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The uncontrolled discharge of organic and inorganic substances causes overenrichment of water bodies by nutrients resulting in eutrophication which disturbs the flora and fauna balance of the lake ecosystem affecting its water quality. Therefore, it is necessary to remove excess nutrients from contaminated lake water. The present investigation was attempted to reduce high organic content and excess nutrients from the sewage-contaminated lake water using microalgae and bacteria in the form of activated sludge. Comparative analyses in three different setups state that maximum efficient removal of nutrients and organic matter (chemical oxygen demand [COD]) was achieved by the symbiotic co-culture than stand-alone cultures of microalgae and activated sludge. The highest removal of nitrates (NO3−) and phosphates (PO4−) was 93% and 99% with maximum removal of COD by 73% in the case of co-culture. The maximum biomass obtained was 7.8 g/L in the co-culture system. Fourier transform infrared spectroscopy confirms the presence of fatty acids and lipids in the microalgae biomass. The effect of cultivation time and pH was studied in optimization for simultaneous biomass production, organic matter reduction and for removal of nutrients using central composite design (CCD) under response surface methodology (RSM). The optimized results were in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

Rapid development of the industrial and domestic sectors has led to the rise of several energy and environmental issues. In accordance with sustainable development and waste minimization issues, biohydrogen production along with biomethane production via two-stage fermentation process using microorganisms from renewable sources has received considerable attention. In the present study, biohythane production with simultaneous wastewater treatment was studied in a two-stage (Biohydrogen and Biomethane) fermentation process under anaerobic conditions. Optimization of high organic content (COD) distillery spent wash effluent (DSPW) with dilution using sewage wastewater was carried out. Addition of leachate as a nutrient source was also studied for effective biohythane production. The experimental results showed that the maximum biohythane production at optimized concentration (substrate concentration of 60 g/L with 30% of leachate as a nutrient source) was 67 mmol/L bio-H2 and with bio-CH4 production of 42 mmol/L. [ABSTRACT FROM AUTHOR]

In the context of proposed uranium mining area, it is very important to evaluate the presence of certain trace metals in groundwater around a proposed uranium mining area at Peddagattu and Seripally areas of Nalgonda district, Telangana (India). The concentrations of certain metals (Cu, Zn, Ni, Pb, Fe, Mn, Cd, Co, Sr, Ba, Cr, Cs and As) were measured in 37 groundwater locations and 10 surface water locations for seven times during 2 years around proposed uranium mining areas. The risk of the chemical toxicant [may be characterized using a hazard quotient (HQ)] is calculated by the results obtained during the study. The HQs of both groundwater (37) and surface water (10) all the considered trace metals were well below the threshold value of 1 as suggested by USEPA. [ABSTRACT FROM AUTHOR]

Phosphorus–nitrogen dual-doped carbon nanoparticles (PN-CNPs) have been successfully synthesised using chemical vapour deposition (CVD), in the presence of triphenylphosphine and acetonitrile. PN-CNPs are used as carbon support for Pd and employed as electrocatalyst in hydrogen evolution reactions. The prepared Pd/PN-CNPs electrocatalyst was subjected to morphological and electrochemical studies carried out using FE-SEM, EDS, ICP, XRD, CV, and LSV techniques. The membrane electrode assemblies (MEAs) were prepared and tested in 25 cm2 area PEM cell setup and the test results obtained are promising as the cell voltage is 1.9 V at 1000 mA cm−2 at 80 °C. Furthermore, the cell setup was operated continuously for 500 h and has shown stable performance without any hindrance in electrochemical activity. [ABSTRACT FROM AUTHOR]

Long-term consumption of water containing excessive fluoride can lead to fluorosis of the teeth and bones. Electrocoagulation is an electrochemical technique, in which a variety of unwanted dissolved particles and suspended matter can be effectively removed from an aqueous solution by electrolysis. Semi continuous flow experiments for fluoride removal were undertaken to investigate the effects of the different parameters such as: applied voltage (10–20 V), flow rate (150–450 mL/min), initial pH (6–8), and initial fluoride concentration (2–10 mg/L) at lowest cost with novel rector. The maximum of 8 mg/L fluoride treated up to World Health Organization drinking limits within 30 min residual time at a flow rate of 300 mL/min, with an applied voltage of 15 V at influent pH 7. The results obtained, showed that this novel semi continuous flow electrocoagulation reactor is an effective for defluoridation of ground water supplies at lower cost. [ABSTRACT FROM AUTHOR]

