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The feasibility of incorporating purified kraft lignin, at different concentrations ranging from 5 to 29%, into fiberboards made from corn residues was studied. The lignin was obtained from black liquor, which is a residue of the paper industry. Corn stalk raw material and its thermomechanically produced fiber were characterized in terms of their chemical composition. The physical and mechanical properties of the resulting fiberboards were evaluated. The fiberboards produced following a wet process had good mechanical and water resistance properties that satisfied the requirements of the relevant standards. In addition, a Life Cycle Thinking (LCT) approach suggested that lignin-based fiberboards are environmentally preferable than those based on thermosetting resins.

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The objective of this study was to investigate the influence of fiber morphology and molding parameters on mechanical and physical properties of fiberboards made from rice straw. The rice straw was thermo-mechanically treated using a twin-screw extruder. Water added at molding (0-20%), lignin content (0-25%), and liquid/solid ratio used for extrudate production (0.33-1.07) were the three parameters investigated. A Doehlert's experimental design was used to evaluate their influence on boards' properties. The results revealed that 0.4 liquid/solid ratio at extrudate production, 5% water added at molding, and 8.9% lignin content were the best tested conditions for bending properties. Density of fiberboard produced from these conditions was 1414 kg/m 3 (i.e. the densest board). Maximum flexural strength and elastic modulus were 50.3 MPa and 8.6 GPa, respectively. Thickness swelling and water absorption were 23.6% and 17.6%, respectively. Using the statistical analysis of the experimental design, a good compromise between density and flexural properties should be obtained from 0% water added, 25% lignin content, and 0.33 liquid/solid ratio at extrudate production. From the polynomial models, the corresponding boards' properties should be approximately 50 MPa maximum flexural strength, 6.0 GPa elastic modulus, 1102 kg/m 3 density, and 24% thickness swelling.

Agricultural expansion and urban development without proper soil erosion control measures have become major environmental problems in Cambodia. Due to a high population growth rate and increased economic activities, land use and land cover (LULC) changes will cause environmental disturbances, particularly soil erosion. This research aimed to estimate total amounts of soil loss using the Revised Universal Soil Loss Equation (RUSLE) model within a Geographic Information System (GIS) environment. LULC maps of Japan International Cooperation Agency (JICA) 2002 and Mekong River Commission (MRC) 2015 were used to evaluate the impact of LULC on soil erosion loss in Stung Sangkae catchment. LULC dynamics for the study periods in Stung Sangkae catchment showed that the catchment experienced a rapid conversion of forests to paddy rice fields and other croplands. The results indicated that the average soil loss from the catchment was 3.1 and 7.6 t/ha/y for the 2002 and 2015 periods, respectively. The estimated total soil loss in the 2002 and 2015 periods was 1.9 million t/y and 4.5 million t/y, respectively. The soil erosion was accelerated by steep slopes combined with the high velocity and erosivity of stormwater runoff. The spatial distribution of soil loss showed that the highest value (14.3 to 62.9 t/ha/y) was recorded in the central, southwestern and upland parts of the catchment. It is recommended that priority should be given to erosion hot spot areas, and appropriate soil and water conservation practices should be adopted to restore degraded lands.