Mixed-valent cobalt phosphate/borophene nanohybrids for efficient electrocatalytic oxygen evolution reaction.

Developing efficient, low-cost, non-precious and stable electrocatalyst is necessary for sustainable electrocatalytic water splitting. Recently, borophene has emerged as a novel two-dimensional material with exciting properties. Although several researchers have theoretically predicted its applicability towards effective electrocatalytic water splitting, studies on its practical applications are still limited. In this regard, a mixed-valent cobalt phosphate/borophene nanohybrid (BCoPi) was synthesized using hydrothermal method, and its activity towards oxygen evolution reaction (OER) was systematically studied. The electron-deficient nature of borophene enables activation of catalytic sites and facilitates electron transport owing to its highly conductive nature. It can act as a proton acceptor along with phosphate groups, as well as provide multiple secondary active sites in addition to Co, breaking the scaling relation of OER. For BCoPi, achieving a current density of 50 mA cm-2, 100 mA cm-2 and 500 mA cm-2 requires an overpotential of 337 mV, 357 mV and 401 mV, respectively, in an alkaline medium, that are superior to pristine cobalt phosphate (CoPi). It also exhibits low Tafel slope of 61.81 mV dec-1, suggesting faster OER kinetics and excellent long-term stability. This study will extend the development and application of borophene-based heterostructures for highly active and stable electrocatalysts for various applications.

Accelerated radical generation from visible light driven peroxymonosulfate activation by Bi2MoO6/doped gCN S-scheme heterojunction towards Amoxicillin mineralization: Elucidation of the degradation mechanism.

A novel S-scheme photocatalyst Bi2MoO6 @doped gCN (BMO@CN) was prepared through a facile microwave (MW) assisted hydrothermal process and further employed to degrade Amoxicillin (AMOX), by peroxymonosulfate (PMS) activation with visible light (Vis) irradiation. The reduction in electronic work functions of the primary components and strong PMS dissociation generate abundant electron/hole (e-/h+) pairs and SO4*-,*OH,O2*-reactive species, inducing remarkable degeneration capacity. Optimized doping of Bi2MoO6 on doped gCN (upto 10 wt%) generates excellent heterojunction interface with facile charge delocalization and e-/h+ separation, as a combined effect of induced polarization, layered hierarchical structure oriented visible light harvesting and formation of S-scheme configuration. The synergistic action of 0.25 g/L BMO(10)@CN and 1.75 g/L PMS dosage can degrade 99.9% of AMOX in less than 30 min of Vis irradiation, with a rate constant (kobs) of 0.176 min-1. The mechanism of charge transfer, heterojunction formation and the AMOX degradation pathway was thoroughly demonstrated. The catalyst/PMS pair showed a remarkable capacity to remediate AMOX-contaminated real-water matrix. The catalyst removed 90.1% of AMOX after five regeneration cycles. Overall, the focus of this study is on the synthesis, illustration and applicability of n-n type S-scheme heterojunction photocatalyst to the photodegradation and mineralization of typical emerging pollutants in the water matrix.

Combined electroosmotic and pressure-driven transport of neutral solutes across a rough, porous-walled microtube.

A number of microfluidic systems of interest essentially consist of micro-scaled channels/tubes, whose walls are inherently rough. The novelty of the current study lies in exploring the impact of the wall roughness on mass transfer in the case of flow through a microtube with porous wall. The current investigation is possibly the first attempt at exploring the effect of mass transfer for a porous-walled, rough microtube, as earlier studies were limited to the analysis of hydrodynamic and thermal effects only in an impervious microtube. In particular, the effects of the corrugation amplitude and the wavenumber on the mass transport have been assessed in detail in this work, via a combination of perturbation approximations and numerical analysis. Several interesting revelations are elicited regarding the effects of these pertinent parameters on the mass transfer coefficient, permeation flux, wall surface concentration, and delivery flux of the neutral solute. It has been unveiled that it is possible to enhance the solute mass flux by 10% via appropriate tuning of corrugation amplitude. The findings of the study can help in better understanding of mass transport for a porous-walled, rough microtube, which has critical relevance in several important applications such as micromixers, targeted drug delivery, and so on.

Adsorptive remediation of aqueous inorganic mercury with surfactant enhanced bismuth sulfide nanoparticles.

