Struvite (magnesium ammonium phosphate) is a phosphate crystal with formula: NH4MgPO4·6H2O. It crystallizes in the orthorhombic system as white to yellowish or brownish-white pyramidal crystals or in platy mica-like forms.
Struvite can form a scale on lines and belts, in centrifuges and pumps, clog system pipes and other equipment including the anaerobic digester itself. Hence their removal becomes important.
Innovations Introduced
Focus is given to specific process design features to reduce maintenance and downtime.
- Adapted curve shaped piping in critical struvite sensitive areas
- Selective coating on impeller or defined reactor sections
- Online phosphate measurement for Mg dosage control
- Minimal redundancy is part of non-compromise design philosophy
- Modular assembly of different technologies both in space and time
- Specific cyclone design with integrated purge chamber and struvite wash unit
- Non-clogging and non-accumulating hair/fibers design features for digestate applications
Struvite ( NH4MgPO4·6H2O) is a phosphate crystal, which can form a scale on lines and belts, in centrifuges and pumps, clog system pipes and other equipment including the anaerobic digester itself. Hence their removal becomes important.
Innovations Introduced
Focus is given to specific process design features to reduce maintenance and downtime.
- Adapted curve shaped piping
- Coating on impeller / reactor
- Magnesium dosage control
- Minimal redundancy design
- Modular tech assembly
- Custom cyclone with purge chamber & wash unit
- Non-clog design for hair/fiber digestate applications
Technology configurations
P recovery as customized solutions with various and distinct advantages aiming towards process optimisation and higher recovery rates.
Technology configurations
P recovery as customized solutions with various and distinct advantages aiming towards process optimisation and higher recovery rates.
The classical application of struvite precipitation is on MWTP at the outlet of the dewatering or on industrial WWTP at the outlet of an UASB reactor. DM contents that can be accepted are between 1 and 2%. A straightforward STRIPPER/CRYSTALISER combination is installed. Struvite harvesting is quite simple because the STRUVITE, at 1.7 specific density, can easily be separated from the effluent.
Digested Sludge Application 1
NuReSys applied on digested sludge as such and has 2 different approaches. Just stripping of the digestate is a simple scaling control to prevent wear damage, pipe clogging and thus reducing process down time and excessive maintenance costs on dewatering equipment and sludge handling line. No chemicals are added and no struvite is harvested.
Digested Sludge Application 2
The second approach directly applied on digested sludge is illustrated below. This is full option NuReSys technology: stripper for pH control and stirred tank reactor with MgCl2 addition to promote active struvite formation. Main advantages are again scaling prevention (based on limiting free soluble phosphate) and improvement of dewatering of the bio solids. Another major advantage is reducing the phosphorus load returning to The head of the MWTP. The option of either harvesting the struvite or not (struvite retained in the dewatered bio solids) is again case dependent.
A smart approach is a combined treatment of both the digested sludge and the centrate: NuReSys-HYBRID. The digested sludge is processed similar as in Digestate Scaling prevention where is solely aimed at scaling control on the dewatering equipment. However after dewatering the remaining centrate can be further processed to ensure reduced phosphorus backflow to head of the MWTP combined with premium fertilizer production. The advantage of effect on dewatering is not attained in this case.
After having experienced excellent results with the NuReSys-P technology at their site in Nieuwkerke, in 2012 Clarebout Potatoes has decided to equip also the Warneton plant with the phosphate recovery technology of NuReSys.
Digested Sludge Application 1
NuReSys applied on digested sludge as such and has 2 different approaches. Just stripping of the digestate is a simple scaling control to prevent wear damage, pipe clogging and thus reducing process down time and excessive maintenance costs on dewatering equipment and sludge handling line. No chemicals are added and no struvite is harvested.
Digested Sludge Application 2
The second approach directly applied on digested sludge is illustrated below. This is full option NuReSys technology: stripper for pH control and stirred tank reactor with MgCl2 addition to promote active struvite formation. Main advantages are again scaling prevention (based on limiting free soluble phosphate) and improvement of dewatering of the bio solids. Another major advantage is reducing the phosphorus load returning to The head of the MWTP. The option of either harvesting the struvite or not (struvite retained in the dewatered bio solids) is again case dependent.
A smart approach is a combined treatment of both the digested sludge and the centrate: NuReSys-HYBRID. The digested sludge is processed similar as in Digestate Scaling prevention where is solely aimed at scaling control on the dewatering equipment. However after dewatering the remaining centrate can be further processed to ensure reduced phosphorus backflow to head of the MWTP combined with premium fertilizer production. The advantage of effect on dewatering is not attained in this case.
After having experienced excellent results with the NuReSys-P technology at their site in Nieuwkerke, in 2012 Clarebout Potatoes has decided to equip also the Warneton plant with the phosphate recovery technology of NuReSys.
Digested Sludge Application 1
NuReSys applied on digested sludge as such and has 2 different approaches. Just stripping of the digestate is a simple scaling control to prevent wear damage, pipe clogging and thus reducing process down time and excessive maintenance costs on dewatering equipment and sludge handling line. No chemicals are added and no struvite is harvested.
Digested Sludge Application 2
The second approach directly applied on digested sludge is illustrated below. This is full option NuReSys technology: stripper for pH control and stirred tank reactor with MgCl2 addition to promote active struvite formation. Main advantages are again scaling prevention (based on limiting free soluble phosphate) and improvement of dewatering of the bio solids. Another major advantage is reducing the phosphorus load returning to The head of the MWTP. The option of either harvesting the struvite or not (struvite retained in the dewatered bio solids) is again case dependent.
A smart approach is a combined treatment of both the digested sludge and the centrate: NuReSys-HYBRID. The digested sludge is processed similar as in Digestate Scaling prevention where is solely aimed at scaling control on the dewatering equipment. However after dewatering the remaining centrate can be further processed to ensure reduced phosphorus backflow to head of the MWTP combined with premium fertilizer production. The advantage of effect on dewatering is not attained in this case.
Technology configurations as IPM
