Dynasand as biofilter in RAS
The DynaSand filter's property as a biofilter in RAS has been documented in a pilot test performed by Litus Akva AS at Marineholmen RASLab in Bergen. DynaSand was used as the only biofilter in the pilot setup. Summary of preliminary conclusions from the experiment:
• DynaSand used as the only biofilter has a very good ability to retain and remove fine particles.
• Sand has a similar nitrification capacity per m3 sand as plastic media used in conventional biofilters
• Low particle concentration and very clear water in fish tanks even at high feed loads (< 1.3 kg feed / m3)
• Very good growth was achieved in the experiment, increasing average weight from 240 g to 910 g over 88 days.
• Excellent fish health in general and especially good gill and skin health.
A report from RASLab will be available during the autumn 2021.
DynaSand for aquaculture
DynaSand filter has a very wide range of applications in Aquaculture:
- Microparticle and suspended solids removal
- BOD reduction and nitrification (aerobic)
- Denitrification and biological phosphorus removal (anaerobic)
Unlike conventional sand filters that must be shut down when backwashing, the cleaning of the sand will not affect the operation of the in DynaSand filter, neither in terms of capacity or performance. This brings around several benefits:
• Low head loss and energy consumption
• No downtime or reduction in filter capacity and performance during washing
• Automatic control over the washing process
• High hydraulic capacity (with up to 25 m hour water velocity through sand beds).
• Assurance that all sand is cleaned*
*all the sand is cleaned during 5 hours of operation. In other words, all the sand will have passed the sand washer and thus washed approx. 5 times a day with continuous washing.
• Low reject water production (minimized by running washing cycles intermittently once per hour)