Heavy metal contamination in water is a growing threat, endangering the environmental stability. Mercury (Hg) is one of the most lethal heavy metals damaging the immune and nervous system irreversibly. A novel synthetic route to prepare bismuth sulfide (Bi2S3) nanoparticles in presence of the surfactant Pluronic (P123) was illustrated in this work. The sorption of Hg (II) by the nanoparticles was investigated. The surfactant assisted nanoparticles showed enhanced surface area and potential compared to the unmodified ones. The effects of adsorbent dose, pH, initial concentration, and temperature were investigated. The maximum Hg (II) adsorption capacity for the surfactant enhanced Bi2S3 was 832 mg/g at 303 K and pH 5. The distribution coefficient (Kd) of the order ∼106 ml/g indicated high selectivity of the synthesized adsorbent toward mercury ions. Chemisorption was identified to be the dominant mechanism of adsorption. The adsorbent also showed excellent reusability (>95%) after 5 cycles. The transport parameters involved in the adsorption, the effective pore diffusivity (Dp: 7.36 × 10-12 m2/s) and the mass transfer coefficient (kf: 1.52 × 10-6 m/s) were estimated from a first principle-based model.

Validation of antioxidant, antiproliferative, and in vitro anti-rheumatoid arthritis activities of epigallo-catechin-rich bioactive fraction from Camellia sinensis var. assamica, Assam variety white tea, and its comparative evaluation with green tea fraction.

The epigallocatechin-rich polyphenolic fraction of Assam variety white tea, traditionally used for the management of diverse inflammatory ailments and health drink, was investigated through eco-friendly green aqueous extraction, TLC, and HPLC characterization, phytochemical screening, in vitro DPPH assay, anti-proteinase, MTT assay on synovial fibroblast and colon cancer cells, apoptotic FACS analysis, cytokine ELISA, p-STAT3 western blotting, and in silico docking analysis. HPLC-TLC standardized white tea fraction (WT-F) rendered higher extractive-yield (21%, w/w), than green tea fraction(GT-F) (12%, w/w). WT-F containing flavonoids and non-hydrolysable polyphenols showed better antioxidant activity, rather than equivalent GT-F. WT-F demonstrated remarkable anti-rheumatoid-arthritis activity via killing of synovial fibroblast cells (66.1%), downregulation of TNF-α (93.33%), IL-6 (87.97%), and p-STAT3 inhibition (77.75%). Furthermore, WT-F demonstrated better anti-proliferative activity against colon cancer cells (HCT-116). Collectively, our study revealed that the white tea fraction has boundless potential as anti-rheumatoid arthritis and anti-proliferative agent coupled with apoptotic, antioxidant anti-proteinase, and anti-inflammatory properties. PRACTICAL APPLICATIONS: Our eco-friendly extracted bioactive aqueous fraction of white tea, characterized by TLC-HPLC study and phytochemical screening have demonstrated remarkable anti-rheumatoid arthritis property and anti-proliferative action on colon cancer cells including potential anti-oxidant, anti-inflammatory, and anti-proteinase efficacy. The test WT-F sample has shown impressive safety on normal mammalian cells. WT-F has demonstrated better efficacy against rheumatoid arthritis and cancer model compared to equivalent green tea fraction. Traditionally, it is extensively used for boosting immunity, and energy, with cosmetic, and agricultural applications by the native inhabitants. So, the aqueous fraction of WT is suggested to be used as a prophylactic nutraceutical supplement and or therapeutic agent in commercial polyherbal formulation to attenuate and management of auto-inflammatory rheumatoid arthritis and carcinogenesis of colon. It is additionally suggested to establish in vivo rheumatoid arthritis animal and clinical study to validate their pharmacokinetic stability and dose optimization coupled with anti-inflammatory, cytotoxicity, and anti-oxidant property.

Enhanced photodegradation of reactive dyes in textile effluent with CoFe2O4/g-CN heterostructure-mediated peroxymonosulphate activation.

