The study was aimed to examine the effects of alkaline and thermal-alkaline pre-treatment on sewage sludge solubilisation with different alkali and its doses ranging from 40 mg alkali/g TS to 120 mg alkali/g TS. Initially, the effect of alkali pre-treatment was monitored with four alkali at room temperature, to further enhance soluble chemical oxygen demand (sCOD) and reduce treatment time, thermal-alkaline pre-treatment was performed with varying temperature from 40 to 70 °C. To explore and optimise the effects of temperature, alkali, and alkali doses on COD solubilisation, response surface methodology was employed. Statistical analysis of the variance was conducted to identify the relationship between experimental data and the proposed model. The thermal-alkaline process was optimised for maximum COD solubilisation with optimal conditions achieved at 65.61 °C of 66.57 mg alkali /g TS for NaOH and 27 °C of 20 mg/g TS for KOH. The maximum COD solubilisation achieved at these optimised conditions for NaOH and KOH was 21.28 % and 16.13 %, respectively. The results demonstrated a significant improvement in protein and carbohydrate concentration and a 16–20 % reduction in sludge solid content after thermal-alkali pre-treatment.

中文翻译：

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低温热碱预处理对废弃活性污泥溶解的影响


本研究旨在考察碱和热碱预处理对不同碱剂量（40 mg碱/g TS至120 mg碱/g TS）溶解污泥的影响。最初，在室温下用四种碱监测碱预处理的效果，为了进一步提高可溶性化学需氧量（sCOD）并减少处理时间，在40至70℃的不同温度下进行热碱预处理。为了探索和优化温度、碱和碱剂量对 COD 溶解的影响，采用了响应面方法。进行方差统计分析，以确定实验数据与所提出模型之间的关系。热碱工艺经过优化，可最大程度地溶解 COD，最佳条件为 NaOH 为 65.61 °C，碱浓度为 66.57 mg/g TS，KOH 浓度为 27 °C，碱浓度为 20 mg/g TS。在这些优化条件下，NaOH 和 KOH 的最大 COD 溶解度分别为 21.28% 和 16.13%。结果表明，经过热碱预处理后，蛋白质和碳水化合物浓度显着提高，污泥固体含量降低了 16-20%。