Constructed wetlands and soil-aquifer treatment systems: Effects on the character of effluent organic matter

Persistent Link:
http://hdl.handle.net/10150/284227
Title:
Constructed wetlands and soil-aquifer treatment systems: Effects on the character of effluent organic matter
Author:
Quanrud, David Matson
Issue Date:
2000
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Within the context of potable reuse, there is a need for a more comprehensive examination of the quality of dissolved organic matter (DOM) in treated wastewater and the efficacy of different treatment schemes in removing or transforming DOM. In particular, there are significant information gaps regarding the character, fate, and health risks associated with effluent organic matter (EfOM). Two research goals guided this research. The first goal was to evaluate the efficacy of constructed wetlands for wastewater polishing in a hot, arid environment, from the perspective of season-dependent effects on DOM. To this end, behavior of organics was evaluated over a 22-month period during treatment in a local constructed wetlands facility. The second goal was to examine changes in character of EfOM that accompany passage through natural treatment systems (either constructed wetlands or soil aquifer treatment, SAT). This was accomplished via isolation and characterization of organics collected along flowpaths of these treatment systems. Wetland effluent concentrations of dissolved organic carbon (DOC) and nonbiodegradable DOC were positively correlated with temperature. That is, the highest concentrations occurred in summer and were attributed to the combined effects of evapotranspiration (ET) by wetland vegetation along with production of wetland-derived natural organic matter (NOM). There was little if any change in the hydrophobic-hydrophilic character of DOM attending wetland treatment. Biodegradation of labile EfOM combined with contribution of wetland-derived NOM resulted in modest (at best) changes in distribution of carbon moieties in hydrophobic (HPO) and hydrophilic (HPI) acid isolates. Aliphatic carbon decreased during wetland treatment. Elemental analysis suggested that microbial activity is the dominant process controlling the character of wetland-derived NOM. Reactivity of isolates in forming trihalomethanes (THMs) during chlorination increased as consequence of wetland treatment. Wetland-derived NOM was more reactive than EfOM in forming THMs. Uniform trends occurred among isolates of EfOM and wetland-derived NOM between biodegradability and THM production upon chlorination. Ultrahydrophilic EfOM was preferentially removed during vadose zone percolation of secondary effluent. The chemical character of EfOM (HPO- and HPI-acids) became more similar to NOM as a consequence of SAT. Genotoxicity of HPO-acids, on a per mass basis, increased after SAT.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Hydrology.; Environmental Sciences.; Engineering, Environmental.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Hydrology and Water Resources
Degree Grantor:
University of Arizona
Advisor:
Conklin, Martha; Arnold, Robert

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleConstructed wetlands and soil-aquifer treatment systems: Effects on the character of effluent organic matteren_US
dc.creatorQuanrud, David Matsonen_US
dc.contributor.authorQuanrud, David Matsonen_US
dc.date.issued2000en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractWithin the context of potable reuse, there is a need for a more comprehensive examination of the quality of dissolved organic matter (DOM) in treated wastewater and the efficacy of different treatment schemes in removing or transforming DOM. In particular, there are significant information gaps regarding the character, fate, and health risks associated with effluent organic matter (EfOM). Two research goals guided this research. The first goal was to evaluate the efficacy of constructed wetlands for wastewater polishing in a hot, arid environment, from the perspective of season-dependent effects on DOM. To this end, behavior of organics was evaluated over a 22-month period during treatment in a local constructed wetlands facility. The second goal was to examine changes in character of EfOM that accompany passage through natural treatment systems (either constructed wetlands or soil aquifer treatment, SAT). This was accomplished via isolation and characterization of organics collected along flowpaths of these treatment systems. Wetland effluent concentrations of dissolved organic carbon (DOC) and nonbiodegradable DOC were positively correlated with temperature. That is, the highest concentrations occurred in summer and were attributed to the combined effects of evapotranspiration (ET) by wetland vegetation along with production of wetland-derived natural organic matter (NOM). There was little if any change in the hydrophobic-hydrophilic character of DOM attending wetland treatment. Biodegradation of labile EfOM combined with contribution of wetland-derived NOM resulted in modest (at best) changes in distribution of carbon moieties in hydrophobic (HPO) and hydrophilic (HPI) acid isolates. Aliphatic carbon decreased during wetland treatment. Elemental analysis suggested that microbial activity is the dominant process controlling the character of wetland-derived NOM. Reactivity of isolates in forming trihalomethanes (THMs) during chlorination increased as consequence of wetland treatment. Wetland-derived NOM was more reactive than EfOM in forming THMs. Uniform trends occurred among isolates of EfOM and wetland-derived NOM between biodegradability and THM production upon chlorination. Ultrahydrophilic EfOM was preferentially removed during vadose zone percolation of secondary effluent. The chemical character of EfOM (HPO- and HPI-acids) became more similar to NOM as a consequence of SAT. Genotoxicity of HPO-acids, on a per mass basis, increased after SAT.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectHydrology.en_US
dc.subjectEnvironmental Sciences.en_US
dc.subjectEngineering, Environmental.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineHydrology and Water Resourcesen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorConklin, Marthaen_US
dc.contributor.advisorArnold, Roberten_US
dc.identifier.proquest9992051en_US
dc.identifier.bibrecord.b41166012en_US
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