The aim of the present study was to find the natural radioactivity in surface soils at different locations of the uranium-rich mineralized zones of Lambapur-Peddagattu and Seripally areas in Telangana state, India. The mean activity concentration of 238U, 234Th, and 40K in the soil found to be 48.07 ± 22.30, 230.77 ± 89.26 and 807.08 ± 255.87 Bq.kg"1 respectively. The gamma absorbed dose and the annual effective dose in surface soil estimated from the obtained results. The annual effective dose found to be comparable with similar studies in India and the other regions of the world (UNSCEAR, 2000). [ABSTRACT FROM AUTHOR]

Hydrogen production by PEM water electrolysis is one of the most efficient methods, due to the produced high purity of gases, high efficiency, and devoid of harmful emissions. In this study, phosphorus-doped carbon nanoparticles (P-CNPs) were synthesized by spray pyrolysis method in chemical vapor deposition (CVD). The synthesized P-CNPs were used as electron carrier support materials for the preparation of P-CNPs-supported palladium (Pd/P-CNPs) electrocatalyst and also used as the hydrogen evolution reaction (HER) electrode in PEM water electrolysis. These synthesized Pd/P-CNPs were characterized by field emission scanning electron microscope, energy-dispersive X-ray spectroscopy, X-ray diffraction, and cyclic voltammetry methods. The membrane electrode assemblies (MEAs) were fabricated using Pd/P-CNPs as a cathode catalyst for the HER and RuO2 as the anode for oxygen evolution reaction (OER). The fabricated MEA electrochemical performances along with their corresponding yields of hydrogen production were evaluated in PEM water electrolyzer single cell assemblies at various experimental conditions. The obtained results showed that the synthesized Pd/P-CNPs observed a current density of 1 A cm−2 at 2 V at 80 °C. Further, long-term stability tested for up to 500 h continuously and showed the reasonable stability with similar electrochemical activity compared to commercial Pt/CB. Hence, the synthesized Pd/P-CNPs could be used as the alternative to Pt-based catalysts for HER. [ABSTRACT FROM AUTHOR]

The RuxPd1-xO2 bimetallic electrocatalyst was synthesized by modifying Adams fusion method and used as the oxygen evolution reaction (OER) electrocatalyst in PEM water electrolysis. These synthesized RuxPd1-xO2 electrocatalysts morphology and electrochemical performances were characterized using FE-SEM, EDS, XRD, and cyclic voltammetry (CV) methods. The membrane electrode assemblies (MEAs) were fabricated using the synthesized RuxPd1-xO2 as the anode and 30% Pt/CB as a cathode and its electrochemical performance evaluated in single-cell PEM water electrolyzer at various experimental conditions and compared with pure RuO2. The results observed that the synthesized Ru0.8Pd0.2O2 electrocatalyst has shown better performance and stability compared to RuO2, a current density of 1 A/cm2 at the cell voltage of 2.03 V in 80 °C temperature. This synthesized Ru0.8Pd0.2O2 electrocatalyst can be used as the alternative to RuO2 at the oxygen evolution reaction (OER). [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOFs) are a rapidly growing class of porous materials and are considered as best adsorbents for their high surface area and extraordinary porosity. The MOFs are synthesized by using various chemicals like triethylamine, terepthalic acid, zinc acetate dihydrate, chloroform, and dimethylformamide (DMF). Synthesized MOFs are intercalated with palladium/activated carbon, carbon black, and carbon nanomaterials by chemical reduction method for the purpose of enhancing the hydrogen adsorption capacities. We have observed that the palladium doped activated carbon on MOF-5 showed high hydrogen storage capacity. This may be due to the affinity of the palladium toward hydrogen molecule. The samples are characterized by X-ray diffraction, scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area analysis. We have observed a clear decrease in the BET surface area and pore volume. The obtained results show a better performance for the synthesized sample. To our best knowledge, no one has reported the work on palladium-doped carbon materials (activated carbon, carbon black, carbon nanomaterials) impregnated to the metal-organic framework-5. We have attempted to synthesize carbon nanomaterials using indigenously fabricated chemical vapor deposition (CVD) unit as a support. We have observed an increase in the hydrogen storage capacities. [ABSTRACT FROM AUTHOR]

