鉄塩凝集剤と乳製カゼインを用いた凝集・泡沫分離法による懸濁物除去に関する基礎的研究

カゼインの役割

抄録

Foam separation using a coagulant (iron or aluminum) and milk casein is effective for removing suspended matter such as kaolin particles, suspended solids in wastewater, and phytoplankton. However, the function of casein in this separation is unclear. In this study, to clarify the role of casein in coagulation and foam separation, the characteristics of casein adsorption onto flocs that were made up of kaolin and Fe(OH)₃ and the removal of suspended substances by the separation were investigated.
Both of adsorbing casein onto the flocs as a collector and remaining casein in the solution as a frother were necessary in order to obtain the high removal rate (above 90%). The optimum pH range was 6.8-7.6. The required amount of adsorbing casein onto the flocs was 0.5g-casein/g-Fe. To obtain more than 90% turbidity removal from the suspended solution of kaolin (200mg·l^-1), greater than 5mg·l^-1 of residual casein with 10mg-Fe·l^-1 of coagulant dosage was needed. The amounts of adsorbing casein and the concentration of residual casein were estimated from the adsorption rate of casein. The suitable dosage of casein and the mixing time for the foam separation were determined by the adsorption rate.