Systematic evaluation of PDA/PAM/MAH-modified basalt fibre as biofilm carrier for wastewater treatment

Abstract

ABSTRACT In this study, three kinds of modified basalt fibre (MBF) were used as biofilm carrier to treat wastewater, mainly for the removal of organic matter and nutrient pollutants, which was evaluated the feasibility of modification by pollutants removal performance. Polydopamine modified basalt fibre (PAD-BF) via the surface coating method were obtained. Polyacrylamide modified basalt fibre (PAM-BF) and maleic anhydride-modified basalt fibre (MAH-BF) via the surface grafting method were prepared. The surface physicochemical properties, biomass attachment capacity and pollutants removal efficiency of MBF were systematically investigated. Electron microscope scanning (SEM) revealed that the surface roughness of BF was obviously improved by modification. Besides, fourier transform infrared (FTIR) suggested that the MBF had more surface-active functional groups. The results of sludge immobilization tests showed that PDA/PAM/MAH-BF had higher bio-affinity than ordinary BF with 1.5∼2.3 times on immobilization ratio of microorganisms (IRM). Furthermore, the performances of PDA/PAM/MAH-BF as biofilm carrier for pollutants were significantly higher than that of ordinary BF group. Among them, the highest removal efficiency of COD in PAD-BF biofilm reactor was 95.29 ± 0.99%, while that of BF group was 86.30 ± 3.09%. PAM-BF group had the best removal effect of nutrients with the removal efficiency of 90.83 ± 7.69% for TP and 91.25 ± 6.43% for TN, respectively, while the removal rate of BF group was only about 70%. The improvement of dissolved oxygen (DO) in the MBF reactors was consistent with the enhancement of contaminant removal. Therefore, PDA/PAM/MAH-BF can be used as promising biological carrier fillers in wastewater treatment engineering.