Comparable Characterization of Nanocellulose Extracted from BleachedSoftwood and Hardwood Pulps

In this study, the characteristics of nanocellulose extracted from bleached softwood and hardwood pulps by formic acid hydrolysis followed by TEMPO-mediated oxidation were compared using transmission electron microscopy(TEM), atomic force microscopy(AFM), Fourier transform infrared analysis(FT-IR), X-ray diffraction(XRD), and thermal gravimetric analysis(TGA). The experimental results showed that the nanocellulose products derived from spruce pulp exhibited a relatively larger particle size, higher crystallinity, and higher thermal stability, compared with the corresponding products obtained from aspen pulp under the same conditions.Furthermore, the study helped establish that the properties of the nanocellulose products were highly dependent on the nature of the starting materials under identical processing conditions.

Rice Husk Bio-Chars as Adsorbent for Methylene Blue and Ethinylestradiol from Water

Biobased adsorbents are eco-friendly materials used for water and wastewater treatment and air cleaning.This research work explores the potential use of rice husk chars as a low-cost adsorbent for pollutants from water,such as methylene blue and ethinylestradiol.Rice husk chars are prepared by combustion of rice husks(RH-Char)or pre-treated rice husks(PT-Char).A third char(M-Char)supplied by a local company which uses rice husks as combustion material is also studied.The chars are characterized by field emission scanning electron microscopy(FE-SEM)in conjunction with energy dispersive X-ray spectroscopy(EDX),X-ray powder diffraction(XRD),and zeta-potential measurements.The three bio-chars are tested as adsorbent for the removal of two wastewater contaminants:methylene blue(MB)and ethinylestradiol(EE2).According to the results,RH-Char and PT-Char present zeta-potential values near−52 mV,whereas M-Char shows a zeta-potential value of−32 mV.Both RH-Char and PTChar are rich in amorphous SiO_(2) and M-Char has crystalline SiO_(2)(cristobalite).The bio-chars remove MB and EE2 efficiently showing the following results for the adsorption capacity of MB(inμmol g^(−1)):769.2(RH-Char),41.2(PT-Char),and 31.7(M-Char).The adsorption capacity values for EE2(inμmol g^(−1))are:33.1(RH-Char),19.1(PT-Char),and 16.9(M-Char).The information gathered in the present work evidences the potential of rice husks bio-chars for bio-remediation and may in future contribute to the conversion of a side-stream from the rice industry into value-added materials.