An inclusive physico-chemical perspective on food waste: Textural and morphological structure

Abstract

In recent years, thanks to their advantages such as low cost, easy availability, reusability as adsorbent materials, and high metal ion removal capacities in aqueous solutions, food waste attract the attention of researchers. In this study, almond shell (AS), peanut shell (PS), walnut shell (WS), and pumpkin seed hull (PSH) were characterized using analytical methods such as Fourier Transform Infrared (FTIR) Spectroscopy, Scanning Electron Microscope (SEM)/Energy dispersed X-ray (EDX), and Brunauer–Emmett–Teller (BET). The surface morphologies, functional groups, surface area, and pore size of AS, PS, WS, and PSH were evaluated together, and their specific properties were revealed. According to EDX analysis, %C and %O content is high for all biosorbents. Using FTIR analysis, carboxylic (–COOH), amines (N–H) and hydroxyl groups (–OH) in the structure of AS, WS, PS, and PSH were determined. Pore morphologies were determined as mesopore (2<d < 50 nm) and macropore (>50 nm) for AS, PS, WS, and PSH. Surface areas for AS, PS, WS and PSH were determined as 6.20, 4.12, 3.98 and 2.74 m2/g, respectively. In addition, using the Principal Component Analysis (PCA) model, the effect levels of AS, PS, WS, and PSH on the adsorption process were determined by FTIR and EDX data sets. With the increasing interest in environmental preservation, it is anticipated that low-cost food waste-based biosorbents will be utilized in various applications in the future.