Zahedi S, Rivero M, Solera R, Perez M
Department of Environmental Technologies, University of Cadiz, Faculty of Marine and Environmental Sciences (CASEM), Pol. Río San Pedro s/n, 11510 Puerto Real (Cádiz), Spain.
Waste Manag. 2017 Oct;68:398-404. doi: 10.1016/j.wasman.2017.07.008. Epub 2017 Jul 23.
The aim of this research is to enhance the mesophilic anaerobic digestion of municipal sludge from Cadiz-San Fernando (Spain) wastewater treatment plant at 20days hydraulic retention time (HRT). Two different strategies were tested to improve the process: co-digestion with the addition of soluble organic matter (1% v/v); and alkali sludge pre-treatment (NaOH) prior to co-digestion with glycerine (1% v/v). Methane production (MP) was substantially enhanced (from 0.36±0.09 L CH l/d to 0.85±0.16 L CH l/d), as was specific methane production (SMP) (from 0.20±0.05 L CH/g VS to 0.49±0.09 L CH/g VS) when glycerine was added. The addition of glycerine does not seem to affect sludge stability, the quality of the effluent in terms of pH and organic matter content, i.e. volatile fatty acids (VFA), soluble organic matter and total volatile solid, or process stability (VFA/Alkalinity ratio<0.4). Alkali pre-treatment prior to co-digestion resulted in a high increase in soluble organic loading rates (more than 20%) and acidification yield (more than 50%). At 20days HRT, however, it led to overload of the system and total destabilization of the mesophilic anaerobic co-digestion of sewage sludge and glycerine.
本研究的目的是在20天水力停留时间（HRT）条件下，强化西班牙加的斯-圣费尔南多污水处理厂城市污泥的中温厌氧消化。测试了两种不同策略来改进该工艺：添加可溶性有机物（1% v/v）进行共消化；以及在与甘油（1% v/v）共消化之前对污泥进行碱预处理（NaOH）。添加甘油后，甲烷产量（MP）显著提高（从0.36±0.09 L CH₄/d提高到0.85±0.16 L CH₄/d），比甲烷产量（SMP）也显著提高（从0.20±0.05 L CH₄/g VS提高到0.49±0.09 L CH₄/g VS）。添加甘油似乎不影响污泥稳定性、出水的pH值和有机物含量（即挥发性脂肪酸（VFA）、可溶性有机物和总挥发性固体）等出水质量，也不影响工艺稳定性（VFA/碱度比<0.4）。共消化之前的碱预处理导致可溶性有机负荷率大幅提高（超过20%）和酸化率提高（超过50%）。然而，在20天HRT条件下，这导致系统过载以及污水污泥和甘油中温厌氧共消化完全失稳。
