Alterkaoui Aya, Eskikaya Ozan, Keskinler Bulent, Dizge Nadir, Balakrishnan Deepanraj, Hiremath Pavan, Naik Nithesh
Department of Environmental Engineering, Mersin University, 33343, Mersin, Turkey.
Department of Energy Systems Engineering, Tarsus University, 33400, Tarsus, Turkey.
Sci Rep. 2025 Jan 23;15(1):2916. doi: 10.1038/s41598-025-85365-9.
To prevent water scarcity, wastewater must be discharged to the surface or groundwater after being treated. Another method is to reuse wastewater in some areas after treatment and evaluate it as much as possible. In this study, it is aimed to recover and reuse the caustic (sodium hydroxide, NaOH) used in the recycling of plastic bottles from polyethylene terephthalate (PET) washing wastewater. Chemical substances used in the industry will be significantly reduced with chemical recovery from wastewater. Ultrafiltration (UP150) and nanofiltration (NP010 and NP030) membranes were used for this purpose in our study. Before using nanofiltration membranes, pre-treatment was performed with coagulation-flocculation process to reduce the pollutant accumulation on the membranes. Different coagulants and flocculants were used to find suitable coagulants and flocculants in pre-treatment. The pre-treated wastewater using aluminum oxide, which supplied the highest chemical oxygen demand (COD) removal (76.0%), was used in a dead-end filtration system to be filtered through NP010 and NP030 membranes at different pressures (10-30 bar). In the same filtration system, raw wastewater was filtered through a UP150 membrane. Among these treatment scenarios, the best method that could remove pollutants and provide NaOH recovery was selected. After each treatment, pH, conductivity, COD, and NaOH analyses were performed. The maximum NaOH recovery (98.6%) was obtained with the UP150 membrane at 5 bar.
为防止水资源短缺，废水必须在处理后排放到地表水或地下水中。另一种方法是在某些地区对处理后的废水进行再利用，并尽可能对其进行评估。在本研究中，旨在从聚对苯二甲酸乙二酯（PET）洗涤废水中回收并再利用塑料瓶回收过程中使用的苛性碱（氢氧化钠，NaOH）。通过从废水中进行化学回收，工业中使用的化学物质将显著减少。在我们的研究中，为此目的使用了超滤（UP150）和纳滤（NP010和NP030）膜。在使用纳滤膜之前，采用混凝-絮凝工艺进行预处理，以减少膜上的污染物积累。使用不同的混凝剂和絮凝剂来寻找预处理中合适的混凝剂和絮凝剂。使用去除化学需氧量（COD）最高（76.0%）的氧化铝预处理后的废水，在死端过滤系统中以不同压力（10 - 30巴）通过NP010和NP030膜进行过滤。在同一过滤系统中，原废水通过UP150膜进行过滤。在这些处理方案中，选择了能够去除污染物并实现NaOH回收的最佳方法。每次处理后，进行pH、电导率、COD和NaOH分析。在5巴压力下，使用UP150膜获得了最大NaOH回收率（98.6%）。