Graphitic carbon nitride (g-C3N4) was employed as a sacrificial substructure and two-dimensional support to develop magnetic cobalt ferrite-carbon nitride (CoFe2O4/g-CN) composite via a one-step solid combustion method. The catalyst activated peroxymonosulphate (PMS), through the interconversion of Co2 + /3+|surf. and Fe2 + /3+|surf. on its surface for degradation of reactive dyes (RDs). Excellent ferromagnetic nature (44.15 emu g-1) of the catalyst led to its efficient magnetic separation. With an optimum catalyst and PMS dose of 0.4 g L-1 and 1.5 g L-1, 99% RD removal was achieved for textile effluent (pH 9.5-10), under UV irradiation (48 W). In-depth radical scavenging experiments and EPR analysis confirmed the dominance of radical-based degradation process. Plausible degradation and mineralization pathways of RDs were proposed through identification of intermediates by LCMS/MS analysis. In brief, this study elucidates an exclusive strategy towards the use of g-C3N4 as fuel for facile synthesis of magnetic CoFe2O4/g-CN as a remarkable photocatalyst for activation of PMS towards mineralization of various industrially relevant RDs.

Graphene oxide wrapped Mix-valent cobalt phosphate hollow nanotubes as oxygen evolution catalyst with low overpotential.

Development of an efficient, stable and inexpensive catalyst for oxygen evolution reaction (OER) is critical to electrochemical water splitting. In this regard, a precious-metal free electrocatalyst has been synthesized employing a hydrothermal route. The prepared graphene oxide wrapped cobalt phosphate nanotubes deposited on Ni foam electrode shows a low overpotential of 234 mV at a current density of 10 mA/cm2 for OER in 1(M) KOH, lower than a benchmarking electrocatalyst IrO2 at the same current density. The performance figures clearly defy the volcano limitations. The mixed-valency induced delocalization of charge satisfies Sabatier Principle for ideal catalysts and graphene oxide ensures improved charge transfer. Moreover, the designed electrocatalyst performs efficiently even on prolonged use under mass transfer limitation conditions.

Pectinase hydrolysis of guava pulp: effect on the physicochemical characteristics of its juice.

The objective of this research is to assess the effect of enzymatic treatment of guava puree on the physicochemical parameters of the juice. Pectinases from Aspergillus niger were applied to the puree at 43 ± 3 °C under constant stirring. Enzyme concentrations used were: 0.033 % (w/w), 0.055% (w/w), 0.078 % (w/w) and 0.1 % (w/w). For each enzyme concentration, the treatment times were varied from 3 - 90 min. Physicochemical parameters of raw puree and enzymatically treated juice were determined. These were: viscosity, pH, electric conductivity, protein and polyphenol content, galacturonic acid content, color, TSS, and antioxidant capacity. Particle distribution, homogeneity of raw puree and juice samples dried extracts were assessed using a Field Emission Scanning Electron Microscopy (FESEM). A 91% viscosity decrease was recorded for each enzyme concentration after 3 min of enzyme reaction. That drecrase was accompanied by an increase in galacturonic acid content with increasing depectinization factors. Enzyme treatment of guava puree led to a decrease in pH, protein and polyphenol contents and an increase in conductivity and color. Analysis of FESEM images of guava samples bestowed a decrease in particle size, a scattering of particles in the medium, an increase in continuous phase proportion and an improvement of sample homogeneity with increasing values of processing parameters, due to the breaking-down of bigger particles and the solubilization during depectinization.

Multicomponent transport model-based scaling up of long-term fixed bed adsorption of reactive dyes from textile effluent using aminated PAN beads.

Novel functionalized polymeric beads have been prepared by a simple phase inversion technique and its potential as an effective sorbent for reactive dyes is studied. Polyacrylonitrile was used as the base polymer for the beads that were further functionalized using diethylenetriamine. Scanning electron microscopy, FTIR spectroscopy, BET technique, TGA analysis, and zeta potential measurement were used for characterization of the functionalized beads. The adsorption characteristics of the beads were analyzed through adsorption isotherms. A first-principle-based pore diffusion-adsorption model was employed to study adsorption process of the functionalized beads and to determine various mass transfer parameters, i.e., mass transfer coefficient and effective pore diffusivity, in both single and multicomponent cases. For different reactive dyes, the beads have adsorption capacities in the range of 170-230 mg/g. Effects of different operating parameters, i.e., inlet concentration of solute, influent rate, and bed depth were studied to determine the breakthrough performance of the columns prepared with the beads. Industrial dye effluent, containing four reactive dyes at different initial concentrations, was used to study multicomponent adsorption in the columns. The regeneration efficiency of the beads was determined using aqueous cationic surfactant solution. Finally, scaling up of the fixed bed columns was carried out using a first principle-based transport model based on pore diffusion-adsorption processes.

