Published on May 30th, 2014 | by Tina Casey4
Sewage Mining-In-A-Box Yields Mother Lode Of Bioplastic
May 30th, 2014 by Tina Casey
Now that the age of fossil fuels and petrochemicals is winding down, sewage mining is obviously the Next Big Thing. The wastewater-to-biogas angle is already going strong and a number of companies are busily reclaiming other useful raw materials, too. Here’s one that just crossed our wire: Applied CleanTech, which has come up with a compact, transportable system called SRS™ for Sewage Recycling System.
The product resulting from SRS is something Applied CleanTech calls Recyllose™, but we’re calling it the Sham Wow of sewage mining because it does so, so many things.
The Bottom Line For Sewage Mining
SRS and Recyllose involve one of those sustainability twofers that we can’t get enough of. Actually, let’s make that a threefer.
Unlike fossil fuel harvesting, SRS results in (1) a useful product that (2) does not involve ripping up virgin land and (3) solves a major bottom line problem.
Starting with the bottom line issue, modern wastewater treatment is an enormously expensive, energy-sucking endeavor that drags down municipal budgets. Sewage mining offers a way out of the mess by enabling communities to recover value from their wastewater.
Harvesting biogas is becoming a popular solution, because the gas can be used right at the wastewater facility to offset energy costs. New York City, for example, has been harvesting and reusing biogas for years. The city also recently added a pilot project to add food scraps to the biogas stream, with the aim of reducing its solid waste disposal costs, too.
SRS comes into the bottom line equation because it cuts down on the amount of sludge (tiny particles of suspended solids) that goes through the wastewater treatment process, by up to 50 percent. That substantially reduces the energy required to pump wastewater through the treatment facility.
By removing sludge before the conventional treatment process begins, SRS also frees up capacity within the existing plant, enabling local communities to grow while forestalling the need for an expensive wastewater treatment plant expansion.
Applied CleanTech estimates that operating expenses are cut by about 30 percent and capacity is increased by about 30 percent, but we’re guessing that could vary quite a bit depending on the nature of the existing facility.
Since SRS traps the cellulosic particles in sludge (hence the name Recyllose), which otherwise would not be digested during biogas production, you can still get your biogas, too.
Renewable Bioplastic From Sewage
Skipping back to #1, Recyllose is a very useful product indeed. It comes in the form of pellets or pulp consisting mainly of reclaimed cellulose fibers, which makes it suitable for use as a fuel, an additive to pulp and paper, or a bioplastics additive.
The bioplastics angle is a particularly interesting one because it could enable wastewater treatment plant operators to harvest bioplastic feedstock at two different points in the process; by capturing sludge at the beginning, as provided for by SRS, and by capturing biogas at the end, as demonstrated by a company called NewLight Technologies.
Mining From The Built Environment
As for #2, we’re totally fascinated by this whole sewage mining thing because it dovetails with building integrated solar cells and other emerging systems for harvesting renewable energy and other forms of value from the built environment, rather than tearing into virgin lands to extract single-use resources.
In addition to harvesting value from the wastewater treatment process itself, the remote location and expansive grounds of many treatment plants also offer ample opportunity for solar arrays and wind turbines.
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