. In the past decade, iron based technologies, microbial remediation, biological sulphate reduction and various adsorbents played versatile and efficient remediation roles. Keeping the sustainability issues and environmental ethics in mind, the technologies encompassing natural chemistry, bioremediation and biosorption are recommended to be adopted in appropriate cases. In many places, two or more techniques can work synergistically for better results. Processes such as chelate extraction and chemical soil washings are advisable only for recovery of valuable metals in highly contaminated industrial sites depending on economical feasibility.

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• Emulsion stabilization using ionic liquid [BMIM]+[NTf2]- and performance evaluation on the extraction of chromium.

  Authors: Rahul Kumar Goyal, N S Jayakumar, M A Hashim

  Journal of hazardous materials. 03/2011; 195:55-61.

  This study focuses on the role of a hydrophobic ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [BMIM](+)[NTf(2)](-) in the preparation of emulsion liquid membrane (ELM)This study focuses on the role of a hydrophobic ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [BMIM](+)[NTf(2)](-) in the preparation of emulsion liquid membrane (ELM) phase containing kerosene as solvent, Span 80 as surfactant, NaOH as internal phase and TOMAC (tri-n-octylmethylammonium chloride) a second ionic liquid as carrier. The first time used [BMIM](+)[NTf(2)](-) in ELM was found to play the role of a stabilizer. The emulsion prepared using [BMIM](+) [NTf(2)](-) has a long period of stability of about 7h (at 3% (w/w) of [BMIM](+)[NTf(2)](-)) which otherwise has a brief stability up to only 7 min. The stability of the emulsion increases with the increase in concentration of [BMIM](+)[NTf(2)](-) up to 3% (w/w). Nevertheless, with further increase in concentration of [BMIM](+)[NTf(2)](-), a reduction in the stability occurs. The extraction experiments were carried out after holding the ELM for 2h after the preparation and a removal efficiency of approximately 80% was obtained for Cr. The destabilization of the emulsion was studied by observing the change in the interface height. An empirical correlation for the stability of the emulsion has been proposed.

• Experimental and theoretical investigation of parametric sensitivity and dynamics of a continuous stirred tank reactor for acid catalyzed hydrolysis of acetic anhydride.

  Authors: N. S. Jayakumar, A. Agrawal, M. A. Hashim, J. N. Sahu

  Computers & Chemical Engineering. 01/2011; 35:1295-1303.

• Performance evaluation of supported ionic liquid membrane for removal of phenol

  Authors: S. Nosrati, N.S. Jayakumar, M.A. Hashim

  Journal of Hazardous Materials. 01/2011;

• Extraction performance of chromium (VI) with emulsion liquid membrane by Cyanex 923 as carrier using response surface methodology

  Authors: S. Nosrati, N.S. Jayakumar, M.A. Hashim

  Desalination. 01/2011; 266:286-290.

• Performance evaluation of organic emulsion liquid membrane on phenol removal.

  Authors: Y S Ng, N S Jayakumar, M A Hashim

  Journal of hazardous materials. 12/2010; 184(1-3):255-60.

  The percentage removal of phenol from aqueous solution by emulsion liquid membrane and emulsion leakage was investigated experimentally for various parameters such as membrane:internal phase ratio,The percentage removal of phenol from aqueous solution by emulsion liquid membrane and emulsion leakage was investigated experimentally for various parameters such as membrane:internal phase ratio, membrane:external phase ratio, emulsification speed, emulsification time, carrier concentration, surfactant concentration and internal agent concentration. These parameters strongly influence the percentage removal of phenol and emulsion leakage. Under optimum membrane properties, the percentage removal of phenol was as high as 98.33%, with emulsion leakage of 1.25%. It was also found that the necessity of carrier for enhancing phenol removal was strongly dependent on the internal agent concentration.

• Copper biosorption on immobilized seaweed biomass: column breakthrough characteristics.

  Authors: K H Chu, M A Hashim

  Journal of environmental sciences (China). 02/2007; 19(8):928-32.

