| There are three main problems in the traditional chemical pulping: high cost and energy consumption, low pulp yield and serious environmental pollution. Currently, being short of resource and energy and being polluted seriously, it is urgent and very important to develop bio-pulping methods with less pollution, lower energy consumption and higher pulp yield.Bio-pulping methods make use of the microorganism with lignin degradation ability to decompose lignin in plant fiber. At present, it includes two methods: one uses white-rot fungi to degrade lignin partly and then to adopt mechanical pulping,as a result, the quality of the pulp obtained is similar to CTMP, but the refining energy is reduced obviously; the other uses some enzymes to degrade lignin directly, which is on the beginning stage because high efficiency lignin enzy nes are difficult to be obtained .In this paper, poplar wood scrap was used as material and the high efficiency fungi- Agaricus sp. G1 was selected from many kinds of fungus, based on the treated pulp physical properties .The conditions of shake flask ferment for Agaricus sp. G1 were optimized, and the process conditions of bio-pretreatment with Agaricus sp. G1, such as pH, temperature and time as well as the temperature and time for softening treatment, were also optimized. The results indicate that the Agaricus sp. G1 tolerate wide variations of treatment pH and temperature, and it had high efficiency. After 48h biological pretreatment, the breaking length and ring crush index of bio-pretreatment sample were 17% and 24% higher than those of the control, respectively. Pretreatment time was reduced obviously(from 7 days for the previous methods to around 2 days for the current).In this way, the bio-pretreatment mechanical pulp with good physical properties were obtained, and it can be used as a furnish for the manufacture of high strength corrugated medium.Combining the biological pretreatment with non-chemical cooking, the pulp quality could be improved significantly,mean while, high pulping yield were maintained with less pollution. |
