Advanced wastewater treatment with autoclaved aerated concrete particles in biological aerated filters

Autoclaved aerated concrete particles (AACP) were tested as biofilter carriers in biological aerated filters (BAF) to solve the disposal problems of construction wastes. AACP were characterized using X-ray diffraction, X-ray fluorescence, scanning electron microscopy, and porosimetry analysis. Results showed that the main crystalline phases of SiO2, Ca5Si6O18H2, CaO, and Al2O3 were the major oxides and hydrous silicates in AACP. In addition, AACP had a high total porosity of 89.21% and a high specific surface area of 81 m(2)/g. Different from commercially available ceramsite (CAC), AACP had an open macroporous structure that was suitable for immobilizing microorganisms. AACP and CAC were loaded into two identical BAFs to compare the efficiency of their microbial treatment of wastewater. AACP BAF was more efficient than CAC BAF in terms of TOC, NH3-N, TN, and PO43- removal. Therefore, AACP, as a novel product of recycling construction waste, provide a promising way to utilize construction waste. (C) 2015 Elsevier Ltd. All rights reserved.