Maragkaki A E, Fountoulakis M, Gypakis A, Kyriakou A, Lasaridi K, Manios T
Laboratory of Solid Waste & Wastewater Management, School of Agricultural Technology, Technological Educational Institute of Crete, Heraklion 71500, Crete, Greece; Harokopio University, Department of Geography, 70 El. Venizelou, 176 71 Kallithea, Athens, Greece.
Laboratory of Solid Waste & Wastewater Management, School of Agricultural Technology, Technological Educational Institute of Crete, Heraklion 71500, Crete, Greece.
Waste Manag. 2017 Jan;59:362-370. doi: 10.1016/j.wasman.2016.10.043. Epub 2016 Nov 3.
Due to low degradability of dry solids, most of the digesters at wastewater treatment plants (WWTP) operate at low loading rates resulting in poor biogas yields. In this study, co-digestion of sewage sludge (SS) with olive mill wastewater (OMW), cheese whey (CW) and crude glycerol (CG) was studied in an attempt to improve biogas production of existing digesters at WWTPs. The effect of agro-industrial by-products in biogas production was investigated using a 220L pilot-scale (180L working volume) digester under mesophilic conditions (35°C) with a total feeding volume of 7.5L daily and a 24-day hydraulic retention time. The initial feed was sewage sludge and the bioreactor was operated using this feed for 40days. Each agro-industrial by-product was then added to the feed so that the reactor was fed continuously with 95% sewage sludge and 5% (v/v) of each examined agro-industrial by-product. The experiments showed that a 5% (v/v) addition of OMW, CG or CW to sewage sludge significantly increased biogas production by nearly 220%, 350% and 86% as values of 34.8±3.2L/d, 185.7±15.3L/d and 45.9±3.6L/d respectively, compared to that with sewage sludge alone (375ml daily, 5% v/v in the feed). The average removal of dissolved chemical oxygen demand (d-COD) ranged between 72 and 99% for organic loading rates between 0.9 and 1.5kgVSmd. Reduction in the volatile solids ranged between 25 and 40%. This work suggests that methane can be produced very efficiently by adding a small concentration (5%) of agro-industrial by-products and especially CG in the inlet of digesters treating sewage sludge.
由于干固体的降解性较低，污水处理厂（WWTP）的大多数消化器在低负荷率下运行，导致沼气产量较低。在本研究中，对污水污泥（SS）与橄榄果渣废水（OMW）、奶酪乳清（CW）和粗甘油（CG）进行了共消化研究，旨在提高污水处理厂现有消化器的沼气产量。在中温条件（35°C）下，使用一个220L中试规模（工作体积180L）的消化器，每日总进料体积为7.5L，水力停留时间为24天，研究了农业工业副产品对沼气生产的影响。初始进料为污水污泥，生物反应器使用该进料运行40天。然后将每种农业工业副产品添加到进料中，使反应器连续进料95%的污水污泥和5%（v/v）的每种受试农业工业副产品。实验表明，向污水污泥中添加5%（v/v）的OMW、CG或CW可显著提高沼气产量，分别达到34.8±3.2L/d、185.7±15.3L/d和45.9±3.6L/d，比仅使用污水污泥（每日375ml，进料中占5% v/v）时分别提高了近220%、350%和86%。对于0.9至1.5kgVSmd的有机负荷率，溶解化学需氧量（d-COD）的平均去除率在72%至99%之间。挥发性固体的减少幅度在25%至40%之间。这项工作表明，通过在处理污水污泥的消化器入口添加低浓度（5%）的农业工业副产品，特别是CG，可以非常有效地产生甲烷。
