Instituto de la Grasa (IG-CSIC), Building 46, Ctra. Utrera km 1, 41013 Seville, Spain.
Centro IFAPA Las Torres (CAPDER - JA), Apartado de Correos Oficial, 41200-Alcalá del Rio, Seville, Spain.
Sci Total Environ. 2020 Dec 1;746:141150. doi: 10.1016/j.scitotenv.2020.141150. Epub 2020 Jul 22.
Table olive wastewaters are seriously polluting and a difficult to treat effluent worldwide, mainly due to their high content in sodium. An alternative approach could be the treatment of the olives with KOH instead of NaOH, in order to reuse the olive streams as biofertilizers. In this study, the debittering of olives with KOH was investigated at pilot plant scale in two olive seasons. The results indicated that a concentration between 1.7 and 2.0% of KOH (similar to that employed with NaOH) led to a fermented product with the same physicochemical and organoleptic characteristics than the traditional one. The spent lyes and washing waters from the KOH treatments were gathered and vacuum evaporated, giving rise to a concentrated solution rich in potassium (52 g/L) that was tested as biofertilizer in open tomato fields. Furthermore, the drip irrigation of the tomato plants with a combined olive solution and mineral fertilizer (NHNO) produced similar tomato yield and quality than the irrigation with only mineral fertilizer (NHNO + KNO). Overall, it has been demonstrated that Spanish-style green olives can be processed with KOH and the effluents valorized to be used as biofertilizer.
橄榄废物废水是一种严重的污染源，也是一种难以处理的废水，这在全球范围内都是如此，主要原因是其钠含量很高。一种替代方法是用 KOH 而不是 NaOH 处理橄榄，以便将橄榄流重新用作生物肥料。本研究在两个橄榄季节的中试规模上研究了用 KOH 脱苦的问题。结果表明，KOH 的浓度在 1.7%到 2.0%之间（与使用 NaOH 时的浓度相似），会产生具有与传统橄榄相同理化和感官特性的发酵产品。KOH 处理的废碱液和洗涤水被收集并真空蒸发，得到一种富含钾的浓缩溶液（52g/L），该溶液被测试为开放式番茄田的生物肥料。此外，用橄榄溶液和矿物肥料（NHNO）滴灌番茄植物，与只用矿物肥料（NHNO+KNO）灌溉相比，产生了相似的番茄产量和质量。总的来说，已经证明西班牙式绿橄榄可以用 KOH 加工，并且废水可以被回收利用作为生物肥料。
