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Lithium-ion batteries are used for energy storage and as an energy source in a wide range of applications from small handheld to powering consumer-driven vehicles. With the global change from fuel-based vehicles to electric vehicles and the rise in use of batteries for other functions, it is imperative to start considering industrial-scale recycling of spent batteries to recover the critical components and reduce the ecological footprint generated by untreated disposal of the batteries. The present work was carried with the objective to check the environmental impact of leaching with mild phosphoric acid by using the material and energy flow data obtained from laboratory experiments. Lithium and cobalt were recovered from dead cell phone batteries that were composed of Lithium Cobalt Oxide (LiCoO2) on aluminum foils as cathodes and graphite on copper foils as anodes. The mass and energy flow data from the experiments performed were tabulated and used for the estimation of the environmental impact by executing a Life Cycle Impact Assessment (LCIA) using Umberto NXT universal software with ReCiPe (endpoint) method of analysis.

Biological route is one of the viable options to mitigate CO2 from its point sources. The major purpose of the review article is to discuss the possible utilization of microbial cultures for the mitigation of CO2. The article also highlights the scaling-up approach for biological processes especially when microbial cultures are utilized for the same. Few recent studies reported the chemoautotrophic fixation of CO2(g) by catalyzing thermodynamically favored but kinetically inhibited oxidation-reduction or electron donor-acceptor scheme of dissolved inorganic compounds. The previous studies have confirmed the utilization of different bacterial strains for the mitigation of 5%, 10%, and 15% CO2(g) in the absence of light and its simultaneous conversion into valuable products in the lab scale bioreactor. The recent studies also revealed the possibility of prokaryotes to assimilate CO2(g) via carbon concentration mechanism (CCM). The article summarizes the biological route for the natural assimilation of CO2(g) into biomass at the expense of very less energy penalty, via photoautotrophy and chemolithotrophy. The chemolithotrophs utilizes different concentrations of CO2 and thiosulfate salts as an energy source for the non-photosynthetic process. The identification of products using Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectroscopy (GCMS) studies is also entailed. The concept of material balance approach is explained to established the mechanism of CO2(g) mitigation through bacterial route. The obtained results pave the way for further development of CO2 utilization technology at larger scales.

Today’s society is faced with many upfront challenges such as the energy crisis, water pollution, air pollution, and global warming. The greenhouse gases (GHGs) responsible for global warming include carbon dioxide (CO2), methane (CH4), nitrous oxide (NOx), water vapor (H2O), and fluorinated gases. A fraction of the increased emissions of CO2 in the atmosphere is due to agricultural and municipal solid waste (MSW) management systems. There is a need for a sustainable solution which can degrade the pollutants and provide a technology-based solution. Hence, the present work deals with the custom design of a loop photobioreactor with 34 L of total volume used to handle different inlet CO2 concentrations (0.03%, 5%, and 10% (v/v)). The obtained values of biomass productivity and CO2 fixation rate include 0.185 ± 0.004 g L−1 d−1 and 0.333 ± 0.004 g L−1 d−1, respectively, at 10% (v/v) CO2 concentration and 0.084 ± 0.003 g L−1 d−1 and 0.155 ± 0.003 g L−1 d−1, respectively, at 5% (v/v) CO2 concentration. The biochemical compositions, such as carbohydrate, proteins, and lipid content, were estimated in the algal biomass produced from CO2 mitigation studies. The maximum carbohydrate, proteins, and lipid content were obtained as 20.7 ± 2.4%, 32.2 ± 2.5%, and 42 ± 1.0%, respectively, at 10% (v/v) CO2 concentration. Chlorophyll (Chl) a and b were determined in algal biomass as an algal physiological response. The results obtained in the present study are compared with the previous studies reported in the literature, which indicated the feasibility of the scale-up of the process for the source reduction of CO2 generated from waste management systems without significant change in productivity. The present work emphasizes the cross-disciplinary approach for the development of bio-mitigation of CO2 in the loop photobioreactor.

