Utilization of lignocellulosic waste for ethanol production: Enzymatic digestibility and fermentation of pretreated shea tree sawdust

Enzymatic hydrolysis and fermentation methods were evaluated on alkaline peroxide pretreated shea tree sawdust conversion to ethanol. Optimum pretreatment conditions of 120 oC reaction temperature, 30 min reaction time, and 20 mL L−1 of water hydrogen peroxide concentration (1%(v/v)H2O2) solubilized 679 g kg−1 of hemicellulose and 172 g kg−1 of lignin. 617 g kg−1 cellulose was retained in the solid fraction. The maximum yield of reducing sugar with optimized enzyme loadings by two enzyme preparations (cellulase and β-glucosidase) was 165 g kg−1 of dry biomass. The ethanol yield was 7.35 g L−1 after 72 h incubation period under the following conditions: 2% cellulose loading, enzyme concentration was 25 FPU (g cellulose)−1 loading, yeast inoculums was 10% (v/v), 32 oC, and pH 4.8. The pretreatments gave information about the hindrances caused by lignin presence in lignocellulosic materials and that hemicelluloses are better hydrolyzed than lignin, thereby enhancing enzymatic digestibility of the sawdust materia

Hydrogen peroxide and lime based oxidative pretreatment of wood waste to enhance enzymatic hydrolysis for a biorefinery: Process parameters optimization using response surface methodology

Response surface methodology (RSM) was adopted for the optimization of process variables in the alkaline peroxide oxidation (APO) pretreatment of Vitellaria paradoxa sawdust based on central composite design (CCD) experiments. A 23 five level CCD with central and axial points was used to develop a statistical model for the optimization of process variables. Maximum response for the pretreatment was obtained when applying the optimum values for temperature (150 �C), time (45 min), and 1% (v/v) H2O2. At the optimum conditions, up to 70% of the initial hemicellulose was removed in treatments, which also caused some delignification (up to 11% of the initial lignin was removed), whereas cellulose was almost quantitatively retained in the solid phase. Alkaline peroxide assisted wet air oxidation (APAWAO) pretreatment at the optimum conditions resulted in enrichment up to 60% cellulose content along with solubilization of 80% hemicellulose and 17% of lignin initially present in the raw sawdust. Reducing sugars yield after 72 h enzymatic hydrolysis of pretreated biomass at optimized APO conditions was 177.89 mg equivalent glucose g�1 dry biomass. Addition of 10 bar air pressure at the optimized pretreatment conditions increased the sugars yield to 263.49 mg equivalent glucose g�1 dry biomass

Influence of the fruit and leaf extract of Psidium guajava linn. on wound healing in Wistar rats.

Abstract: Leaf extract of guava (Psidium guajava Linn.) has been reported to promote wound healing in traditional medicine but there is paucity of information in literature regarding similar activity of fruit extract. Therefore, the present study was planned to investigate the influence of leaf and fruit extract of Psidium guajava Linn. on re-sutured incision, excision, and dead space wounds in male Wistar rats. Wounds were inflicted under light ether anesthesia aseptically. Control animals received vehicle and other groups received aqueous extract of either leaf or fruit orally in the dose of 500mg/kg/day for a period of 10 days in the incision and dead space wounds, whereas treatment continued till complete wound closure in excision wound model. On the 10 th day after estimation of breaking strength of the resutured incision wounds, animals were sacrificed and granulation tissue from dead space wounds were used to estimate the breaking strength and hydroxyproline content. Quantification of granulation tissue and histopathological slides were also carried out. Wound closure rate, epithelization time and scar features were studied in the excision wounds from the day of extract administration till complete closure of wounds. Only aqueous fruit extract significantly (P<0.01) promoted the healing process in all three wound models studied. Histopathological slides revealed increased collagen content and granulation tissue in fruit extract treated group as compared to that of control. In contrast, the leaf extract delayed excision wound healing and had no effect on incision and dead space wounds. These findings merit, clinical evaluation of Psidium gaujava fruit

