Circular economy in drinking water treatment: reuse of ground pellets as seeding material in the pellet softening process.
Calcium carbonate pellets are produced as a by-product in the pellet softening process. In the Netherlands, these pellets are applied as a raw material in several industrial and agricultural processes. The sand grain inside the pellet hinders the application in some high-potential market segments such as paper and glass. Substitution of the sand grain with a calcite grain (100% calcium carbonate) is in principle possible, and could significantly improve the pellet quality. In this study, the grinding and sieving of pellets, and the subsequent reuse as seeding material in pellet softening were tested with two pilot reactors in parallel. In one reactor, garnet sand was used as seeding material, in the other ground calcite. Garnet sand and ground calcite performed equally well. An economic comparison and a life-cycle assessment were made as well. The results show that the reuse of ground calcite as seeding material in pellet softening is technologically possible, reduces the operational costs by €38,000 (1%) and reduces the environmental impact by 5%. Therefore, at the drinking water facility, Weesperkarspel of Waternet, the transition from garnet sand to ground calcite will be made at full scale, based on this pilot plant research.
ARCADIS Nederland BV, P.O. Box 4205, Rotterdam 3006 AE, The Netherlands E-mail: marc.schetters@arcadis.nl.
M J A
MJ
Schetters
Waternet, P.O. Box 8169, Amsterdam 1005 AD, The Netherlands; Delft University of Technology, P.O. Box 5048, Delft 2600 GA, The Netherlands.
J P
JP
van der Hoek
Waternet, P.O. Box 8169, Amsterdam 1005 AD, The Netherlands.
O J I
OJ
Kramer
Waternet, P.O. Box 8169, Amsterdam 1005 AD, The Netherlands.
L J
LJ
Kors
KWR Watercycle Research Institute, P.O. Box 1072, Nieuwegein 3430 BB, The Netherlands.
L J
LJ
Palmen
KWR Watercycle Research Institute, P.O. Box 1072, Nieuwegein 3430 BB, The Netherlands.
B
B
Hofs
Reststoffenunie Waterleidingbedrijven, P.O. Box 1072, Nieuwegein 3430 BB, The Netherlands.
H
H
Koppers
D002119:Calcium Carbonate / Q000737:chemistry*; D060766:Drinking Water / Q000737:chemistry / Q000592:standards*; D004777:Environment; D009426:Netherlands; D059027:Recycling; D012822:Silicon Dioxide / Q000737:chemistry*; D018508:Water Purification / Q000191:economics / Q000295:instrumentation* / Q000379:methods
D060766:Drinking Water; D012822:Silicon Dioxide; D002119:Calcium Carbonate