Bhaskar Sengupta

Publications

• 2.37

  Impact points

  Remediation technologies for heavy metal contaminated groundwater.

  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 of contaminated groundwater is of highest priority since billions of people all over the world use it for drinki... [more] 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 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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• 4.36

  Impact points

  Presence of arsenic in agricultural products from arsenic-endemic areas and strategies to reduce arsenic intake in rural villages.

  Angel A Carbonell-Barrachina, Antonio J Signes-Pastor, Laura Vázquez-Araújo, Francisco Burló, Bhaskar Sengupta

  Molecular nutrition & food research. 05/2009;

  About 100 million rural people in Asia are exposed to arsenic (As)-polluted drinking water and agricultural products. Total and inorganic arsenic (t-As and i-As) intake mainly depend on the quality of drinking and cooking waters, and amounts of seafood and rice consumed. The main problems occur in c... [more] About 100 million rural people in Asia are exposed to arsenic (As)-polluted drinking water and agricultural products. Total and inorganic arsenic (t-As and i-As) intake mainly depend on the quality of drinking and cooking waters, and amounts of seafood and rice consumed. The main problems occur in countries with poor water quality where the population depends on rice for their diet, and their t-As and i-As intake is high as a result of growing and cooking rice in contaminated water. Workable solutions to remove As from water and breeding rice cultivars with low As accumulation are being sought. In the meantime, simple recommendations for processing and cooking foods will help to reduce As intake. For instance, cooking using high volumes of As-free water may be a cheap way of reducing As exposure in rural populations. It is necessary to consider the effects of cooking and processing on t-As and i-As to obtain a realistic view of the risks associated with intake of As in As-endemic areas.
• 2.37

  Impact points

  Adsorption characteristics of Cu and Ni on Irish peat moss.

  B Sen Gupta, M Curran, Shameem Hasan, T K Ghosh

  Journal of environmental management. 05/2008;

  Peat has been widely used as a low cost adsorbent to remove a variety of materials including organic compounds and heavy metals from water. Various functional groups in lignin allow such compounds to bind on active sites of peat. The adsorption of Cu(2+) and Ni(2+) from aqueous solutions on Irish pe... [more] Peat has been widely used as a low cost adsorbent to remove a variety of materials including organic compounds and heavy metals from water. Various functional groups in lignin allow such compounds to bind on active sites of peat. The adsorption of Cu(2+) and Ni(2+) from aqueous solutions on Irish peat moss was studied both as a pure ion and from their binary mixtures under both equilibrium and dynamic conditions in the concentration range of 5-100mg/L. The pH of the solutions containing either Cu(2+) or Ni(2+) was varied over a range of 2-8. The adsorption of Cu(2+) and Ni(+2) on peat was found to be pH dependent. The adsorption data could be fitted to a two-site Langmuir adsorption isotherm and the maximum adsorption capacity of peat was determined to be 17.6mg/g for Cu(2+) and 14.5mg/g for Ni(2+) at 298K when the initial concentration for both Cu(2+) and Ni(2+) was 100mg/L, and the pH of the solution was 4.0 and 4.5, respectively. Column studies were conducted to generate breakthrough data for both pure component and binary mixtures of copper and nickel. Desorption experiments showed that 2mM EDTA solution could be used to remove all of the adsorbed copper and nickel from the bed.
• 1.82

  Impact points

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

  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 due to colloidal fouling of membranes and concentration polarisation. The present work explores the p... [more] 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 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.
• 1.36

  Impact points

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

  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 in a laboratory-scale fixed-bed column and subjected to three consecutive cycles of copper loading and e... [more] 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 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.

  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 experiments were conducted for two different cellulose acetate membrane modules of 0.2 micron and 0.45 micron pore s... [more] 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 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.