The groundwater of many developed and developing countries including India has reported excessive fluoride concentrations. Various technologies are being used to remove fluoride from water but still the problem has remained unsolved. Among the available different technologies, adsorption is one of the best methods due to its easy handling, high efficiency, and lower cost. Adsorption technique with the application of nanoadsorbents has become more efficient, as the adsorption capacity is found to increase significantly due to the large surface area provided by the nanoparticles. Since the last few years, nanomaterial-related technologies have gained much attention in the field of water treatment. The previous studies have discussed the possible mechanism for fluoride ion adsorption on nanoparticles. This chapter discusses the possibility of magnesium oxide nanoparticles as adsorbents for the removal of fluoride from wastewater. This chapter demonstrated the use of modified Hummers' method for synthesizing nano-magnesium oxide (n-MgO) and nanocomposites (n-MgO-coated GOs). The developed adsorbents were characterized using various methods such as FTIR, XRD, SEM-EDX, TEM, etc. The effect of various influencing parameters such as initial pH, initial fluoride concentration, adsorbent dosage, and contact time on fluoride adsorption using developed adsorbents was studied. This chapter demonstrated the efficient removal of fluoride ions from aqueous solution using n-MgO and nanocomposites.

A metal resistant bacterium was isolated from the rhizosphere of Kair ‘Capparis decidua’ and screened for its phytoextraction ability under gradient metal stress conditions. Based on 16S rDNA analysis, the strain was identified as Enterobacter ludwigii. Among the plant growth promoting traits, isolate showed the ACC (1-aminocyclopropane-1-carboxylate) deaminase activity, production of indole-3-acetic acid in tryptophan supplemented medium and solubilize the inorganic phosphate. The isolate was resistant to heavy metals like zinc (Zn), nickel (Ni), copper (Cu), and cadmium (Cd). The fatty acid adaptation of isolate growing at different concentration of Zn (100–300 mg kg−1) was also studied, which indicated that metal concentration strongly influenced the fatty acid composition of bacterium, particularly by increasing the unsaturated fatty acids. Furthermore, inoculation with the test isolate was found to significantly (p

In the present study, H. stevensii was cultivated on a semi-continuous mode in a laboratory scale bio-reactor using CO2(g) [15% (v/v)] as carbon source and thiosulfate (S2O32−) as an energy source for the total duration of three days. Approximately, 100% CO2(g) removal from gaseous phase was achieved. Leachate obtained was subjected to different downstream bio-processing strategies. Biomass harvesting using filtration and recovery of metabolites without cell disruption using solvent extraction from wet biomass was observed as the best downstream processing strategy. Qualitative analysis of products was carried out using gas chromatography and mass spectroscopy (GC–MS) and their results have indicated fatty alcohols (C8–C27) as primary metabolites. Fourier transform infrared spectroscopy (FTIR) analysis, approximate material balance and thermodynamic analysis have confirmed the intracellular assimilation of CO2(g) as HCO3− and its metabolization into fatty alcohols. Economic feasibility of the process has suggested that the developed downstream process has the capability to replace coconut oil based process for the production of fatty alcohols (C12–C14) and it can be utilized for the production of dodecanol as compared to the tetradecanol.

Use of bio fuels is a sustainable solution in the current energy scenario, which is marked by unsustainable use of fossil fuels. Production of biodiesel requires microalgae as feedstock. The micro algae require nutrients, CO2 & light source for its growth. An approach where waste water treatment plant can act as source of nutrients for the growth of microalgae would be beneficial. Hence the present work was carried out to understand the life cycle assessment of biodiesel production from microalgae grown in waste water and associated impacts compared with biodiesel production from fresh water. The system boundary considered in the process includes cultivation of microalgae, flocculation, centrifugation, extraction, and transesterification. The functional unit considered for the study is 1 MJ of energy produced from biodiesel. The life cycle assessments (LCA) for the present case was carried out using Umberto NXT software and inventory was taken from Eco invent database v3.0 and literature. Results has shown that the microalgae grown in waste water requires lesser energy as compared to algae grown in fresh water.

The present study demonstrates the integration between carbon dioxide [CO2 (g)] fixation process with the wastewater treatment and simultaneous production of value added products utilizing Halomonas stevensii (H. stevensii). Laboratory scale experiments were conducted in a bio-reactor (semi-continuous mode) for 6 days to evaluate the potential of H. stevensii towards biofixation of CO2 (g) [10% (v/v)] in deionized water with 100 mM thiosulphate, domestic wastewater with 100 mM thiosulphate and domestic wastewater. H. stevensii grown on domestic wastewater showed maximum biomass yield, maximum specific growth rate and biomass productivity of 5.31 g L−1, 1.19 d−1 and 3.24 g L−1 d−1, respectively which are comparable with the results obtained from two other culture medias. The possibility for the simultaneous removal of various nutrients and pollutant such as NO3–, NH4+, PO43-, COD and SO42– were also carried out. FTIR and GC-MS analysis of leachate confirmed the presence of fatty alcohols and long chain hydrocarbons in all the three culture medias. The GC-MS analysis of cell lysate and supernatant in all the three culture conditions is dominated by the presence of hydrocarbons and fatty alcohols. Techno-economic analysis of the present system was carried out by estimating the total operating cost per batch and per kg of biomass produced. The assessment indicated the feasibility for the use of domestic wastewater as culture media as a replacement of deionized water with thiosulphate ions.

