Study On Preparation Of Biochar Carrier And The Influence On Biofilm Forming

Biofilm process is one of primary sewage treatment technologies which have been used widely in many countries. The carrier is the key to the method. Recent years, high performance, inexpensive carrier has been a priority which researchers are studying.In this paper, as peanut shells for raw materials, we adopted pyrolysis technology to produce bio-char biofilm carriers. The influences of the main operating conditions (pyrolysis time and temperature) are researched, which affects the Physicochemical Properties of biochar. The biomass attachment expriments was done to compare these effects, such as the amount of biofilm culturing, the removal of COD and NH4-N), which is the characteration of the biofilm and property and waste water treatment property. At last, the one which had good performance of bio-char was ultimately determined to be the superiority carrier.According to these experiments, the conclusions are listed as follows:1) As the rise of the pyrolysis temperature, the yield of bio-carbon decreased while the ash content increased. Under the same terminal pyrolysis temperature, the yield of bio-carbon decreased with the extension of pyrolysis time, and the ash content declined, also.2) The percent of bio-carbon increased with the rise of pyrolysis temperature, but the percent of hydrogen, nitrogen and sulfur decreased. With the extension of pyrolysis time, the percent of the four elements all declined.3) The bio-carbon FTIR spectra shows that when the pyrolysis temperature increases, the combination of water from cellulose started to decompose. As heating up the pyrolysis temperature to 500℃-700℃, the lignin started to decompose largely. Four kinds of bio-carbon contain carboxyl, amine, imine, amide and other groups, which are more conducive to microbial adhesion and proliferation, and also more conducive to biofilm. This is also the bio-carbon advantage as biofilm carriers than other inorganic and some organic carrier.4) The bio-carbon specific surface area and total pore volume increased with the increasing pyrolysis temperature and the pyrolysis time. Average pore size decreased with the increasing pyrolysis temperature (300℃-500℃). In contrast, Ceramic's surface area and pore volume are small.5) The water absorption of bio-carbon is a hydrophilic index. With the increase of pyrolysis temperature, pyrolysis time, it is increasing. Biological carbon PC700-3 is the best hydrophilic performance.And relatively speaking, the mechanical strength of biological carbon is poor; they need to further research while good mechanical strength of ceramic, it is a relatively poor hydrophilicity rate, only 0.98%.6) The bio-carbon have a good adsorption capacity to COD, NH4-N, NO3-, NO2-, PO43-. Among them, the strength of its adsorption with the pyrolysis conditions differ, mainly as: PC300-1