Adsorptive treatment of brewery effluent using activated Chrysophyllum albidium seed shell carbon

Chrysophyllum albidium seed shell, an abundant, biodegradable and inexpensive natural resource was used as a precursor to bioadsorbent production for the removal of suspended and dissolved particles (SDP) from initially coagulated Brewery Effluent (BRE). Influence of key parameters such as contact time, bioadsorbent dose, pH and temperature were investigated using batch mode. The thermal behavior studies were evaluated using Thermogravimetric and Differential scanning calorimetric analyses. The morphological observations and functional groups of the bioadsorbents were determined using scanning electron microscopy and Fourier transform infrared spectroscopy, respectively. The adsorption equilibrium, thermodynamics and kinetic of SDP adsorption on H3PO4- treated shell and NH4Cl-treated shell were examined at specified temperatures. Equilibrium data sufficiently fitted the Langmuir isotherm model (R2 > 0.99; SSE < 0.09). The pseudo-second order kinetic model provided the best correlation (R2 > 0.99; SSE < 0.14) with the experimental data. The values of ΔG° and ΔH° indicated the spontaneous and endothermic nature of the process. This study demonstrated that C. albidium seed shell could be utilized as low cost, renewable, ecofriendly bioadsorbent for the uptake of SDP from BRE.http://www.springerplus.com

Electrochromic and electrochemical capacitive properties of tungsten oxide and its polyaniline nanocomposite films obtained by chemical bath deposition method

Polyanine and its nanocomposite WO3/PANI films were deposited on fluorine doped tin oxide (FTO) glassslides by simple chemical bath deposition method. The morphology structure of the composite film wasstudied using atomic force microscopy (AFM) and scanning electron microscopy (SEM), while the elec-trochemical capacitive properties were determined using cyclic voltammetry (CV), chronopotentiometry(CP) and electrochemical impedance spectroscopy (EIS). The WO3/PANI nano-composite exhibited mul-tiple colors (electrochromism) during the CV scans, from brownish green to transparent to light greenthen back to brownish green. Surprisingly, the integration of the PANI with the WO3led to synergisticperformance of nanohybrid wherein a true electrochemical double layer capacitor was obtained. Also,interestingly and unlike literature reports, the CBD method led to excellent capacitance retention (>98%)of the PANI even at 1000 continuous cycles. This work demonstrates that simple CBD can be used toget WO3/PANI films that give good electrochromism and pseudo-capacitance comparable to the onesobtained by other methods. Hence the obtained nanocomposite film of WO3/PANI can be a promisingmaterial for electrochromic and energy storage applications.US Army Research Laboratory–Broad Agency Announcement (BAA) (under Contract number W911NF-12-1-0588).http://www.elsevier.com/locate/electactahb201

A high-rate aqueous symmetric pseudocapacitor based on highly graphitized onion-like carbon/birnessite-type manganese oxide nanohybrids

We present a study on the pseudocapacitive properties of birnessite-type MnO2 grafted on highly graphitized onion-like carbon (OLC/MnO2). In a three-electrode setup, we evaluated two different substrates, namely a platinum disc and nickel foam. The OLC/MnO2 nanohybrid exhibited a large specific capacitance (Csp) of 295 and 323 F g 1 (at 1 A g 1) for the Pt disc and Ni foam, respectively. In addition, the Ni foam substrate exhibited much higher rate capability (power density) than the Pt disc. A symmetrical two-electrode device, fabricated with the Ni foam, showed a large Csp of 254 F g 1, a specific energy density of 5.6 W h kg 1, and a high power density of 74.8 kW kg 1. These values have been the highest for onion-based electrodes so far. The device showed excellent capacity retention when subjected to voltage-holding (floating) experiments for 50 h. In addition, the device showed a very short time constant (s ¼ 40 ms). This high rate handling ability of the OLC/MnO2 nanohybrid, compared to literature reports, promises new opportunities for the development of aqueous-based pseudocapacitors.CSIR. South Africa's Department of Science and Technology (DST) and National Research Foundation (NRF) under the “Nanotechnology Flagship Programme” (supercapacitors and fuel cell project, Grant no: 69849).http://www.rsc.org/MaterialsAhb201

Adsorptive treatment of brewery waste water using activated carbon prepared from <i>Afzelia africana</i> wood sawdust

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