Ask The Brewmasters

Anyone deal with wastewater management and have a centrifuge or decanter implemented to remove further solids from brewery effluent?

We currently have pH neutralization and high strength waste (HSW) diversion, but are looking to further upgrade to remove remaining solids from effluent in pH neutralization tanks going through our flume to the city that we're getting monitored/charged for.

Initial thoughts are putting a centrifuge or decanter on our 2nd (2 of 2) pH tank to discharge solids to our HSW tank and return to pH tank or flume feed. Space is limited, so in need of something that has a relatively small footprint.

Starting initial research and wanted to shoot my shot here to see if anyone has any experience/insight on the matter.

Thanks in advance!

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Nick Okada
Brewery Engineer
Rhinegeist Brewery
Cincinnati OH
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Hi Nick,

When looking at capital upgrades to our Wastewater systems, I always look back at the equation the POTW charges us by.  For us, it includes Volume, BOD, Nitrogen, TSS and at one of our locations, TDS.

We do use a Decanter at one location, But have also added DAF when appropriate.  Not only did that take the solids, but we also knocked out 30-40% of our BOD and Nitrogen.  Big win. 

I know you said space is limited, CWT had some small DAF systems.

Centro vs Decanter?  Depends on the % solids you will be feeding it.  Either way, you will want a homogenous feed.

If you go this route, consider the polymer addition as well in improve removal. 

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John Frederick
Principal Product and Process Innovator
Gallo
Modesto CA
(209) 604-5246
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Hi Nick,

At Pizza Port we installed a screw press solid separator (see attached file for example spec sheet). The brewery we installed that unit at produces appx 50,000 bbls/year. We installed ours prior to pH adjustment to help minimize caustic usage at pH adjustment, although there are pros and cons to installing on either side of pH. (If it's installed post pH adjuster you will likely use more caustic to regulate pH of your effluent, but the chemicals used to promote solid separation like the constant pH and it's much easier to run the separator long term). 

Let me know if you're interested to discuss any details as your developing your solution. While the solid separator makes it incredibly easy to meet our TSS targets for our effluent, it could likely be overkill for your facility. 

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Cheers,
Eric Ritchson
Chief Operating Officer
Pizza Port Brewing Co
Carlsbad, CA
ericr@pizzaport.com
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Hi Nick,

Kroff has quite a bit of knowledge and experience in retrofitting WWTPs to improve effluent quality and compliance.

Without having complete knowledge of the plant design and effluent chemistry it's difficult to know the best approach to reduce suspended solid carryover.

Is there currently any coagulation/flocculation reaction before the pH tank?   Sometimes, simply adding a flocculant will help coalesce the solids into large flocs, improving settling time.  This sludge could then either be dewatered or hauled depending on the sludge amount.  Depending on the quantity or volume of solids, sometimes just an inline filter (filter medias, poly bags, DE, etc) can be a convenient low cost option to reduce carryover.  Sometimes solids will also settle well, but the volume of solids accumulates and eventually starts to carryover, in this case, a dewatering press in combination with structured polymer would be a good option.

Overall, there are likely more than one way to accomplish a reduction in SS carryover, and additional info on limits, footprint, chemistry, and capital considerations should all be considered.

Feel free to shoot me a message if you would like to discuss this further.  Hope this helps get you started!

Thanks!

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Steven Maring
Water Treatment Consultant
Kroff Chemical Co
Pittsburgh PA
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Hi Nick,

A decanter centrifuge can work for this application and is a go-to for high throughput applications, but reliable operation will depend on many factors.  The first of these I can think of is in the consistency of the feed. Screw presses generally offer good value for money, and in some situations a rotary drum press may be favorable.  Most major suppliers for separators will do bench-scale testing of your solids to determine their suitability for dewatering, polymer requirements, etc.  Happy to discuss offline at your leisure; as others have indicated, there's a lot to unpack in your request. Feel free to drop a line via the contact info on my profile.

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Jeff Muston
Technical Services Manager
Sierra Nevada Brewing Company
Mills River NC
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Hi Nick,

Building on this conversation, there's definitely been a push in the industry over the past 24 months or so to decrease waste removal/municipal treatment costs depending on where the brewery is located and how they're being charged. 

I know there's several different technologies that can provide some level of dewatering, but decanter centrifuges are the most sophisticated option and consistently used in industries outside of breweries as well (municipality wastewater treatment, food production, etc.). With the level of g-force created, you can achieve a level of dewatering in a fraction of the square footage. The questions are what is your flow rate, TSS, and requirements downstream on an ROI basis. 

I encourage you or anyone else to reach out to our team to investigate or trial the option if you're seeing these operational expenses continuing to rise. We've been seeing this more and more and suspect it will continue to be a point of efficiency for breweries in the coming years. 

Cheers,

Jacob

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Jacob Foster
GEA Canada Inc
Burlington ON
(365) 378-2757
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