Within the research project HypoWave, a hydroponic system for plant production was investigated. The hydroponic system was fed with wastewater that had undergone specially adapted treatment. The principal aim was to develop a combined system for water treatment and hydroponic plant production, where water and nutrients were reused efficiently to produce marketable food products. Another goal was to find out whether the reuse of pre-treated wastewater for plant growth in a hydroponic system could also present an additional alternative wastewater treatment step for enhanced nutrient removal. A pilot plant, consisting of various treatment steps such as activated sludge process, ozonation and biological activated carbon filtration, was used to produce lettuce with irrigation water of different qualities. The hydroponic pilot plant was operated in two different modes – flow-through and feed & deplete. This paper focuses on the influence of the various modes of operation and accordingly varying nutrient concentrations (N, P, K) on plant growth. Furthermore, heavy metal content in the various types of treated wastewater and in the produced plants was investigated. In addition, the results of the different modes of operation were verified by mass balances for N, P and K.

在研究项目HypoWave中，对用于植物生产的水培系统进行了研究。向水培系统注入经过特殊处理的废水。主要目的是开发一种用于水处理和水培植物生产的组合系统，在该系统中，水和养分可以有效地再利用以生产可销售的食品。另一个目标是找出将预处理的废水再利用用于水培系统中的植物生长是否还可以提供额外的废水替代处理步骤以增强营养去除率。中试工厂由各种处理步骤组成，例如活性污泥法，臭氧化和生物活性炭过滤，被用来生产不同质量的灌溉用水的生菜。水培中试设备以两种不同的模式运行-流通和进料与耗尽。本文着重于各种操作模式的影响以及相应的养分浓度（N，P，K）对植物生长的影响。此外，还研究了各种处理过的废水和生产厂中的重金属含量。此外，通过N，P和K的质量平衡验证了不同操作模式的结果。