Converting Waste Agricultural Biomass into a Resource - UNEP

Detailed Process of Waste Treating Waste: 230
The DEWATS is a plastic septic tank connected to an anaerobic reactor, an
aerobic reactor, and an algal pond.
Septic tank effluent is filtered in the anaerobic and aerobic reactors—
chambers where complementary chemical reactions take place to remove
much of the wastewater’s filth. These chambers have “microbial support
systems” that are capable of turning murky water into clean water.
The microbial support system for the anaerobic reactor consists of “pyrolyzed”
waste biomass residue, and small and large perforated plastic bottles.
Basically, the biomass residues, composed of rice hull or coconut coir dust
that has undergone pyrolysis (a process of decomposition using heat), are
bound together by melted waste plastic, and placed inside small perforated
plastic bottles. These small bottles are then placed inside larger gallon-sized
perforated bottles, and stacked in the anaerobic chamber.
Similarly, the microbial support system for the aerobic reactor uses solid
wastes such as cut-up phone cards and aluminum cans, placed inside small
perforated plastic bottles. They are then placed inside larger perforated plastic
bottles, and lined-up near the tank’s inner walls. Low-cost blowers or air
pumps at the bottom of the tank improve the water’s physical and chemical
make-up through another process called aeration.
Clear water coming from these reactors is then discharged into the algal
pond, lined also with waste plastics, to remove nitrogen and phosphorus
nutrients, and increase the water’s pH-level to eliminate coliforms.
230 Ibid.
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