Integrated Constructed Wetlands (ICW): Ecological Development in Constructed Wetlands for Manure Treatment

Abstract

In Flanders (Belgium), treatment systems based on constructed wetlands have been successfully implemented to treat the liquid fraction of separated pig manure, resulting in water that meets the stringent discharge criteria. As these systems have proven their nutrient removal performance, attention has moved towards the concept of biodiversity development from a perspective of Integrated Constructed Wetlands (ICWs). The spontaneous colonization of constructed wetlands with macroinvertebrates was examined to quantify the added biological value presented by a farmyard treatment wetland. In total, 17 taxa were found. The diversity of macroinvertebrates increased along the water treatment path in the system and was higher in summer than in autumn. Several pollution sensitive taxa like Orthetrum, Ischnura, and Cloeon were found at the last basins of the treatment wetland chain. Most species were insects, since their adults can easily aerially colonize these recently constructed systems. Water quality was assessed using the Multimetric Macroinvertebrate Index Flanders (MMIF), and showed a general increase towards the end of the treatment. The MMIF increased significantly with decreasing nutrient levels. ICWs adequately combine the treatment of wastewater with supporting and enhancing biodiversity in agricultural landscapes.

To What Extent Can Constructed Wetlands Enhance Biodiversity?

“…One wetland studied was a retention pond [39], whereas others had multiple functions for retention and mitigation [65]- [68]. Two examples refer directly to a wastewater treatment pond [69], [70]. The other examples were embedded in the context of nature conservation or biodiversity improvement schemes [40], [71]- [75].…”

“…In two cases heterogeneous treatments within one or two areas were emphasized [64], [78]. Several studies focused on before-after comparisons [65], [66], [70], [73] or combined this approach with ought-is questions using long-term time series [40], [62], [63], [67]. Four studies focused exclusively on the ought-is aspect [63], [71], [79].…”

A review of the potential of surface flow constructed wetlands to enhance macroinvertebrate diversity in agricultural landscapes with particular reference to Integrated Constructed Wetlands (ICWs)

“…Remarkably, there are few studies that have considered biodiversity aspects of constructed wetlands (Spieles & Mitsch, 2000;Knight et al, 2001;Benyamine et al, 2002, Hansson et al, 2005BecerraJurado et al, 2010;Boets et al, 2011) (Table 1). Amongst the biota present in surface flow constructed wetlands, birds have yielded the most extensive data series (Knight et al, 2001;Benyamine et al, 2002, Hansson et al, 2005, although macroinvertebrates have been a group also targeted in most of these biodiversity studies (Spieles & Mitsch, 2000;Knight et al, 2001;Hansson et al, 2005;Becerra-Jurado et al, 2010;Boets et al, 2011).…”

“…Amongst the biota present in surface flow constructed wetlands, birds have yielded the most extensive data series (Knight et al, 2001;Benyamine et al, 2002, Hansson et al, 2005, although macroinvertebrates have been a group also targeted in most of these biodiversity studies (Spieles & Mitsch, 2000;Knight et al, 2001;Hansson et al, 2005;Becerra-Jurado et al, 2010;Boets et al, 2011).…”

Assessing the Ecological Relevance of Organic Discharge Limits for Constructed Wetlands by Means of a Model-Based Analysis

“…Throughout the EU member states, one of the techniques used for the treatment of agricultural and industrial wastes, or run-off are constructed wetlands (CWs), which have been tested and catalogued as a cost-effective an eco-friendly water treatment technique [3,[6][7][8][9][10]. Since agricultural wastes and their proper management are the central target for the EU WFD, strict discharge limits have been imposed to the effluents coming from CWs treating animal manure.…”