Papers by Author: Chuan Chi Chien

Abstract: About 1 million tons of waste rice husk are generated in Taiwan each year. Rice husk has high concentrations of nutrients, such as silicon and potassium. However, it is not decomposed easily because it contains over 70% of cellulose and lignin and hence it is not suitable to be added into soil. In this study, a large quantity of rice husk is carbonized by vertical type continuous carbonization furnace without the presence of oxygen. After it is carbonized, it becomes rice husk charcoal (RHC) and vinegar (RHV). We have found that the addition of RHC carbonized at 600 and 700°C to soil can increase the soil’s concentrations of calcium, magnesium, potassium and silicon as well as its pH value (i.e., lowering its acidity level). Therefore, RHC is a great soil modifier because it can lower the soil’s acidity and increase the soil’s nutrients. According to our experiments, the pH values of the mixtures in different ratios exhibited an increasing and steady of final condition in the 80-day period. The reason was that the CEC (cation exchange capacity) of the mixtures were increased, the specific surface areas of the mixtures increased and the mixtures’ acidity levels were lowered. Therefore, the incorporation of RHC in the soil would benefit the soil on a long-term basis.

Abstract: Mikania micrantha has invasive alien species harmful to many plants; it natively grows in South and Central America area. But now it is found throughout Asia and India area. It has a big reproductive capacity, so several researchers ever used thermal treatment, controlled-environmental treatment, mechanical treatment and biological control treatment to inhibit Mikania micrantha growth. However, rare studies use Mikania micrantha to make building materials. In this paper we will attempt to use untreated and treated (treated by carbonization) Mikania micrantha for making building bricks. Results are shown that the optimal uniaxial compressive strength occurred as 30 wt. % of the carbonized Mikania micrantha; the optimal uniaxial compressive strength took place as 40 wt. % of carbonized Mikania micrantha with an addition of organic acid. But the fresh Mikania micrantha has a lower uniaxial compressive strength, so we used interpolation method to calculate the optimized mixing ratio would be 5:95 for the fresh Mikania micrantha. In addition, Mikania micrantha as building material has no biotoxicity for E. coli.