Using Immobilized White-rot Fungus In The Treatment Of Organic Refractory Wastewater

Organic refractory wastewater is a kind of water which containing a largenumber of organic chemicals which are nonbiodegradable under natural condi-tion. It will be generated a lot during the production process of curriery, dyes andother industries. The organic refractory wastewater has complex compositions,high concentration of pollutants, deep color, high toxicity, stability, and poor bi-odegradability.The technology of immobilized white-rot fungus which is the efficiencytreatment method is very popular in recently. The white-rot fungus has a broadspectrum degradation, which can degrade many kinds of organic refractorywastewater effectivly. The technology of immobilization can improve the pro-cessing efficiency of microorganisms, increase the stability of microorganisms,maintain the activity of microorganisms, and widen the optimum temperaturerange and pH range. In order to provide theoretical basis for the treatment of ac-tual organic refractory wastewater, five kinds of simulated wastewater(quebracho extract, Xili fur red, Xili fur Blue, Jili fur blue and rhodamine B)were chosen as the processing objects of immobilized white-rot fungus, thetreatment efficiency of bio-balls treating quebracho extract wastewater was ex-amined, and processing conditions of the single factor tests and orthogonal teststhat bio-balls treating Xili fur red were optimized, Xili fur blue, Jili fur blue andrhodamine B.The results showed that:(1) The mechanical strength, the stability, anddilatablility of bio-balls were very well, which were benefit to the stablility ofimmobilized balls, the maintenance of microbological activity and the ability ofreusing.(2) The degraded efficiency of quebracho extract wastewater on whichthe white-rot fungus used in this study was not so ideal, both domestic and over-seas could not find any studies which were related to white-rot fungus treatingquebracho extract wastewater, and which made the referrence theoretical basis inavailble.(3) The efficiency of decolorization of nonlaccase production medi-um-bio-balls test was better than that of laccase production medium-bio-ballstest, the operation of former was easier, and which was suited to be applied tosubsequent trials.(4) The results of single factor tests showed that when theamount of bio-balls was6.0g, the biggest decolorization rate of Xili fur red, Xilifur blue and Jili fur blue was95.51%,92.73%and95.51%, respectively; Big-gest decolorization rate of rhodamine B was90.30%when the amount ofbio-balls was6.5g. When the concentration of Xili fur red was20mg/L, themaximum decolorization rate was96.05%; when the concentration of Xili furblue, Jili fur blue and rhodamine B was10mg/L, the maximum decolorizationrate was96.14%,96.28%,86.06%, respectively. When the pH was5, Xili furred had the biggest decolorization rate94.51%; when the pH was1, the biggestdecolorization rate of Xili fur blue, Jili fur blue and rhodamine B was93.37%,93.29%,96.08%, respectively. When the rotating speed of Xili fur red, Xili furblue and Jili fur blue was100r/min, the maximum decolorization rate was96.22%,94.21%,96.22%, respectively; The maximum decolorization rate ofrhodamine B was88.70%when the rotating speed was140r/min.(5) The re-sults of orthogonal experiments showed that, the optimum decoloring conditionsof Xili fur red was that6.0g the amount of bio-balls,50mg/L the concentration,pH3,120r/min the rotating speed; The optimum decoloring conditions of Xilifur blue was that6.0g the amount of bio-balls,20mg/L the concentration, pH3,120r/min the rotating speed; the optimum decoloring conditions of Jili fur bluewas that6.0g the amount of bio-balls,20mg/L the concentration, pH3,120r/min the rotating speed; and the optimum decoloring conditions of rhodamine Bwas that7.0g the amount of bio-balls,10mg/L the concentration, pH1,140r/min the rotating speed.(6) The UV-visible spectrum of rhodamine B before andafter decoloring showed that the decolorization of bio-balls treating to rhodamineB was adsorbed first, and then degraded in48h decoloring.(7) Thedecolorization rate was still over60%ater the bio-balls repeat using4times.