Efficient removal of dyes in the wastewater of dyeing and printing industries is challenging, especially the anionic dyes with strong stability, serious environmental pollution, and difficult degradation. In the present work, a novel cationic adsorbent was synthesized through the quaternization of 2,3-epoxypropyltrimethylammonium chloride (GTA) onto microcrystalline cellulose and characterized by Fourier transform infrared spectroscopy, X-ray diffraction, specific surface and pore size analysis, and scanning electron microscopy. Acid Yellow 128 (AY-128) and Acid Red 1 (AR-1) were selected to investigate their adsorption on quaternized microcrystalline cellulose (QMCC). The experimental adsorption results indicated that (1) the adsorption kinetics of AY-128 and AR-1 on QMCC could be consistent with the pseudo-second-order and Freundlich models, respectively; (2) the adsorption process was spontaneous and feasibly endothermic. The removal efficiency of AY-128 and AR-1 was up to 99 and 95%, respectively. After five times of reuse, the removal efficiency of AY-128 and AR-1 was still 97 and 95%. In conclusion, quaternized microcrystalline cellulose was a promising adsorbent for AY-128 and AR-1.

Carboxymethyl chitosan dialdehyde starch Schiff base (CMCDAS) and its metal complexes were synthesized by corn starch (St), sodium periodate, carboxymethyl chitosan and metal ions (copper, zinc, nickel, silver), and were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermogravimetric analyzer (TGA), energy dispersive spectroscopy (EDS) and X-ray powder diffraction (XRD). The antibacterial activities of CMCDAS against E. coli and S. aureus increased according with its increasing nitrogen content, and the best minimum inhibitory concentrations (MIC) to E. coli and S. aureus were 30 mg/mL, respectively. Furthermore, the minimum inhibitory concentrations (MIC) of the metal Complexes (copper, nickel, silver, and zinc) against S. aureus were 7.50 mg/mL, 30 mg/mL, 30 mg/mL, and 1.88 mg/mL, respectively; and against E. coli were 7.50 mg/mL, 15 mg/mL, 15 mg/mL, and 0.94 mg/mL, respectively.

Carboxymethyl chitosan dialdehyde starch Schiff base (CMCDAS) and its metal complexes were synthesized by corn starch (St), sodium periodate, carboxymethyl chitosan and metal ions (copper, zinc, nickel, silver), and were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermogravimetric analyzer (TGA), energy dispersive spectroscopy (EDS) and X-ray powder diffraction (XRD). The antibacterial activities of CMCDAS against E. coli and S. aureus increased according with its increasing nitrogen content, and the best minimum inhibitory concentrations (MIC) to E. coli and S. aureus were 30 mg/mL, respectively. Furthermore, the minimum inhibitory concentrations (MIC) of the metal Complexes (copper, nickel, silver, and zinc) against S. aureus were 7.50 mg/mL, 30 mg/mL, 30 mg/mL, and 1.88 mg/mL, respectively; and against E. coli were 7.50 mg/mL, 15 mg/mL, 15 mg/mL, and 0.94 mg/mL, respectively.