Evaluation of the potential of various aquatic eco-systems in harnessing bioelectricity through benthic fuel cell: effect of electrode assembly and water characteristics.

Six different types of ecological water bodies were evaluated to assess their potential to generate bioelectricity using benthic type fuel cell assemblies. Experiments were designed with various combinations of electrode assemblies, surface area of anode and anodic materials. Among the 32 experiments conducted, nine combinations evidenced stable electron-discharge/current.

Integrated function of microbial fuel cell (MFC) as bio-electrochemical treatment system associated with bioelectricity generation under higher substrate load.

Function of microbial fuel cell (MFC) as bio-electrochemical treatment system in concurrence with power generation was evaluated with composite chemical wastewater at high loading conditions (18.6 gCOD/l; 56.8 gTDS/l).

Effect of anodic metabolic function on bioelectricity generation and substrate degradation in single chambered microbial fuel cell.

Influence of anodic metabolic function viz., aerobic, anoxic and anaerobic on bioelectricity generation was evaluated in single chamber mediatorless microbial fuel cells (non-catalyzed graphite electrodes; open-air cathode) during wastewater treatment under similar operating conditions (pH 7; ambient temperature/pressure). Despite the fluctuations observed, aerobic metabolic function (379 mV; 538 mA/m2) documented higher power generation compared to anoxic (251 mV; 348 mA/m2) and anaerobic (265 mV; 211 mA/m2) operations.

Sorptive removal of endocrine-disruptive compound (estriol, E3) from aqueous phase by batch and column studies: kinetic and mechanistic evaluation.

Endocrine disruptive compounds (EDC) are a wide variety of chemicals which typically exert effects, either directly or indirectly, through receptor-mediated processes. They mimic endogenous hormones by influencing the activities of hormone activities even at nanogram concentrations and reported to disrupt the vital systems (e.g.

Mixture design as first step for improved glutaminase production in solid-state fermentation by isolated Bacillus.

Aim: Investigation of mixture-design impact on glutaminase production by isolated Bacillus sp.

Methods And Results: An augmented simplex centroid design was used to optimize a three (wheat bran, Bengal gram husk and palm seed fibre) component mixture for glutaminase production. Selected substrate materials showed impact on glutaminase production values at individual level by Bengal gram husk [2789 U gds(-1) (gram dry substrate] and in two-level combination with wheat bran and Bengal gram husk (maximum of 3300 U gds(-1)).

Ex situ slurry phase bioremediation of chrysene contaminated soil with the function of metabolic function: process evaluation by data enveloping analysis (DEA) and Taguchi design of experimental methodology (DOE).

Bioremediation of chrysene in soil matrix was evaluated in soil slurry phase bioreactor in conjugation with metabolic functions (aerobic, anoxic and anaerobic), microenvironment (single and mixed) conditions and nature of mixed consortia (native/resident mixed microflora and bioaugmented inoculum). Twelve experiments were operated independently in agitated-batch reactor keeping all other operating conditions constant (substrate loading rate--0.084 g chrysene/kg soil-day; soil loading rate--10 kg soil/m(3)-day (3:25 soil water ratio); operating temperature--35+/-2 degrees C).

Effect of aeration and agitation regimes on lipase production by newly isolated Rhodotorula mucilaginosa-MTCC 8737 in stirred tank reactor using molasses as sole production medium.

The influence of media and process parameters (aeration and agitation) on fermentation broth rheology and biomass formation has been studied in 1.5-l stirred tank reactor for lipase production using Rhodotorula mucilaginosa MTCC 8737. Molasses, as sole production medium, is used for lipase production by varying aeration (1, 2, and 3 vvm) and agitation speeds (100, 200, and 300 rpm).

Studies on improving the immobilized bead reusability and alkaline protease production by isolated immobilized Bacillus circulans (MTCC 6811) using overall evaluation criteria.

This study uses an overall evaluation criterion for improving the immobilized bead reusability and extracellular enzyme production by immobilized cells by assigning relative weightage to bead reusability, enzyme production, and cell leakage. Initially, alkaline protease production by alginate-immobilized Bacillus circulans (MTCC 6811) was analyzed using L18 orthogonal array (OA). The resultant optimized parameters were further fine-tuned with L9 OA experimentation.

Biomethanation of poultry litter leachate in UASB reactor coupled with ammonia stripper for enhancement of overall performance.

In the present study possibility of coupling stripper to remove ammonia to the UASB reactor treating poultry litter leachate was studied to enhance the overall performance of the reactor. UASB reactor with stripper as ammonia inhibition control mechanism exhibited better performance in terms of COD reduction (96%), methane yield (0.26m(3)CH(4)/kg COD reduced), organic loading rate (OLR) (18.

