Greywater treatment with the submergent Triglochin huegelii—a comparison between surface and subsurface systems

Mars, R., Taplin, R., Ho, G. and Mathew, K. (2003) Greywater treatment with the submergent Triglochin huegelii—a comparison between surface and subsurface systems. Ecological Engineering, 20 (2). pp. 147-156.

Abstract

Initial studies using Triglochin huegelii, a Western Australian species, in wastewater treatment experiments have shown that Triglochin has consistently removed more nitrogen and phosphorus, in all parts of the plant leaves, tubers and roots, than most other indigenous emergent macrophyte species. Our recent results have again shown that these types of plants do effectively assimilate nutrients from greywater. There was an increase in total N and total P in biomass measurements of T. huegelii leaves, roots and tubers during the course of the investigation. Sixteen percent of the greywater input N and 3% of input phosphorus was incorporated in plant tissue. Two further experiments were conducted using different environmental conditions for the plants. A comparison was made between root zone and complete pond conditions, with loading rate and retention times both doubled in some tanks. We found that more nutrients were absorbed by the plants in the pond system, with greater differences in nitrogen levels in the leaves (x 2) than in under-ground roots and tubers (x 1.6). Plants in ponds with the highest nutrient loading (10 1 tanks) demonstrated the greatest growth and nitrogen gain, while tanks having the longest retention time (5 1 tanks) had proportionally more N and P retention.