Potential of sugarcane bagasse in remediation of heavy metals: A review.

Presence of heavy metal (HM) ions in wastewater have emerged as among the most prominent issues for improving water quality and reducing it's consequences for the environment, animal and public health. This paper mainly focuses on the remediation of HM ions from wastewater utilizing the relatively inexpensive and widely accessible agricultural waste-Sugarcane Bagasse (SCB). For this, a brief understanding of HMs was discussed (by understanding the sources and toxicity of HM, advantages and shortcomings of conventional processes). Apart from that, to understand the potential of SCB, this review would provide vital information on employing SCB biosorbent in natural and modified forms for HM removal. Therefore, various ways of SCB modifications (including physical, chemical, and composite formation), essential optimal operational conditions (solution pH, dosage of biosorbent, initial metal concentration, contact time, agitation speed, temperature, suitable isotherm and kinetic model) and involving adsorption mechanism were also studied. Finally, significant study gaps were identified to facilitate future research since SCB has been confirmed as a potential bio-adsorbent for removing HM ions.

Lignocellulosic composition based thermal kinetic study of Mangiferaindica Lam, Artocarpus Heterophyllus Lam and Syzygium Jambolana seeds.

In the present study, pyrolysis of mangifera indica L., Artocarpus heterophyllus L. and jambolana seeds have been performed using thermogravimetric analysis. These biomasses have enriched lignocellulosic composition of hemicellulose (5-10%) and lignin (1-3%) which are unexplored. The TGA analysis was performed at various heating rates of 10, 15, 20, 25 and 30 °C/min from 25 to 600 °C. Kinetic investigation of the pyrolysis method using TGA statistics has been done using iso-conversional models of Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose, Vyazovkin and Vyazovkin AIC. The apparent activation energies value ranged from 179.86 to 226.31 kJ/mol in the fractional conversion range of 0.1 to 0.7.

Structural Characterization of Indian Vitrinite-Rich Bituminous Karharbari Coal.

The detailed investigation of the chemical structure of vitrinite-rich Karharbari coal was performed utilizing advanced analytical techniques. The salient objective of this work is the evaluation of various structural properties of coal, which is necessary for identifying the chemical and physical interactions between coal and various reactants during its utilization. Karharbari coal is a poorly organized coal with high aromatic content. The value of corrected aromaticity (f a') was found to be 0.82 by 13C NMR spectroscopy and was also confirmed by XRD (aromaticity = 0.84) and FT-IR analysis (aromaticity = 0.82). The average molecular weight of the aromatic cluster was found to be 507 amu by the NMR result, which is closer to the result obtained by HRTEM (MW = 530 amu). The structural and lattice parameters of Karharbari coal were obtained by NMR spectroscopy and then compared with the similar rank Argonne Premium coal. The molecular weight distribution was obtained by LD-TOF-MS and compared with HRTEM fringe model analysis. The presence of different heteroatoms like carbon, oxygen, nitrogen, and sulfur with their functionalities was determined by using the XPS technique. Different carbon/oxygen functionalities present in the Karharbari coal were found to be (C-C) and (C-H) 68.5%, (C-O) 23.4%, (COO-) 1.9%, and (C=O) 6.0%. Nitrogen functionalities such as pyridine, pyrrolic, quaternary, and oxidized nitrogen and their compositions (mol %) were 19.3, 45.6, 31.2, and 3.7%, respectively. Different forms of sulfur were also found to be present, namely, thiophenes, sulfones, sulfuric acid, and sulfates with the molar contents of 16.4, 41.6, 21.3, and 20.5%, respectively. This information will be useful in improvising coal utilization techniques.