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Active Water Treatment Systems Environmental & sustainable water treatment by Marine Biologists |
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| | DrydenAqua homepage | AFM homepage | Water treatment homepage| swimming pools | Aquaculture & Aquaria | Drinking water | Sewage effluent | Aeration systems | Leachate treatment | Farm effluent | | ||
leachate treatment home | some water analysis data
| The system comprise of 4 x tanks. Three of the tanks are 20m in diameter by 6 m in depth. The raw leachate water enters tank 1 via an automatic valve which is controlled by both the oxygen level in the first tank and by water volume. The volume of leachate is approx. 200 cubic metres per day, at 600mg/l ammonium and approx, 3000mg/l COD. Ammonium levels are reduced to less than 10mg/l, and better than 95% COD reduction is achieved. |  |
| Dryden Aqua fine bubble diffused aeration is used to mix the water, and to provide oxygen. Fine bubble diffusers are inherently much more efficient than any form of mechanical aeration. It is essential to maintain bacterial floc stability in biological systems. Our fine bubble systems promote a stable floc as opposed to venturi systems and many mechanical system that simply shatter the bacterial colonies. The diffusers maintain a minimum dissolved oxygen level of 2mg/l in tank 1, 4mg/l in tank 2, 6mg/l in tank 3 and 95% + saturation in the discharge tank. |  |
| The process technology employed is sequential batch fine bubble diffused aeration incorporated stabilized nitrification. Our fine bubble air diffusers are central in achieving this task. The air is supplied to our diffusers using roots type blowers. The first part of the pipe is in steel (for heat dissipation). The steel pipe then connects onto MDPE pipe. The system in this report, uses 2 x 22kw blowers, each absorbing approx. 15kw of energy and delivering 1000 cubm/hr of air, with a transfer efficiency of approx. 20% which equates with approx. 1400 Kg of oxygen per day. |  |
| The aeration system is helping to provide the right conditions for the bacteria to treat the effluent. It is therefore very
important to keep the bacteria in the system and to provide a very highly clarified effluent. To achieve this task, all of the water after stage 3
aeration tank is pumped through our AFM filter. The AFM filer removes all particles down to approx. 5 microns. The filter is back-flushed back
into the system in order to recycle the bacteria. The AFM filtered product water is sent to tank 4 for continual discharge. The water is normally
sent directly for irrigation, river discharge, or sewer discharge.
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| The photograph opposite shows the front end of our AFM filter and automatic valves. The complete process is automatic from start to finish. The water is treated to a very high standard, and there is no concentrated effluent discharge as you have with Reverse Osmosis. However if you are required to achieve almost potable water standard, Ozonation, UVc ad sub micron filtration can be added onto the end of the process. This is relatively easy to accomplish, because the water has already been treated to a high standard. Reverse Osmosis If you are required to reduce the salt content of the leachate then reverse osmosis will be required, however the treated leachate is much easier to treat by RO than the raw leachate. The Dryden Aqua system will reduce the TDS and conductivity of the leachate by up to 50%. The TDS reduction is a function of the water chemistry and will depend upon how much ammonium is present in the leachate. However the lower TDS will reduce the pressure required on the membranes and thereby reduce operation costs. In addition because you are not recycling high levels of ammonium back into the site, you don't have the same feed-back inhibition of bacteria activity in the site, and the leachate is of a high quality. |
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| Control panel, A simple electrical control panel and a PC control the entire process. The PC is connected to a telephone line for remote telemetry. |
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