Removal Of Sulfate From Biodiesel Production Wastewater Through Hybrid Oil-Water Filtration And Gypsum Precipitation-Nanofiltration

• Main Author: Teo, Yao Aik
• Format: Monograph
• Language: English
• Published: Universiti Sains Malaysia 2022
• Subjects: T Technology; TP Chemical Technology
• Online Access: http://eprints.usm.my/55703/1/Removal%20Of%20Sulfate%20From%20Biodiesel%20Production%20Wastewater%20Through%20Hybrid%20Oil-Water%20Filtration%20And%20Gypsum%20Precipitation-Nanofiltration.pdf; http://eprints.usm.my/55703/

Over the past few decades, an increased degree of scrutiny and attention had been developed over the production of industrial effluents with elevated sulfate concentration owing largely to its health and environmental impacts. In this particular report, a hybrid wastewater treatment method had been introduced for the treatment of highly sulfate-containing biodiesel production wastewater. The initial main focus of this study was performed on stripping off the fatty acid phase from the wastewater through the utilization of as-prepared superhydrophobic copper mesh filter. Such superhydrophobic and low-surface energy membrane was prepared through simple chemical oxidation process with its surface morphology and wettability being characterized and evaluated through the methods of field emission scanning electron microscopy, energy dispersive x-ray, Fourier-transform infrared spectroscopy and contact angle goniometry respectively. Despite the success on this superhydrophobic mesh filter fabrication for the treatment purpose of non-treated wastewater, a filtration failure was attained with in-vain fatty acid elimination due to the complete loss of surface superhydrophobicity during the separation process. Such happening fervently contributed into the necessary development of wastewater pre-treatment requirement which was fulfilled by the application of chemical precipitation upon the raw biodiesel wastewater, prior to the main NF treatment process. Higher sulfate removal efficiency through gypsum precipitation was recorded at the highest lime precipitant concentration and the lowest solution temperature respectively. With the utilization of these optimized experimental conditions to partially treat the raw industrial wastewater in terms of its sulfate concentration, the quality of precipitated wastewater solution was then further polished through the use of NF operation under higher transmembrane pressure to a level that acceptably fulfilled the industrial effluent standard range specified for sulfate ions (500 – 1500 ppm). Thus, results of this work had distinctly proven the practicability of such integrated wastewater treatment system for effectively handling the industrial biodiesel production wastewater with higher sulfate contamination, subsequently promoting its potential to be introduced into commercial based applications in the near future with better sustainability characteristics being demonstrated.