Development of Synthetic Soils from Biosolids

Over twenty years, the stakeholders have been developing synthetic soils from biosolids. In the 1980s, N-Viro International and Chemfix Technologies, Inc. developed Class A disinfected biosolids from alkaline stabilization that could be utilized as aglime agents and landfills cover. In addition, these applications yielded a low cost high volume endues product. These processes cost approximately 150 to 200 dollars per day ton of product. Composting and heat drying also produced organic fertilizers and organic amenders. The cost of these products were in the range of 10 to 50 dollars per ton, but the cost of these processes were still greater than 150 to 300 dollars a dry ton. A major advancement in NViro thermophilic alkaline stabilization was the alkaline composting process. This biological stabilization process required only 9 days instead of the 60 to 120 days by normal compost processing time. In the 21st Century, there has been a movement to produce higher value products at a lower dollar cost. Table 1 elucidates potential end uses of these soils. Engineered soiles cover topsoil, remediation soils and designer soils. The ornamental horticultural fertilizers go into short and long-term available nutrients in the same fertilizers. Finally, the development of high grade activated carbon, which has a high affinity for metals and polar organics such as triholomethane is another high value additive for synthetic soils.