Lignin. Corn cob. Adsorption. Produced water. Dye.
The growth of the world population and the increase in per capita consumption have stimulated the industrial sector to increase its production of goods and services. Consequently, the production of pollutants has also increased, and the improper disposal of these into the environment can affect human health and ecosystems. Water produced from oil wells is a significant by-product of oil extraction. This water is naturally found in underground reservoirs and is brought to the surface along with the oil during the production process. Generally, produced water contains a variety of substances such as salts, heavy metals, and organic compounds. In this context, water polluted with dyes from the textile industry has also aroused the interest of researchers as a relevant environmental problem. During the dyeing process of fabrics and fibers, a variety of chemical dyes are used to impart vibrant colors to the garments. However, much of these dyes are not absorbed by the textile fibers and end up being discharged with wastewater, resulting in contaminated effluents. The dyes present in these effluents can persist for long periods, affecting the transparency and quality of water in receiving water bodies. To mitigate these problems, recent studies have focused on the use of lignin as an adsorbent material for contaminant removal. This substance shows promise due to its abundance in nature, being the second most abundant biopolymer after cellulose, and the presence of multiple functional groups along its polymeric chain. Brazil is one of the largest corn producers in the world, and associated with grain production is the generation of a high volume of corn cob, a material that contains about 15% lignin. The use of biomass from the agricultural sector can provide cost savings and double environmental benefits to the treatment process, as it not only treats pollutant disposal but also ensures proper disposal of agro-industrial waste. In this context, this dissertation proposal aims to study the extraction and modification of lignin from corn cob and evaluate its use for the treatment of polluted water as an adsorbent material. Therefore, the work will be divided into phases. The first phase will be the treatment of biomass from corn cob and the extraction of lignin. The second phase will be the modification of lignin with various reagents aiming for the best interaction for contaminant removal and their characterizations. And the final phase will be bench-scale testing to assess the efficiency of the produced material as an adsorbent for pollutant removal in contaminated effluents.