Treatment Of Triphenylmethane Dye Wastewater By Immobilized Cells

Triphenylmethane dyes are one of the most widely used dyes.They produce a large amount of wastewater with strong toxicity,high color,and difficult to degrade pollutants,which brings greater environmental pollution.Immobilized cell technology can improve the high cell concentration per unit volume,strong environmental adaptability,fast reaction speed,and recyclability,make up for the shortcomings of microbiological methods,and thus effectively treat triphenylmethane dye wastewater.In this paper,immobilized cells were used to treat triphenylmethane dye wastewater.Malachite green and crystal violet were used as pollutants to separate and purify the dominant degradation bacteria.By optimizing the immobilization conditions,the influence of environmental factors on the degradation ability of free bacteria and immobilized cells was analyzed,and the differences before and after immobilization were compared to explore the treatment effect of immobilized cell technology on triphenylmethane dye wastewater in practical applications.The main research results are as follows:(1)Through screening of malachite green and crystal violet degrading bacteria,the malachite green dominant degrading bacteria M1 and crystal violet dominant degrading bacteria C2 were isolated and purified from the sampled sludge.It was found that the degradation rate of malachite green by M1 reached 81.47% in 5 days,and the degradation rate of crystal violet by C2 was 37.92% in 15 days.(2)The degradation of malachite green and crystal violet at different environmental conditions showed that temperature,pH and initial substrate concentration affected the degradation of malachite green and crystal violet to a certain extent.The degradation of malachite green by M1 was the best at 30 ?.Malachite green can be degraded well in pH 5~8.When malachite green is lower than 30mg/L,the degradation ability of M1 is better.With the increase of temperature,the degradation rate of crystal violet decreases gradually.C2 degrades crystal violet better at 20 ? ~ 30 ?,suitable for neutral to alkaline environment to degrade crystal violet,and has the best degradation effect at pH = 7.In addition,the initial concentration of crystal violet is 10 mg / L,the degradation rate is the fastest.(3)The physical properties and degradation rate of malachite green of the immobilized cell particles were compared by orthogonal experiment.After comprehensive comparison,the results showed that the immobilized cell granules had the best performance when the concentration of polyvinyl alcohol was 8%,the concentration of sodium alginate was 2%,and crosslinked with 18 h in 6% calcium chloride solution.(4)The degradation of malachite green and crystal violet by immobilized cell particles under different conditions was better than that by free bacteria.Temperature has little effect on the degradation of malachite green and crystal violet by immobilized cell particles.The pH range of immobilized cell particles degrading malachite green and crystal violet is wide.The initial concentration change has a significant effect on the degradation of malachite green and crystal violet by immobilized cell particles.(5)The biodegradation process of malachite green and crystal violet under different conditions conforms to the first-order degradation kinetic equation.The effects of temperature,pH and initial substrate concentration on the degradation of malachite green and crystal violet are significant.