With the rapid growth of the pharmaceutical, dye, and cosmetics industries, p-aminobenzoic acid (PABA) has become an essential intermediate. However, the high-concentration, highly toxic, and poorly biodegradable organic wastewater generated during its production has become a serious environmental challenge and major cost burden for many manufacturers. Traditional treatment methods for PABA wastewater—such as biological processes and adsorption—often suffer from low efficiency, high operating costs, risks of secondary pollution, and an inability to recover valuable resources.
How can companies achieve both environmental compliance and economic benefits? Liquid–liquid extraction technology, combined with the new generation of CWL-M series centrifugal extractor, offers an efficient, economical, and reliable solution to break through these challenges.
Wastewater containing p-aminobenzoic acid typically has the following characteristics:
- High concentration: COD (chemical oxygen demand) levels often reach tens of thousands or even hundreds of thousands of mg/L.
- High toxicity: The benzene ring structure has an inhibitory effect on microorganisms, making direct biochemical treatment extremely difficult.
- High value: The p-aminobenzoic acid present in the wastewater is itself a valuable raw material that can be recovered.
Effectively separating and recovering p-aminobenzoic acid from wastewater not only significantly reduces the pollutant load at the source, creating favorable conditions for subsequent advanced treatment (such as biochemical methods), but also transforms waste into valuable resources, directly generating economic benefits.
Core Technology: Liquid-Liquid Extraction + CWL-M Centrifugal Extractor
High-Efficiency Liquid-Liquid Solvent Extraction Process
Liquid-liquid extraction is a classic unit operation for separating and purifying substances. Its principle is based on the difference in solubility of p-aminobenzoic acid in organic solvents and the aqueous phase. By selecting a specific high-efficiency extractant, p-aminobenzoic acid in the wastewater is concentrated into the organic phase, thus achieving separation from the wastewater.
Advantages
High selectivity: Specific extraction of p-aminobenzoic acid without introducing new impurities.
High recovery rate: Single-stage or multi-stage countercurrent extraction can achieve a high recovery rate of over 98%.
Resource utilization: The extract phase, rich in p-aminobenzoic acid, can be easily back-extracted and refined to obtain a high-purity product, achieving resource recovery.
Key Equipment: CWL-M Centrifugal Extractor
Traditional extraction equipment, such as stirred tanks and packed columns, suffer from problems such as low efficiency, large footprint, easy emulsification, and high solvent loss. The emergence of the CWL-M centrifugal extractor has perfectly solved these problems,making it the preferred equipment for modern extraction processes.
Advantages of the CWL-M Centrifugal Extractor
- 1.High-efficiency mass transfer and rapid phase separation
Utilizing the powerful centrifugal force generated by high-speed rotation, the two liquid phases are thoroughly mixed for mass transfer in a very short time, and the separation of light and heavy phases is quickly completed. The entire process takes only tens of seconds, completely solving the problem of "difficult phase separation" caused by small density differences and easy emulsification, improving processing efficiency several times over. - 2.Continuous operation and high degree of automation
The equipment can achieve 24-hour continuous feeding and continuous discharge, seamlessly connecting with upstream and downstream production processes, greatly improving production efficiency and reducing manual operation and intervention. - 3.Small footprint and strong sealing
With a compact structure, one medium-sized centrifugal extractor can replace an entire large mixer settler system, greatly saving factory space. Fully enclosed operation effectively prevents the escape of volatile organic solvents (VOCs), ensuring production safety and improving the working environment. - 4.Low solvent retention and low operating costs
The equipment has a very low internal liquid retention volume, which not only reduces the initial solvent investment cost but also minimizes material loss during troubleshooting or shutdown. - 5.Strong anti-emulsification ability and wide applicability
The powerful centrifugal force can effectively break emulsions, performing exceptionally well when treating wastewater prone to emulsification, thus ensuring the long-term stable operation of the system.
Process Flow for the Treatment of p-Aminobenzoic Acid Wastewater
- 1.Pre-treatment: The wastewater undergoes simple filtration to remove suspended solid particles.
- 2.Extraction stage: The pre-treated wastewater and a selected extractant are simultaneously pumped into a CWL-M centrifugal extractor. Efficient mixing and rapid phase separation are completed within the machine. The raffinate (aqueous phase with most of the PABA removed) enters the subsequent biochemical or advanced treatment system for easy compliance with discharge standards.
- 3.Back-extraction stage: The organic phase loaded with PABA enters another CWL-M centrifugal extractor, where it comes into contact with a back-extractant (such as an alkaline solution). PABA is transferred to the back-extraction solution, and the regenerated organic phase is returned to the extraction stage for recycling.
- 4.Resource Recovery: The concentrated back-extraction solution containing enriched PABA is processed through steps such as concentration, crystallization, and filtration to recover high-purity p-aminobenzoic acid product.
Why choose our CWL-M centrifugal extraction solution?
- Significant economic benefits: The recovered PABA product can directly offset part of the operating costs, or even generate profit, typically recovering the equipment investment within 1-2 years.
- Outstanding environmental benefits: Reduces pollutants by over 90% at the source, significantly lowering subsequent treatment costs and easily meeting increasingly stringent environmental regulations.
- Mature and reliable technology: Tiei Extraction provide a complete solution from process development, pilot testing, and equipment manufacturing to installation and commissioning, ensuring project success from the start.
- Excellent equipment quality: The CWL-M centrifugal extractor is manufactured with special materials, offering corrosion resistance and a long service life. Core components undergo precise dynamic balancing, ensuring stable operation and easy maintenance.
This technology has become a significant breakthrough in achieving cleaner production of chemical wastewater, helping companies meet emission standards while also creating considerable economic benefits. For more information about the CWL-M centrifugal extractor, welcome contact us.
Email: sales@tieiextraction.com
Whatsapp: +86 19069612820
