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Surfactant-modified alumina (SMA) was prepared and used for the removal of Mn(II), Ni(II), and Cu(II) from aqueous environment. Batch studies were conducted to find out optimum pH of the medium, adsorbent dose of SMA, and contact time. They were further optimized using response surface methodology (RSM). In the present study, a three-factor, three-level Box–Behnken experimental design was used to derive a second-order polynomial equation and construct three-dimensional (3D) surface plots and two-dimensional (2D) contour plots to examine the response. The level of significance for each independent variable and their interaction effects were examined by means of analysis of variance (ANOVA), F test, and Student’s t test results. In addition, the percentage effects of the different factors and their interactions on the removal efficacy were also investigated by plotting a Pareto chart. The models were validated for accurate prediction of the percentage (%) removal by performing numerical optimization. The optimum values of three tested variables were determined at pH 6.2, 8.2, and 5.3; adsorbent dose = 20, 5, and 4 g/L; and contact time = 30, 60, and 75 min for the adsorption of Mn(II), Ni(II), and Cu(II) ions, and the corresponding removal efficiency was found to be 77.04, 93.83, and 97.23 %, respectively.

The development of new methods for the correct disposal of waste is unavoidable for any city that aims to become eco-friendly. Waste management is no exception. In the modern era, the treatment and disposal of infectious waste should be seen as an opportunity to generate renewable energy, resource efficiency, and, above all, to improve the population’s quality of life. Northern Italy currently produces 66,600 tons/year of infectious waste, mostly treated through incineration plants. This research aims to explore a more ecological and sustainable solution, thereby contributing one more step toward achieving better cities for all. Particularly, this paper presents a conceptual design of the main sterilization chamber for infectious waste. The methodology selected was Design Thinking (DT), since it has a user-centered approach which allows for co-design and the inclusion of the target population. This study demonstrates to the possibility of obtaining feasible results based on the user’s needs through the application of DT as a framework for engineering design.

Different alkaline pretreatment methods (NaOH, NaOH+10% urea and aqueous ammonia) were optimized for maximum delignification of Saccharum spontaneum at 30°C. Maximum delignification were obtained as 47.8%, 51% and 48% from NaOH (7% NaOH, 48h, and 10% biomass loading), NaOH+urea (7% NaOH+10% urea, 48 h and 10% biomass loading) and 30% ammonia (40 days and 10% biomass loading) respectively. H(2)SO(4) 60% (v/v), 10% biomass loading at 30°C for 4h, were optimized conditions to solubilize the cellulose and hemicellulose from solid residue obtained after different optimized alkaline pretreatments. Slurry thus obtained was diluted to obtain final acid concentration of 10% (v/v) for real hydrolysis of cellulose and hemicellulose at 100°C for 1h. Among all pretreatment methods applied, the best result 0.58 g (85%) reducing sugars/g of initial biomass after acid hydrolysis was obtained from aqueous ammonia pretreated biomass. Scheffersomyces stipitis CBS6054 was used to ferment the hydrolysate; ethanol yield (Y(p/s)) and productivity (r(p)) were found to be 0.35 g/g and 0.22 g/L/h respectively.

AbstractAgeratum conyzoides, an herb found throughout the year, is generally considered as a weed: it causes reduction in soil productivity and leads to health hazards for cattle and humans. However, its biomass can easily represent a cost‐effective source, which can be used for lignocellulosic biofuel production. The conversion of lignocellulosic biomass to ethanol has drawn much attention in recent times due to abundance of biomass. In the present study, the cellulose and hemicellulose biomass of the leaf and stem of A. conyzoides was converted to sugars using acid hydrolysis.146.01 ± 02 mg/g of fermentable sugar was obtained from A. conyzoides. The maximum ethanol concentration 11.89 g/L was obtained after 7 days. Scanning electron microscopy was used to characterize the surface morphology after acid hydrolysis of biomass. In the current study, the residues of acid hydrolysis and fermented wastewater was used for biogas production through anaerobic digestion. The yield of biogas from the residues of acid hydrolysis and fermented wastewater was 204 L kg−1VS. The results obtained indicate that A. conyzoides may be considered as a promising feedstock for bioethanol and biogas production.