Influence of anodic biofilm growth on bioelectricity production in single chambered mediatorless microbial fuel cell using mixed anaerobic consortia.

The effect of anodic biofilm growth and extent of its coverage on the anodic surface of a single chambered mediatorless microbial fuel cell (MFC) was evaluated for bioelectricity generation using designed synthetic wastewater (DSW) and chemical wastewater (CW) as substrates and anaerobic mixed consortia as biocatalyst. Three MFCs (plain graphite electrodes, air cathode, Nafion membrane) were operated separately with variable biofilm coverage [control; anode surface coverage (ASC), 0%], partially developed biofilm [PDB; ASC approximately 44%; 90 days] and fully developed biofilm [FDB; ASC approximately 96%; 180 days] under acidophilic conditions (pH 6) at room temperature. The study depicted the effectiveness of anodic biofilm formation in enhancing the extracellular electron transfer in the absence of mediators.

Effect of substrate loading rate of chemical wastewater on fermentative biohydrogen production in biofilm configured sequencing batch reactor.

The influence of substrate loading rate on fermentative hydrogen (H2) production was studied in biofilm configured sequencing batch reactor using chemical wastewater as substrate. Reactor was operated with selectively enriched anaerobic mixed microflora at different organic loading rates (OLRs; 6.3, 7.

Biochemical evaluation of bioelectricity production process from anaerobic wastewater treatment in a single chambered microbial fuel cell (MFC) employing glass wool membrane.

Biochemical functioning of single chambered microbial fuel cell (MFC) using glass wool as proton exchange membrane (PEM) operated with selectively enriched acidogenic mixed culture was evaluated in terms of bioelectricity production and wastewater treatment. Performance of MFC was studied at two different organic/substrate loading rates (OLR) (2.64 and 3.

Modelling and optimization of fermentation factors for enhancement of alkaline protease production by isolated Bacillus circulans using feed-forward neural network and genetic algorithm.

Aim: Modelling and optimization of fermentation factors and evaluation for enhanced alkaline protease production by Bacillus circulans.

Methods And Results: A hybrid system of feed-forward neural network (FFNN) and genetic algorithm (GA) was used to optimize the fermentation conditions to enhance the alkaline protease production by B. circulans.

Bioremediation of anthracene contaminated soil in bio-slurry phase reactor operated in periodic discontinuous batch mode.

Bioremediation of soil-bound anthracene was studied in a series of bio-slurry phase reactors operated in periodic discontinuous/sequencing batch mode under anoxic-aerobic-anoxic microenvironment using native soil microflora. Five reactors were operated for a total cycle period of 144 h (6 days) at soil loading rate of 16.66 kg soil/m(3)/day at 30 +/- 2 degrees C temperature.

Monitoring of fluoride concentration in ground water of Prakasham District in India: correlation with physico-chemical parameters.

Fluoride concentrations in surface and ground water samples were determined in eight villages of Prakasham district in India. Thirty-eight samples were collected and analysed for fluoride content along with pH, electrical conductivity, total dissolved solids (TDS), total hardness, total alkalinity, chlorides (C1), sulfates (SO2-) and nitrates (NO ). Fluoride concentrations in surface and ground water samples of these villages varied between 0.

Evaluation of various parameters of calcium-alginate immobilization method for enhanced alkaline protease production by Bacillus licheniformis NCIM-2042 using statistical methods.

Calcium-alginate immobilization method for the production of alkaline protease by Bacillus licheniformis NCIM-2042 was optimized statistically. Four variables, such as sodium-alginate concentration, calcium chloride concentration, inoculum size and agitation speed were optimized by 2(4) full factorial central composite design and subsequent analysis and model validation by a second-order regression equation. Eleven carbon, 11 organic nitrogen and seven inorganic nitrogen sources were screened by two-level Plackett-Burman design for maximum alkaline protease production by using optimized immobilized conditions.

Bioslurry phase remediation of chlorpyrifos contaminated soil: process evaluation and optimization by Taguchi design of experimental (DOE) methodology.

Design of experimental (DOE) methodology using Taguchi orthogonal array (OA) was applied to evaluate the influence of eight biotic and abiotic factors (substrate-loading rate, slurry phase pH, slurry phase dissolved oxygen (DO), soil water ratio, temperature, soil microflora load, application of bioaugmentation and humic substance concentration) on the soil bound chlorpyrifos bioremediation in bioslurry phase reactor. The selected eight factors were considered at three levels (18 experiments) in the experimental design. Substrate-loading rate showed significant influence on the bioremediation process among the selected factors.