This paper presents a life cycle assessment (LCA) of waste water treatment plant (WWTP) in a university campus in India. Various emissions coming from the WWTP along with their impact factors are analyzed using a LCA software Umberto NXT Universal utilizing Eco-invent database v3.0. It has been found that the recycled water from the plant provides positive impact on the assessed categories. Effect of treatment system is overriding the effect of recycled water in other categories like terrestrial eco-toxicity potential, global warming potential, particulate matter formation, fossil depletion potential, etc. However, the social effect of untreated sewer and environmental effect of compost produced by the system have not been studied.

The present study was aimed to isolate, Klebsiella pneumoniae from activated sludge. It was used to remove Zn 2+ from aqueous solution in batch and continuous modes. Batch study was conducted for 20–200 mg L −1 of initial Zn 2+ concentration to determine the optimum value of initial Zn 2+ concentration. Batch bioremediation studies were also performed to determine the optimum values of solution pH, minimal salt medium (MSM) dosage, macronutrients amount, aerobic & facultative anaerobic conditions, temperature and inoculum volume. The optimum solution pH for the growth of K. pneumoniae was found as 7 for the Zn 2+ bioremediation. The growth of K. pneumoniae was found optimum in aerobic condition and in the temperature range of 37–40 °C. In continuous mode, the removal of Zn 2+ from aqueous solution was investigated in a hybrid biofilter column packed with coal and compost as medium over a period of 60 days. K. pneumoniae was used as a potential metal removing agent. The maximum removal efficiency was obtained as 91.5% during phase II for 10 mL min −1 flow rate of Zn 2+ and 20 mg L −1 of Zn 2+ inlet concentration. Biofilter column was run under shock loading conditions for 14 days immediately after 60 days of operation which revealed the stable nature of the column with fluctuating inputs. Field emission scanning electron microscopy with electron dispersive X-ray (FESEM-EDX) analysis confirmed the presence of Zn 2+ and change in surface morphology after Zn 2+ sorption on the outer surface of K. pneumoniae .

Sequestration of single heavy metal contaminant from industrial wastewater using pure bacterial strains has received much attention. However, application of a bacterial consortium in multiple metals sequestration is scarce. The present study was aimed to develop a consortium from three bacterial strains for the simultaneous sequestration of ternary metal ions (Cr6+, Cu2+ and Zn2+) from aqueous solution. Kinetic studies showed that the individual strain, Pseudomonas taiwanensis; Acinetobacter guillouiae and Klebsiella pneumoniae were able to remove Cr6+, Cu2+ and Zn2+ respectively. These bacterial strains were utilized to develop an indigenous consortium based on metal removal affinities and positive interferences between them. Consortium showed improved performance over individual strains for the removal of single as well as simultaneous removal of three metal ions. Fourier transform infrared (FTIR) spectral analysis showed the possible involvement of carboxyl, amino, hydroxyl, methyl, phosphate and sulphonate groups in metal ions sequestration. Consortium exhibits greater adaptability in ternary metal ions mixture which indicates its robust growth mechanism over individual bacterial strains.

Introduction: The study was aimed at the development of low-density gastroretentive bioadhesive microsponges of cinnarizine by two-pronged approach (i) coating with bioadhesive material and (ii) exploration of acconon MC 8-2 EP/NF as bioadhesive raw material for fabrication. Materials and Methods: Microsponges were prepared by quasi-emulsion solvent diffusion method using 3 2 factorial design. Capmul GMO was employed for bioadhesive coating. In parallel, potential of acconon for the fabrication of bioadhesive floating microsponges (A8) was assessed. Results: Formulation with entrapment efficiency = 82.4 ± 3.4%, buoyancy = 82.3 ± 2.5%, and correlation of drug release (CDR 8h ) = 88.7% ± 2.9% was selected as optimized formulation (F8) and subjected to bioadhesive coating (BF8). The %CDR 8h for A8 was similar to BF8 (87.2% ± 3.5%). Dynamic in vitro bioadhesion test revealed comparable bioadhesivity with BF8. The ex vivo permeation across gastric mucin displayed 63.16% for BF8 against 56.74% from A8; affirmed the bioadhesivity of both approaches. Conclusion: The study concluded with the development of novel bioadhesive floating microsponges of cinnarizine employing capmul GMO as bioadhesive coating material and confirmed the viability of acconon MC 8-2EP/NF as bioadhesive raw material for sustained targeted delivery of drug.

