i would suggest our nanobubble DOF( Dissolved ozone floatation system) . In a demo at a sugar plant in UP we could reduce organic loads at the equalisation stage ( water post anerobic process) by pretreatment from 3500 COD approx to 50/60percent and then because of breaking up of the complex chains their aerobic biological process seemed to be working more efficiently and able to reduce to around 80/90 percent the microbes found it easy to process..So could remove the odour / Colour and bring COD to discharge levels..Infact if given further treatment we could get it to reuse levels.What sets us apart is the generation of hydroxyl radicals which has oxidation potential almost double of ozone.At the same time very excellent ability of nanobubbles for oil separation Send me your details and maybe we could discuss and understand better.. My email ID is harish@acsipl.com
The scheme you need to follow post anaerobic digester which could further give you biogas production as you BOD/COD values are quite promising for post anaerobic digestion as we have experiencen in doing same in one distillery.
Then you need to have aerobic treatment to bring down the BOD/COD up to discharge standards.
For sludge that could be used as soil conditioner or if added NPK then can used as fertiliser.
We have actually implmented some systems for BOD/COD removal. Sometimes treating systems more upstream to help remove any oil (which leads to COD/BOD production). We have done this with implementing SiC membranes upstream to help reduce BOD/COD downstream..
You can email me, rmitra@h2osystems.ca We can potentially help you. Where are you located?
As Dave has said, the first thing to check is whether the waste can be minimised at source, or the effluent can be beneficially reused.
If you have to treat it, 60-70% COD removal in the UASB stage is reasonably good. You can test to see whether the waste is amenable to further anaerobic digestion at lab scale and, if so, you might want to check the efficiency of mixing in the UASB or consider a separate post-digestion anaerobic stage. I guess you're already recovering the biogas and using it? The sludge yield is an inevitable byproduct - it is material that was not digested in the UASB either because of poor mixing/ inadequate retention time or it is simply not degradable under anaerobic conditions. Pre-hydrolysis or ultrasonication techniques might improve digestion slightly, but at a price.
The UASB effluent can then pass to an aerobic process such as activated sludge to reduce BOD and other parameters to as low as needed. To meet zero liquid discharge requirements for recycling or reusing the water you may need to add additional filtration stages.
OK, understood. So now we need to establish what form the carbon is in. First is it particulate and can it be removed by prefiltration before the nano? If so we may be able to help using our FilterClear system.
If it is soluble then we need to check how biodegradable is the residual carbon? You could check the BOD:COD ratio and carry out a respirometry test to check. If it is biodegradable at a reasonable rate then it suggests that the biological treatment isn't working efficiently. If it is slowly degradable you could consider advanced oxidation (using UV, ozone or peroxide but probably not chlorine due to effects on membranes).
Hello Shashikant; it sounds with COD values like that a lot can be done about preventing loss from the processing plant. This will save them money also! Secondly an out of the box thought... this waste could be of value as animal feed if zero liquid discharge means you have to evaporate the liquid anyway why not concentrate the waste to a syrup and sell as animal food?
I recommend a settler as the first step as an easy way to reduce BOD into the USAB. If the USAB effluent is greater than 5000 mg/L BOD add a second USAB- follow with Activated sludge -- Thicken and dewater the sludges for disposal.