Adsorptive removal of heavy metals from battery industry effluent using MOF incorporated polymeric beads: A combined experimental and modeling approach.

In this study, the metal organic framework (MOF) ZIF-8 was investigated as potential adsorbent for heavy metal ions. The MOF powder was used further to prepare mixed matrix beads (MMBs) using polysulfone as the base material. Both the MOF powder and the MMBs were characterized using Field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller (BET) analyzer and zetasizer. Adsorption capacity of the MMBs were 164-220 mg/g for Pb and 92-161 mg/g for Cd. A fundamental pore diffusion-adsorption model was used to predict the batch kinetics for both single and multicomponent cases and effective pore diffusivities and mass transfer coefficients were determined. Mutual interactions among heavy metals were quantified using interaction parameters. ZIF-8, incorporated in the PSF matrix, plays the predominant role in capturing the metal ions through surface complexation with the NH and metal-OH groups. A first principle-based model involving convection, diffusion and adsorption was used to quantify the breakthrough behavior for the continuous fixed bed column using the MMBs. The column performance was tested with battery industry effluent. The saturated beads were suitably regenerated using 0.1(M) HCl solution. Finally, the model parameters were used for scaling up of the columns.

In situ photodecyanation of steel industry wastewater in a pilot scale.

The photodegradation of cyanide from steel industry wastewater was explored in pilot plant scale using hydrogen peroxide (H2O2) under UV irradiation. However, it was interesting to notice that only H2O2 or only UV was inefficient to degrade the cyanide from industrial wastewater. There was a synergy between H2O2 and UV radiation for the degradation of cyanide. The generated hydroxyl radicals from irradiated H2O2 were responsible for the efficient degradation of cyanide. Besides, the dissolved oxygen had a significant role on the degradation process. The photodecyanation rate was faster initially and decreased gradually thereafter ensuring the industrial viability of the process. The dozing rate of H2O2 and the UV lamp power were systematically optimized and they were found to be 8 l/m3 and 640 W, respectively. The photodecyanation kinetics was also explored simultaneously and the rate constant was found to be 3.21 × 10-2 min-1 at the selected dosage of 8 l/m3. This work demonstrates a scalable and facile decyanation technique from steel plant effluent without generation of toxic by-products.

Mass transfer of a neutral solute in polyelectrolyte grafted soft nanochannel with porous wall.

A soft nanochannel involves a soft interface that contains a polyelectrolyte layer (PEL) sandwiched between a rigid surface and a bulk electrolyte solution. Mass transfer of a neutral solute in a combined electroosmotic and pressure driven flow through a polyelectrolyte grafted charged nanochannel with porous wall is presented in this work. Assuming the PEL as fixed charged layer and PEL-electrolyte interface as a semi-penetrable membrane, analytical solutions were obtained for potential distributions (for small wall potential). Velocity profiles were also derived in the same domains, for both inside and outside the PEL. Convective-diffusive species balance equation was semi-analytically solved inside the PEL. Expression of length averaged Sherwood number was also obtained and effects of different parameters, namely, drag parameter (α), Debye parameter (κ¯) , and PEL thickness were studied in detail. The variation of permeate concentration and permeation flux across the porous wall was obtained.

Synthesis of NiAl- layered double hydroxide with nitrate intercalation: Application in cyanide removal from steel industry effluent.

Cyanide contamination in steel plant wastewater is a challenge. Nitrate intercalated nickel aluminum layered double hydroxide (LDH) is specially designed and synthesized for adsorption of cyanide from wastewater. The LDH was characterized by Field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and BET surface analyzer. Formation of nanosized plate like LDH particles was confirmed by FESEM analysis. FTIR analysis confirmed the intercalation of nitrate ions in the interlayer space of nickel-aluminum layered double hydroxide. Adsorption of cyanide in the LDH matrix was identified by FTIR study. Ion exchange was the prevalent mechanism of cyanide adsorption. The specific surface area of LDH was 142 m2/g with average pore size of 1.9 nm. The spent LDH could be regenerated using a chemical method and was reused up to five cycles. The efficiency of the LDH was evaluated using real life cyanide containing wastewater from steel plant.

