Is your Wastewater Treatment Plant ready for Winter?   Every year as fall fades into winter, cold weather is a challenge for wastewater plant managers. Low temperatures have a negative impact on the wastewater unit and treatment efficiency drops off drastically. More than likely, the winter months result in effluent BOD and TSS levels that push permit limits.

Wastewater treatment in itself can have many ups and downs. So many things can impact how successful the wastewater process is at removing the critical components of BOD, TSS and nutrients.
 
Winter, with it's fluctuating temperature changes can have a significant impact on the wastewater treatment process.  Snow, icing, and freezing rain can cause huge problems for some wastewater treatment plants.
 
Remember that temperature is one of the critical 5 components in a wastewater treatment plant. Temperature can significantly impact whether you are winning the time and numbers game. Wastewater treatment is always a time and numbers game. Since you really are limited by the time component- (in reality this is the size of the treatment plant) the only thing you can play with and change is the numbers factor. That means adjusting the numbers of bacteria or MLSS in the aeration basin.
 
Another thing to consider, for every ten degree °F change in the weather, the bacteria loose one logs growth of activity. If your outside weather drops 20 to 30 degrees in one day, that can significantly impact the activity in your system, if you do not have a high temperature influent consistently. That means you have to adjust the amount of RAS and WAS in your system to reflect the temperature changes. You can only adjust the MLSS as quickly as your pumping capabilities allow.  Another thing to remember, the bacteria are finicky. They do not like significant changes. Any time a change of more than 10 percent is made, on any variable that is critical to them, they get temperamental
 
1.)    Snow, Freezing rain
2.)    Hydraulic washout due to excessive freezing rains from storms or melting snows
3.)    Changes in BOD loading
4.)    Sludge Age changes due to activity changes
5.)    Loss in removal efficiency.
6.)    Icing problems for equipment or freezing pipes.

Primary Clarification and/or Pre-treatment
BOD/COD Removal Optimization
Nitrification Maintenance/Nitrification Recovery
Cold Shock Recovery
Sludge Dewatering Effectiveness
Secondary Clarification Efficiency
TSS Reduction
Biosystem Upset Recovery Program
 

Why is my system acting up? It happens every time the cold weather is here.     Are your BOD degradation rates dropping and your TSS increasing? Did you know that for every 10° F drop in temperature results in a significant decrease- up to even 1 log's growth- in normal bacterial metabolic rates. Augmenting your biomass will increase sluggish degradation rates, improve the floc forming capability of the biomass, and maintain the biological health of your system.

Winter Filaments, Nocardia, Microthrix parvicella and 1863  

 There is nothing worse than having a filamentous problem that is ten times worse during the winter months. Who wants to worry about frozen foam and scum on clarifiers that can break rakes, pumps, or may be a mess to clean up.   What causes these filaments to grow worse in the winter? What types are they usually?  

M. parvicella typically grow and thrive in the colder months. Microthrix parvicella is usually caused by low F/M and high wastewater grease and fat, or colder temperatures. This filament, since it grows internally, can be overlooked.       This filament can cause serious settling problems, make it harder to dewater and increase polymer consumption as well as solids handling costs. This filament is easy to identify as it is Gram positive and has like spaghetti like tangles.  

Nocardia is a filament that typically likes also a longer MCRT, excess grease, oils and fats and usually warmer temperatures, yet we have seen a significant increase in this filament in municipalities and food plants during the winter. Since biological activity is slower in the winter, it may be that the normal carbonaceous floc forming bacteria have not consumed the grease as effectively, thus the Nocardia takes over. Frozen foam, as you have seen in the earlier pictures on a clarifier is not fun or easy to remove.      

This filament is easy to identify as it is gram positive, but the only filament with real branching.   Nocardia and M. parvicella are very easy to identify if you blow up the sample. If you just look at low power, 40x or 100x, you may overlook these filaments. Use 400x, use instant stains, Lactophenol cotton blue if necessary; even use Gram and Neisser stains. Make a process change, adjust the grease removal in your primaries and if needed, bioaugmentation upstream to help with elimination of the grease. Make sure to adjust the sludge age based upon higher life forms not volume and mass balance numbers. Fluffy, filamentous bulking sludge will take up more room than floc formation, and will give you false numbers as far as MCRT and F/M rations.

What are some additional ways to help your plant with weather changes?

Upset Recovery Programs- Some plants keep a small amount of bacterial products on hand for upset conditions. Temperature swings can impact a plant if the weather changes significantly. Loading swings can also impact the plant more in the fall and winter months.
For many industrial plants, if a significantly high loading comes through the plant, bioaugmentation can be used to instantly get the plant up to speed and beat the time and numbers game without delay or impact to the final effluent quality. Since many plants can only return so much RAS to the front end and are limited by pumping speed, or even the amount of bacteria in the current system, the use of biological products is a quick and easy way to help increase the activity instantly.

Remember it does not take a ton of product to instantly bump up the system. A typical maintenance dosage is only 1 lb of product for every 1MGD a day if the typical flow is around 2-300 parts of BOD. You can do the math, if your flow is lower, but the BOD higher, make adjustments. See our Math calculations where in 24 hours 6.7 lbs of product equal the equivalent of trucking in a 4000 gallons of MLSS from the neighboring plant!

Sometimes being prepared for an upset is better than waiting for it to happen and scrambling. The bacteria products usually have a pretty long shelf life- 6 months to a year, so having a small amount on hand can be a good idea if your plant has the potential for upset conditions or wide swings in influent loading.  Lagoon systems, especially in Papermills, typically have a harder time meeting BOD permits in winter, They almost always use some type of bioaugmentation program Ask about our Dual Programs today.