The increasing generation of agro-industrial waste has intensified soil and water contamination, as well as the eutrophication of water bodies, impacting biodiversity and human health. This highlights the need for responsible management to meet Sustainable Development Goals (SDGs) 3, 6, 12, 13, 14, and 15, which promote health, access to clean water, responsible consumption, climate action, and the protection of life on land and below water. This study aimed to produce activated carbon from cocoa, baru, and monguba residues for the removal of contaminants dyes (methylene blue, bromocresol green, and methyl red) presented in wastewater. The three materials were carbonized at 500 °C for one hour under a nitrogen atmosphere and activated with H₃PO₄. The samples were characterized using TGA, SEM, XRD, FT-IR, pH_PZC, and ASAP, in addition to conducting kinetic and thermodynamic parameter assays for the dyes. Monguba carbon exhibited the highest pore volume (1.57 cm³·g⁻¹), surface area (1604 m²·g⁻¹), and adsorption capacity for methylene blue and methyl red (50 mg·g⁻¹). The data were analyzed using pseudo-first and pseudo-second order kinetic models. It was concluded that monguba carbon shows potential for the sustainable removal of organic dyes and molecules with similar characteristics in contaminated water or wastewater.

Potato pulp waste (PPW) drying was investigated under different experimental conditions (temperatures from 50 to 70 °C and air flow from 0.06 to 0.092 m³ m- 2 s- 1) as a possible way to recover the waste generated by potato chip industries and to select the best-fit model to the experimental results of PPW drying. As a criterion to evaluate the fitting of mathematical models, a method based on the sum of the scores assigned to the four evaluated statistical parameters was used: regression coefficient (R²), relative mean error P (%), root mean square error (RMSE), and reduced chi-square (χ²). The results revealed that temperature and air velocity are important parameters to reduce PPW drying time. The models Midilli and Diffusion had the lowest sum values, i.e., with the best fit to the drying data, satisfactorily representing the drying kinetics of PPW.

In this article, the role of surface sites of modified zeolites with semiconductor nanoparticles as alternative photocatalyts for protecting post-harvest foodstuff from the detrimental effects of ethylene is addressed. Two single and one double catalyst based on zinc and copper oxides supported over modified zeolite samples were prepared. Physical, chemical, and surface properties of prepared materials were studied by several characterization methods. UV-Vis absorption spectra show that the applied modification procedures increase the optical absorption of light in the UV and visible regions, suggesting that an increase in the photocatalytic activity could take place mainly in the obtained co-impregnated catalyst. An ethylene conversion around 50% was achieved when the parent natural zeolite support was modified with both transition metal oxides, obtaining higher removal efficiency in comparison to single oxide catalysts. Adsorption and photocatalytic oxidation experiments were also performed using single and double catalysts supported over fumed silica, attaining lower ethylene conversion and thus highlighting the role of zeolite surfaces as adsorption sites for ethylene during photocatalytic reactions. Operando diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) studies reveal that a synergistic mechanism occurs, involving ethylene adsorption at acidic sites of zeolite and its photocatalytic oxidation due to the generation of radicals by the light activation of nanoparticles of zinc and copper oxides.

Ethylene is a plant hormone regulator that stimulates chlorophyll loss and promotes softening and aging, resulting in a deterioration and reduction in the post-harvest life of fruit. Commercial activated carbons have been used as ethylene scavengers during the storage and transportation of a great variety of agricultural commodities. In this work, the effect of the incorporation of copper oxide over activated carbons obtained from baru waste was assessed. Samples were characterized by X-ray diffraction (XRD), N₂ adsorption-desorption at −196 °C, field-emission scanning electron microscopy (FESEM) coupled with energy-dispersive X-ray spectroscopy (EDS), and infrared (IR) spectroscopy. The results showed that the amount of ethylene removed using activated carbon obtained from baru waste and impregnated with copper oxide (1667 μg g⁻¹) was significantly increased in comparison to the raw activated carbon (1111 μg g⁻¹). In addition, carbon impregnated with copper oxide exhibited better adsorption performance at a low ethylene concentration. Activated carbons produced from baru waste are promising candidates to be used as adsorbents in the elimination of ethylene during the storage and transportation of agricultural commodities at a lower cost.

Objective: Prepare a global overview of agro-industrial residues used for activated carbon (CA) production, seeking caffeine removal of water bodies. Theoretical reference: Aiming the adequate understand of involved processes, as well as each stage when adsorption occurred. The theoretical concepts might help to analyse how important is pollution of emerging contaminants in water bodies, as a current environmental problem. Method: A data survey was developed in general perspective, using information from literature published in online repositories, such as Scopus and Science Direct, trough investigations that seek the use of agro-industrial residues for production of activated carbons and, also, their caffeine removal parameters analysis. Results and conclusion: The analysis results of the different methodologies applied in studies for activated carbon production from agro-industrial residues, showed that good caffeine adsorption process and the adequate characteristics of each adsorbent material, depend on processes and conditions adopted by each researcher. In this way, the different studies here analysed showed the importance of using industry waste, helping to reduce waste volumes in landfills and, at the same time, the search for new technologies that could help to remove emerging contaminants, such as caffeine. Originality/value: This study provides different basic and methodological concepts related to carbonization processes from agro-industrial waste, verified and studied by different authors for caffeine elimination; and also the importance of tracking new economical and environmentally friendly precursor materials.