Investigation of removal of some water pollutants from the aqueous phase and supercapacitor performance of nanoporous carbonaceous materials produced from industrial processed red pepper waste under different conditions

To produce nanoporous carbonous materials at different production conditions for the first time from industrial processed red pepper wastes whose waste values are very high and to examine their performances used as electrode material and their power to adsorbate various water pollutants. For this purpose, first of all, the waste's compatibility used as raw materials to produce nanoporous carbonous materials was determined by using thermogravimetric, biochemical component, proximate and ultimate analyses. Then from this waste, was prepared biosorbent; activated carbon at the optimum production conditions which was determined by single-step KOH-activation (impregnation ratio: 1,5:1,0 gKOH:gKBA, carbonization temperature: 700 oC, carbonization time: 1 hour); pyrolytic biocarbon at 700 oC carbonization temperature and 1 hour carbonization time; physically activated biocarbon with CO2 produced pyrolytic biocarbon at 800 oC carbonization temperature and 1 hour carbonization time; magnetic biocarbon produced by the co-precipitation of FeSO4 and FeCl3 nanoparticles in basic medium with the produced pyrolytic biocarbon and hydrolytic biocarbon at autogenic pressure, 5,0:1,0 gwater:gKBA impregnation ratio, 250 oC carbonization temperature and 10 hours carbonization time. These materials were analysed with such physicochemical techniques as proximate, ultimate, nitrogen gas adsorption at 77 K temperature, iodine, and methylene blue index, pore structure, X-ray diffraction, scanning electron microscope- energy dispersive X-ray, Fourier transform infrared spectrophotometer, Raman spectrophotometer, surface zero charge pH value, and Boehm titration. After that, adsorption studies remove water pollutants belonging to different groups like methylene blue, methanil yellow, 2,4-dichlorophenoxyacetic acid, diclofenac sodium, copper, and nitrate from the aqueous medium at 25 oC temperature and at their natural pH value were conducted to identify adsorptive capacities form an aqueous solution. Moreover, supercapacitor performance was examined to test their use in electrochemical cells as electrode material. For this purpose, cyclic voltammetry, constant current charge-discharge, and electrochemical impedance spectroscopy were used to test the supercapacitor performance of nanoporous carbonous materials. In conclusion, it was concluded that red pepper waste whose characterization was conducted with physicochemical techniques can be used as a good raw material to produce both biosorbent and different nanoporous carbonous materials. In addition, it was identified that active carbon has the highest performance of removing aqueous solution from pollutants and being used as electrode material at adsorption and electrochemical cells of all nanoporous carbonous materials.