  The biosorption of copper by the brown seaweed Sargassum baccularia, immobilized onto polyvinyl alcohol (PVA) gel beads, was investigated with fixed-bed experiments. Laboratory-scale column testsThe biosorption of copper by the brown seaweed Sargassum baccularia, immobilized onto polyvinyl alcohol (PVA) gel beads, was investigated with fixed-bed experiments. Laboratory-scale column tests were performed to determine breakthrough curves with varying flow rates and feed concentrations. A theoretical fixed-bed model, known as the Bohart-Adams equation, was evaluated in simulating the experimental breakthrough curves. The Bohart-Adams model qualitatively predicted the breakthrough trends. PVA-immobilized seaweed biomass beads were amenable to efficient regeneration with aqueous solution containing the chelating agent ethylenediaminetetraacetic acid (EDTA). The biosorbent retained most of its original uptake capacity over three cycles of use. The excellent reusability of the biosorbent could lead to the development of a viable metal remediation technology.

• Effects of colloidal fouling and gas sparging on microfiltration of yeast suspension.

  Authors: B Sen Gupta, S Hasan, M A Hashim, Z F Cui

  Bioprocess and biosystems engineering. 11/2005; 27(6):407-13.

  Cross-flow microfiltration is an important step in separating Baker's yeast (Saccharomyces cerevisiae) from aqueous suspension in many processes. However the permeate flux often declines rapidly dueCross-flow microfiltration is an important step in separating Baker's yeast (Saccharomyces cerevisiae) from aqueous suspension in many processes. However the permeate flux often declines rapidly due to colloidal fouling of membranes and concentration polarisation. The present work explores the possibility of maintaining acceptable permeate flux by co-current sparging of gas along with the feed, which would scour away colloidal deposits and reduce concentration polarisation of membranes. In this work, both washed and unwashed yeast were used to study the effect of washing to reduce protein fouling of membranes. It was found that permeate flux increased by 45% for liquid throughput of 75 kg/h for a feed concentration of 2.0 kg/m3 of washed yeast as compared with unwashed yeast suspension without gas sparging. For washed yeast suspension, the increase in gas flow rate from 0.5 lpm to 1.5 lpm (30 l/h to 90 l/h) had beneficial effect on permeate flux. It is concluded that in the present case, the gas flow rate should be less than or equal to the liquid flow rate for enhancement of permeates flux.

• Studies on fixed-bed biosorption and elution of copper using polyvinyl alcohol-immobilized seaweed biomass.

  Authors: K F Tan, K H Chu, B Sen Gupta, M A Hashim

  Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering. 11/2002; 37(9):1621-32.

  Biosorption of copper by inactivated biomass of the brown marine alga Sargassum baccularia immobilized in polyvinyl alcohol (PVA) beads was investigated. PVA-immobilized biomass beads were packed inBiosorption of copper by inactivated biomass of the brown marine alga Sargassum baccularia immobilized in polyvinyl alcohol (PVA) beads was investigated. PVA-immobilized biomass beads were packed in a laboratory-scale fixed-bed column and subjected to three consecutive cycles of copper loading and elution. Bound copper was eluted with solutions containing a range of ethylenediaminetetraacetic acid (EDTA) concentrations. Up to 100% of the bound copper was consistently recovered from immobilized biomass using an aqueous solution containing 4mM EDTA in repeated loading/elution cycles. The PVA-immobilized biomass beads were shown to be robust and stable with little decrease in the copper uptake capacity under dynamic flow conditions. The excellent reusability of the new biosorbent could lead to the development of a viable metal removal technology.

• A study on the effect of operating parameters on the cross-flow microfiltration of yeasts.

  Authors: M A Hashim, B Sen Gupta

  Bioseparation. 02/1997; 7(1):17-23.

  The effects of pump speed, cumulative permeate volume and concentration of feed (yeast cells) on the permeate flux have been studied on a batch cross-flow microfiltration process. The experimentsThe effects of pump speed, cumulative permeate volume and concentration of feed (yeast cells) on the permeate flux have been studied on a batch cross-flow microfiltration process. The experiments were conducted for two different cellulose acetate membrane modules of 0.2 micron and 0.45 micron pore size. A three factor experiment was designed for this purpose and the effect of the operating parameters on the filtration rate was studied by the analysis of variance (ANOVA). It is concluded from the analysis of the experimental data that pump speed has the maximum bearing upon the permeate rate within the operating range of parameters. Fouling conditions were examined in the light of colloids deposition on membranes due to surface interactions. However this paper looks into the relationship and sensitivity of the operating parameters in a cross-flow microfiltration unit rather than exploring the theoretical principles behind the observed phenomena.