In this study, a dual chamber MFC was constructed for simultaneous removal of organic matter and nitrogenous pollutants and bioelectricity generation from synthetic and complex industrial wastewaters and it was operated in batch and continuous mode. When the cell potential was stable after 16 days of batch mode operation, the MFC was converted to continuous mode (from batch mode) and operated for 125 days with different organic loading rates (OLR) and ammonia loading rates (ALR) and fixed hydraulic retention time (HRT) of 40 h. The OLR of 1.49 kg COD m(-3) d(-1) and ALR of 0.58 kg NH3(-) m(-3) d(-1), for anodic and cathodic chambers, respectively, gave the best results. The highest value of cell potential on these OLRs was 310 mV with current density of 85.11 mA m(-2), power density of 26.38 mW m(-2) and volumetric power density of 192.20 mW m(-3). During this period, COD reduction was 78-83% in the anodic chamber and the ammonia reduction was 36-38%. After stable operation with synthetic wastewater one case study was performed with complex industrial wastewater. Continuous mode operation was performed at two different OLR and HRT with a constant ALR. A stable power density and volumetric power density of 23.56 mW m(-2) and 112.50 mW m(-3), respectively were achieved after 24 days of continuous operation at an OLR of 0.35 kg COD/m(3) day with an ALR of 0.43 kg NH3(-) m(-3) day(-1) and corresponding HRT of 68 h. A maximum of 89% COD removal and 40% removal of ammonia was obtained after 50 days. A stable voltage of 300 mV was obtained across 1000 Ω resistance. These findings suggest that BMFC can be used for the treatment of industrial wastewater, with carbon removal in anodic chamber and electricity generation.

In recent years, increasing efficiency in organic solar cells is due to the bulk heterojunction concept. Hybrid solar cell (HSC) based bulk heterojunction is flourishing in the field of solar cell. This device is the combination of inorganic and organic materials. The efficacy of the power conversion efficiency has reached above 5% by following this combination method. This review provides general introduction, principle, working and characterization in the HSC involving the blend of organic/inorganic material as active layer. Different material combinations of the active layer and their performance are tabulated for better understanding of the HSC. This review ensures total compliance by discussing the fabrication technologies in terms of the HSC concept.

The study reports estimates of above ground phytomass carbon pools in Indian forests for 1992 and 2002 using two different methodologies. The first estimate was derived from remote sensing based forest area and crown density estimates, and growing stock data for 1992 and 2002 and the estimated pool size was in the range 2,626–3,071 Tg C (41 to 48 Mg C ha-1) and 2,660–3,180 Tg C (39 to 47 Mg C ha-1) for 1992 and 2002, respectively. The second methodology followed IPCC 2006 guidelines and using an initial 1992 pool of carbon, the carbon pool for 2002 was estimated to be in the range of 2,668–3,112 Tg C (39 to 46 Mg C ha-1), accounting for biomass increment and removals for the period concerned. The estimated total biomass increment was about 458 Tg over the period 1992–2002. Removals from forests include mainly timber and fuel wood, whereby the latter includes large uncertainty as reported extraction is lower than actual consumption. For the purpose of this study, the annual extraction values of 23 million m3 for timber and 126 million m3 for fuel wood were used. Out of the total area, 10 million ha are plantation forests with an average productivity (3.2 Mg ha-1 year-1) that is higher than natural forests, a correction of 408 Tg C for the 10 year period was incorporated in total estimated phytomass carbon pool of Indian forests. This results in an estimate for the net sink of 4 Tg C year-1. Both approaches indicate Indian forests to be sequestering carbon and both the estimates are in agreement with recent studies. A major uncertainty in Indian phytomass carbon pool dynamics is associated with trees outside forests and with soil organic carbon dynamics. Using recent remote-sensing based estimates of

Continuous column adsorption studies were performed in this work using native and biochar form of Tectona grandis leaves to remove Ni (II) and Co (II) ions from aqueous solution. Column performance was evaluated by varying the bed height, flow rate and inlet metal ion concentration. Further, column adsorption models including Adam‐Bohart, Thomas, and Yoon‐Nelson were applied to evaluate different column parameters. Thomas model was found to be in good agreement with higher R2 and closer experimental and theoretical uptake capacity values. Interpretation of the breakthrough curves indicated that the exhaustion time of column extended with increasing bed height and decreasing flow rate and metal ion concentration. Column desorption studies using hydrochloric acid signified the potential of the adsorbents to effectively desorb the adsorbed metal ions. Thus, evaluation of the adsorption potential of Tectona grandis in this study revealed its adequate inherent potential with high adsorption capacities to remove nickel and cobalt ions from aqueous solution evidencing its practical applicability as adsorbent. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1030–1038, 2017