Electrohydrodynamic transport of non-symmetric electrolyte through porous wall of a microtube.

Transport of salt through the wall of porous microtube is relevant in various physiological microcirculation systems. Transport phenomena based modeling of such system is undertaken in the present study considering a combined driving force consisting of pressure gradient and external electric field. Transport of salt is modeled in two domains, in the flow conduit and in the pores of porous wall of the microtube. The solute transport in the microtube is presented by convective-diffusive mass balance and it is solved using integral method under the framework of boundary layer analysis. The wall of the microtube is considered to be consisting of series of straight parallel cylindrical pores with charged inner surface. The solute transport through the pores is considered to be composed of diffusive, convective and electric potential gradient governed by Nernst-Planck equation. Transport in the microtube and pores is coupled through the osmotic pressure model for the solvent and Donnan equilibrium distribution for the solute. The simulated results agree remarkably well with the experimental data conducted by in-house experimental set up. The charge density of the porous wall is estimated through the minimization of errors involved between the experimental and simulated data for different operating conditions.

Defluoridation using novel chemically treated carbonized bone meal: batch and dynamic performance with scale-up studies.

Novel defluoridating adsorbent was synthesized by chemical treatment of carbonized bone meal using aluminum sulfate and calcium oxide. Precursor for chemical treatment was prepared by partial carbonization of raw bone meal at 550 °C for 4 h. Maximum fluoride removal capacity was 150 mg/g when carbonized bone meal (100 g/L) was treated with aluminum sulfate (500 g/L) and calcium oxide (15 g/L). Morphological analysis revealed formation of a coating layer consisting of aluminum compounds on the precursor surface. This was verified by stretching frequency of aluminum hydroxide (602 cm-1) in the infrared spectra. Presence of hydroxylapatite (2θ = 30° and 2θ = 24°) and aluminum mineral phases (2θ = 44°) in the adsorbent were identified from the X-ray diffractograms. Adsorption capacity decreased from 150 mg/g (30 °C) to 120 mg/g (50 °C) indicating exothermic adsorption. Adsorption experiments under batch kinetic mode were simulated using shrinking core model. Effective fluoride diffusivity in the adsorbent and the mass transfer coefficient were estimated as 5.8 × 10-12 m2/s and 9 × 10-4 m/s, respectively. Desorption was maximum at basic pH and desorption efficiency was decreased by 31% after third cycle. Dynamic filtration with artificially fluoride-spiked solution showed that the empty bed contact time for a packed column with equal weight of carbonized and chemically treated adsorbent was 4.7 min and number of bed volumes treated (till WHO limit of 1.5 mg/L) was 340 for a column of 3-cm diameter and 18-cm length. The system was successfully tested using contaminated groundwater from an affected area. Fixed-bed column experiments were simulated from the first principles using convective pore diffusion-adsorption model for both synthetic solution and contaminated groundwater. Axial dispersion coefficient was found to be one order of magnitude less than the pore diffusivity indicating dominance of fluoride diffusion within porous network of adsorbent. The developed adsorbent exhibited antibacterial property as well.

Novel carbonized bone meal for defluoridation of groundwater: Batch and column study.

Low cost naturally available bone meal was carbonized and its fluoride adsorption capacity was explored. Carbonized bone meal (CBM) produced at 550°C, 4 h carbonization time and a heating rate of 60°C/min, showed fluoride adsorption capacity of 14 mg g-1. Adsorbent was characterized using scanning electron microscopy, X-ray diffraction, X-ray fluoroscence, thermogravimetric analysis and Fourier transform infrared spectroscopy to highlight its physical and chemical properties. Best fluoride uptake capacity was observed for 0.2 mm particle size, 7 g L-1 adsorbent concentration and at pH 6.5. Fluoride uptake was endothermic and chemisorption in nature. Effective diffusivity and mass transfer coefficient were obtained as 6 × 10-11 m2 s-1 and 9 × 10-5 m s-1 from shrinking core model. Sulphate and carbonate showed the highest interference effect on adsorption of fluoride by CBM. Maximum desorption was observed at basic pH (pH 12). Fixed bed study was performed and effect of different parameters (bed height, inlet flow rate and initial concentration) was investigated. Efficiency of the adsorbent using real life fluoride contaminated groundwater solution was also observed.

