Purification of bathing wastewater by double suspended layer fluidized bed reactor

Abstract

Abstract An external radial magnetic field and built-in stainless steel balls formed a magnetic suspended layer (MSL), as observed in this study. Under the condition of crossflow inflow, the flocculating agent and coagulant aids form a flocculated particles suspension layer (FPSL). Thus a double suspended fluidized bed reactor was constructed to treat bathing wastewater. A particle image velocimetry device was used to detect flow patterns and analyze the flocculation conditions. The results showed that under the condition of crossflow inflow, at the same time, the flooding water was 0.023–2.101 m3/h, and the dosage of poly aluminum chloride (PAC) and polyacrylic amide (PAM) was 90 mg/L and 1.5 mg/L, respectively, and removal rates of turbidity, chemical oxygen demand (CODCr) and linear alkylbenzene sulphonates (LAS) reached more than 99, 90, and 80%. Filtration, grid flocculation and particle interception were functions of the MSL. Meanwhile, the crossflow input created additional vortexes, increasing the likelihood of flocculation particle collision, improving the flocculation conditions and cleaning the MSL. The reactor aids in the development of the initial flocculated particles suspension layer, flocculation strengthening, chemical dosage reduction, effluent qualities improvement, and effluent stability maintenance.