Biological Alteration of Zinc Complexation Characteristics of Dissolved Organic Matter in Domestic Wastewater Treatment Plant Effluent under River Water Environment

• Published in: Journal of Water and Environment Technology Vol. 8; no. 4; pp. 403 - 411
• Main Authors: G, Tushara CHAMINDA G., NAKAJIMA, Fumiyuki, KASUGA, Ikuro
• Format: Journal Article
• Language: English
• Published: Tokyo Japan Society on Water Environment 01.01.2010; Japan Science and Technology Agency
• Subjects: biodegradation; dissolved organic matter; river water; wastewater treatment plant effluent; zinc complexation
• ISSN: 1348-2165; 1348-2165
• DOI: 10.2965/jwet.2010.403

Naturally occurring processes such as biological reaction might modify the properties of dissolved organic matter (DOM) for binding with heavy metals. Complexation of heavy metals with DOM determines their environmental and ecological impacts. In this study, biodegradation experiments were carried out separately for river water and river water spiked with DOM in wastewater treatment plant (WWTP) effluent to evaluate the biological alteration of zinc complexation characteristics of DOM under river water environment. Zinc complexation parameters, conditional stability constant and binding site concentrations were determined using anodic stripping voltammetry with Scatchard linearization. Total ambient zinc binding site concentration of river water DOM was reduced from 410 nM to 74 nM (82% decline) during two weeks of incubation. Compared to the river water DOM, 1-month incubation of DOM in WWTP effluent under the river water environment, showed only 22% decline in total ambient Zn binding sites. On the other hand, conditional stability constants, for Zn binding sites of DOM from WWTP effluent, did not vary during 1 month of incubation. The result suggests that metal (Zn) binding sites of DOM from WWTP effluents are biologically persistent in the urban river water environment.