Closed Loop versus Open System

Closed systems like this seem capitol intensive and finicky, needing full time tinkering and are subject to unexplained perturbations . Our idea of  Typha and Scirpus as biological water treatment seem to be a more logical approach in warm climates at least. 

The only issue to consider with domestic sewage plant water is concentration of heavy metals and pharmaceuticals by food species. However putting the food production on the downstream side of the biological treatment may mitigate for this problem. We need to look into this angle, and any pilot program could include monitoring and testing of protein production and quality of fish, shellfish and mussels grown.  

There is also nutrient rich waters of rivers downstream from urban/agricultural districts. In the district Ben and i are studying these places have huge potential for biological water treatment on regional scale. 

An aquaculture system in a subtropical or temperate water cleanup system should be vegetarian, detritis feeders or filter feeders. Not carnivores like trout or salmonids. However creating rearing habitat for an anadromous species (ie a fish that migrates to Ocean)  like the salmon could use enhanced habit for juvenile rearing and overwintering before migration then return 2 to 4 years later. 

From August 28, 2008  Scientific American

Angling for a better way to grow fish and vegetables too.

Images

'Growing food crops at Cabbage Hill takes place in long, shallow tubs on the south side of the greenhouse, which are filled with newly nutritious water from the bioreactor. On so-called rafts (repurposed polystyrene insulation panels) floating in the tubs, basil, bok choy and lettuce plants grow hydroponically—that is, without soil—their bare roots dangling through holes in the rafts to draw nutrients directly from the water below.

Stripped of its nitrate, the water is ready for return to the fish tanks, having essentially been filtered by the roots of fast-growing, edible, high-value plants.'

or-------

Stripped of its nitrates the waters of the Parana river are returned to the natural drainage system from which they were lifted with biomass powered harmonic pumps, upstream,  a weeks earlier. Biofuels and fiber products are harvested from the enhanced wetland treatment system and in return these waters provide improved ecosystem services that allow marine harvest of anadromous salmon in offshore waters. 


Visioning