Study On The Process And Effect Of Organic Degradation Of Recycled Fiber Papermaking Wastewater Based On Bioaugmentation Technology

Compared with the traditional papermaking process,the renewable fiber paper has the advantages of low water consumption and less sewage discharge.But its water tends to be closed and the refractory organic macromolecular pollutants accumulate with the increasing number of cycles,which easily causes the degradation cycle system to collapse and seriously limits the development of the renewable fiber paper industry.Bioaugmentation technique has low equipment cost,high efficiency of concentrated sewage treatment,high pertinence and so on.It is the key technology to strengthen the treatment process of organic wastewater,and it is also an effective way of improving wastewater treatment for small and medium-sized papermaking enterprise with large fluctuation of wastewater discharge and weak economic strength.In this study,UV-visible,Infrared Spectroscopy,GC-MS and other organic pollutants were used to characterize organic pollutants.Three kinds of engineering microbial agents were selected,and the degradation effect was optimized by using the mixture design to optimize the optimal proportion of bacterial agents.Based on the single factor test,the response surface method was used to optimize the intensified biological treatment process conditions.Based on the bioaugmentation technique,the organic matter degradation process of the recycled fiber papermaking wastewater,the degradation mechanism of macromolecular organic matter,the optimal carbon-nitrogen enzyme replenishment amount and the timing of the addition were studied.The main research results are as follows:(1)Application routine water quality analysis method,UV-vis spectrum analysis method,according to the small regenerated fiber paper mill wastewater quality analysis,studying the characteristics of wastewater quality and composition,it has been concluded that this kind of wastewater has high concentration,volatile,deep chromaticity,high viscosity and other characteristics,organic matter in waste water is given priority to possession small molecules,macromolecules accounts for less and mainly exists in the form of aromatic structure of lignin and its derivatives,cellulose and hemicellulose.The composition of organic pollutants mainly includes low carbonic acid,fatty acid,alcohol and a small amount of ketone nearly 40 kinds of organic pollutants.The contents of Mg2+and Al3+in wastewater were higher and contained trace heavy metal ions.(2)According to the characteristics of high color and high viscosity of recycled fiber papermaking wastewater,three kinds of fungicides,namely,EM bacteria,PP bacteria and sukhohan bacteria,were selected.The best activation time was determined by analyzing the growth characteristics of microorganisms,and the best effect was determined by comparing different dosing methods.By using the mixture design to optimize the ratio of bacterial agent,it is concluded that the best ratio is 77.91%for PP and 11.09%for sukhohan,and the removal rates of lignin,color and viscosity can reach 35.06%,44.08%and 43.08%,respectively.(3)On the basis of single-factor experiment,the response surface center combination method in the Design-Expert software was selected,and the experimental data were fitted with inoculum,temperature,dissolved oxygen concentration and pH value as independent variables,and the removal rate of lignin and chromaticity as response values,then we obtained the quadratic multiple regression equation.The model and its coefficients were tested for significance,and we found that the inoculation amount and temperature had significant effects on the lignin degradation.To optimize the model,the optimal process conditions for microbial inoculation amount to 14%,the temperature is 28?,dissolved oxygen concentration of 2.8 mg/L,pH value of 7 wastewater lignin and chroma removal rate can reach 55.13%and 65.01%,respectively.(4)The best nitrogen and carbon sources were ammonium chloride and sucrose,and ammonium oxalate inhibited the degradation of lignin.The optimal sucrose and ammonium chloride dosage were 2g/L and 0.5g/L,respectively,without excessive sucrose.The laccase activity was determined by adding carbon and nitrogen,and the appropriate initial C/N ratio played an important role in laccase production.(5)On the basis of the construction of composite microbial agents,optimal process conditions control and optimal carbon-nitrogenase analysis,the conventional water quality analysis method,FTIR and other spectral analysis methods were used to study the treatment process and effect of intensified biological treatment of renewable fiber papermaking wastewater organic matter.It is concluded that the conventional water quality index and heavy metal content in the treated wastewater are greatly reduced;the degradation ratio of lignin,cellulose and hemicellulose is increased to over 70%,and the degradation products are mainly alkane.The dissolved organic matter after treatment increased from 37 to 50.Through optimization research on cellulase components,the optimal ratio of cellulase components was obtained,which laid a foundation for further improvement of subsequent process efficiency.To sum up,the regenerated papermaking wastewater organic matter microorganism degradation technique helps to promote small and medium renewable fiber paper industry wastewater treatment capacity,can provide informative for paper industry sewage.It can also sludge recycling use of experiment data and reliable theoretical basis,and for renewable fiber papermaking waste water to achieve closed cycle to explore new ways.