Search

BACKGROUND: Nanoscale tapioca starch (NTS) was successfully developed by high‐speed jet in our previous study. In this study, the adsorption capacity of Cu2+ onto NTS was further discussed. The optimal adsorption conditions (pH, contact time, contact temperature, initial Cu2+ concentration, and adsorbent concentration), adsorption kinetics, isotherms, and thermodynamic were also evaluated. RESULTS: The results showed that NTS exhibited excellent performance in adsorption of Cu2+, with adsorption capacities of 122.31 mg g−1 for Cu2+ (pH 7, 0.04 g L−1, 0.2 g L−1, 313.15 K and 10 min). The pseudo‐second‐order and Langmuir isotherms models could be used to explain the adsorption kinetics and adsorption equilibrium, respectively. The thermodynamic results showed that the adsorption process was spontaneous and endothermic with an increase in entropy. Cu2+ was adsorbed onto NTS, which was confirmed by energy dispersive spectrometry analysis. CONCLUSION: These findings indicated that NTS might be an effective, environment‐friendly and renewable bio‐resource adsorbent for removing heavy metals in industrial effluent. © 2021 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Tapioca starch-water suspension was subjected to high speed jet (HSJ) treatment and the physical properties were investigated by Particle size analysis, Differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscope (SEM). Particle size analysis revealed a significant increase in volume mean diameter from 17.00 to 40.35 μm. SEM studies showed that treated tapioca starch (TS) was prone to aggregate with each other and markedly damaged at starch granule surface which eventually disintegrated into gel-like structures at high pressure level. XRD patterns showed that all samples exhibited A-type and there was an evident loss of crystallinity after treated over 160 MPa. The TS showed similarity on FTIR spectral pattern but had different intensity in some peaks at increasing pressure. DSC analysis confirmed that TS was partly gelatinized after HSJ treatment, and the degree of gelatinization increased to 34.34 ± 1.0% when the pressure was 240 MPa. These results provided the basic information on the physical properties of TS treated at different pressures and indicated the potential possibility of HSJ for starch modification. [ABSTRACT FROM AUTHOR]