Hydrogen is an energy carrier of the future need. It could be produced from different sources and used for power generation or as a transport fuel which mainly in association with fuel cells. The primary challenge for hydrogen production is reducing the cost of production technologies to make the resulting hydrogen cost competitive with conventional fuels. Thermocatalytic decomposition (TCD) of methane is one of the most advantageous processes, which will meet the future demand, hence an attractive route for CO free environment. The present study deals with the production of hydrogen with 30 wt% of Ni impregnated in commercially available activated carbon and carbon black catalysts (samples coded as Ni/AC and Ni/CB, respectively). These combined catalysts were not attempted by previous studies. Pure form of hydrogen is produced at 850 °C and volume hourly space velocity (VHSV) of 1.62 L/h g on the activity of both the catalysts. The analysis (X-ray diffraction (XRD)) of the catalysts reveals moderately crystalline peaks of Ni, which might be responsible for the increase in catalytic life along with formation of carbon fibers. The activity of carbon black is sustainable for a longer time compared to that of activated carbon which has been confirmed by life time studies (850 °C and 54 sccm of methane). [ABSTRACT FROM AUTHOR]

This paper reports on recycling of industrial wastes (three pharmaceutical industrial sludges) into environmental friendly value-added materials. Stabilization/Solidification (S/S or bricks) process was applied to make a safer way for the utilization of pharmaceutical waste. The additives in this study include binders (cement, lime and bentonite) and strengthening material (pulverized fuel ash (PFA), silica fume and quarry dust) was used at different compositions. Bricks were cured for 28 days, and the following analysis-like compressive strength, leachability of heavy metals, mineralogical phase identity by X-ray diffraction (XRD) spectroscopy, Fourier transform infrared spectroscopy (FTIR) and thermal behaviour by thermogravimetric-differential thermal analysis (TG-DTA) had done. All the bricks were observed to achieve the standard compressive strength as required for construction according to BIS standards. Metal concentration in the leachate has reached the dischargeable limits according to Brazilian standards. Results of this study demonstrate that production of bricks is a promising and achievable productive use of pharmaceutical sludge. [ABSTRACT FROM AUTHOR]

The increasing clinical importance of drug-resistant fungal and bacterial pathogens has stimulated microbiological research into and development of new antimicrobial agents. Hence, in this study, we synthesized novel series of 2-(pyridin-3-yl)-1 H-benzo[ d]imidazoles and 2-(pyridin-3-yl)-3 H-imidazo[4,5- b]pyridine derivatives. The structures of the compounds were confirmed by spectral and CHN analysis. The compounds were examined for in-vitro antimicrobial activity against Gram-positive bacteria ( Staphylococcus aureus and Bacillus subtilis), Gram-negative bacteria ( Escherichia coli and Pseudomonas aeruginosa), and the fungus Candida albicans. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

In the present paper, the performance of electrocoagulation (EC) for the treatability of mixed metals (chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn)) from metal plating industrial wastewater (EPW) has been investigated. The study mainly focused on the affecting parameters of EC process, such as electrode material, initial pH, distance between electrodes, electrode size, and applied voltage. The pH 8 is observed to be the best for metal removal. Fe-Fe electrode pair with 1-cm inter-electrode distance and electrode surface area of 40 cm at an applied voltage of 8 V is observed to more efficient in the metal removal. Experiments have shown that the maximum removal percentage of the metals like Cr, Ni, Zn, Cu, and Pb are reported to be 96.2, 96.4, 99.9, 98, and 99.5 %, respectively, at a reaction time of 30 min. Under optimum conditions, the energy consumption is observed to be 51.40 kWh/m. The method is observed to be very effective in the removal of metals from electroplating effluent. [ABSTRACT FROM AUTHOR]

Synthesis and antibacterial activity of some novel biologically active sulfonamide derivatives at C-8 alkyl chain of anacardic acid ( 7a-7l), prepared from commercially available anacardic acid mixture ( 1a-d). These compounds were tested for Gram positive and Gram negative bacterial cultures; most of the compounds showed higher antibacterial activity compared with standard drug ampicillin. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

In the present study, a comparative assessment of 2,4,6-T (2,4,6-Trichlorophenol) degradation by different AOPs (Advanced Oxidation Processes – UV, UV/ H2O2, Fenton, UV/Fenton and UV/TiO2) in the laboratory scale is performed. The effects of different reactant concentrations and pH are assessed. 2,4,6-T removal, Total Organic Carbon mineralization (TOC) and dechlorination are monitored. Of all the AOPs, UV/Fenton process is more effective in degrading 2,4,6-T. The optimum conditions obtained for the best degradation with UV/Fenton are: pH = 3, Fe+2 concentration of about 5 ppm, and peroxide concentration of 100 ppm for an initial 100 ppm of 2,4,6 T concentration at room temperature. In these conditions, a pseudo first-order rate constant is evaluated. The degradation rate of 2,4,6 T followed the order: [ABSTRACT FROM AUTHOR]

