Contributions of Schoenoplectus californicus in a Constructed Wetland System Receiving Copper Contaminated Wastewater

Abstract

Functional roles of Schoenoplectus californicus, giant bulrush, were evaluated in an 3.2 ha (8-acre) constructed wetland treatment system receiving copper-contaminated water. The constructed wetland used in this research was designed to decrease bioavailable copper concentrations in a wastestream and eliminate associated toxicity to downstream biota by exploiting the thermodynamic processes responsible for copper speciation. This was achieved by integrating carbon, sulfur and copper biogeochemical cycles. In this system, S. californicus, which represents an integral part of the carbon cycle, provides a physical, chemical and biological role in removing metals from the aqueous phase. The specific contributions of S. californicus in this system are to provide a sustainable carbon source for removal of copper by (1) provision of an organic ligand for sorption of copper entering the system, (2) production of organic ligands through growth of S. californicus, (3) accretion of organic ligands over time due to decomposition of S. californicus detritus, and (4) use of organic carbon as an energy source for dissimilatory sulfate production. Shoots and roots of viable S. californicus sorbed 0.88% and 5.88%, respectively, of copper entering the system. The half-life of S. californicus detritus in the constructed wetland system was approximately 184 d, indicating that sufficient detritus will accrete over time, providing binding sites for copper and an energy source for bacterial metabolic processes that contribute to copper immobilization in wetland systems.

Floating Treatment Wetland influences on the fate of metals in road runoff retention ponds

“…Therefore even if plant uptake contributed to dissolved metals removal, it is likely not responsible for the noticed improved outlet EMCs. Several other researchers have identified that plant uptake wasn't a dominant process responsible for metal removal in wetlands or FTWs (Murray-Gulde et al, 2005;Kadlec and Wallace, 2009;Sekomo et al, 2011;Tanner and Headley, 2011).…”

Macrophyte Sorption and Bioconcentration of Elements in a Pilot Constructed Wetland for Flue Gas Desulfurization Wastewater Treatment

“…Uncontaminated plants were also harvested from on-site nursery wetland cells to serve as controls. Plants were rinsed with deionized water to remove sediment, and separated into roots, submerged shoots (from roots to water surface), emerged shoots, and seeds (Murray-Gulde et al 2005). Adsorbed Hg, Se, and As were measured by separately rinsing submerged shoots and roots with 15% trace metal grade nitric acid.…”

Natural zinc enrichment in peatlands: Biogeochemistry of ZnS formation

“…Thus, reducing conditions and high organic matter content seem to be essential for the formation of metal sulfides by sulfate reduction (Debusk et al, 1996). Organic matter in wetlands can also promote microbial sulfide production by providing a carbon source for sulfate-reducing microorganisms (Murray-Gulde et al, 2005;Du Laing et al, 2009). Culture experiments with sulfate reducing microorganisms from wetland sediments demonstrated the potential for microbial activity to remove metals from solution while simultaneously producing sulfide (Webb et al, 1998) whereas laboratory-based experiments demonstrated ZnS precipitates formed in the presence of sulfate-reducing bacteria from solutions containing dissolved zinc and sulfate (Peltier et al, 2011).…”