• Prediction of protein breakthrough behavior using simplified analytical solutions

  Authors: M.A. Hashim, K.H. Chu

  Separation and Purification Technology.

  The predictability of the breakthrough behavior of lysozyme on the strong cation exchanger SP Sepharose FF was evaluated using two different but related analytical solutions. The first solution,The predictability of the breakthrough behavior of lysozyme on the strong cation exchanger SP Sepharose FF was evaluated using two different but related analytical solutions. The first solution, known as the Thomas equation, assumes that adsorption can be represented by a pseudo second-order reaction rate law which translates into a Langmuir isotherm at equilibrium. The second solution, known as the Bohart–Adams equation, assumes that adsorption can be described by a quasi-chemical rate law which reduces to a rectangular isotherm at equilibrium. The Bohart–Adams solution can be regarded as a limiting form of the Thomas solution. The equilibrium and rate parameters embedded in the two solutions were extracted from batch experiments. Predictions using the two simplified solutions agreed with experimental breakthrough data. When the isotherm is highly favorable the simpler Bohart–Adams solution can be used as a practically useful modeling tool in lieu of the mathematically complicated Thomas solution.

• Biosorption of cadmium by algal biomass: Adsorption and desorption characteristics

  Authors: K.H. Chu, M.A. Hashim, S.M. Phang, V.B. Samuel

  Water Science and Technology.

  The adsorption and desorption characteristics of a biosorption process comprising the biomass of the marine alga Sargassum baccularia, cadmium ions and desorbing agents hydrochloric acid andThe adsorption and desorption characteristics of a biosorption process comprising the biomass of the marine alga Sargassum baccularia, cadmium ions and desorbing agents hydrochloric acid and ethylenediaminetetraacetic acid (EDTA) were investigated using a batch reactor system. Both desorbents were effective in stripping adsorbed cadmium from the biomass. It was found that HCl at pH 2 could desorb 80% of the cadmium initially loaded onto the biomass. Almost complete recovery of cadmium was achieved by a 3.24 mM EDTA solution. The reusability of the biomass was tested in five consecutive adsorption-desorption cycles. The quantity of cadmium desorbed over the five cycles with either HCl or EDTA as desorbent corresponded well to the quantity loaded, indicating that complete desorption was readily achieved. However, the cadmium uptake capacity of the biomass deteriorated with repeated use of HCl or EDTA. HCl was found to have reduced cadmium uptake by 56% while the reduction for EDTA was nearly 40% over the five adsorption-desorption cycles. EDTA thus emerged as a slightly better desorbing agent compared with HCl. After completion of the five cycles it was found that 30% of the original biomass weight had been lost with HCl as the desorbent. EDTA exhibited desorption behaviour similar to that of HCl by causing a biomass loss of 16%. The loss of biomass indicates that some dissolution of biomass components containing cadmium binding sites apparently occurred, reducing the cadmium uptake capacity of the biomass in multiple cycles of adsorption-desorption.

• Copper biosorption on immobilized seaweed biomass: Column breakthrough characteristics

  Authors: K.H. Chu, M.A. Hashim

  Journal of Environmental Sciences.

  AbstractThe biosorption of copper by the brown seaweed Sargassum baccularia, immobilized onto polyvinyl alcohol (PVA) gel beads, was investigated with fixed-bed experiments. Laboratory-scale columnAbstractThe biosorption of copper by the brown seaweed Sargassum baccularia, immobilized onto polyvinyl alcohol (PVA) gel beads, was investigated with fixed-bed experiments. Laboratory-scale column tests were performed to determine breakthrough curves with varying flow rates and feed concentrations. A theoretical fixed-bed model, known as the Bohart-Adams equation, was evaluated in simulating the experimental breakthrough curves. The Bohart-Adams model qualitatively predicted the breakthrough trends. PVA-immobilized seaweed biomass beads were amenable to efficient regeneration with aqueous solution containing the chelating agent ethylenediaminetetraacetic acid (EDTA). The biosorbent retained most of its original uptake capacity over three cycles of use. The excellent reusability of the biosorbent could lead to the development of a viable metal remediation technology.