Waste water purification system

In order to protect the BluElephant sphere halves from the considerable forces of water pressure and ”silt loading”, BPO has deployed its expertise. Using advanced finite element simulations, BPO has been able to advise Jotem water solutions B.V. to optimise the strength and stiffness of the design. This has led to cost savings and geometric improvements, resulting in a robust and successful end product.

The BluElephant is a mobile, decentralised wastewater purification system that can process up to 6 m3 of wastewater (from approx. 50-150 people) per day. With a capacity of almost 2000 liters per half sphere and a height of almost 2.5 meters, the BluElephant halves of the spheres are subjected to considerable forces. In addition, long-term exposure to outdoor conditions is possible with temperatures of up to 40°C, which can cause creep over time and affect the loading of internal components. To overcome these challenges, BPO and Jotem jointly designed a metal skeleton, which effectively supports the plastic housing.

The sphere halves were produced using rotational moulding. Rotational moulding is a production method used to make hollow plastic products. A hollow mould is filled with powdered plastic resin, placed in an oven and rotated. With this technique, the wall thickness of a product can be changed relatively easily during series production, by adding more or less material to the mould. Before manufacturing the mould, BPO performed simulations and made recommendations to optimise the geometry of the mould. This prevents the need for costly changes to the shape of the mould afterwards. At the same time, the wall thickness was optimised, which allowed the product price to be reduced.

With these adjustments and recommendations, BPO has contributed to a reliable, sustainable and cost-efficient design for the BluElephant.

Designer Rob van Opdorp designed this innovative shape. The device is designed to meet a global need for decentralised purification, with a minimal footprint, minimal energy consumption and optimal effluent quality. The system contains sludge consisting of hundreds of millions of bacteria that convert the contamination in the water into carbon dioxide (CO2), water (H2O) and neutral air nitrogen (N2). The water is then separated from the sludge with ultrafiltration membranes. UV disinfection is then applied as an additional barrier for pathogenic contamination.

This installation offers a cost-efficient solution for locations without central wastewater treatment, such as local communities, residential areas, industrial estates, recreational areas and remote locations. By using the BluElephant, a circular water supply is created, not only for domestic use, but also for applications such as irrigation. In this way, the BluElephant makes a sustainable and infinite water supply feasible.
For more information about the BluElephant, please visit the BluElephant and Jotem web pages.