Study On The Formation Mechanism Of Anaerobic Granular Sludge And The Structure Of Microbial Community Of The High Concentration Paper Making Wastewater

Paper-making industry is close to the development of national economic and social cause as an important foundation for industrial raw materials.Paper industry waste water emissions account for the national total industrial waste water emissions of 16.99 percent.In recent years, Waste paper regeneration becomes the mainstream of paper-making industry.The proportion of waste paper pulp accounted for 56%of the proportion of paper pulp.The anaerobic-aerobic process is the main process to deal with a high concentration of waste paper pulp waste water, Anaerobic efficient processors is the most critical equipment in this process.The efficient bacteria-granular sludge is the key to start anaerobic processor.At present,Domestic processors running better and anaerobic granular sludge were imported.Therefore the development of exclusive high-performance micro-organisms and advanced anaerobic reactor is urgent to control pollution of paper-making industry in china. This study concerning high concentrations of biological treatment of waste pulp important section-Tower anaerobic biological treatment (UASB),using PCR-RFLP method to analysis the anaerobic granular sludge microbial community structure and composition of the ratio formed by it.The results show that there are mainly two species of methanogenic archaea in the anaerobic granular sludge,methane bacteria and hairy uncultured euryarchaeote gene in which methane bacteria hairy accounted for 75.34 percent,accounting for an absolute majority.In addition,in the detection of anaerobic bacteria,Rumen bacterium, Thermaectogenium sp,Ruminococcus albus,Flavobacterium sp, Clostridium islandicum,Lachnospiraceae bacterium account for non-methanogenic bacteria of the total number of 3.16%, 4.21%,3.16%,6.32%,7.37%,6.32%,30.53%respectivly.These studies show the ecological role of these major microbia in the course of degradation of waste water and establish the corresponding relationship between the micro-organisms of different species and their habits.On this basis,putting forward the view that the formation of anaerobic granular sludge is based on certain characteristitcs of the micro-organisms,which spontaneously form microbial community aggregates.According to the ecological survey and the running characteristics of the reactor,Methanosaeta concilii play an important role in the process of the formation of granular sludge,Methanosarcina is not the key bacteria to the formation of granular sludge.This study affirmed the role of the hydrolysis of cellulose is the restrictive steps to the methane fermentation.Taking the formed anaerobic granular sludge for microscopic observation through a scanning electron microscope,we found that in the formation of particles it gathered a large number of rod-shaped,filamentous fungi and some of the streptococcus,which may play the role of a bridge.The observing results coincide with the ecological surveys containing high concentrations of Methanosaeta concilii.In the conditions of laboratory,Studying the factors as pH, temperature,Ca²⁺ ion concentration,wastewater COD concentration on the formation of particles,the results show that the proposed regulation of pH control in the 7.0 to 7.8,7.0 for the best,as far as possible Avoided in acidic range.The best temperature of the reactor to control is 38℃, rather than the usual 35℃,So the temperature can be controlled between 34℃AND 39℃;When COD acheves at 2000mg/L and above,the formation of particles gradually increases,the peak is 2700mg/L.Ca and other metal ions have a catalytic role on the formation of sludge particles, but when Ca²⁺ concentration reaches 50mg/L,this promotion has no clear effect.Full hybrid can promote a more granular sludge formation, not just the up-flow in order to form granular sludge.Thus,an acid pool was put forward the process as a standard pre-treatment before the anaerobic reactor.The results on the high concentration of waste paper anaerobic treatment of waste water have a value of theory and application.