Effect of different operating conditions in cloud point assisted extraction of thymol from Ajwain (Trachyspermum Ammi L.) seeds and recovery using solvent.

Cloud point assisted extraction of thymol from water extract of Ajwain (Trachyspermum Ammi L.) seeds has been reported. Effects of different operating conditions, i.e., concentration of surfactant, heating time and temperature in extraction efficiency were investigated. It was observed that maximum extraction efficiency of thymol was achieved with 30% (v/v) of SPAN 80 surfactant, 45 min of heating at 65 °C. Recovery of thymol from the surfactant complex was optimal at 1:3 coacervate phase to solvent (acetone) volume ratio. A semi-empirical correlation was proposed at the optimum time to predict the concentration of surfactant and temperature required for a desired yield.

Investigation of antifouling and disinfection potential of chitosan coated iron oxide-PAN hollow fiber membrane using Gram-positive and Gram-negative bacteria.

Chitosan coated iron oxide nanoparticles were impregnated into polyacrylonitrile based hollow fiber membrane. The molecular weight cut off was varied in the range of 120 to 145kDa with the concentration of nanoparticles. Incorporation of nanoparticles improved the permeability, mechanical property and hydrophilicity of the membrane. The contact angle of the membrane decreased from 80° to 51° and the permeability increased by 31% at 0.5wt% nanoparticles concentration. The antibacterial and antifouling property of the membrane were investigated with two biofilm causing Gram positive and Gram negative bacteria. The damage of cell membrane was directly confirmed by release of cellular constituent absorbing in 260nm. The cellular deformation on the membrane surface was evident by direct microscopic observation in FESEM. This damage was likely caused by electrostatic interaction between NH3+ group of nanoparticles and anionic components of phosphoryl group of bacteria. The hollow fiber membrane shows promising antibiofouling property even after long experimental run as evident by 95% flux recovery ratio. The effect of operating conditions on rejection and flux profile was investigated during long experimental run. The result indicated that there was no detectable iron in the permeate sample that could impose adverse health hazard.

Effects of overlapping electric double layer on mass transport of a macro-solute across porous wall of a micro/nanochannel for power law fluid.

Effects of overlapping electric double layer and high wall potential on transport of a macrosolute for flow of a power law fluid through a microchannel with porous walls are studied in this work. The electric potential distribution is obtained by coupling the Poisson's equation without considering the Debye-Huckel approximation. The numerical solution shows that the center line potential can be 16% of wall potential at pH 8.5, at wall potential -73 mV and scaled Debye length 0.5. Transport phenomena involving mass transport of a neutral macrosolute is formulated by species advective equation. An analytical solution of Sherwood number is obtained for power law fluid. Effects of fluid rheology are studied in detail. Average Sherwood number is more for a pseudoplastic fluid compared to dilatant upto the ratio of Poiseuille to electroosmotic velocity of 5. Beyond that, the Sherwood number is independent of fluid rheology. Effects of fluid rheology and solute size on permeation flux and concentration of neutral solute are also quantified. More solute permeation occurs as the fluid changes from pseudoplastic to dilatant.

A socio-economic study along with impact assessment for laterite based technology demonstration for arsenic mitigation.

Arsenic contamination mitigation technologies have been adsorption-based, but the most widely-used and traditionally available adsorbents suffered inherent limitations, including cost infeasibility and problems associated with regeneration and disposal of the spent adsorbent. The present technology is based on indigenously developed activated laterite prepared from the naturally and abundantly available material, and can hence easily be scaled up for community usage and large scale implementation. The total arsenic removal capacity is 32.5mg/g, which is the highest among all naturally occurring arsenic adsorbents. A major issue in earlier adsorbents was that during regeneration, the adsorbed arsenic would be released back into the environment (leaching), and would eventually contaminate the groundwater again. But the adsorbent in this filter does not require regeneration during its five-year lifespan and does not leach upon disposal. An attempt is made to test and demonstrate the practical implementation of the technology - its effectiveness and viability in three community (primary schools - one in Malda and two in north 24 Parganas, West Bengal, India) and 20 household filters, catering to over 5000 people in different areas of West Bengal exposed to high arsenic contamination of groundwater (ranging from 0.05 to 0.5mg/l). The work also focuses on the social impact of the real life technological solution on the lives on the affected people in the worst hit arsenic affected communities, perhaps the greatest public health risk emergency of the decade.