ABSTRACT
Ethylene, a plant hormone, is a gas that plays a crucial role in fruit ripening and senescence. In this work, a novel ethylene scavenger was prepared from amorphous silica-alumina derived from sugar cane bagasse ash (SC-ASA) and used to prolong the shelf life of mango fruits during storage. KMnO4 at 2, 4, or 6 wt %/w was loaded on SC-ASA using an impregnation method. The results showed that 4% w/w KMnO4 loaded on SC-ASA (4KM/SC-ASA) was superior for ethylene removal at an initial ethylene concentration of 400 µL L-1 for 120 min under ambient conditions (25-27 °C and 70-75% relative humidity), resulting in 100% ethylene removal. The kinetic study of ethylene removal showed that the adsorption data were best fitted with a pseudo-first-order kinetic model. The effects of 4KM/SC-ASA as sachets on the quality changes of the mango fruits were investigated, with the results showing that mango fruits packed in cardboard boxes with 4KM/SC-ASA had significantly delayed ripening, low levels of ethylene production, respiration, and weight loss, high fruit firmness, low total soluble solids, and high acidity compared to those of the control treatment. These findings should contribute to developing an ethylene scavenger to extend the shelf life of fruits, reduce the waste of the sugar and ethanol industries, and make it a valuable material.
ABSTRACT
Itaconic acid is an organic acid with a wide range of applications in the fields of polymer chemistry, pharmacy, agriculture, textile industry, etc. A bio-synthetic process of itaconic acid production in this study was carried out with Aspergillus terreus K17 having empty palm oil fruit bunches as a feedstock. Bio-synthesis of itaconic acid was compared with commercial maleic acid, itaconic acid and 1, 2, 3, 4-butanetetracarboxylic acid (BTCA) as anti-crease agents with sodium hypophosphate (SHP) as an esterification catalyst for cotton fabric finishing. The results showed that mechanical properties of cotton fabrics treated with bio-synthesized itaconic acid were better than those treated with the commercial ones whereas their whiteness index was lower. The best conditions for crease recovery were obtained from 8% w/v itaconic acid with 8% w/v SHP applied on cotton fabrics with a technique of 2-dip-2-nip, dried at 85 °C for 3 min and cured at 180 °C for 2 min. Even though the anti-crease properties of cotton fabrics treated with bio-synthesized itaconic acid were still lower than those treated with commercial maleic acid and BTCA, the finished cotton fibers retain the mechanical properties of cotton fabric. This study would be beneficial in producing itaconic acid as an eco-friendly anti-crease agent for cotton fabrics from waste empty palm oil fruit bunches by a bio-synthesis process.
ABSTRACT
Pineapple leaves were used as a natural fiber source to prepare various modified microcrystalline cellulose (MCC) samples as sorbents for H2S sorption. Pineapple leaf fibers were first extracted from pineapple leaves, followed by hydrolyzing to produce MCC before various modifications using primary amine (3-aminopropyltrimethoxysilane, APS), secondary amine (N-methyl-3-aminopropyltrimethoxysilane, MAPS), or tertiary amine (N,N-dimethyl-3-aminopropyltrimethoxysilane, DAPS). The characterization results proved that all the aminosilane groups were successfully grafted onto the MCC. In addition, the thermal stability and the porosity of the modified sorbents were enhanced relative to those of unmodified MCC. The H2S sorption studies of MCC modified with APS, MAPS, and DAPS at 0, 3, or 5%w/w showed that MCC-MAPS had better H2S sorption performance than MCC-APS and MCC-DAPS, respectively, when comparing the H2S sorption performance at the same loading level. The optimum H2S sorption performance of each aminosilane group was achieved from MCC-APS at 5%, MCC-MAPS at 3%, and MCC-DAPS at 5%. An additional study of H2S sorption of these three sorbents in the presence of CO2 showed that MCC-DAPS at 5% was the best sorbent for selective H2S removal. Our results indicated that MCC modified with the aminosilane groups, especially MAPS, were promising materials for H2S sorption, with potential application in gas separation.
Subject(s)
Ananas , Plant LeavesABSTRACT
Since large amounts of pineapple leaves are abandoned after harvest in agricultural areas, the possibility of developing value-added products from them is of interest. In this work, cellulose fiber was extracted from pineapple leaves and modified with ethylenediaminetetraacetic acid (EDTA) and carboxymethyl (CM) groups to produce Cell-EDTA and Cell-CM, respectively, which were then used as heavy metal ion adsorbents. A solution of either lead ion (Pb2+) or cadmium ion (Cd2+) was used as wastewater for the purpose of studying adsorption efficiencies. The adsorption efficiencies of Cell-EDTA and Cell-CM were significantly higher than those of the unmodified cellulose in the pH range 1-7. Maximum adsorptions toward Pb2+ and Cd2+ were, for Cell-EDTA, 41.2 and 33.2 mg g-1, respectively, and, for Cell-CM, 63.4 and 23.0 mg g-1, respectively. The adsorption behaviors of Cell-CM for Pb2+ and Cd2+ fitted well with a pseudo-first-order model, but those of Cell-EDTA for Pb2+ and Cd2+ fitted well with a pseudo-second-order model. All of the adsorption behaviors could be described using the Langmuir adsorption isotherm. Desorption studies of Pb2+ and Cd2+ on both adsorbents using 1 M HCl suggested that regenerability of Cell-EDTA was, for both adsorbates, better than that of Cell-CM. Moreover, adsorption measurements in a mixture of Pb2+ and Cd2+ at various ratios showed that for both adsorbents the adsorption of Pb2+ was higher than that of Cd2+, while the adsorption selectivity for Pb2+ of Cell-CM was greater than that of Cell-EDTA. This study showed that the modified cellulosic adsorbents made from pineapple leaves were able to efficiently adsorb metal ions.