Sugar Ka Saathi – A Case Study Designing Digital Self-management Tools for People Living with Diabetes in Pakistan

This paper presents the results of an iterative participatory process to design a smart self-management tool for less-literate people living with diabetes in Pakistan. Initially, interviews and focus groups with sixty-nine people living with diabetes identified issues that they face when self-managing including un-controllable factors, lack of diabetes awareness, low-tech mobile phones, and poor internet availability. We developed personas grounded in the scoping results and adjusted our PD approach to focus on more tangible design artefacts before running narrative scoping PD sessions. Working from older, illiterate persona, we designed a phone-line delivered Interactive Voice Response (IVR) system. We developed a functional IVR Prototype “Sugar ka Saathi” (Diabetes Companion) with input from a group of 4 Pakistan-based healthcare professionals, to act as a design probe in the PD process. We tested the IVR probe with fifty-seven of the original scoping participants which validated the knowledge transferred by the IVR and its acceptability. Invisible design videos were shown to elaborate the IVR and community concept to thirteen participants through two filmed videos using our existing persona characters from the scoping studies, these videos helped to engage older people with diabetes in PD sessions

Optimization of pretreatment conditions using full factorial design and enzymatic convertibility of shea tree sawdust

In this study alkaline wet air oxidation (WAO), alkaline peroxide assisted wet air oxidation (APAWAO), and enzymatic hydrolysis methods were evaluated for conversion of wood residue (sawdust) to reducing sugars. Cellulose content, hemicellulose solubilization, and lignin removal forWAOpretreatment conditions were optimized by statistical analysis using a 23-full factorial design with reaction temperature, air pressure, and reaction time as the process parameters. An optimum WAO condition of 170 �C, 1.0 MPa, 10 min was predicted and experimentally validated to give 518 g kg-1 cellulose content, 580 g kg-1 hemicellulose solubilization, and 171 g kg-1 lignin removal in the solid fraction. About 7 g L-1 reducing sugars was detected in the pretreated liquid fraction. Presoaking the dry raw biomass for 24 h in H2O2 followed by wet air oxidation (APAWAO) at the optimized conditions resulted in enrichment up to 683 g kg-1 cellulose content in the solid fraction along with solubilization of 789 g kg-1 hemicellulose and 280 g kg-1 lignin removal. The yield of reducing sugars from WAO optimized conditions by two enzyme preparations (cellulase and b-glucosidase) was 131mgg-1 of dry substrate, while the APAWAO yielded 274mgg-1. Pretreatments used in this study showed to have a disrupting effect on the lignocellulosic biomass, making the treated materials accessible for enzymatic hydrolysis. The combination of presoaking inH2O2 before WAO pretreatment and enzymatic hydrolysis was found to give the highest sugar yield

Treatment of waste gas containing diethyldisulphide (DEDS) in a bench scale biofilter

Waste gas containing diethyldisulphide (DEDS) is generated from various industries including pulp and paper, refinery, rayon and molasses based distilleries, etc. DEDS has odour threshold detection with an average concentration of 10�9 mg/m3 at 25 �C. DEDS is toxic to bacteria, fungus and also to mammals when exposed for a long period. Waste gas containing DEDS require proper treatment prior to discharge into the environment. DEDS containing waste gas was treated in a biofilter, packed with compost along with wooden chips and enriched with DEDS degrading microorganisms. The biofilter could remove DEDS to the extent of 94 ± 5% at a loading of 1.60 g/m3/h with an empty bed retention time of 150 s. At optimal operating conditions, the average moisture content required by the biofilter was in the range of 60–65%. The biodegradative products of DEDS were thiosulphate and sulphate

Energy efficient—Advanced oxidation process for treatment of cyanide containing automobile industry wastewater