Assessment of aerosol (PM10) and trace elemental interactions by Taguchi experimental design approach.

An attempt has been made to assess the trace elemental interactions of atmospheric aerosol through Taguchi orthogonal array (OA) experimental design (DOE) approach. Seven toxic trace metals (Cu, Cd, As, Pb, Cr, Co and Ni) along with aerosol mass (PM(10)) at three different concentration levels were considered for this study. The annual mean concentrations of PM(10) and its trace components observed at Tirupati, southern peninsular India, and 50% lower and 50% higher values to the permissible exposure limit (PEL) of each factor in air were considered for level 1, level 2, and level 3 respectively.

L-asparaginase production by isolated Staphylococcus sp. - 6A: design of experiment considering interaction effect for process parameter optimization.

Aims: Evaluation of fermentation process parameter interactions for the production of l-asparaginase by isolated Staphylococcus sp. - 6A.

Methods And Results: Fractional factorial design of experimentation (L18 orthogonal array of Taguchi methodology) was adopted to optimize nutritional (carbon and nitrogen sources), physiological (incubation temperature, medium pH, aeration and agitation) and microbial (inoculum level) fermentation factors.

Biohydrogen production from chemical wastewater treatment in biofilm configured reactor operated in periodic discontinuous batch mode by selectively enriched anaerobic mixed consortia.

Molecular hydrogen (H(2)) production with simultaneous wastewater treatment was studied in biofilm configured periodic discontinuous/sequencing batch reactor using chemical wastewater as substrate. Anaerobic mixed consortia was sequentially pretreated with repeated heat-shock (100 degrees C; 2 h) and acid (pH-3.0; 24 h) treatment procedures to selectively enrich the H(2) producing mixed consortia prior to inoculation of the reactor.

Microbial conversion of sulfur dioxide in flue gas to sulfide using bulk drug industry wastewater as an organic source by mixed cultures of sulfate reducing bacteria.

Mixed cultures of sulfate reducing bacteria (SRB) were isolated from anaerobic cultures and enriched with SRB media. Studies on batch and continuous reactors for the removal of SO(2) with bulk drug industry wastewater as an organic source using isolated mixed cultures of SRB revealed that isolation and enrichment methodology adopted in the present study were apt to suppress the undesirable growth of anaerobic bacteria other than SRB. Studies on anaerobic reactors showed that process was sustainable at COD/S ratio of 2.

Bioelectricity production from wastewater treatment in dual chambered microbial fuel cell (MFC) using selectively enriched mixed microflora: Effect of catholyte.

The performance of aerated and ferricyanide catholytes on the bioelectricity production was evaluated in dual chambered microbial fuel cell (MFC) (mediatroless anode; graphite electrodes) employing selectively enriched H(2) producing mixed consortia as anodic inoculum. Two MFCs with aerated catholyte (MFC(AC)) and ferricyanide catholyte (MFC(FC)) were operated separately to elucidate the difference in power generation potential and carbon removal efficiency under similar operating conditions [ambient pressure; room temperature (28+/-2 degrees C); acidophilic microenvironment (pH 6)]. The experimental data demonstrated the feasibility of in situ bioelectricity generation along with wastewater treatment.

pH regulation of alkaline wastewater with carbon dioxide: a case study of treatment of brewery wastewater in UASB reactor coupled with absorber.

Studies were carried out with carbon dioxide absorber (CA) to evaluate the usage of carbon dioxide (CO(2)) in the biogas as an acidifying agent by Up-flow Anaerobic Sludge Blanket (UASB) reactor. Investigation on the 5l absorber revealed that ratio of brewery wastewater (BW) flow rate to biogas flow rate of 4.6-5.

Removal of fluoride from aqueous phase by biosorption onto algal biosorbent Spirogyra sp.-IO2: sorption mechanism elucidation.

This communication presents results pertaining to the adsorptive studies carried out on fluoride removal onto algal biosorbent (Spirogyra IO2). Batch sorption studies were performed and the results revealed that biosorbent demonstrated ability to adsorb the fluoride. Influence of varying the conditions for removal of fluoride, such as the fluoride concentration, the pH of aqueous solution, the dosage of adsorbent, the temperature on removal of fluoride, and the adsorption-desorption studies were investigated.

Biosorption of fluoride from aqueous phase onto algal Spirogyra IO1 and evaluation of adsorption kinetics.

Non-viable algal Spirogyra IO1 was studied for its fluoride sorption potential in batch studies. The results demonstrated the ability of the biosorbent for fluoride removal. The sorption interaction of fluoride on to non-viable algal species obeyed the pseudo-first-order rate equation.