Wastewater reuse is a significant challenge around the world, especially in arid and semi-arid regions. In order to analyse wastewater reuse applications, chemical oxygen demand (COD) is an essential factor for tertiary treatment processes. The purpose of this study is to design an approach to evaluate COD removal from low-strength wastewater (COD 70 mg/L) for reuse. This algorithm involves two steps: 1) Activated carbon-activated sludge (AC-AS) and activated sludge-algae (AS-Algae) were investigated, and 2) Optimal conditions were determined through statistical analysis of data. Despite its inherent advantages and robustness, fuzzy logic is a well-recognised alternative algorithm in control applications. As a result of the AC-AS process, an 85% COD removal rate was achieved in 8 hours by combining 0.05 g/L AC and 5 mL/L AS. Under optimal experimental conditions (5 mL/L of AS and 7 mL/L of Algae), a 60% COD removal rate in 7 h was achieved for the AS-Algal process. Both the AC-AS and the AS-Algal systems were found to have 85% and 59% removal efficiencies, respectively. Experimental and predicted values of the AC-AS system and the AS-algal system showed excellent correlation, with a determination coefficient of 0.99 (AC-AS system) and 0.93 (AS-algal system).

废水再利用是世界范围内的一项重大挑战，特别是在干旱和半干旱地区。为了分析废水回用应用，化学需氧量 (COD) 是三级处理过程的重要因素。本研究的目的是设计一种方法来评估从低浓度废水 (COD 70 mg/L) 中去除 COD 以供再利用。该算法包括两个步骤：1）研究了活性炭-活性污泥（AC-AS）和活性污泥-藻类（AS-Algae），2）通过数据统计分析确定了最佳条件。尽管具有固有的优势和鲁棒性，但模糊逻辑是控制应用中公认的替代算法。作为 AC-AS 工艺的结果，通过结合 0.05 g/L AC 和 5 mL/L AS，在 8 小时内实现了 85% 的 COD 去除率。在最佳实验条件（5 mL/L AS 和 7 mL/L 藻类）下，AS-Algal 工艺在 7 小时内实现了 60% 的 COD 去除率。发现 AC-AS 和 AS-Algal 系统的去除效率分别为 85% 和 59%。AC-AS 系统和 AS-algal 系统的实验和预测值显示出良好的相关性，决定系数为 0.99（AC-AS 系统）和 0.93（AS-algal 系统）。