| In this study,different concentrations of sulfuric acid were used to pretreat the chaff of white fungus and mixed with microbial for aerobic fermentation at normal atmospheric temperature.The effects of pretreatment with different acid concentrations as?A0??0.1?A1??0.3?A2??0.5mol/L?A3?on the fermentation process of white fungus were studied.The dynamic changes of water content,volatile ammonia C/N,organic matter and germination index in composting process were analyzed,and discussed the optimum concentration of all acid pretreatments in the fermentation,in order to shorten the fermentation time and improved compost quality for providing theoretical basis.By adding bentonite,vermiculite and so on materials in the decomposed white fungus,to studied for the plant height,stem base width,seedling strength index,emergence rate and chlorophyll index,etc.in rice seedling substrate prepared with different ratio.The optimum scheme of rice seedling medium was selected,which provides a new way for the comprehensive utilization of agricultural wastes such as fungus chaff.The results are as follows:?1?Analysis of physical Indexe as temperature,pH,EC,etc.during the composting period.the highest temperature in A0,A1,A2 and A3 were 56?,59?,48?,and 32?;At the end of composting,and processing of A0 pH?6.63?without adding sulfuric acid compared to A1,A2and A3 decreased 1.37,4.73,5.105;A0,A1,A2 and A3 EC values were 1.625,2.775,4.15 and6.025 S·cm-1;Comprehensive results show that A0 and A1 were completely maturity,in which A1 temperature was the highest.The results showed that the optimum concentration of acid pretreatment can increase the maximum temperature and duration of fermentation,make the reactor reach harmless treatment.?2?According to the analysis of total N and C/N,the whole C/N of C/N in A0,A1,A2,A3showed a downward trend,and at the end of composting,they decreased by 12.58,12.44,10.06,0.95,respectively,and the N content of each treatment increased by 40.5,32.8%,18.7%and0%.The results showed that the content of organic carbon was decreased in composting process.However,the total nitrogen content increased,A0 and A1 treatments reached the compost maturity standard.?3?The content of organic matter in four treatments of compost quality A0 and A1 were63.42%and 59.86%,respectively,that of A2 and A3 treatment were 59.24%and 53.89%.The results showed that the content of organic matter in each treatment showed decreasing trend,which indicated that acid pretreatment could effectively degrade some complex organic substances,make the microorganisms better use and decompose during fermentation,and accelerate the process of composting.?4?The total potassium and total phosphorus indexes of compost products were determined and analyzed.The phosphorus contents of each treatments were 0.723,0.745,0.519 and 0.303respectively.The potassium contents were 0.0402,0.043,0.0308 and 0.0288 respectively.The results showed that the potassium content of A0,A1 and A2 treatments showed upward trend except for A3 treatment.And the proper concentration of acid pretreatment can improve the nutrient content.?5?By analyzing the dynamic indexes of ammonia volatilization in composting process,the N content of each treatment increased by 40.5%,32.78%,18.2%and 0%respectively,the accumulated ammonia volatilization were 1.01325,0.805,0.182 and-0.10675 g/kg·h,respectively.Compared with A0,the other treatments showed an obvious decreasing trend.Acid pretreatment significantly reduced the amount of NH3 volatilization,nitrogen loss,nitrogen fixation and air pollution.?6?Based on the analysis of germinating index,the germination index of each treatment were 86%,114%,75%and 0%,respectively.It can be judged that the treatment A0 and A1 fully met the standard of rotting,indicating that the proper concentration of sulfuric acid pretreatment can significantly increase the germination index.The suitable weak acid environment is favorable for the growth of seeds and crops.?7?From the fiber structure and scanning electron microscope,the cellulose degradation rate of A1 treatment was 24.1%,the hemicellulose degradation rate was 31.33%,and the other treatment degradation rates were obviously lower than that of A1 treatment.From the angle of scanning electron microscope,the A1 treatment improved the fiber structure,the cellulose,lignin and other organic substances which were hard to decompose,compared with the other treatment.The crystalline structure of cellulose can promote the decomposition of internal fibrous structure by microorganisms,accelerate the process of maturity,while other treatments are less effective.?8?Analysis on the emergence rate of rice seedling by using different material ratios,the average emergence rate of rice seedlings in AB group is 85.8%,which is about 6%higher than that in AC group and the highest emergence rate in AB group is 94%.The overall emergence rate of 85%in AC group.The AB group was neat.In AC group,the emergence rate was low,the emergence rate was uneven and the growth was different.?9?Through the evaluation of the comprehensive quality of rice seedlings,the 1-6 seedling index in the AB group was 0.10443 same as CK seedling index 0.10703,and the rest were obviously smaller than CK;And the strongest seedling index in the AC group was the closest to CK,the 2-6 was 0.08200.Showed that the seedling quality of the AB group was better,and there was no significant difference between the control soil CK and the strong seedlings.The number is higher and the overall quality is better.?10?The rice seedling quality of each treatment was analyzed.The best quality of rice seedling was 1-6 treatment,which indicated that this ratio was suitable for rice seedling raising,and the ratio of bacterial bran:bentonite:vermiculite:vermiculite was 92:3:5.?11?The compost quality and decay degree of white fungus were treated as the best composting products,and the ratio of bentonite and vermiculite could effectively enhance the quality of rice seedlings. |
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