Economic analysis of worm reduction in sludge engineering application

Table 9-12 is mainly based on the design data in Table 9-11 and the research results of STOWA and Elissen (see Table 9-13), and estimates the annual savings of sludge reduction by worms in the above-mentioned small wastewater treatment plants, mainly indicating the savings Where does it come from at most? It does not include the cost saved by the reduction in the size of the required sludge treatment equipment (the maintenance cost is reduced), but this part of the content should be included in the further detailed economic feasibility study
.

Table 9-12 35,000 (population equivalent) small sewage plants use worms to reduce the cost of sludge savings.
Statistical unit: 1,000 euros/year

It can be seen that worm reduction of sludge only saves a small part of the cost, and the greatest effect comes from the transportation of concentrated sludge, because the concentration of worm dung after concentration is twice the original sludge concentration
.

The value of worms has a great influence on the economics of worm reactors
.

Table 9-13 Unit cost of applying worm reactor