Abdul Ghaffar

Water purification by electrical discharges

There is a continuing need for the development of effective, cheap and environmentally friendly processes for the disinfection and degradation of organic pollutants from water. Ozonation processes are now replacing conventional chlorination processes because ozone is a stronger oxidizing agent and a more effective disinfectant without any side effects. However, the fact that the cost of ozonation processes is higher than chlorination processes is their main disadvantage. In this paper recent developments targeted to make ozonation processes cheaper by improving the efficiency of ozone generation, for example, by incorporation of catalytic packing in the ozone generator, better dispersion of ozone in water and faster conversion of dissolved ozone to free radicals are described. The synthesis of ozone in electrical discharges is discussed. Furthermore, the generation and plasma chemical reactions of several chemically active species, such as H2O2, O•, OH•, HO2•, O3*, N2*, e-, O2-, O-, O2+, etc, which are produced in the electrical discharges are described. Most of these species are stronger oxidizers than ozone. Therefore, water treatment by direct electrical discharges may provide a means to utilize these species in addition to ozone. Much research and development activity has been devoted to achieve these targets in the recent past. An overview of these techniques and important developments that have taken place in this area are discussed. In particular, pulsed corona discharge, dielectric barrier discharge and contact glow discharge electrolysis techniques are being studied for the purpose of cleaning water. The units based on electrical discharges in water or close to the water level are being tested at industrial-scale water treatment plants.}

Adsorption syntax of Au(III) on unloaded polyurethane foam

The nature of adsorption behavior of Au(III) on polyurethane (PUR) foam was studied in 0.2M HCl aqueous solution. The effect of shaking time and amount of adsorbent were optimized for 3.16·10−5M solution of Au(III) in 0.2M HCl. The classical Freundlich and Langmuir adsorption isotherms have been employed successfully. The Freundlich parameters 1/n and adsorption capacityK are 0.488±0.016 and (1.40±0.22)·10−2 mol·g−1, respectively. The Langmuir constants of saturation capacityM and binding energyb are (1.66±0.08)·10−4mol·g−1 and 40294±2947 l·g−1, respectively, indicating the monolayer chemical sorption. The mean free energy (E) of adsorption of Au(III) on PUR foam has been evaluated using D-R isotherm and found to be 11.5±0.16 kJ·mol−1 reflecting the ion exchange type of chemical adsorption. The effect of temperature on the adsorption has also been studied. the isosteric heat of adsorption was found to be 44.03±1.66 kJ·mol−1. The thermodynamic parameters of ΔG, ΔH, ΔS and equilibrium constantKc have been calculated. The negative values of ΔG, ΔH and ΔS support that the adsorption of Au(III) on PUR foam is spontaneous, exothermic and of ion exchange chemisorption. The nature of the Au(III) species sorbed on PUR foam have been discussed.

Dechlorination/detoxification of aromatic chlorides using fly ash under mild conditions

An efficient dechlorination/detroxification method for p-nitrochlorobenzene, p-chloroanisole and 1-chloronaphthalene on municipal waste incinerator fly ash in presence of reducing agents with water/alcohol mixtures was developed. Dechlorination% was higher in water/isopropanol mixture at temperature <100 degrees C. Metal contents of fly ash played a vital role in enhancing dechlorination at low temperature. Moreover, the fly ash particles provided the surface to accomplish reduction and substitution reactions by adsorbing the chlorinated aromatic compound, hydrogen and hydroxyl ions. The mechanism of dechlorination was envisaged.

Enhanced dechlorination of chlorobenzene compounds on fly ash: effects of metals, solvents, and temperature

Abstract Dechlorination of di-chlorobenzene and tri-chlorobenzene on fly ash was optimized. Solutions of sulfur with alkaline solutions of potassium hydroxide, sodium hydroxide, and calcium hydroxide were applied for dechlorination of chlorobenzene compounds. Higher dechlorination (%) on surface of fly ash was achieved in sulfur and calcium hydroxide mixture, which further was enhanced with the addition of sodium hydroxide. Higher dechlorination (%) was obtained at 90°C, where metals in general, and copper and lead, in particular, enhance the catalytic potential of fly ash for dechlorination by hydrodechlorination and substitution reactions. But at high temperatures (120–170°C), dechlorination process was adversely affected by these metals. Moreover, the fly ash particles provided the surface to accomplish reduction and substitution reactions by adsorbing the chlorinated aromatic compound, hydrogen, hydroxyl, and thiol ions. The effects of water, organic solvents, and temperature were studied and reactions conditions were optimized to get maximum dechlorination.

Efficient DDT and trichlorophenol detoxification using NaBH4 and Devarda alloy

DDT—1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane—is a pesticide that has been widely used to control insects in agriculture. TCP—2,4,6-trichlorophenol—has been used in pesticide formulations as a preservative, disinfectant and antiseptic. Detoxification of DDT and TCP is very difficult due to their stable chemical structure. Here, a mixture of NaBH4 and Devarda alloy was applied for the first time to detoxify DDT and TCP. Results show 94xa0% dechlorination of DDT at 100xa0°C and 97xa0% dechlorination of TCP at 80xa0°C. The presence of diphenyl ethane suggests the complete dechlorination of DDT. The formation of benzene suggests a strong reduction. The method is efficient, cost-effective and may be applied at the industrial-level.