In recent years, the biofiltration technique has gained significant importance for the removal of toxic organic compounds. However, very limited studies on biofiltration were carried out for the removal of divalent copper [Cu(II)] from aqueous solution using indigenous packing material. There are no reports in the literature that deal with the performance evaluation and kinetic modeling of the biofilter column for the removal of Cu(II). In the present study, a lab- scale biofilter column was fabricated and packed with a mixture of compost and coal as a packing material. The seeding of the column was done using an indigenous bacterial strain Acinetobacter guillouiae . The removal of divalent copper [Cu(II)] was investigated in this column for a period of 55 days. The maximum removal efficiency of 97.5% was achieved during phase II for Cu(II) inlet concentration of 20 mg L −1 . During shock loading, maximum removal efficiency obtained was 87% for initial Cu(II) concentration 28.5–30 mg L −1 . The Michaelis–Menten kinetic constants obtained were 0.2 mg L −1 min −1 and 13.03 mg L −1 . It was found that the Ottengraf model with zero-order diffusion-limitation fits the experimental data quite well for phase II, III and V.

The delivery of drugs through the oral route is regarded as most optimal to achieve desired therapeutic effects and patient compliance. However, poor pharmacokinetic profiles of oral drug candidates remains an area of concern, and approaches to enhance their bioavailability are widely cited in the literature. Traditionally, the approaches have been confined to molecular optimization of the drug molecule, which has gradually evolved into development of microsized and nanosized formulations. Nanoformulations, by virtue of their nanosize, are widely acclaimed for circumventing the obstacles of poor pharmacokinetics. In this review, an attempt has been made to discuss existing challenges of bioavailability and approaches to overcome the same, with in-depth compilation of the literature on nanoformulations. The nanoformulations reviewed include nanocrystals, nanoemulsions, polymeric nanoparticles, self-nanoemulsifying drug delivery systems, dendrimers, carbon nanotubes, polymeric micelles and lipid nanocarriers. This review confirms the potential of nanomedicines to improve the pharmacokinetics of drugs via nanoformulations. Chemotherapeutic applications and patent reports are also compiled in the review. Despite the promising benefits, nanomedicines are associated with hazards to human health. Hence, the review also deals with toxicological consequences of nanomedicines, and with in vitro/in vivo screening methods to assess bioavailability as per regulatory considerations. Nanotechnology has been shown to facilitate the clinical translation of drug candidates that were deemed to be bioavailability failures. Conclusively, nanotechnological approaches to particle design and formulation are beginning to expand the market for many drugs with improved bioavailability and therapeutics. However, dedicated efforts are needed to develop advanced nanomedicines with minimal or no adverse effects.

An aerobic mixed culture collected in the form of activated sludge was enriched for Cr(VI) reduction. An indigenous microorganism was isolated from the enriched aerobic mixed culture and identified as Pseudomonas taiwanensis. Bioremediation studies were carried out for treating Cr(VI)-contaminated wastewater using the indigenous microorganism. The kinetic studies were carried out for initial Cr(VI) concentrations ranging from 20 to 200 mg L−1. The maximum consumption of Cr(VI) obtained was 108.3 mg L−1 for an initial Cr(VI) concentration of 150 mg L−1 at a solution pH of 7.0. The effect of nutrient dosage and pH were studied to get their optimum values. The same isolated bacterial strain was also used to treat Cr(VI)-contaminated industrial wastewater collected from a local plating industry. Various growth kinetic models, such as Monod, Powell, Haldane, Luong, and Edward models, were fitted with the obtained experimental data. The obtained results for different growth kinetic models indicate that ...

The salt concentration have a pronounced effect on fatty acid composition, therefore the adaption of fatty acid composition of a halophilic bacterium Bacillus licheniformis HSW-16, grown at different concentration of NaCl (0 mM, 150 mM, 175 mM, 200 mM) was studied. The common fatty acid observed at various salt concentration were tetratriacontane, triacontane, tetracosane and pentacosane etc..As the salinity increases from 150 mM to 200 mM, the bacterium started to accumulating the long chain alkanes and fatty alcohol, suggesting the adaption of bacterium through accumulation varying fatty acids for counteracting the increased salinity and maintaining its osmotic balance in the changing environment.

