ice-cream because wastewater is cool

ice ice baby

After the first week doing back-to-school shenanigans, I found myself… in the ice cream aisle… on the prowl. Anyone else? Just me?

Because I’m all about #adulting, I believe that five pints of ice cream is a good sub for dinner three nights in a row. Easy, fast delicious. Prove me wrong. Summer in Texas does not come to a close just because there’s learning to be done.

For this post, NadaMoo! let me in on a few of their facility functions. They’re a mid-sized ice cream factory based out of Austin, Texas with all the normal industrial engineering… though for them, it’s contracted out to a “co-packing” facility.

the scoop on NadaMoo! (NM)

Vegan ice cream typically doesn’t have a lot of water used in the final product. However, for a manufacturing plant water is the life source. It’s used for washdown, for cooling and condensing (refrigeration), soaking fruits or nuts, and for domestic uses such as toilets and sinks. All of that water has to be potable-grade.

How do they get their water?

Industrial water users make up some of the biggest water users–up to about 59% of water. (For more info see my past post about major water users!) Similar to many other food manufacturing processes, NM takes in pre-treated water from a nearby municipal city. Generally cities have a bulk water user billing rate meant for these industrial users. This is because the industrial use is steady and predictive. The city gets a reliable customer and the factory gets a consistent supply of high quality water. Win-win.

Some factories then go on and do additional treatment on their influent water. This is where you’d hire a water engineer that can specialize in mechanical process engineering. They would then design a system that would lower levels of certain minerals, or add other minerals, to get your recipe just perfect. I couldn’t quite pin down if NadaMoo! added anything to their water at their factory. This is because they create their recipe, and then source it out to a co-packing facility that is expected to perform to the “specifications”–that’s how they get the taste and smell and feel and quality just purrfect.

NM is vegan, organic, non GMO, fair trade, and gluten-free! It’s some of the best. Even Zanzamittens thinks so.
How much water is that?

At NM they produce 60-90 pints per minute. Similar to how I start projects, I did some back-of-the-napkins conversions using an 8-hour production day and five day work week. Some quick math comes out to…

3,000 – 5,400 gallons of ice cream a day! Or 18,000 – 27,000 gallons of ice cream a week! Holy moo! That’s a lot of ice cream.

How much water is that? A boatload! (I looked for some exact numbers but was unsuccessful. Sorry y’all.) And all the water that’s not consumed has to go somewhere… in this case, right back to the city municipal as industrial wastewater (and domestic wastewater from the toilets and sinks). This is where the wastewater engineers come in.


the nutty gritty details

Because NM is produced in Texas USA, they fall under the U.S. EPA National Pretreatment Program as well as Texas Commission of Environmental Quality (TCEQ) pretreatment requirements for discharge to municipal sewer lines. These requirements, called the Texas Pollutant Discharge Elimination System (TPDES), are put in place to limit the potential of hazards being released to the environment.

In the case of food, we’re possibly looking at fats, oils and greases (FOG) as the pollutant of concern. FOG is considered a “conventional pollutant” aka something that would be in domestic wastewater and should already be treated by the wastewater treatment plant (WWTP). However, because FOG can clog sewer lines there’s generally strict procedures or extra surcharges for the factory to limit the amount of FOG which they discharge. Then when it gets to the WWTP, the primary clarifiers are sufficient enough to drop the FOG out of the water mixture. (Need a refresher on clarifiers? Check out this old blog post.)

What are some of the ways we can remove FOG?

If there’s a significant amount of FOG expected in the WWTP’s influent water, the engineers might design the plant with a treatment technique typically used for FOG removal. A common practice for oils is an oil/water separator. Think about when you leave a bottle of salad dressing on the counter too long: the oil naturally rises to the top because it is less dense. The lighter oil collects at the top of the oil/water separator and can be skimmed off and disposed.

a basic schematic describing the oil/water separation process which uses the densities of the two fluids to naturally separate them

Another method is dissolved air flotation (DAF). Though to be honest, this procedure wouldn’t be used for the small about of FOG found in ice cream factory wastewater. It’s more suited for oils found at oil refineries.

DAF works by injecting tiny bubbles into a tank of wastewater under pressure. The tiny micron-size bubbles attach to the contaminants and float to the surface of the tank. Similar to before, we can then skim off the contaminants and send the effluent on to the next step in the plant.

Image result for dissolved air flotation
tiny bubbles come in contact with the contaminants and provide the buoyancy needed to rise them to the surface in order to be skimmed off

mint to be

Zanzamittens isn’t the only one who sneaks her whiskers into the ice cream around our apartment. NM sent me over a box of ice cream (the 5 pints I mentioned earlier) and they didn’t last long. I’ve never been a huge fan of cookies & cream flavors but this one takes the cake. Err, takes the creme? It even beat out the birthday cake cookie dough flavor as my fav. Next time you find yourself hunting for a sweet kick, give them a try!

 


If you missed it, check out my youtube unveiling of the NM delivery. I get super excited over dry ice. H&S tip? Don’t put your face over dry ice and breathe in.  X.X


Working: Placing wells, using ArcGIS, along a river where there is an alluvium layer (called alluvial wells). We need 112 wells to get the demand of water required so…there’s no way the client is going to actually want to go to construction of that many wells. On top of that, they would be “groundwater under the influence of surface water” and would require extra treatment. But I am still going to site them and cost them so we have a good, qualitative comparison of the different water supply sources.

Listening: Coffee Break Spanish Season 3. I’ve been learning so so much Spanish this way.

Reading: Harry Potter y la piedra filosofal. See reason from above.

Disclaimer: The ice cream was free but the opinions are my own. 😛

 

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