Kagiso S More, Johannes P Maree, Mlungisi Mahlangu
{"title":"Cost-Effective Leachate Treatment and Resource Recovery in Hazardous Waste Landfills through Pipe Freeze Crystallization.","authors":"Kagiso S More, Johannes P Maree, Mlungisi Mahlangu","doi":"10.1007/s40710-025-00757-3","DOIUrl":"10.1007/s40710-025-00757-3","url":null,"abstract":"<p><p>This study aimed to develop a practical, economically viable solution for treating hazardous landfill leachate using Pipe Freeze Crystallization (PFC) technology. The objective was to concentrate and solidify leachate from an effluent treatment plant processing approximately 8750 m<sup>3</sup> annually, achieving resource recovery and environmental compliance. A 300 L h<sup>-1</sup> cooling demonstration plant was designed and implemented, incorporating a chiller, a secondary refrigerant mixture (40% ethylene glycol and 60% water), a clarifier, a reactor, and pumps. Μodelling with OLI software estimated recovery rates for salt and ice, providing a basis for operational adjustments. Leachate samples (2000 L) and concentrate (1000 L) were processed to evaluate the plant's performance in recovering clean water and Na<sub>2</sub>SO<sub>4</sub>. Experimental results confirmed the model predictions, with 302 L of concentrate yielding 102.9 kg of Na<sub>2</sub>SO<sub>4</sub> over 6 h and 273 L of leachate producing 118.7 kg of high-purity ice over 5.5 h. The energy consumption was measured at 171 kWh t<sup>-1</sup> of ice, aligning with theoretical predictions for a coefficient of performance of 1. These results validate the efficiency and feasibility of PFC in resource recovery. This study highlights the importance of PFC as a low-cost, energy-efficient technology for hazardous leachate treatment. Its scalability and ability to recover valuable resources such as Na<sub>2</sub>SO<sub>4</sub> and clean water present a sustainable alternative to conventional methods, contributing to zero-waste management goals in waste treatment practices.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s40710-025-00757-3.</p>","PeriodicalId":51583,"journal":{"name":"Environmental Processes-An International Journal","volume":"12 2","pages":"15"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11956536/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143755793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}