Extraction of Organosolv Lignin from Rice Husk under Reflux Conditions
Marcelo Pereira da Rosa, Paulo Henrique Beck, Daniele Gomes Müller, Juliana Botelho Moreira, Jessica Silveira da Silva and Ana Maria Munaretto Durigon
School of Chemistry and Food, Federal University of Rio Grande, CEP 96217-820 Rio Grande, RS, Brazil.
Abstract: The rice husk is a very abundant residue, being rich in cellulose and lignin, whose main destination in the southern Brazil is burning for power generation. This study aims at extracting the lignin from the rice husk, applying a methodology called Organosolv, in a modified process by the use of atmospheric pressure. As the extraction solution, a mixture of ethanol/water with ethanol concentrations of the 25 to 100% v/v were used. As the catalyst for extraction, concentrated sulfuric acid, in proportions of the 0.5 to 3.0% v/v under reflux and heating by 24 hours were used. The yields obtained were between 3 and 48% for the amount of Klason lignin analyzed. The tests, which applied smaller quantities of ethanol and catalyst (sulfuric acid), presented lower yields, while the highest yields was found in the extraction solutions with 75% v/v of ethanol and 3% of catalyst. The extracted lignin was characterized by spectroscopic, chromatographic and thermal analysis. The extracted samples showed great structural homogeneity, good thermal stability, low polydispersivity (< 2,0) and low presence of contaminants such as cellulose and hemicellulose. The studied procedure aims at the reuse of an abundant agro-industrial waste, in order to reduce the environmental impact of its burning and to obtain the lignin, a natural polymer with great potential for industrial application.
Keywords: Lignin, Organosolv, reflux, rice husk, waste.
Pages: 87 – 98 | Full PDF Paper
Assessing Impacts of Climate Change and Water Induced Disasters from Gendered Perspective in Darchula, Nepal
Sajani Shrestha, Ph.D and Sushila Chatterjee Nepali, Ph.D
1. Department of Biology, Faculty of Science and Arts, Sinop University, 57000, Sinop, Turkey.
2. Department of Biology, Faculty of Science, Ankara University, 06100 Tandoğan, Ankara, Turkey.
Abstract: Climate change induced natural disasters are predicted to be increasing and its impacts are predominantly floods, rainfall variation and temperature rise with melting water towers and low water during rainy season. Especially the water induced disasters have impacted on involuntarily displacement which is likely to increase vulnerability of human communities, their livelihoods and ecosystems. Among the flood disasters linking to climate change is also seen in 2013 in Darchula in Mid-June with unprecedented rainfall in Uttarakhand and Far West of Nepal. The Gendered perspective of impacts on climate change and coping with disasters so far have not been assessed in detail. Thus, this study was designed to understand and assess Impacts of Climate Change and Water Induced Disaster with Coping Strategies from Gendered Perspective in Darchula District, Nepal. The research findings based on focus group discussion and key informant interview indicates that the families living in Shree Bagad, Khalanga, Dhap, Ukku and Galfaiarea were affected severely and lost their fertile land and houses. According to the respondents both men and women highlighted that the poorest of the poor in the village were displaced and the richer communities migrated to Mahendra Nagar. 90% of the respondents mentioned the major hazards mapped in the regions are directly and indirectly linked to climate change. The impacts observed since BS 2050 onwards are floods and landslides, which has made the whole Darchula more vulnerable than the last 30 years. Finally, both the respondents felt that sufficient coping strategies by people themselves and government are inadequate and climate change awareness for adaptation and building resilience capacity is needed.
Keywords: vulnerability, climate change, adaptation, floods and landslides.
Pages: 99 – 120 | Full PDF Paper