Landfill leachate, a highly complex wastewater generated from municipal solid waste landfills, poses significant challenges due to its high concentrations of organic pollutants (BOD₅, COD), heavy metals, and ammonia nitrogen, coupled with unstable water quality and quantity. In response to these challenges, the two-stage Disc Tube Reverse Osmosis (DTRO) process has emerged as a compact, efficient, and reliable technology, particularly suitable for small-scale leachate treatment projects in areas like Yunnan Province, China. Process Overview The two-stage DTRO system integrates pre-treatment, primary reverse osmosis (RO), and secondary RO units into a single skid-mounted device, making it ideal for decentralized applications. The core of the process lies in the disc tube membrane module, which features a unique design with high mechanical strength and resistance to fouling. This allows the system to handle raw leachate with minimal pre-treatment, reducing operational complexity. Key Advantages
1. Exceptional Treatment Efficiency: A case study in Yunnan Province demonstrated that the two-stage DTRO process achieved effluent quality far exceeding regulatory standards. The effluent COD₍ₙ₎ was less than 34 mg/L, BOD₅ ≤ 17 mg/L, NH₃-N ≤ 8 mg/L, TN ≤ 10 mg/L, and SS at 0 mg/L—all meeting the strict requirements of China’s Standard for Pollution Control on the Landfill Site of Municipal Solid Waste (GB16889-2008).
2. Compact and Scalable Design: The integrated skid-mounted configuration minimizes land occupation, a critical advantage for small-scale landfill sites in mountainous regions like Yunnan. Its modular design also allows for easy expansion to adapt to changing treatment demands.
3. Robustness to Fluctuations: The DTRO membrane’s tolerance to high pollutant loads and variable influent quality ensures stable performance even under dynamic conditions, addressing the inherent variability of leachate.
4. Sustainable Concentrate Management: Concentrated liquor generated during treatment can be reinjected into the landfill, leveraging the landfill’s natural attenuation capacity and avoiding secondary pollution risks. Engineering Application in Yunnan In Yunnan’s organic town landfill project, the two-stage DTRO system was implemented with a treatment capacity of 15 m³/day. The on-site installation enabled “local treatment and local discharge,” eliminating the need for long-distance wastewater transportation and reducing operational costs. The system’s low energy consumption (approximately 1.2 kWh/m³) and minimal maintenance requirements further enhanced its economic viability, with a total operational cost of around $1.5 per cubic meter of treated leachate. Conclusion The two-stage DTRO process represents a breakthrough in small-scale landfill leachate treatment, combining high efficiency, compactness, and sustainability. As demonstrated in Yunnan’s rural waste management initiative, this technology provides a practical solution for addressing leachate pollution in decentralized settings, contributing to improved environmental hygiene and public health. Its successful application offers valuable insights for推广 similar projects globally, especially in regions facing challenges of limited infrastructure and variable wastewater characteristics.
