Análise da eficiência do carvão ativado da vagem de algaroba (Prosopis juliflora) como adsorvente na remoção de gasolina em corpos d’água.

Abstract

Problems related to environmental contamination are an important theme and focus on research, especially when it involves fundamental resources such as water, which is vital to life. Contamination arising from industrial leaks represent a major problem when contaminant is gasoline, as its composition can be harmful to health. Thus, adsorption emerges as an extremely effective and viable method, since possibilities of biomasses found easily in nature are applied are real and cause low cost of process. In present case, algaroba (Prosopis juliflora) was used, which was efficient in research of Lima and Farias (2019; 2020). From these results and reviewing the literature, it was deducted that application of activated coal could increase adsorption efficiency of algaroba pod in gasoline removal in water. Thus, objective of this work was to evaluate ability to adsorption of algaroba pod coal as an adsorbent agent for removal of hydrocarbon and make a comparison between in natura biomass, physically activated coal (PAC) and physically and chemically activated coal (CPAC), regarding amount of contaminant removed from water. For preparation of physically activated charcoal (PAC), algarob was dried in a greenhouse, then ground in knife mill, moving to carbonization in muffle for 30 minutes to 500 °C. For chemical activation, PAC was subjected to agitation with a potassium hydroxide solution (KOH) for 30 minutes under agitation of 140 rpm. Methodology used to kinetics and equilibrium studies was proposed by Lima et al. (2014). Experiments were performed to adsorption kinetics study, in which times of 05 to 60 minutes were evaluated (with 5 minutes intervals) and equilibrium adsorption, whose contaminant concentrations ranged from 5 to 50% (with rate of variation of 5%). In results of kinetics, maximum adsorption of PAC occurred at 30 minutes (5,000 g.g-1), and CPAC at 25, 50 and 60 minutes (5,000 g.g-1). In equilibrium, maximum amount adsorbed with presence of PAC was 7.13 g.g-1, with a concentration of 31.06% contaminant, while for CPAC, it was 7.13 g.g-1, with a concentration of 32, 44%. Isotherms confirmed that adsorption of PAC occurred in single and CPAC in multi -ways. However, it can be said that KOH activation was inefficient for algaroba pod coal, as the result with in natura material reached a maximum of 14.812 g.g-1, with concentration of 15.78%.