The present study deals with the biofiltration of methyl isobutyl ketone (MIBK), which is considered to be a highly toxic volatile organic compound. It is released from the paint and petrochemical industries and is one of the major contributors to air pollution. The biofiltration study was carried out on a lab scale for two months in the presence of acclimated mixed culture. The performance of the biofilter column was evaluated for different inlet loads of MIBK at air flow rates ranging from 0.18 to 0.3 m3 h(-1). The maximum removal efficiency of 93% was obtained after 60 days of biofilter operation for an inlet MIBK concentration of 0.45 g m(-3), and a microbial concentration of 2.36 x 10(8) CFU g(-1) of packing material was obtained. This led to a study of shock loadings for 20 days, by varying the inlet MIBK load and air flow rate after every five days, to observe the behaviour of the biofilter column in removing sudden loads of MIBK. The biokinetic constants r(max) and Ks were obtained using the Michaelis-Menten kinetics and were found to be 1.046 g m(-3) and 0.115 g m(-3) h(-1),respectively, with a coefficient of determination (R2) of 0.993. The obtained experimental results were validated with the Ottengraf and Van den Oever kinetic model. The critical inlet concentration, critical inlet load and biofilm thickness were also estimated using the results obtained from the model predictions.

Methyl iso-butyl ketone (MIBK) is a widely used volatile organic compound (VOC) which is highly toxic in nature and has significant adverse effects on human beings. The present study deals with the removal of MIBK using biodegradation by an acclimated mixed culture developed from activated sludge. The biodegradation of MIBK is studied for an initial MIBK concentration ranging from 200-700 mg l(-1) in a batch mode of operation. The maximum specific growth rate achieved is 0.128 h(-1) at 600 mg l(-1)of initial MIBK concentration. The kinetic parameters are estimated using five growth kinetic models for biodegradation of organic compounds available in the literature. The experimental data found to fit well with the Luong model (R(2) = 0.904) as compared to Haldane model (R(2) = 0.702) and Edward model (R(2) = 0.786). The coefficient of determination (R(2)) obtained for the other two models, Monod and Powell models are 0.497 and 0.533, respectively. The biodegradation rate found to follow the three-half-order kinetics and the resulting kinetic parameters are reported.

Biological methods have been successfully used to mitigate heavy metal pollution problem in wastewater. The present study was aimed towards isolation of a novel indigenous bacterial strain, Acinetobacter guillouiae from activated sludge and its subsequent application in remediation of copper (Cu(2+)) from aqueous solution. Kinetic study of bioremediation was performed for initial Cu(2+) concentrations ranging from 40 to 150 mg L(-1). Optimum values of nutrient dosage, pH, macronutrients [Nitrogen (N)-Phosphorus (P)-Potassium (K)] dosage, aerobic and facultative anaerobic conditions, temperature, and inoculum volume were determined by conducting separate batch bioremediation studies at 80 mg L(-1) initial concentration of Cu(2+). Kinetic study showed that A. guillouiae removed 98.7 % Cu(2+) for 80 mg L(-1) initial concentration of Cu(2+) after 16 h at an optimum solution pH of 7.0. Results also revealed that A. guillouiae showed maximum growth at double the standard composition of N, P and standard composition of K in nutrient dosage. Experimental data obtained in present study were utilized to validate different growth kinetic models such as Monod, Powell, Haldane, Luong, and Edwards. Growth kinetics of A. guillouiae was better understood by Luong model (R (2) = 0.97). Higher values of coefficient of determination (R (2) = 0.97-0.99) confirmed the suitability of the three-half-order kinetic model for representing the Cu(2+) bioremediation. A. guillouiae showed a robust removal mechanism for the bioremediation of Cu(2+).

Low solubility causing low dissolution in gastrointestinal tract is the major problem for drugs meant for systemic action after oral administration, like cinnarizine. Pharmaceutical products of cinnarizine are commercialized globally as immediate release preparations presenting low absorption with low and erratic bioavailability. Approaches to enhance bioavailability are widely cited in the literature. An attempt has been made to review the bioavailability complications and clinical therapeutics of poorly water soluble drug: cinnarizine. The interest of writing this paper is to summarize the pharmacokinetic limitations of drug with special focus on strategies to improvise bioavailability along with effectiveness of novel dosage forms to circumvent the obstacle. The paper provides insight to the approaches to overcome low and erratic bioavailability of cinnarizine by cyclodextrin complexes and novel dosage forms: self-nanoemulsifying systems and buoyant microparticulates. Nanoformulations need to systematically explored in future, for their new clinical role in prophylaxis of migraine attacks in children. Clinical reports have affirmed the role of cinnarizine in migraine prophylaxis. Research needs to be dedicated to develop dosage forms for efficacious bioavailability and drug directly to brain.

