Adsorption of heavy metals (Cr, Cd, Pb, Ni, and Cu) onto Activated Teff Straw (ATS) has been studied using batch-adsorption techniques. This study was carried out to examine the adsorption capacity of the low-cost adsorbent ATS for the removal of heavy metals from textile effluents. The influence of contact time, pH, Temperature, and adsorbent dose on the adsorption process was also studied. Results revealed that adsorption rate initially increased rapidly, and the optimal removal efficiency was reached within about 1 hour. Further increase in contact time did not show significant change in equilibrium concentration; that is, the adsorption phase reached equilibrium. The adsorption isotherms could be fitted well by the Langmuir model. The value in the present investigation was less than one, indicating that the adsorption of the metal ion onto ATS is favorable. After treatment with ATS the levels of heavy metals were observed to decrease by 88% (Ni), 82.9% (Cd), 81.5% (Cu), 74.5% (Cr), and 68.9% (Pb). Results indicate that the freely abundant, locally available, low-cost adsorbent, Teff straw can be treated as economically viable for the removal of metal ions from textile effluents.

DSSCs fabricated from benzo[3,4-b]pyrazine-based metal-free sensitizers have efficiencies of 9.03% under 1 sun and 18.95% under 300 lux irradiance.

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A new series of benzimidazole (BIm)-based dyes (SC32 and SC33) and pyridoimidazole-(PIm) based dyes (SC35, SC36N and SC36) were synthesized as sensitizers for dye-sensitized solar cells (DSSCs). The N-substituent and C-substituent at the BIm and PIm cores were found to be the dominating factor in determining the electronic properties of the dyes and their DSSCs performance. The efficiency of BIm-based dyes (SC35 and SC36) was found to be higher than that of the PIm-based dyes (SC32 and SC33) due to better light harvesting. The C-substituents in SC36, a 4-hexylloxybenzene and a hexyl chain, are beneficial to dark current suppression, and hence SC36 achieves the best efficiency of 7.38 % (≈85 % of N719). The two BIm dyes have better cell efficiencies than their congeners with a bithiophene entity between the BIm and the anchor due to better light harvesting of the former.

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MFCs are bio-electrochemical devices that are capable of transforming chemical energy stored in waste organic matter into direct electrical energy through catalytic activity of microorganisms under anaerobic conditions. Bio-electrochemical systems, such as microbial fuel cells (MFCs), serve as greener alternatives to conventional fuel energy. In recent years, MFCs have drawn science community interest as a method for direct bioelectricity recovery from wastewater while simultaneously treating the wastewater. Moreover; they gain a competitive advantage over other water treatment technologies due to their unique features such as huge energy benefits, less environmental impact, good operating stability, and high economic efficiency. Reports reveal that MFCs are the subject of much interest to researchers, and the number of papers on MFCs in wastewater treatment is increasing. The ever-growing demand for green waste management and renewable sources of energy has enthused research efforts all over the world. This study, therefore, investigated the effect of process variables on the bio-electrical performance of H-type microbial fuel cells fueled with brewery wastewater and inoculated with distillery plant waste. From the experimental results, 1150mV maximum voltage output, 92.85%, 91.40%, 68.87%, and 70.10% removal efficiencies of COD, BOD, TN and TP respectively were obtained at 35ºC, pH 7, and 5 days. These results confirmed that brewery wastewater effectively treated would generate a considerable amount of direct bio-electricity. Results also revealed that the MFC provides an alternative insight into an effective treatment of wastewater that can simultaneously generate a direct bio-electricity in a sustainable and eco-friendly manner.