Optimal Variable Combinations of Co-pelletization of Eucalyptus Sawdust and Natural Forest Sawdust

Eucalyptus sawdust is a residue from fast-growing forest processing.Utilization of Eucalyptus sawdust as fuel by co-pelletization with natural forest sawdust could solve problems of waste disposal and material supply limitation of pellet production.This work targeted at providing a useful reference for improving pellet properties and optimizing variable combinations.Experiments were arranged using response surface methodology with a central composite design and carried out using a uniaxial piston-cylinder densification apparatus.Based on the analysis of variance of effects of variables on responses,the optimal models were all selected as quadratic and expressed in the form of regression equations.The differences between adjusted R2 and predicted R2 are all within 0.2 and the adequate precision is all greater than four illustrating the reliability of the established models.The optimal variable combinations were obtained according to the desired response goals and validation experiments were conducted.Errors between response predicted and actual values were calculated and applied to improve the model accuracy.After modification,final errors were reduced to less than 9%and could be accepted by pellet production.Experimental results also demonstrated that pellet properties and higher heating value were all increased by co-pelletization and optimization.This will be very beneficial for pellet application.Furthermore,these results could provide the required data for designing a suitable machine of pellet production.

Relationship between physicochemical properties and dewaterability of hydrothermal sludge derived from different source

Sewage sludge（SS） and deinking sludge（DS） were used to comparatively study the hydrothermal dewatering of sludge with different components. For a better overview, an insight into the relationship between physicochemical properties and dewaterability of hydrothermal sludge was provided. Results found that not all kinds of sludge were suitably conditioned by hydrothermal treatment（HT） in term of the elevation of dewaterability.Higher hydrothermal temperature tended to enhance the dewaterability of SS rather than DS, which was supported by the variation of their physicochemical properties（including water distribution, bonding energy, extracellular polymeric substance（EPS）, particles size,acid functional groups and zeta potential in this study）. In addition, the changes in surface morphology suggested that the reverse effect of HT on sludge dewaterability was mainly due to their dewatering behavior. For SS, the destruction of EPS structure leaded to the release of bound water, thereby strengthening sludge dewatering. Conversely, ＂Bridging effect＂ generated by lignocellulose in DS was beneficial for sludge dewatering; however, the increasing hydrothermal temperature degraded part of lignocellulose and weakened＂bridging effect＂, finally resulting in worse dewaterability of DS.

Three nitrogen-containing metabolites from an algicolous isolate of Trichoderma asperellum

As one of the most productive species,Trichoderma asperellum,especially isolated from marine algae,has contributed a number of new terpenes and nitrogen-bearing compounds,encouraging our continuous efforts to further explore them.Consequently,three new nitrogen-containing secondary metabolites,including cyclo(L-5-MeO-Pro-L-5-MeO-Pro)(1),5'-acetoxy-deoxycyclonerin B(2),and 5'-acetoxy-deoxycyclonerin D(3)were isolated from the marine alga-derived endophytic fungus Trichoderma asperellum A-YMD-9-2.Their structures and relative configurations were fully elucidated through spectroscopic techniques,mainly including 1D/2D NMR and MS.The absolute configurations of 1 and 2 were ascertained on the basis of X-ray diffraction(Cu Kα radiation)and ECD data,respectively.The isolation of these new nitrogen-bearing compounds adds to the structural diversity of marine algicolous Trichoderma spp.,and they display potent inhibition against some marine phytoplankton species.