Theoretical energy requirements for maintenance of green plants in hydroponic wastewater treatment.
2004 (English)In: Vatten, ISSN 0042-2886, no 3, 187-191 p.Article in journal (Other academic) Published
Hydroponic wastewater treatment takes advantage of the nutrient removing capacity of green plants. In addition to the nutrient assimilation, the roots provide a growth substrate for microorganisms involved in the biological treatment processes. However, to maintain year-round performance by the plants, additional energy muse be provided at higher latitudes, even if the hydroponics are situated in a greenhouse. To evaluate the energy demand by hydroponics in Sweden, two theoretical operational conditions have been compared. These conditions were based on A: requirements by winter resting plants, 10°C and 400 lux 16 h day-1, and B: good growth. 20°C and 2000 lux 16 h day-1. Further, five Swedish cities at different latitudes and their respective demands to reach the two conditions were compared. These cities were Lund (55°72' N), Visbv (57°38' N) Stockholm (59°35’ N), Ostersund (63°20’ N) and Kiruna (67°83’ N). The calculations showed that under Swedish conditions, the extra heat demand always exceeds the light demand on a yearlv basis except for the high temperature and light standard in Lund. The yearly light requirements are similar for the five cities, whereas the heat energy displays strong latitude dependence, e.g. the yearly heat demand in Kiruna is almost seven times higher than in Lund to reach an average indoor temperature of 10°C.
Place, publisher, year, edition, pages
2004. no 3, 187-191 p.
energy, greenhouse, heat, hydroponics, latitude, light, wastewater treatment.
IdentifiersURN: urn:nbn:se:kth:diva-25258OAI: oai:DiVA.org:kth-25258DiVA: diva2:356843
QC 201010142010-10-142010-10-142010-10-14Bibliographically approved