ABSTRACT

In this research, chitosan based membrane blended with rice hull ash (RHA) silica and polyethylene glycol (PEG) has been applied as adsorbent of Ca(II), Mg(II), Zn(II) and Cd(II) based on the adsorption data at initial metal ion concentration and contact time variations, respectively. Results showed that the optimum condition of adsorption was at pH 9.0 for Ca(II), 6.0 for both Mg(II) and Zn(II) and 5.5 for Cd(II), and contact time of 24 h for all ions investigated. Kinetics of all investigated metal ion adsorption followed a kinetic model of pseudo-second-order. Adsorption of Ca(II) and Mg(II) on the membrane fitted toFreundlich model with the affinity of 1.266 and 1.099, respectively; and Zn(II)

CaO is a very good catalyst for oil transesterification reactions into biodiesel, but requires a reaction time of 2 hours to obtain equilibrium. The time of CaO catalysis reaction can be accelerated by modifying the CaO catalyst with SrO. Synthesis biodiesel of waste cooking oil has been successfully conducted by transesterification reaction that used batch reactor assisted by CaO.SrO catalyst. The aim of this study is to determine the characteristics and catalytic activity of catalyst in the transesterification reaction. Catalysts have been successfully synthesized by coprecipitation method with oil to methanol molar ratio of 1:1, and its calcined at 800 o C for 3 hours. Catalyst was characterized by XRD to determine the crystallinity. The smaller catalyst crystallinity obtained as the decline in intensity and shifts diffraction angles of CaO modified SrO catalyst. Surface area of catalyst characterized by SAA, that allow surface area between CaO modified SrO by 10.217 m 2 /g. Transesterification reaction performed on variation time (30, 60, 90, 120, 150 minutes), and the catalysts amount (1, 2, 4, 6, 8% w /v). The optimum condition of catalytic activity in reaction for 2 hours and the catalyst amount is 1% w /v of reactants that produce yield of biodiesel is 96.4%.

Seawater bittern is a liquid that still exists after most of the NaCl has crystalized in the production of salt from seawater. The main components of the liquid are MgCl2 and NaCl. This study aims to recover the NaCl present in bittern through the precipitation method with NaOH and evaporation. The initial stage of this research was collection of bittern in the salt production process in a salt pond. The obtained bittern samples were then added with NaOH to precipitate the MgCl2 components as Mg(OH)2 and leave NaCl as filtrate. The precipitate and the filtrate were separated by filtration. The obtained NaCl filtrate is then evaporated to obtain high purity NaCl. The product obtained was then determined the NaCl contents by argentometric titration. NaCl crystal was characterized using FTIR spectroscopy XRD spectroscopy, and Scanning Electron Microscope (SEM). The recovery results showed that the NaCl obtained had a high purity of 98.75% w/w and yield 30,45%. The IR spectra and diffractogram obtained showed compatibility with the characteristics of the reference NaCl.

This article discusses the research results on the synergetic effect of chitosan and vitamin C in overcoming free radical effect due to blood lead (Pb 2+ ) accumulation. Blood lead level and enzymatic activities of superoxide dismutase (SOD), catalase oxidase (CAT), and Glutathione peroxidase (GPx) were used as the main parameters. Thirty adult male albino rats were divided into six groups. Group 1 was normal control group; group 2 was the negative control group treated with lead acetate at 175 mg kg -1 body weight (BW). Group 3 was treated with 64 mg kg -1 BW of chitosan day -1 . Group 4, 5, and 6 were treated with chitosan and vitamin C combination at the dose of 100, 200, and 300 mg kg -1 BW, respectively. All groups were inducted using 175 mg kg -1 BW of Pb-acetate, excluding control group. Results showed that chitosan and vitamin C treatment at the dose of 300 mg kg -1 BW decreased blood Pb 2+ level in rats exposed to Pb-acetate. The combination also significantly increased enzymatic activities from SOD, CAT, and GPx compared to the other groups. In conclusion, the combination of chitosan and vitamin C could elevate the several antioxidative enzymes activities in Pb-acetate induced rats.Keyword: chitosan; antioxidative enzyme; lead-induced rat.Efeito sinérgico do chitosano e da vitamina C no estado da enzima oxidativa em ratos expostos ao acetato de chumbo RESUMO. Este artigo discute os resultados da pesquisa sobre o efeito sinérgico da quitosana e da vitamina C na superação do efeito dos radicais livres devido ao acúmulo de chumbo no sangue (Pb 2+ ). O nível de chumbo no sangue e as atividades enzimáticas de superóxido dismutase (SOD), catalase oxidase (CAT) e glutationa peroxidase (GPx) foram utilizados como parâmetros principais. Trinta ratos albinos adultos foram divididos em seis grupos. Grupo 1 foi grupo controle normal; o grupo 2 foi o grupo controle negativo tratado com acetato de chumbo a 175 mg kg -1 de peso corporal (PC). O grupo 3 foi tratado com 64 mg kg -1 PC de quitosana dia -1 . Os grupos 4, 5 e 6 foram tratados com combinação de quitosana e vitamina C nas doses de 100, 200 e 300 mg kg -1 PC, respectivamente. Todos os grupos foram induzidos usando 175 mg kg -1 de PC de Pb-acetato, excluindo o grupo controle. Os resultados mostraram que o tratamento com quitosana e vitamina C na dose de 300 mg kg -1 PC diminuiu o nível de Pb 2+ no sangue em ratos expostos ao acetato de Pb. A combinação também aumentou significativamente as atividades enzimáticas de SOD, CAT e GPx em comparação com os outros grupos. Em conclusão, a combinação de quitosana e vitamina C pode elevar as várias atividades das enzimas antioxidativas em ratos induzidos com acetato de Pb.Palavras-chave: enzima antioxidante; quitosana; rato induzido por chumbo.