ABSTRACT
We pretreated sawdust (Castanopsis fissa Rehd.et Wils) by solid state fermentation (SSF) with Phanerochaete chrysosporium, and then compressed it into pellets with the moisture content of 15% and the pressure of 98 MPa, to solve the problem of low density, low Meyer hardness, high water uptake, and short storage period of pellet in the woody pellet industry. We studied the effects of fermentation time on pelletization and pellets's characteristics (including energy consumption, density, Meyer hardness, and hydrophobicity). SSF affected the heating values of pellet. Compared with fresh sawdust, SSF consumed more energy at the maximal value by 6.98% but saved extrusion energy by 32.19% at the maximum. Meanwhile, SSF could improve the density, Meyer hardness and hydrophobicity of pellet. Pellet made of sawdust pretreated by SSF for 48 d had best quality, beneficial for long-term transportation and storage of pellets.
Subject(s)
Biofuels , Fermentation , Hydrophobic and Hydrophilic Interactions , Phanerochaete , Water , WoodABSTRACT
Biosurfactant is a high surface active agent synthesized by microorganism Compared with chemical surfactant, biosurfactant has a low toxicity to ecological system of Earth So biosurfactant is gradually applied to many aspects of environmental pollution control A review is made from several aspects: screening of biosurfactant producing microorganism, optimization of culture brooth, isolation of biosurfactant et al In addition, on the foundation of the analysis, several suggestions about the development of biosurfactant are proposed in the end
ABSTRACT
Objective To understand the control of medical waste disposal in Changsha. Methods The kinds, output, collection and disposal of medical wastes were investigated in three general hospitals, one tumor hospital and one paediatric hospital in Changsha. Results The main components of medical wastes were glass, plastic and cotton, which took 55%, 20% and 12% of the total output respectively. The daily outputs of medical wastes were 0.48?0.63 and 0.43 kg per bed in three general hospitals, 0.58 and 0.71 kg per bed in paediatric hospital and tumor hospital respectively. Based on these data, the daily output of medical wastes in Changsha was estimated about 9.390 t. The recovery rate of medical wastes mainly including glass and plastic was 49.32%. The disposal rate of medical wastes only was 1.34%. The rest of medical wastes of 49.34% were mixed into domestic wastes or landfilled. Conclusion The management of medical wastes wasn't perfect in Changsha, which presented potential environmental pollution.