Digester wastewaters are by-products of biogas production in anaerobic digesters. They require treatment prior to disposal. To meet regulation compliance, treatment options range from minor interventions such as selective contaminant removal, to major interventions such as minimum and zero liquid discharge (MLD/ZLD).
Ammonia Stripping & Scrubbing with Crystallization Options
Extract ammonia, even from wastewaters containing high TDS, organics, or particulate. AmmoniaSelect is a robust, self-cleaning, ammonia stripper-scrubber solution. Spend less time cleaning packing and more time operating. Make solid ammonium sulfate on the backend with one comprehensive system.
Stripper-scrubbers are important, well-established technology, used to extract ammonia from wastewaters too concentrated for sewer discharge or biological processes. Systems consist of two towers: (1) a stripper to remove ammonia, and (2) a scrubber to reabsorb it. The stripper is high-pH spray tower that liberates the ammonia from the feed solution as gas in an air stream. The scrubber is a low-pH spray tower that captures ammonia in an acidic solution, generating a clean ~35% ammonium sulfate solution. The clean ammonium sulfate is often used as a fertilizer.
Conventional stripper-scrubbers work quite well. However, the input wastewater solution can present a host of challenges for operators, particularly in keeping the dirtier stripper tower clean. Long and labour-intensive outages may be required, during which the packing material is removed and cleaned. At Saltworks, we engineer to minimize maintenance and down-time. That’s why we developed AmmoniaSelect, a robust stripper-scrubber that stays clean while it operates. This is particularly important for wastewaters such as anaerobic digester centrate.
We developed AmmoniaSelect to offer the sector a robust, compact, and easy to install package that will extract ammonia from the toughest waters.
AmmoniaSelect helps clients achieve:
- Compact modular design for rapid installation at a low cost
- No single point-of-failure, with three strippers and three scrubbers in each AmmoniaSelect System
- Low clogging packing with access hatches for rapid pressure-washing
- All wetted parts are corrosion-free engineered plastics, suitable for high-TDS, high-temperature and high-ammonia operation.
- Self-cleaning system built-in with easy to use operation
Make Solid Ammonium Sulfate
On its own, AmmoniaSelect can produce a solution of ~35% (NH4)2SO4. Some blend this with liquid fertilizers. Other customers seek a solid ammonium sulfate output.
We can package AmmoniaSelect with a crystallizer from our SaltMaker family to deliver an end-to-end ammonia extraction and solidification solution. This means you can reduce the mass of waste leaving your site by an additional 2.8×, while also recovering additional clean water. Our SaltMaker crystallizers come in a variety of configurations that enable optimization for your energy sources, including waste-heat driven solutions. Contact us to learn more.
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