Characterization of Biochar Derived from Rubber Wood Sawdust through Slow Pyrolysis on Surface Porosities and Functional Groups

Biochars were prepared by conducting slow pyrolysis of rubber wood sawdust (RWSD) derived from sawn timber. Eventhough researches on preparation of biochar from biomass have been reported by many researchers, limited work has been reported for investigation of biochar RWSD for its surface porosities and functional groups. Surface porosity of biochars provides a suitable dimension for cluster of microorganism to grow and higher porosity for better water holding capacity. Surface functional groups contain oxygen may help to improve the soil fertility by increasing the cation and anion exchange capacities to reduce the nutrient leaching in soil. The pyrolysis process was carried out at temperatures ranging between 300 °C to 700 °C at the heating rate of 5 °C/min for 3 hours with continuous nitrogen purging. The influence of pyrolysis temperatures on the biochars pores were investigated by using X-Ray Diffraction (XRD), Brunauer-Emmett-Teller (BET) surface analysis and Scanning Electron Microscopy (SEM). The surface functional groups were examined by Fourier Transform Infrared (FT-IR). SEM analysis clearly showed the development of well-defined pores distributed on biochars surface. It was found that the maximum BET surface area and total pore volume were 5.493 m2/g and 0.0097 cm3/g respectively for biochar pyrolysis at 700 °C. The FT-IR spectrum analysis showed the functional groups decreased with the increasing of pyrolysis temperature. The results highlighted the effect of pyrolysis temperature on biochar pores accumulative that associated with soil fertility and nutrient retention in soil which could be beneficial to the agricultural industries

Xyloglucan is released by plants and promotes soil particle aggregation.

Soil is a crucial component of the biosphere and is a major sink for organic carbon. Plant roots are known to release a wide range of carbon-based compounds into soils, including polysaccharides, but the functions of these are not known in detail. Using a monoclonal antibody to plant cell wall xyloglucan, we show that this polysaccharide is secreted by a wide range of angiosperm roots, and relatively abundantly by grasses. It is also released from the rhizoids of liverworts, the earliest diverging lineage of land plants. Using analysis of water-stable aggregate size, dry dispersion particle analysis and scanning electron microscopy, we show that xyloglucan is effective in increasing soil particle aggregation, a key factor in the formation and function of healthy soils. To study the possible roles of xyloglucan in the formation of soils, we analysed the xyloglucan contents of mineral soils of known age exposed upon the retreat of glaciers. These glacial forefield soils had significantly higher xyloglucan contents than detected in a UK grassland soil. We propose that xyloglucan released from plant rhizoids/roots is an effective soil particle aggregator and may, in this role, have been important in the initial colonization of land

Influence of heating temperature and holding time on biochars derived from rubber wood sawdust via slow pyrolysis

Biochar samples were produced from rubber wood sawdust (RWSD), which is a by-product from sawmills, via slow pyrolysis. Biochar is a potential additive for agricultural soil as a soil amendment and for agronomics. The approach proposed in the current study considers the effects of heating temperature and holding time on the surface functional groups and morphologies of RWSD-derived biochars. The pyrolysis was performed in a vertical tube furnace heated at 5 °C/min from room temperature to maximum heating temperatures of 300 °C, 400 °C, 500 °C and 700 °C under nitrogen gas purging at a rate of 30 ml/min. Two sets of biochars were produced with holding times of (i) 1 h and (ii) 3 h. Proximate and ultimate analyses were performed on the raw RWSD using thermogravimetric analysis (TGA) and carbon–hydrogen–nitrogen (CHN) elemental analysis. The influence of heating temperature and holding time on biochar surface functional groups and porosities was investigated using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Boehm titration, pH alkalinity, Brunauer–Emmett–Teller (BET) surface area analysis, scanning electron microscopy (SEM) and SEM with energy-dispersive X-ray (SEM–EDX) spectrocopy. The FT-IR spectra indicated the presence of acidic functional groups, such as carboxylic, phenolic and lactonic groups, and these groups were quantified by Boehm titration. The number of acidic functional groups decreased as the heating temperature and holding time increased. The maximum amount of acidic functional groups was determined to be 1.9 mmol/g at 300 °C for a 1-h holding time compared to 1.3 mmol/g for a 3-h holding time and 1.0 mmol/g with a 1-h holding time at 700 °C. All of the biochars produced at heating temperatures above 400 °C were alkaline, and the pH value increased as the heating temperature and holding time increased. The biochar produced at 300 °C with a 1-h holding time had a pH of 6.72 and the sample produced with a 3-h holding time had a pH of 7.67. In addition, the sample produced when the temperature was increased to 700 °C with a 1-h holding time had a pH of 11.44. The BET surface area analysis reported maximum values of 5.49 m2/g, and the total pore volume was 0.0097 cm3/g at a heating temperature of 700 °C with a 3-h holding time. SEM micrographs clearly showed the development of well-defined pores in the biochars, and the SEM–EDX spectra indicated localised carbon and oxygen content in all the samples. The results indicated that biochars produced from RWSD are potentially beneficial as soil amendments. However, an extensive study of biochar sustainability is worth investigating

How 'universal' is the United Nations' Universal Periodic Review process? An examination of the discussions held on polygamy

In 2006, United Nations Human Rights Council was tasked to establish a new human rights monitoring mechanism: Universal Periodic Review process. The primary aim of this process is to promote and protect the universality of all human rights issues and concerns via a dialogical peer review process. The aim of this investigation isto ask the following question: has this claim of promoting and protecting the universality of the human rights been met, or challenged, during state reviews in the UPR process? The issue of polygamy has been selected as the focus for this investigation to be used, primarily, as a tool to undertake an in-depth analysis of the discussions held during state reviews in the review process. In addition, this paper will employ scholarly debates between universalism and cultural relativism, as well as the sophisticated and nuanced approaches that fall in between the polarised opposites, to analyse the discussions held on human rights during state reviews. Ultimately, the findings and discussion of this investigation will provide a unique and valuable insight to the work and operation of the UPR process, so far

A fresh look at the evolution and diversification of photochemical reaction centers

In this review, I reexamine the origin and diversification of photochemical reaction centers based on the known phylogenetic relations of the core subunits, and with the aid of sequence and structural alignments. I show, for example, that the protein folds at the C-terminus of the D1 and D2 subunits of Photosystem II, which are essential for the coordination of the water-oxidizing complex, were already in place in the most ancestral Type II reaction center subunit. I then evaluate the evolution of reaction centers in the context of the rise and expansion of the different groups of bacteria based on recent large-scale phylogenetic analyses. I find that the Heliobacteriaceae family of Firmicutes appears to be the earliest branching of the known groups of phototrophic bacteria; however, the origin of photochemical reaction centers and chlorophyll synthesis cannot be placed in this group. Moreover, it becomes evident that the Acidobacteria and the Proteobacteria shared a more recent common phototrophic ancestor, and this is also likely for the Chloroflexi and the Cyanobacteria. Finally, I argue that the discrepancies among the phylogenies of the reaction center proteins, chlorophyll synthesis enzymes, and the species tree of bacteria are best explained if both types of photochemical reaction centers evolved before the diversification of the known phyla of phototrophic bacteria. The primordial phototrophic ancestor must have had both Type I and Type II reaction centers

Can weight loss prevent cancer?

We review and update evidence on obesity, weight gain and weight loss in relation to leading cancers since the International Agency for Research on Cancer report of 2002. Emphasis is placed on the time course of disease and implications for weight control to prevent cancer. We conclude that weight loss could prevent a major portion of common cancers