How to remove struvite?
6" pipe from CAFO operation that our Struvite Remover cleared
The Struvite Problem
When looking at photographs of struvite filled piping and clogged valves, it always leads to the question, “How do you remove struvite from waste water treatment plants (WWTP) or Concentrated Animal Feeding Operations (CAFO) without causing a major interruption?”
One of the easiest ways to stay on top of a struvite or vivianite problem is to utilize the plant data that you are collecting 24 hours a day, seven days a week and take full advantage of it. One of the pieces of data that you will have in your logs is the time it takes for a batch of solids to process through the plant and in some cases you have the data that tells you how long it takes to move from the anaerobic digester to your sludge tanks.
There was one WWTP that had a fourteen inch (14”) diameter transfer line that moved sludge from the anaerobic digester to the sludge holding pond. They noticed that it was taking 45 minutes to transfer when it should only take 4 minutes to pump the sump. When it got to the point that it was interfering with their process, they ended up replacing the valve – and it was then that they discovered that struvite had completely blocked the valve. This particular plant had periodically maintained the valve by mechanically cleaning by hydro-jetting, but that only cleaned the easy to dislodge struvite. If they had wanted to really clean the valve mechanically, they would have had to use a grinder, and that would have meant not having the valve available for a week or more.
Struvite Removal Solution
An alternative method for removing struvite that is much easier to administer and control than mechanical grinding and spraying. We offer a liquid solution, environmentally safe product that has proven itself over time to remove struvite efficiently and cost-effectively. It is very effective at safely attacking and dissolving the struvite crystal (rock) by targeting the magnesium component of struvite. Struvite is a compound made up of three elements: magnesium, ammonia and phosphate. In WWTPs when these three elements specific weight ratio (1:1:1) is met, struvite precipitates out of the plant’s liquid. WWTPs attempt to control struvite precipitation by controlling the pH and magnesium level of the liquid, as well as the CO2 release from the anaerobic digester. It attacks the magnesium in the existing struvite crystal, causes it to go back into solution and the struvite breaks down. The rate at which it takes to dissolve the struvite is a function of time and concentration.