Applications
Timber Processing
Aeration Diffuser Failure
Aquatic Aerators
Landfill Ammonia Reduction in raw leachate
Paper Manufacturing
Replacing paddle aeration
Supplementary Aeration in a Cereal manufacturing process
Surface Water
Timber Processing
Chip-board manufacturing requires large volumes of water in its processing, this water is contaminated with high levels of wood pulp requiring it to be stored in settlement ditches, and the removal by tanker of the residue. Various methods of reducing the contaminate levels were tried but proved unsuccessful in complying with the 5mg/l discharge level consent.
Aeration of the settlement ditches with the WMS-510 oxygenator reduces the ammonia, formaldehyde, BOD, COD and SSP levels to 3mg/l of ammonia as well as a reduction in the other contaminants. The company has decided to pump the treated effluent back into the plant for use as process water.
Two large cost savings can now been achieved.
1. Complying with the discharge consent levels avoids prosecution.
2. The volume of the water purchased is reduced, saving on water charges.
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Aeration Diffuser Failure: Water Utility STP
Aeration diffusers in water companies sewerage treatment plant had failed., and it was suspected that unauthorised liquids were being discharged into the sewers causing the problem. A site visit to the plant revealed the break down of the aerator heads and the resultant poor quality of the effluent. As the diffusion system was built into the tanks, they could not be repaired without taking them offline. To resolve the situation WMS oxygenator were floated into the treatment tanks, with their unique fluid distribution system and infused microbubbling technique the WMS units set to work. The results proved very successful with no further failures.
To date the WMS oxygenator have proved completely satisfactory with consistent effluent discharge levels being attained.
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Aquatic Aerators
Lakes:
When fish were found dead in a lake , tests showed that the oxygen level was very low. The installation of a WMS floating oxygenator. Since introducing the oxygenator there is less weed build up on the bottom of the lake (due to a reduction in ammonia and B.O.D from aerobic biological treatment) and the fish are livelier.
Tanks:
A fish rearing company wanted to oxygenate fish stock tanks. The WMS oxygenator has proved very successful, allowing for a greater number of fish to be kept in each tank. These fish are used to re-stock fishing lakes.
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Landfill ammonia reduction in raw leachate
WMS oxygenators can be used to reduce ammonia levels and improve the consistency of the leachate whilst maintaining the highest energy efficiency possible.
Example Data
* Lagoon capacity 1000 m3
* Daily treatment 100m3 per 24hrs as specified in the consent document.
* Raw leachate input from cells at 5.5l/s
* Existing aerators 2 x 15kw floating vertical spindle aerators
* Current ammonia consent level 150 mg/l
* Complaints regarding the smells and noise from the outlaying town
* Unable to reduce the higher levels of ammonia to comply with consent level
* Prone to sinking during freezing weather
The landfill site had 2 existing 15kw vertical paddles aerators, which were unable to cope with the fluctuating strength of the raw extracted leachate, during freezing weather they prone to sinking due to the water freezing on the floats and therefore no aeration could take place.
Two 15kw vertical paddle aerators can be replaced by WMS floating oxygenators. Immediately is was obvious the WMS oxygenators were generating foam. The foam fractionator attachment was installed which collected the foam into concentrated liquor, further reducing the DOC and ammonia levels.
The WMS unit will do this job more efficiently and use less power.
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Paper Manufacturing
A paper manufacturing company uses a large lagoon aeration of the pulp effluent and their existing method of aeration was by using 180 tons of oxygen per day and supplemented by 10 x 75kw vertical paddle aerators this type of aeration was proving unsatisfactory, as the aeration was only effective in a given radius around the aerators. Beyond this radius the un-aerated effluent could clearly be seen, a septic paper mache crust covered the corners of the lagoon.
The Company placed an order for 2x WMS floating aerators, which were initially installed in the septic corners of the lagoon.
The WMS method of oxygenation is completely different to the two types of aeration used by the Company; The vertical paddle method cascades the effluent into the atmosphere absorbing air as it returns to the effluent. WMS direct infusion forces microbubbles of air directly into the circulating effluent.
The WMS method positions the aerator mid-depth in the effluent, sucking in air from the atmosphere, mixing it with the liquid and discharging the micro-bubbles into the liquid mass in all directions producing the following effects:
* Micro-bubble oxygenating
* Full depth aeration
* Re-suspension
* Mixing
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Replacing paddle aeration
One of the drawbacks of paddle aerators is paddle failure
A sewage treatment works has two aeration ditches each ditch having 2 x 25kw paddle aerators. One day, one paddle aerator broke down requiring major repairs. WMS floating oxygenators were quickly installed after the sediment depth was established and adjustments were made to the intake depth.
The WMS floating oxygenators supplemented the remaining 25kw paddle aerator, and oxygen level was maintained ,saving 13kw.
Due to the success of the WMS aerators, the paddle was never replaced.
Over time the sediment has disappeared.
Usually if a ditch is emptied the sediment has to be dug out, so the cost of removal and disposal of tons of sediment has been saved The disappearance of sediment is due to the fact the WMS also fulfills the mixing requirements of the process retaining all solids in suspension whilst also meeting aeration requirements.
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Supplementary aeration in a Cereal manufacturing process
A cereal manufacturer uses wall mounted aerators in circular tanks to process their process effluent.
WMS aquafoil oxygenators can be used to reduce COD levels, as new legislation makes the disposal of dry sediment to land fill difficult.
The wall aeration system could not reduce the COD level lower than 1400 mg/l. The cost of disposal is very expensive and will increase each year.
The existing aeration equipment was producing large air bubbles which results in low oxygen transfer..
The installation of the WMS aquafoil aerator causes thorough mixing of the effluent, tests were carried out indicating the COD level had been reduced from 1400 to 300 mg/l
This significant reduction in COD levels was achieved by the correct positioning of the discharge jet on the WMS aquafoil aerator to produce a rotating effect in the circular tank. This rotating effect also rotated the aerated liquid produced by the tank mounted aerators giving an overall increase in retention time, resulting in a higher dissolved oxygen transfer level whilst lowering the COD levels.
From a few large bubbles to a mass of fine bubbles gives a far greater oxygen transfer; the net result is a considerable reduction in the cost of disposing of their trade effluent.
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Surface Water
A manufacturing company experienced problems with their surface water, which was failing to comply with consent to discharge levels for many years.
Their traditional method was to collect the surface water in a lagoon and dilute using mains water to satisfy consent levels prior to discharge into the sewers, this method was proving very expensive and wasteful and against environmental policies. The WMS floating oxygenator was used to reduce the BOD, COD and SSP to comply with the consent discharge levels.
The system runs automatically involving no labour charges, no more water charges and is now discharging into the sewers and is environmentally friendly, no splashing, no smells and no aerosol is released.
Dirty water run off
All livestock farmers are compelled to store yard water run off in lagoons, pending distribution onto fields at the appropriate time of year, the continuous treatment of the lagoon with the WMS floating oxygenator allows the discharge of the treated water into watercourses and ditches once consent is given.
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