Sustainable conversion of agriculture wastes into activated carbons: energy balance and arsenic removal from water

Abstract

The aims of this study are to investigate the production of activated carbons (AC) from Senegal agricultural wastes such as cashew shells, millet stalks and rice husks and to implement them in adsorption processes devoted to arsenic (V) removal. AC were produced by a direct physical activation with water steam without other chemicals. This production of AC has also led to co-products (gas and bio-oil) which have been characterized in terms of physical, chemical and thermodynamical properties for energy recovery. Considering the arsenic adsorption results and the energy balance for the three studied biomasses, the first results have shown that the millet stalks seem to be more interesting for arsenate removal from natural water and an energy recovery with a GEE of 18.9%. Cashew shells, which have shown the best energy recovery (34.3%), are not suitable for arsenate removal. This global approach is original and contributes to a recycling of biowastes with a joint recovery of energy and material.

ADSORPTION OF As(III) FROM AQUEOUS SOLUTION ONTO IRON IMPREGNATED USED TEA ACTIVATED CARBON: EQUILIBRIUM, KINETIC AND THERMODYNAMIC STUDY

“…The X m and K values calculated from the slope and intercept of the plots are given in Table 3. The sorption energy was calculated from the following mathematical expression: (21) The values of sorption energy (E) in the range 8 -16 kJ mol -1 indicate chemisorption (ion exchange mechanism) while E values below 8 kJ mol -1 represent physisorption [43]. In the present study, sorption energy was found to be 10 kJ mol -1 , which indicates that anion exchange mechanism is responsible for the sorption of arsenite onto the surface of Fe-UTAC.…”

“…A variety of raw materials, namely pistachio-nut shell, guava seeds, peanut hulls, coconut shell, apricot stone, date pits, peach stone, coffee bean husks, chestnut wood, grape seed, corn cob, oat hulls, olive stone, rice husks and sugarcane bagasse have been exploited by researchers for the production of activated carbon [19][20][21].…”

Inorganic arsenic species removal from water using bone char: A detailed study on adsorption kinetic and isotherm models using error functions analysis

“…Recently, a number of researchers investigated As(V) and As(III) removal from water using different adsorbent materials and methods (Liu et al, 2020), such as activated carbon (Dieme et al, 2017;Hashim et al, 2019;Kalaruban et al, 2019), zeolite (Meher et al, 2016;Soni and Shukla, 2019), biochar (Niazi et al, 2018b;Singh and Mohan, 2020;Tabassum et al, 2019).…”

Challenges in the Application of Circular Economy Models to Agricultural By-Products: Pesticides in Spain as a Case Study

“…Therefore, recovered biomolecules from agricultural waste may present a wide range of applications in the food industry, like natural additives, to improve the organoleptic properties of food or even to formulate functional foods [28][29][30]. Livestock, paper, construction, fuels, fiber, bio-compounds, colorants [38][39][40] Abbreviations: mhL: million hectoliters; mT: million tons.…”