Ontzand

Ontzand is a Dutch term that translates to "desanding" or "degritting" in English. It refers to a process of removing sand and grit from a substance, typically water or wastewater. This is an essential step in many industrial and municipal treatment processes to prevent damage to equipment and ensure the quality of the final product.

In the context of water treatment, ontzand is often carried out using settling tanks or hydrocyclones. In settling tanks, water flows slowly, allowing heavier sand particles to settle to the bottom where they can be removed. Hydrocyclones use centrifugal force to separate sand from water. For wastewater treatment, ontzand is crucial before biological treatment stages, as the sand can clog filters and disrupt microbial activity.

The removed sand and grit can sometimes be repurposed. Depending on its composition and contamination levels, it might be used in construction, as landfill cover, or for other industrial applications. However, in many cases, it is considered waste and requires proper disposal. The efficiency of ontzand is monitored by measuring the amount of suspended solids or grit in the water before and after the process. Maintaining effective ontzand is vital for the longevity of treatment infrastructure and the overall success of water purification.