A new and accurate chiral liquid chromatographic method has been developed for the separation of palonosetron hydrochloride (PALO) and its ( R,R)-enantiomer in bulk drug samples with an elution time of about 20 min. The chromatographic separation was carried out by normal phase chromatography using an immobilized cellulose based chiral stationary phase (Chiralpak-IC) with a mobile phase composed of n-hexane:ethanol:1,4 dioxane:trifluoroacetic acid:diethylamine (65:30:5:0.3:0.3, v/v) pumped at a flow rate of 1.0 mL min−1. The resolution ( R s ) between the enantiomers was found to be greater than 3.0 and interestingly the ( R,R)-enantiomer was eluted prior to the ( S,S)-enantiomer (PALO) in the developed method. Mobile phase additives, trifluoroacetic acid and diethylamine played a key role in achieving chromatographic resolution between the enantiomers and also in enhancing chromatographic efficiency. The limit of detection (LOD) and limit of quantification (LOQ) of the ( R,R)-enantiomer were found to be 0.03 and 0.1 μg respectively for 10 μL injection volume. The developed method shows excellent linearity ( r 2 > 0.999) over a range of LOQ to 0.3% for the ( R,R)-enantiomer. The percentage recovery of the ( R,R)-enantiomer in bulk drug samples ranged from 97.2 to 102.3 revealing good sensitivity of the developed method. Robustness studies were also carried out on the developed method. [ABSTRACT FROM AUTHOR]

A new and accurate chiral liquid chromatographic method has been developed for the determination of enantiomeric purity of darifenacin [( S)-enantiomer] in bulk drugs and extended release tablets. Normal phase chromatographic separation was performed on an immobilized cellulose based chiral stationary phase (Chiralpak-IC) with n-hexane:ethanol:diethylamine (50:50:0.3, v/v/v) as mobile phase at a flow rate of 1.0 mL min−1. The elution time was ~15 min. The resolution ( R s ) between the enantiomers was greater than four and interestingly the ( R)-enantiomer was eluted prior to darifenacin in the developed method. The limit of detection (LOD) and limit of quantification (LOQ) for the ( R)-enantiomer were 0.02 μg and 0.07 μg, respectively, for a 10 μL injection volume. The method was extensively validated in terms of linearity, precision and accuracy and satisfactory results were obtained. Robustness studies were also conducted. The sample solution stability of darifenacin was determined and the compound was found to be stable for a study period of 48 h. [ABSTRACT FROM AUTHOR]

A new and accurate chiral liquid chromatographic method has been developed for the separation and quantification of ( S,R,S)-enantiomer (unwanted enantiomer) and ( R,R,R)-isomer (key intermediate) of aprepitant in bulk drug and formulation samples of apprepitant. The elution time was approximately 20 min using an immobilized amylose-based chiral stationary phase (Chiralpak-IA). The mobile phase was n-hexane and ethanol (90:10, v/v) and was delivered at a flow rate of 1.0 mL min−1. Detection was carried out with a wavelength set to 220 nm. The resolution factor between enantiomers was found to be greater than five. Limit of detection for both ( S,R,S) enantiomer and ( R,R,R) isomer of aprepitant was 0.035 µg, and limit of quantification for both ( S,R,S) enantiomer and ( R,R,R) isomers of aprepitant was 0.1 µg, for a 10 µL injection. The developed method showed excellent linearity ( r > 0.999) for both isomers. When the method was applied to bulk drug samples and in pharmaceutical formulations recoveries were obtained ranging from 97.2 to 103.1%. Aprepitant sample solutions were found to be stable when characterized over a period of 48 h. [ABSTRACT FROM AUTHOR]