Rapid industrialization has been adversely affecting the environment. Industrial effluents containing toxic and heavy metals are the main source of water contamination. Heavy metal pollution poses a serious environmental threat to humans and other living creatures due to the toxic effects of these metals and their accumulation throughout the food chain. In the last few decades, the concentration of these heavy metals in river water and sediments has been increasing at an alarming rate. Build-up of these toxic metals in vegetables grown in contaminated soils is posing adverse effects on human health. Numerous research projects on metal remediation through physico-chemical methods have been explored. However, most of these methods are either expensive or unsuitable for cases of voluminous effluents containing complex organic matter and low metal concentrations. In recent years, biological techniques have been shown to be a promising approach towards metal remediation in the laboratory and on an industrial scale. Microorganisms including bacteria, algae, fungi and yeasts can efficiently accumulate heavy metals from aqueous solutions, especially when the metal concentrations in the effluent ranges from less than 1 to 20 mg L−1. Biological systems employing processes such as bio-reduction, bioaccumulation or biosorption using dead/pretreated microbial biomass have been extensively studied for their roles in heavy metal removal from synthetic and industrial wastewater. However, many a times, biosorption alone may not suffice for an effective metal remediation technique when real industrial effluent is tested. Under such situations, application of living microbial cells might be a better option as they offer the ability of self-replenishment and the potential for optimization through development of resistant species and immobilization of the cell surface. These issues form the theme of the present chapter in addition to a brief overview of the various physico-chemical methods available and a detailed illustration of the bioremediation technique used for toxic metal detoxification. In addition, focus has also been given to the applicability of an enriched consortium of living metal-resistant cells for metal scavenging. This effort is directed towards the development of a green and economically viable technique for treatment of metal-rich effluents.

Iso-propyl alcohol (IPA) is an organic chemical regarded as a potential pollutant. The permissible exposure limit (PEL) of IPA specified by Occupational Safety and Health Administration (OSHA) is 400 mg L-1. In this study the aerobic biodegradation of IPA is carried out by an acclimated mixed culture obtained by sewage treatment plant, for the range of 200-700 mg L-1 of initial IPA concentration. The batch degradation study demonstrated that the maximum growth rate obtainable is 0.337 h-1. To explain the inhibition effects, different kinetic growth models such as Haldane, Luong and Edward models are applied. The experimental data are found to fit well with inhibition models having the values of coefficient of determination (R2) of 0.989, 0.986 and 0.984 respectively for Haldane, Luong and Edward models. Based on the disappearance of IPA, degradation is modeled by the three-half-order kinetics and the resulting kinetic parameters are reported.

The removal of toxic methyl ethyl ketone (MEK) is studied in a lab scale biofilter packed with mixture of coal and matured compost. The biofiltration operation is divided into 5 phases for a period of 60 days followed by shock loading conditions for three weeks. The maximum removal efficiency of 95% is achieved during phase II for an inlet concentration of 0.59 gm(-3), and 82-91% for the inlet concentration in the range of 0.45-1.23 gm(-3) of MEK during shock loads. The Michaelis-Menten kinetic constants obtained are 0.086 gm(-3)h(-1) and 0.577 gm(-3). The obtained experimental results are validated using Ottengraf-van den Oever model for zero-order diffusion-controlled region to understand the mechanism of biofiltration. The critical inlet concentration of MEK, critical inlet load of MEK and biofilm thickness are estimated using the results obtained from model predictions.

Environmental concerns are gaining importance in ground water resource management. Reverse osmosis (RO) systems are commonly used for filtration of surface and ground water for domestic and commercial purposes. This study aims to analyze the environmental impacts of electricity, fresh water and material consumption in various types of RO systems. The evaluation tool used for this study is life cycle assessment (LCA) and for this purpose Umberto NXT Universal software with Eco-invent version 3.0 database has been utilized. The inventory analysis has been done for RO systems of four different capacities, viz 25, 50, 250, and 500 liters per hour (LPH). This research also provides comparison of quantitative impacts of different capacity RO systems. All inclusive, the study presents an insight into the environmental impacts of various RO systems used in India and also discuss the alternative technologies for filtration of surface and ground water.