Frequently Asked Questions

Q. Does the filter come off-line for backwashing?

A. No the DynaSand^® is a continuously backwashed filter with a small proportion of the cleaned flow used to backwash the media.

Q. Does the DynaSand^® remove BOD?

The DynaSand^® does not directly remove BOD, but it does remove TSS, and therefore any insoluble BOD associated with the TSS.

Q. What is the typical headloss through the filter?

A. The operating headloss is 0.6 to 0.8 m at full flow; please allow 1.2 m in designing pumping systems.

Q. How is even distribution ensured between multiple units?

All the filters are fed from the same header, and are therefore under approximately the same pressure, as a particular filter captures more solids than another the flow reduces to that filter, allowing it to wash more effectively whilst the other filters take slightly more flow. This allows the bank of filters to self regulate, such that each filter takes an even flow +/- 10%.

Q. Can DynaSand^®s be used in potable water treatment?

A. Yes, they are very effective at it, as they do not suffer the problems discontinuous processes have with chemical dosing. DynaSand^®s are a major part of a vast number of potable water treatment plants.

Q. Can DynaSand^®s remove phosphates?

A. DynaSand^®s can remove phosphates as part of a chemical phosphate removal process.

Q. Can DynaSand^®s remove Ammonia and Nitrates?

A. DynaSand^®s remove a very small amount of Ammonia, for significant nitrification DynaOxy should be used, and DynaDeni can be used for nitrate removal by biological denitrification.

Q. Is a strainer required before the filters?

A. This depends on the site, if the filter is likely to see screening in excess of 6 mm, or is subject to heavy leaf fall then we strongly advise a strainer on the inlet line.