Study On Treatment Of Printing And Dying Wasterwater Containing Reactive Turquoise Blue KN-G By Combined SBR Process

The treatment efficiencies of printing and dying wasterwater were researched by three combined sequencing batch reactors (SBRs) containing Reactive Turquoise Blue KN-G (RTB), the removal of TN and TP were also analyzed. This thesis emphasized on the operational parameters for the removal of RTB, TN and TP in synthetic printing and dyeing wastewater in the systems of three SBRs. The lab scale tests for the best system were carried out to investigate the RTB removal effect and optimum systematic operation parameters through orthogonal experiments.The mechanism of RTB was also comprehensive analyzed by batch adsorption and degradation tests. The adsorption kinetics was then discussed. The influence of Na2SO4 concentration, pH and temperature on bioadsorption of RTB was also investigated.Firstly, three common different SBR systems were chosen in this paper (1#SBR is aerobic SBR ((O)SBR),2#SBR is alternating anaerobic-aerobic-anoxic SBR ((A/O)3SBR),3#SBR is anaerobic-aerobic SBR ((A/O)SBR)). Furthermore, it was observed that hydraulic retention time (HRT) and sludge retention time (SRT) matter a lot on the degradation of RTB, and comparatively, long HRT and SRT were beneficial to the removal of RTB. Considering to the removal efficiency of RTB, TN, TP and B/C in effluent, the system of SBR with alternating anaerobic-aerobic-anoxic is best.In order to get the optimum conditions in (A/O)3SBR, Several operational parameters of SBR such as hydraulic retention time (HRT), sludge retention time (SRT) and the ratio of aerobic to anoxic time was studied using orthogonal experimental method. The optimal value of the operational parameters was obtained under the experimental conditions, which were 30h for HRT,25d for SRT,0.9 for the ratio of aerobic to anoxic time. A relatively optimal hydration condition was put forward. Under optimum circumstances, primary indicators in Discharge Standard of water pollutants for dyeing and finishing of textile industry GB4287-2008 (exposure draft) were surveyed and analyzed, all of them can reach emission standard of existing enterprises, even newly-built ones, except BOD5 and chroma. The results can provide theoretical foundation and technical parameter for transformation of existing enterprises.The removal of dyes in printing and dyeing wastewater rely on adsorption and degradation. The proportion of adsorption to remove RTB is bulk by means of calculation. However, the studies on its application and theory on dye adsorption are still expected to be carried out further. So the removal mechanism of adsorption and preliminary degradation process is presented in this paper. Some effects were investigated after the study of adsorption isotherms, kinetics and thermodynamics. The main achievements are as follows:It was found that the adsorption isotherm of RTB on aerobic sludge (AS) satisfied both Langmuir and Freundlich models, while an evaluation on both accuratity and stability indicates that the Freundlich equation is the best. The adsorption of RTB on AS was analyzed using pseudo first-order, pseudo second-order adsorption and intrapartical diffusion kinetic models, and the pseudo second-order kinetic model could best describe the adsorption. The intrapartical diffusion kinetic models found that the adsorption process of RTB on AS controlled by both intrapartical diffusion and membrane diffusion. The E value of activation energy was below 40kJ·mol-1, which illustrate that physisorptions were the main effects. Both⊿H0 and⊿S0 were above zero, which indicate that the process was endothermic reaction. The experimental results indicated that salt, the initial pH value and temperature were the important parameters affecting the adsorption of RTB, especially the initial pH value and the adsorption capacity of AS decreased with the increase of pH value. Addition of Na2SO4 makes distribution ratio increasing, hence it enlarge adsorbance. Under 60℃, increased temperature favours adsorbing capacity.From the UV-Vis and IR spectrum of dye before and after degradation, the degradation process of RTB and preliminary degradation products were discussed. The absorption peak at 600-700nm in the visible region, at 300-340nm in the ultraviolet region decreased sharply, but the absorption peak is still existed, only decreased uniform proportion. It proved that phthalocyanine structure didn't degradate completely, the removal of RTB mostly through adsorption. The results were in accordance with calculation. From IR spectrum, degradation products may contain aniline...