Leachate treatment for residual-waste landfill

In the greater Kuala Lumpur area, a Malaysian management company operates a landfill for the disposal of residual materials from several waste management companies. Due to the wide range and high degree of contamination of the residues and concentrates, also from the industry, the leachate of this landfill is rather complex and difficult to treat. The high concentrations of boron, salts and nitrogenous organic compounds can only be oxidised or eliminated by combining different process steps.

The existing conventional treatment plant is unable to meet the required discharge values, so that they were regularly exceeded. To comply with these requirements, the company was looking for a plant constructor with a treatment concept suitable for this complex task. The approach to reduce the boron concentration was decisive. After confirmation of the treatment concept by laboratory testing, Wehrle, as a solutions provider for the treatment of complex wastewater, was selected from a total of eight suppliers. Wehrle’s treatment solution includes a combination of four different process steps to purify this wastewater.

To oxidise the high concentrations of organic compounds, such as nitrogen, a dissolved air flotation (DAF) system will be combined with a membrane bioreactor (MBR) based on the BIOMEMBRAT technology. A reverse osmosis system will be used for the separation of salts and the high concentrations of boron. The concentrate produced will then be treated in an evaporator. The objective is to treat a total of 600m3/day for direct discharge into the nature.

Simon Götz, area manager for South East Asia at Wehrle, said: “This is definitely a challenging task, especially because the customer has had a negative experience with conventional process technologies and now understandably places the highest demands on the plant technology. We at Wehrle are proud that our expertise in treating such difficult wastewater has been recognised, and we are looking forward to demonstrating our knowledge in this field.”

The plant will be delivered as turnkey system including construction technology and test operation, and the commissioning will be carried out by the employees of Wehrle Asia, with headquarters in Kuala Lumpur, in August 2022.