Research On Low-cost Production And Application Of High-effective Heavy Metal Removal Biosorbents

Cultivating high-effective chromium removal fusion strain by using Low-cost culture media and preliminary method of application were discussed in this research, including low-cost material selection,optimal cultivate condition,facture of immobilized biosorbent,kinetics and thermodynamics of the biosorption,mechanism of biosorption on heavy metal.Investigation on cultivating high-effective heavy metal removal fusion strain(R32) by using low-cost medium showed that an effective biosorbent was produced by using 3% abandoned molasses and 20g/L municipal sludge as the cultivated substrate of fusion strain.The optimal conditions were set as followings:initial pH 3.0-4.0,ferment time 40h, by that conditions,biosorbent productivity was more than 40g/L and the best adsorptive property can up to 99.9%.The scale-up culture of high-effective Cr removal fusion strain by using adlittoral brush cultivated equipment was investigated,and the result showed that both batch and continuous cultivation could be used to fulfil this cost-effective culture and the concentration of the fusion strain was around 19×10⁷cells/ml when cultivated temperature was 30℃,rotation speed 600 to 800r/min,culture volume 1.5L,and brush submersing depth 1 to 1.5cm.Three types of kinetics models and Freundlich thermodynamics model.can correspond well with the adsorption of biosorbent.The adsorption rate increased with the increasing of temperature,but the adsorption stabilization declined.Nutrition in the adsorption system improved the inside transportation trend of Cr and increased the adsorption capacity.Immobilized biosorbent with good physical properties and highest adsorption capacity can be obtained by 1.5%sodium alginate and 50g/L fusion strain.When the immobilized biosorbent dosage was 50g/L(contain 6g/L fusion strain),Cu and Cr in the actual electroplating wastewater(pH:2.67,Cu:1.70mg/L,Cr:20.62 mg/L,Ni:29.97 mg/L, Zn:1.11mg/L) were completely removed also the removal ratio of Ni and Zn were 48.05% and 61.09%,respectively.The result of packed column continuous adsorptive experiments implied that when flow rate were 150ml/h and 250ml/h the quantity of treatment waste water were 7.2 and 11.5L,respectively by one time.The process of Cr⁶⁺ reduction and adsorption was accompanied by the H⁺ consumption.The main adsorptive groups included amino,hydroxyl,phosphate group and amide,in which phosphate group played vital role in the chromium accumulation, and the removal rate of chromium and reduction rate of hexavalent chromium declined 70%and 46%,respectively while phosphate group was masked.Biosorption process of Cr by fusion strain turned to transport the Cr ions adsorbed on surface into the cell and combine them with inclusion to form steady species and this took 90 min to reach the equilibrium.The biosprption and reduction of Cr would increase cell membrane permeability.