邹永杰, 陈羚, 蒋伟忠, 吴新燕, 杨锦. 固体稀释倍数和超声波对豆渣厌氧发酵酸化过程的影响[J]. 农业工程学报, 2017, 33(6): 207-213. DOI: 10.11975/j.issn.1002-6819.2017.06.027
    引用本文: 邹永杰, 陈羚, 蒋伟忠, 吴新燕, 杨锦. 固体稀释倍数和超声波对豆渣厌氧发酵酸化过程的影响[J]. 农业工程学报, 2017, 33(6): 207-213. DOI: 10.11975/j.issn.1002-6819.2017.06.027
    Zou Yongjie, Chen Ling, Jiang Weizhong, Wu Xinyan, Yang Jin. Effect of substrate dilution ratio combined with ultrasonic irradiation on acidification of bean dregs anaerobic fermentation[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2017, 33(6): 207-213. DOI: 10.11975/j.issn.1002-6819.2017.06.027
    Citation: Zou Yongjie, Chen Ling, Jiang Weizhong, Wu Xinyan, Yang Jin. Effect of substrate dilution ratio combined with ultrasonic irradiation on acidification of bean dregs anaerobic fermentation[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2017, 33(6): 207-213. DOI: 10.11975/j.issn.1002-6819.2017.06.027

    固体稀释倍数和超声波对豆渣厌氧发酵酸化过程的影响

    Effect of substrate dilution ratio combined with ultrasonic irradiation on acidification of bean dregs anaerobic fermentation

    • 摘要: 为了优化超声波对固体废弃物酸化过程的调节作用,缓解酸化产物抑制,该文研究超声波处理时不同稀释倍数对基质性质的影响及对处理后基质发酵性能的影响,根据基质的挥发性有机酸去除率和发酵性能选取较佳的超声波处理参数。试验结果表明,超声波对不同浓度酸化基质的处理可去除有机酸中80%以上的非电离有机酸,减小对微生物的毒害,同时可减小基质的颗粒尺寸。处理后的基质经10 d发酵以评价不同浓度条件下的酸化性能,当基质挥发性有机酸质量浓度在18.8 g/L左右时,将基质稀释至固体质量浓度为46 g/L后再进行超声波处理,基质的挥发性有机酸增长率和挥发性固体降解率可分别从仅经过超声波辐射处理的51.8%、14.7%提高到197.4%、26.8%,表现出较佳的处理性能。可为超声波调节固体废弃物酸化过程提供参考。

       

      Abstract: Abstract: Anaerobic digestion has been applied widely used in treatment of municipal solid wastes due to its advantages of energy recovery and environmental protection. However, in the case of particle-substrate digestion, the acidification products were prone to accumulate, which inhibited not only methanogenesis, but also hydrolysis and acidification. In order to alleviate the acid inhibition during acidification of solid organic wastes, ultrasonic irradiation was introduced to destroy the product-films and promote the acidification performance. The previous study demonstrated that direct ultrasonic irradiation could desorbed VA from particle surfaces, and elevated the VS degradation rate from 0.8% to 1.3% per day. The volatile acid increasing ratio and VS degradation ratio were increased from 166.7% to 732.0%, and 17.0% to 26.7%, respectively, by the modified ultrasonic treatment (3-times dilution, 20 min ultrasonic irradiation filtration). However, ultrasonic wave energy intensity would be attenuated during its propagation in the medium, so at the same ultrasonic frequency, the higher the medium concentration was, the greater the intensity attenuation. The substrate concentrations of solid wastes during the ultrasonic irradiation would have a role on treatment effect and equipment requirements. The selection of substrate concentration should not only combine with the VA removal rate and the fermentation performance, but also the fermentation device volume and water consumption. In this study, the effects of substrate concentration during ultrasonic treatment on the fermentation properties were investigated. Fermentation broth from previous acidification (volatile acid concentration was 18.8 g/L) was diluted by 1, 2, 3, 4, 5 and 6 times (to ensure consistent radiation areas, the total mass of the treated medium and the water in the container was always the same). After that they were imposed on ultrasonic irradiation for 20 minutes, and filtrated to the initial weight. The samples of treated broth were withdrawn to determine pH value, total solid (TS), volatile solid (VS), volatile acid (VA) concentration and particle size distribution. The results demonstrated that dilution combined with ultrasonic irradiation treatment played a key role to VA removal. Higher VA removal rate and smaller particle size was obtained by the treatment with higher dilution ratio. Considering that higher dilution ratio would result in more water consumption and bigger reactor volume, dilution ratio with 1, 2 and 3 times were chosen to next fermentation. The broth with ultrasonic irradiation and dilution ratio of 1, 2 and 3 times were fermented for 10 days in a rotational drum fermentation system. A control with untreated broth was also investigated. The experiments were set up in duplicate. The experiment results showed that the broth fermentation with higher dilution ratio got not only more VA production, but also rapid substrate degradation. On the other hand, due to the almost saturated VA removal, the improvement of fermentation performance with the broth diluted by 2 and 3 times was not obviously. Taking water consumption and reactor volume into account, the conditions of the diluted fermentation broth 46 g/L, ultrasonic irradiation 20 min and filtration were more suitable to promote the acidification of solid organic wastes when their VA concentrations were between 10 and 20 g/L.

       

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