Destruction of cyanide (CN) from an automobile industry wastewater by advance oxidation process (AOP) has been evaluated. The operating conditions (in an digenously designed photoreactor) for three different treatment strategies have been optimized. The treatment strategies involved use of, ultra violet light (UV), hydrogen peroxide (H2O2) and ozone (O3) in various combinations. Treatment of automobile industrywastewater (250 mg/L CN) showed fastest CN destruction, which was significantly (P < 0.05) faster than that observed with syntheticwastewater (with similar CN concentration). A combined application of H2O2/O3 was found to be the best option for maximum CN destruction. This treatment allows CN to reach the regional/international limit (of 0.02 mg/L) for safe industrial wastewater discharges to the receiving water bodies. The specific energy consumption by the photoreactor following this treatment was comparable to that obtained by conventional treatments, which use photocatalyst. Since the present treatment does not use catalyst, it provides an excellent energy efficient and economical option for treatment and safe disposal of CN containing industrial wastewater. © 200

Life cycle assessment of microalgae based biodiesel production to evaluate the impact of biomass productivity and energy source

In the present study the life cycle assessment (LCA) of three scenarios for biodiesel production from Scenedesmus dimorphus, a freshwater microalgae, cultivated in open raceway ponds using primary and secondary data was investigated. The main differences in the scenarios were related to biomass productivity, mode of culture mixing and type of energy source. The process steps included algal cultivation in open raceway ponds, harvesting by chemical flocculation, dewatering by mechanical drying option (MDO)/Spray Drying (SD) followed by extraction, reaction, and purification. Supplementation of the cultivation process with electricity derived from defatted algal biomass waste was also analyzed. The scenarios were evaluated for energy demand and environmental impacts amongst the boundary conditions based on a "cradle-to-gate" inventory. The results revealed that among all the scenarios, cultivation in raceway pond was ascertained to be the most energy intensive process with the mode of culture mixing and biomass productivity being the principal determinants. The impacts were found to be directly linked to energy demand and had an inverse relationship with biomass productivity. The geographic location of the energy sources affected the environmental implications of a given process. The integration of defatted algal biomass waste derived electricity with the cultivation system showed a minor reduction in the overall energy demand. (C) 2017 Elsevier B.V. All rights reserved

Treatment of waste gas containing low concentration of dimethyl sulphide in a high performance biotrickling filter

1018-1023A bench-scale biotrickling filter was operated in the laboratory for the treatment of dimethyl sulphide (DMS). The biotrickling filter was packed with pre-sterilized polyurethane foam and seeded with biomass developed from garden soil enriched with DMS. The biotrickling filter was operated for the generation of process parameters. The biotrickling filter could remove an average removal efficiency of 40.95 % at an effective bed contact time of 84 sec with an average loading rate of 0.56 mg/m3/h. Evaluation of microbiological status of the biotrickling filter indicated the presence of other bacterial cultures viz. Paenibacillus polymyxa, and Bacillus megaterium, besides Bacillus sphaericus.</i

Defatted algal biomass as a non-conventional low-cost adsorbent: Surface characterization and methylene blue adsorption characteristics

The present study investigates the use of defatted algal biomass (DAB) as a non-conventional low cost adsorbent. The maximum adsorption capacity of biomass (raw, defatted and sulfuric acid pretreated DAB) was determined by liquid phase adsorption studies in batch mode for the removal of methylene blue present at various concentrations (1, 2, 3, 4, and 5 mg L (1)) from aqueous solutions. The data was well fitted with Langmuir and Freundlich isotherms. The maximum adsorption capacity for raw, defatted and sulfuric acid pretreated DAB was found to be 6.0, 7.73 and 7.80 mg g (1), respectively. The specific surface area of raw, defatted and sulfuric acid pretreated DAB was estimated to be 14.70, 18.94, and 19.10 m(2) g (1), respectively. To evaluate the kinetic mechanism that controls the adsorption process, pseudo-first order, pseudo-second order, intraparticle diffusion and particle diffusion has been tested. The data fitted quite well with pseudo-second order kinetic model. (C) 2014 Elsevier Ltd. All rights reserved