Use of Barley for the Purification of Aquaculture Wastewater in a Hydroponics System

Abstract

Barley was examined for its ability to remove nutrients from aquaculture wastewater. The effects of seed sterilization using ethanol and bleach and seed density on germination and plant growth were investigated. Surface sterilization of barley seeds had a negative impact on germination. Increasing the ethanol concentration and/or the bleach concentration reduced the germination percentage. Barley seeds were first germinated in water in the hydroponics system. The seedlings then received wastewater from an aquaculture system stocked with Arctic charr. During the experiment, the crops grew rapidly and fairly uniformly and showed no signs of mineral deficiency or disease. The average crop height at harvest was 25.5 cm and the yield varied from 25 to 59 t ha 1 , depending on the seed density. The hydroponically grown barley was able to significantly reduce the pollution load of the aquaculture wastewater. The TS, COD, NH 4 + -N, NO 2 --N, NO 3 --N, and PO 4 3--P reductions ranged from 52.7 to 60.5%, from 72.9 to 83.1%, from 76.0 to 76.0%, from 97.6 to 99.2%, from 76.9 to 81.6% and from 87.1 to 95.1%, respectively. However, the effluent produced from the hydroponics system had slightly higher levels of TS (420-485 mg L 1 ) than the 480 mg L 1 recommended for aquatic animals. A sedimentation/filtration unit should be added to the hydroponics system.

Effect of support medium, hydraulic loading rate and plant density on water quality and growth of halophytes in marine aquaponic systems

“…Plant density can also cause nutrient limitations, although deficiencies ultimately depend on the ratio of plants to fish. In Snow and Ghaly (), seed quantity was not found to impact plant height. However, when the plant to fish ratio was increased in Endut et al .…”

“…Regardless of media type, treatments with plants had lower mean nitrate concentrations than the no-plant treatments (Table 1). Similarly, Snow and Ghaly (2008) produced barley hydroponically on aquaculture wastewater and found that the presence of barley resulted in significantly lower nitrate concentrations.…”

Utilization of treated sewage wastewater for green forage production in<br>a hydroponic system

“…Recent studies have indicated that nutrients from treated wastewater could be purified by using some plant species in a hydroponic system (Vaillant et al, 2004;Yang et al, 2008;Snow and Ghaly, 2008;Rababah and Ashbolt, 2000;Rababah and al-Shuha, 2009). Moreover, hydroponics (soilless) culture could lead to solve the global issues such as the shortage of water, environmental pollution, and instability of ecological system in various ways.…”

Synthesis and biological activity of 1,3,4-oxa(thia)diazole, 1,2,4-triazole-5-(thio)one and S-substituted derivatives of 3-((2-carboxyethyl)phenylamino)propanoic acid

“…Each Petri dish contained ten seeds and was sealed with a strip of parafilm to prevent evaporation. Seeds were germinated in the dark for 7 days at room temperature (22°C) [30]. After 7 days number of leaves was counted, height of seedlings and length of roots were measured.…”