Rincón B, Sánchez E, Raposo F, Borja R, Travieso L, Martín M A, Martín A
Instituto de la Grasa (CSIC), Avda. Padre García Tejero 4, 41012 Sevilla, Spain.
Waste Manag. 2008;28(5):870-7. doi: 10.1016/j.wasman.2007.02.030. Epub 2007 May 4.
A study of the effect of the organic loading rate (OLR) on the anaerobic acidogenic fermentation of two-phase olive mill solid residue (OMSR) derived from fruits with a low ripening index was carried out in a laboratory-scale completely stirred tank reactor at mesophilic temperature (35 degrees C). Eight experimental runs were carried out at OLRs of 3.2, 5.6, 7.4, 9.6, 11.0, 12.9, 14.0 and 15.1g T-COD/ld, which were equivalent to hydraulic retention times of 50.0, 28.8, 21.8, 16.9, 14.7, 12.4, 11.5 and 10.7d, respectively. The experimental results obtained demonstrated that the optimum value of OLR for the acidogenic fermentation process was 12.9 g T-COD/ld, for which a maximum production of acetic acid was achieved. It was found that inhibition of the process occurred at OLRs higher than 12.9 g T-COD/ld. This was characterized by a significant decrease in the acetic acid concentration in the effluent and an increase in the concentration of other volatile acids that may affect the methanogenic step. The process inhibition was also characterized by the plateau in the curves of the effluent substrate concentration versus the OLR applied. It was found that a first-order kinetics satisfactorily described the influence of non-acetic acid soluble organic matter concentration (S-COD( *)) on the rate of soluble organic matter conversion to acetic acid (R(S-COD)( *)), and the influence of acetic acid concentration (AcH) on the rate of acetic acid production (R(AcH)), while a potential equation type adequately described the influence of acetic acid concentration on the volumetric hydrogen production (R(ACH) ). The kinetic constant for soluble organic matter removal was 0.145 d(-1), while the constant for acetic acid formation was found to be 0.075 d(-1).
在中温（35℃）下，于实验室规模的全混式搅拌槽反应器中，开展了有机负荷率（OLR）对源自低成熟度指数果实的两相橄榄果渣固体残余物（OMSR）厌氧产酸发酵影响的研究。在3.2、5.6、7.4、9.6、11.0、12.9、14.0和15.1 g T-COD/（l·d）的OLR条件下进行了8次实验运行，这些OLR分别相当于水力停留时间为50.0、28.8、21.8、16.9、14.7、12.4、11.5和10.7 d。所获得的实验结果表明，产酸发酵过程的OLR最佳值为12.9 g T-COD/（l·d），此时乙酸产量达到最高。研究发现，当OLR高于12.9 g T-COD/（l·d）时，该过程会受到抑制。其特征表现为流出物中乙酸浓度显著降低，以及可能影响产甲烷步骤的其他挥发性酸浓度增加。过程抑制还表现为流出物底物浓度与所施加OLR的曲线出现平稳段。研究发现，一级动力学能令人满意地描述非乙酸可溶性有机物浓度（S-COD（））对可溶性有机物转化为乙酸速率（R（S-COD）（））的影响，以及乙酸浓度（AcH）对乙酸生成速率（R（AcH））的影响，而一个势方程类型能充分描述乙酸浓度对体积产氢量（R（ACH））的影响。可溶性有机物去除的动力学常数为0.145 d⁻¹，而乙酸形成的常数为0.075 d⁻¹。