A simple, sensitive gradient RP-LC assay method has been developed for the quantitative determination of amtolmetin guacyl in bulk drug, used as anti-inflammatory drug. The developed method is also applicable for related substances determination. Efficient chromatographic separation was achieved on a C18 stationary phase with simple mobile phase combination delivered in a gradient mode and quantification was carried out using ultraviolet detection at 313 nm at a flow rate of 1.0 mL min−1. In the developed LC method the resolution between Amtolmetin Guacyl and its three potential impurities was found to be greater than 2.0. Regression analysis shows an r value (correlation coefficient) greater than 0.99 for amtolmetin guacyl and its three impurities. This method was capable to detect all three impurities of amtolmetin guacyl at a level of 0.002% with respect to test concentration of 0.5 mg mL−1 for a 10 μL injection volume. The inter- and intra-day precision values for all three impurities and for amtolmetin guacyl was found to be within 2.0% RSD at its specification level. The method has shown good and consistent recoveries for amtolmetin guacyl (99.2–101.5%) and its three impurities (94.5–104.8%). The test solution was found to be stable in diluent for 48 h. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. Considerable degradation was found to occur in oxidative stress conditions. The stress samples were assayed against a qualified reference standard and the mass balance was found close to 99.6%. The developed RP-LC method was validated with respect to linearity, accuracy, precision and robustness. [ABSTRACT FROM AUTHOR]

A new and accurate chiral liquid chromatographic method has been developed for determination of the enantiomeric purity of montelukast sodium ( R enantiomer) in bulk drugs and dosage forms. Normal phase chromatographic separation was performed on an immobilized amylose-based chiral stationary phase with n-hexane–ethanol–1,4-dioxane–trifluoroacetic acid–diethylamine 65:25:10:0.3:0.05 ( v/v) as mobile phase at a flow rate of 1.0 mL min−1. The elution time was approximately 15 min. The resolution ( R S) between the enantiomers was >3. The mobile phase additives trifluoroacetic acid and diethylamine played a key role in achieving chromatographic resolution between the enantiomers and also in enhancing chromatographic efficiency. Limits of detection and quantification for the S enantiomer were 0.07 and 0.2 μg, respectively, for a test concentration of montelukast sodium of 1,000 μg mL−1 and 10 μL injection volume. The linearity of the method for the S enantiomer was excellent ( R 2 > 0.999) over the range from the LOQ to 0.3%. Recovery of the S enantiomer from bulk drug samples and dosage forms ranged from 97.0 to 103.0%, indicative of the high accuracy of the method. Robustness studies were also conducted. The sample solution stability of montelukast sodium was determined and the compound was found to be stable for a study period of 48 h. [ABSTRACT FROM AUTHOR]

A stability-indicating HPLC assay method was developed for the quantitative determination of tadalafil in bulk samples and in pharmaceutical dosage forms in the presence of the degradation products. It involved a 250 mm × 4.6 mm, 5 μm C-18 column. The gradient LC method employs solution A and B as mobile phase. Solution A contains a mixture of buffer (phosphate buffer and tetra- n-butyl ammonium hydrogen sulfate) pH 2.5: acetonitrile (80:20, v/v) and solution B contains a mixture of water: acetonitrile (20:80, v/v). The flow rate was 1.0 mL min−1 and the detection wavelength was 220 nm. The retention time of tadalafil is about 17 min. Tadalafil was subjected to different ICH prescribed stress conditions. Degradation was found to occur in hydrolytic and to some extent in oxidative stress conditions, while the drug was stable to photolytic and thermal stress. The drug was particularly labile under alkaline hydrolytic conditions. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. The assay of stress samples was calculated against a qualified reference standard and the mass balance was close to 99.5%. The developed RP-LC method was validated with respect to linearity, accuracy, precision and ruggedness. [ABSTRACT FROM AUTHOR]

An isocratic reversed-phase liquid chromatographic method has been developed for quantitative determination of candesartan cilexetil, used to treat hypertension, in the bulk drug and in pharmaceutical dosage forms. The method is also applicable to analysis of related substances. Chromatographic separation was achieved on a 250 mm × 4.6 mm, 5 μm particle, CN column with a 50:50 ( v/v) mixture of phosphate buffer, pH 3.0, and acetonitrile as mobile phase. The flow rate was 1.0 mL min−1 and the detection wavelength was 210 nm. Resolution of candesartan cilexetil and six potential impurities was greater than 2.0 for all pairs of compounds. The drug was subjected to hydrolytic, oxidative, photolytic, and thermal stress and substantial degradation occurred in alkaline and acidic media and under oxidative and hydrolytic stress conditions. The major product obtained as a result of basic hydrolysis was different from that produced by acid hydrolysis and aqueous hydrolysis. The stress samples were assayed against a reference standard and the mass balance was found to be close to 99.6%. The method was validated for linearity, accuracy, precision, and robustness. [ABSTRACT FROM AUTHOR]

The authors discusses the pollution control and energy advanced technologies, including synthetic materials such as plastics, polychlorinated biphenyls, and pesticides.