A modified method for removal and stabilization of cesium metal in the vitrified matrix

Laboratory experiments were designed to investigate the separation and stabilization of cesium metal. Cesium was removed from simulated waste through sorption under certain physicochemical conditions. Silica sand (locally purchased) was used to remove cesium from simulated liquid waste. The range of pH and temperature was optimized and maximum removal (94–98%) of cesium was achieved with pH 10 at the temperature 36°C. Under optimized conditions with a temperature range of 301–315K ΔH, ΔSand ΔG309 K for 150 ppm solution are −27.22 ± 0.18 KJ/mol, −74.1 ± 0.96 J/mol and −3071 ± 2.1 KJ/mol respectively, and for 200 ppm solution thermodynamic entities are ΔH = −20.2 ± 0.20 KJ/mol, ΔS = −47.86 ± 0.66 J/mol and ΔG301 K = −4344 ± 3.7 KJ/mol. The sorbed metal ion has chances of desorption under changed physicochemical conditions in final disposal. To overcome this problem the final “secondary waste (metals on sorbents)” was stabilized by converting it into a stable vitreous borosilicate matrix through the vitrification process to prevent leaching. It was found that the sorbed cesium was evaporated during heating at 1250°C. The evaporation of cesium during vitrification was overcome by modifying the process. This modified vitrification process is found excellent to immobilize the sorbed cesium. Stability was tested by desorption attempts at different pH.

Expression of pectinase gene from alkaliophilic Bacillus pumilus SS2014 in E. coli for its potential use in industrial processing of poultry feed

V and analogous organophosphorous (OP) compounds display their toxicity by rapidly inhibiting acetylcholinesterases (AChE) in the central nervous system. Upon binding of the OP compound to the catalytic serine, AChE and similar naturally occurring enzymes are frequently reported to undergo ‘aging’. In this process the enzymatic activity is inhibited by irreversible binding of OP compounds to the histidine in the catalytic site. The membrane protein phospholipase A2 (Group VIII) is an exception and is widely resistant against aging, allowing the use of oximes as strong nucleophile in a competitive substitution reaction to restore the catalytic activity. Rosetta has been previously used to create new enzymes based on phosphotriesterases (PTE) obtained from soil bacteria. Further optimization of the catalytic efficiency is however needed. The well conserved α, β-hydrolase-type fold of the phospholipase A2 (group VIII) has been chosen as starting point of this alternate de novo design approach for the reason of the slow aging rates. Key part of this 60 residue minimal core is a flat beta sheet that is composed of 3 parallel strands with a length of 5 residues each. This sheet is surrounded by at least three alpha helices. The small size of this design asks for the introduction of disulfide bonds for stabilization. Herein we present our experimental setup to secrete these de novo designed disulfide-rich proteins using fusion constructs with different leader sequences of the Sec-, SRPand TAT-secretion pathways.T presentation will provide an overview of Renascions Association Links (ReAL), an innovative approach to drug development during clinical stages. This technology is a unique translational platform that combines drug MOAs, pathway genetics, population genetics and clinical outcomes in order to link genotypic information to phenotypic outcomes in clinical trials. Through ReAL, clinical data are redistributed into genetically based subgroups and clinical outcomes (efficacy and or safety) in sub-populations are examined more closely in order to yield higher clinical efficiency. The integration of genomic technologies into clinical development is complex for example, it consists of biomarker discovery, retrospective validations, prospective validations, etc. Renascions offers the Renascions Association Links (ReAL) approach, a unique method based on its proprietary collections of data samples to generate sub-population distributions based on the genetics of drug MOA and allows pharmaceuticals to redistribute its clinical outcomes and reexamine its efficacy and side effects in each sub-group with ReAL distributions. ReAL has worked with a half dozen clinical programs and has proven that its applications are not limited by drug type or disease. With clear MOAs, ReAL has successfully improved clinical outcome by increasing efficacy and safety profiles in clinical trials. In this presentation, Renascions will share our experience and challenges and the future potential of using ReAL technologies.

Production and Characterization of Streptokinase Enzyme by Using Streptococcus mutans Strain in Liquid State Fermentation through Corn Steep Liquor (CSL) Substrate

Background: Enzymes play a very important and central role in the chemical reactions, occurring in biological systems. The study of enzymes has an immense practical importance. They have high catalytic power, many times greater than the synthetic catalysts. Vascular blockage can cause serious consequences leading to death by a thrombus (blood clot) developed in the circulatory system. Streptokinase is an extracellular protein Trans-located by many strains of beta-hemolytic Streptococci. By converting the plasminogen, to fibrin lytic enzyme, plasmin, it favor’s the blood clot lysis. nResults: The main objective of this research was the production of streptokinase in liquid state fermentation using CSL substances as substrate from Streptococcus species which was grown on blood agar media. Streptococcus mutans was selected for streptokinase production using corn steep liquor as substrate. Corn steep liquor (CSL) was applied in different concentrations ranging from 0.1% to 0.8% in liquid state fermentation culture medium and fibrin clot lysis method was used for enzyme assay. nConclusion: Among different concentrations of CSL 0.3% was selected as optimum concentration, 44% blood lysis was observed by CSL in liquid state fermentation culture medium for streptokinase production.