RESUMO
Phosphorus (P) is a nutrient necessary for agricultural production and a potential originator for eutrophication in water bodies, resulting in qualitative changes; it may also affect the aquatic ecosystem and human health. In addition, as a finite resource, the importance of studying strategies to remove it from water is evident, thus making possible its recycling. Many studies have used powdered materials, including biochars, for P water decontamination; however, the difficulty of separating and collecting these materials from water after adsorption may be difficult. Therefore, using hybrid materials in which the fine particles (powder) are impregnated into larger, solid particles by means of a polymeric host can facilitate collection and reuse after P adsorption. In this context, this study aimed the synthesis and characterization of a new hybrid film formed by the biopolymer cellulose acetate (CA) and biochar (FAC-B) for P adsorption in aqueous solution. We obtained biochar from the pyrolysis of carrot residue (Daucus carota L.) and doped it with magnesium. As a biodegradable polymer and the most abundant natural polysaccharide in the environment, using CA as a biochar support material is an environmentally friendly alternative. We prepared the CA film with the casting method, and the biochar was inserted into the filmogenic solution in the same amount as the CA. The film was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), molecular absorption spectroscopy in the infrared region with an attenuated total reflectance (FTIR/ATR) accessory, and X-ray Photoelectron Spectroscopy (XPS). We evaluated the thickness, weight, density, H2O uptake and H2O solubility of the produced FAC-B. The maximum adsorption capacity of P by FAC-B was 21.57 mg g-1, in agreement with the Langmuir isotherm model. The adsorption value suggests that the film has the potential to be used as an efficient P adsorbent in water.
RESUMO
The production of biodegradable plastic materials using natural resources has aroused increased attention due to environmental concerns. This study aimed to manufacture novel, commercially feasible, biodegradable sheets by flat die extrusion-calendering process produced with thermoplastic starch/plasticized cellulose acetate (TPS/PCA) and thermoplastic starch/plasticized cellulose acetate/poly (butylene adipate-co-terephthalate) (TPS/PCA/PBAT) blends, and to investigate the effects of composition and processing conditions, morphological characteristics, and thermal properties. The results showed that TPS/PCA and TPS/PCA/PBAT biodegradable sheets properties were highly dependent upon both composition and processing temperature. The morphological characteristics and thermal properties of the sheets demonstrated the good compatibility between TPS and PCA in TPS/PCA blends, mainly at higher processing temperatures, whereas TPS/PCA/PBAT sheets present a heterogeneous structure due to the poor compatibility between the components. TPS/PCA biodegradable sheets presented suitable processability and handleability characteristics that allow them to be considered as a novel eco-friendly, economically feasible alternative to conventional plastic materials.