| With the rapid development to economy in world and the increasing need for resources,the agriculture as a biomass resource is developing rapidly.However,harvesting fruit supervenes with a large number of agricultural wastes,which badly brings about environmental pollution and ecological damage.Meanwhile,all the countries in world are facing the problems of resource shortage and energy crisis after the prompt development of national economy.It will produce great economic benefits if the agricultural wastes as a rich biomass resource can be recycled and utilized,which not only relieves the two problems,but also eases the environmental pressure resulted from agricultural wastes.This study selected the banana pseudo-stem from characteristic plants in Hainan province as the research object,explored environmentally friendly technology as degumming processes to rapidly extract high-valuable cellulose from the banana pseudo-stem,analyzed the performances of products based on different degumming technologies,and probed the practical value in different fields to enhance their economic additional values.Firstly,the components including crude protein,crude fat and soluble sugar in banana pseudo-stem are analyzed according to the standard method of cellulosic materials.The test results shown that the banana pseudo-stem has nutritional value to produce feed,compost and biogas.Additionally,the contents of water,ash,fat and wax,water soluble,pectin,hemicellulose,lignin and cellulose.The results investigated high-content cellulose(30.11%)in banana pseudo-stem,suggesting the suitable applications of spinning,paper-making and cellulose extraction after pre-treatment technologies.Based on the physiological,biochemical characteristics and 16S rRNA gene sequence analysis,the strain Ralstonia sp.ZLXH-4 belongs to the genus of Ralstonia,which often used to be applicated in enzyme production,powder detergent manufacture,water treatment and so on.Pectinase yield was used as the index in single-factor combining orthogonal experiments to optimize conditions for enzyme production.The results show that the optimal condition for pectinase production was pH=7,120 r/min of rotary speed,2 g/L of twain concentration,15 g/L of glucose concentration.The table revolve speed have the most remarkable effect on pectinase yield of Ralstonia sp.ZLXH-4 and the highest yield can be 3323.27 U/mL.This paper explored Ralstonia sp.ZLXH-4's degumming application on banana pseudo-stem and the degumming process was summarized.The biotreatment process follows:(1)mechanical preprocess;(2)biological degumming:20%inoculation rate,pH=6,1 g/L of carbamide concentration,0.5 g/L of dipotassium phosphate concentration,bath ratio 1:20,temperature 37 ?,degumming time 48 d;(3)chemical reprocessing:15%of H2O2,3%of sodium silicate concentration,8 g/L of NaOH,bath ratio 1:20,scouring temperature 37 ?,scouring time 90 min.According to the result of the pilot scale test of biological degumming,the contents of cellulose in the raw material and fiber raised from 30.11%to 68.21%,and bulk of the gum was eliminated.After chemical reprocessing,the degumming rate and residual lignin rate of banana pseudo-stem fiber could be 43.79%and 9.36%,the contents of cellulose could be 79.74%.A serious of performance analysis are employed to characterize the products derived from banana pseudo-stem.FTIR,SEM and TG measures were used to analyze the constitution,exterior feature,micromorphology and thermal properties,illustrating that heat stability of the fibers improved and the gum had been removed effectively in different degree by the treatment above.The results have shown that cellulose content of banana pseudo-stem raised with the process stage shifting,could ultimately reach 79.74%,the fibers have become detached and well-proportioned.Bulk of gum can be removed by the biological degumming assisted by mechanical pretreatment and chemical reprocessing,especially as the hemicellulose and lignin. |
PDF Full Text Request