Characterizing the Interception Capacity of Floor Litter with Rainfall Simulation Experiments

Floor litter can reduce the amount of water reaching the soil layer through rainfall interception. The rainfall interception capacity of floor litter varies with the physical features of the litter and rainfall characteristics. This study aimed to define the maximum and minimum interception storages (Cmx, Cmn) of litter layers using rainfall simulation experiments, and examine the effects of litter type and rainfall characteristics on rainfall retention and drainage processes that occur in the litter layer. Different types of needle-leaf and broadleaf litters were used: Abies holophylla, Pinus strobus, Pinus rigida, Quercus acutissima, Quercus variabilis, and Sorbus alnifolia. Our results indicate a wide variation in interception storage values of needle leaf litter, regardless of the rainfall intensity and duration. The A. holophylla needle-leaf litter showed the highest Cmx and Cmn values owing to its short length and low porosity. Conversely, the lowest interception storage values were determined for the P. strobus needle leaf litter. No significant differences in interception storage were established for the broadleaf litter. Moreover, except for A. holophylla litter, the broadleaf litter retained more water than the needle leaf litter. An increase in the intensity or duration of rainfall events leads to an increase in the water retention storage of litter. However, these factors do not influence the litter’s drainage capacity, which depends primarily on the force of gravity.

Controlled retention and drainage of microfibrillated cellulose in continuous paper production

In the current study, an attempt has been made to scale up microfibrillated cellulose (MFC) reinforced paper using a pilot scale experimental paper machine (XPM) in continuous mode.

Circular action treatment (CAT): a new strategy for mechanical treatment of old corrugated containers II – comparison of CAT with low-consistency beating

In Korea, old corrugated containers (OCC) are a common material for paperboard production. Unfortunately, the quality of Korean OCC (KOCC) is low due to irreversible effects such as hornification that could occur by repeated drying and wetting during paper recycling. Generally, beating is a fibrillation method for improving paper strength. However, beating also results in fiber shortening and excessive fines. Circular action treatment (CAT) is a new method designed for the mild mechanical treatment of KOCC containing undesirable materials and fines. The effect of CAT and low-consistency beating on KOCC were analyzed at various conditions. The results show that increased revolution speed and passing length of CAT resulted in higher water retention values and paper strength without a sudden change in the freeness, fiber length and fines content. While paper strength was higher upon beating compared to the case of CAT, the intensive beating action in the former resulted in fiber damage, generating excessive fines and decreasing fiber length. The fines generated by beating might be negative to retention and drainage in wet-end. Therefore, CAT is a promising new strategy for KOCC mechanical treatment, and an increase in the revolution speed and passing length of CAT could improve KOCC quality.