Physical, Chemical, and Rheological Properties of Rice Husks Treated by Composting Process

Abstract

A composting treatment was employed in an effort to improve the processability of rice husks. Changes in the chemical composition, physical structure, and rheological properties of modified rice husks were analyzed. The results indicated that the average diameter of composttreated samples was significantly higher than that of the untreated samples because they were able to adhere to each other by the bacterial protein. Scanning electron microscopy images showed that the epidermis became rugged and lumpy because the composition of rice husks (cellulose, hemicellulose, lignin, and pectin) was partially decomposed, an effect confirmed by the chemical composition and FTIR analysis. Thermogravimetric analysis showed that the composted samples had better thermal stability than the untreated ones. Stress-strain curves showed that the treated samples displayed a moderately significant change of slope at about 0 to 10% strain, and they had better mechanical properties than untreated samples. Juxtaposing the rheological properties of both untreated and treated samples determined that the latter had higher apparent viscosity as a result of degradation and bacterial protein effects. All results indicated that the composting treatment changed the physical, chemical, and rheological properties of the rice husks, which are beneficial for its utilization and processability.

Characterization of Pyrolytic Tars Derived from Different Biomasses

“…The distributions of lignocellulose components in sawdusts were similar and consistent with previously reported values [43]. Rice husk composition was in line with other reports: 25-40% cellulose, 8-21% hemicellulose, 15-31% lignin, 15-17% ash and waxes, 2-8% other soluble substances and up to 3% proteins [44,45]. Particularly, Costa et al [46] studied the contents of the lignocellulosic components of zoita sawdust to evaluate its potential as a pyrolysis raw material and reported 23.5 %wt.…”

Characteristics of organic fertilizer derived from fleshing waste with teak (Tectona grandis) wood scrap

“…Previous research found that rice husks had moisture content of 9.5%, 48.1% of total carbon, 0.78% nitrogen total (Wu et al, 2015), and C/N ratio at 73.4 (Bian et al, 2019). As shown in Table 1, teak (Tectona grandis) wood scraps sample displayed a relatively similar character with rice husks, except C/N ratio.…”

Caracterização química de compostos e vermicompostos produzidos com casca de arroz e dejetos animais

“…micro-organismos que são capazes de produzir enzimas celulases e às xilases que degradam a celulose e a hemicelulose (Wu et al, 2015). Maior teor de lignina (Tabela 5) foi verificado quando utilizado dejeto de suínos (9,40%) e menor com dejeto de bovinos (7,2%), tanto em compostagem quanto em vermicompostagem.…”