DATE POSTED: September 3, 2021
We’ve dewatered a lot of stuff over the years.
Everything from ordinary wastewater sludge and excess soil from construction sites, to noxious slurries containing really smelly organics, industrial process wastewater, and even low-level radioactive materials.
Over that time, we’ve learned a couple of things.
First, that our Bishop Solids Management Solution is extremely versatile. It can be used to collect, dewater and consolidate almost any type of slurry material.
The second thing is that our Solids Management Solution is one of the most efficient and cost-effective ways to get the job done. Our passive, gravity-based dewatering system is often compared against more complex, energy-intensive processes such as centrifuges, belt presses, and filter presses. In most cases, we can demonstrate that the Bishop Solids Management Solution can achieve similar or better dewatering performance at a lower cost and using less energy than alternatives.
The Bishop Solids Management Solution not only retains and consolidates solids, it also provides water treatment—greatly reducing TSS, nutrients and other contaminants of concern. This can be an effective pretreatment step or, depending on regulatory requirements, the filtrate can meet standards for discharge to the environment or even reuse in non-potable applications.
Our process starts by obtaining a sample of the sludge and performing a dewatering test. The test reveals a lot of important information such as the solids concentration of the slurry, the polymer that will provide the best dewatering performance and how much water can potentially be removed.
We also need to know the approximate volume of sludge to be dewatered. This information, combined with the results from the dewatering test enables our team to calculate the number of Geotube® dewatering containers that will be needed, how large the dewatering cell will be, how much polymer will be needed and of course, how long the project will take.
Contact us to discuss your solids management needs and learn how simple, low-energy solutions from Bishop Water can help.
Learn more about the Bishop Solids Management Solution.
DATE POSTED: February 27, 2020
Geotube containers that are filled late in the year are often left onsite over the winter to experience the dewatering advantages that the freeze-thaw cycle brings. Once the thawing begins, those previously frozen Geotube® containers can give up a lot of water—in some cases up to 50% of their volume.
This dramatic reduction in volume means that the containers can be topped up with additional slurry materials once they are fully thawed. Or, if the solids are destined for disposal, the reduced volume will mean much less material to transport and lower costs for hauling and tipping fees.
Dewatering benefits from the freeze-thaw cycle because water expands as it freezes. The Bishop Solids Management Solution, with Geotube® containers, can attain 15 – 18% solids within a few days of dewatering, but that means there’s still a good amount of water remaining as cold temperatures set in. The formation of ice crystals and the expansion of the water compress the solids and once the thaw occurs, more water is released and the solids are further consolidated.
The results can be quite dramatic. At a recent wastewater lagoon desludging project, our crew filled Geotube® containers to a maximum height of 7.5 feet. The containers were left on site over the winter and after thawing in the spring, the height was reduced almost by half.
Some of our clients that are equipped with a permanent Bishop Solids Management Solution take full advantage of freeze-thaw cycles in their sludge management plans.
The North Rustico Wastewater Treatment Facility in Prince Edward Island, Canada uses several large Geotube® containers setup outdoors to dewater waste sludge, with a smaller container in a greenhouse that is used during the winter months. The outdoor containers are left to freeze over the winter and can be topped up in the spring once they thaw and release more water. This enables the plant to use Geotube containers for several seasons, replace them less often, and reduce operating costs.
Read the feature article about the North Rustico WWTF in Go With the Flow magazine published by the Atlantic Canada Water and Wastewater Association.
Learn more about Geotube® containers for solids dewatering.
Contact us with your questions about the Geotube® freeze/thaw/consolidation cycle and to arrange for a dewatering test of your solids.