Kyongmi Chon

Science Walden: new horizons of combined ecological sanitation with separated urine/feces and treatment wetlands

AbstractA new engineering concept, designed with separated urine/feces and graywater recovery, was proposed, and the first steps in taking this concept from the planning stage to implementation have been taken using pilot experiments within a small village. The village employs ecological toilet, equipped with 24 h ventilation, and constructed treatment wetlands consisting of both vertical and horizontal subsurface wetlands for graywater recovery. The quality of recovered graywater was similar to that of the water found in the adjacent stream, which is a concept of zero discharge system with graywater. Separated urine, in either fresh or stored form, was diluted with collected rainwater and with reused water without any detergent from a sink, to be supplied to vegetable garden as fertilizer. Separated dried feces were composted in the garden for approximately 3 months and then used as fertilizer. Dried and composted feces, together with stored urine, were characterized in terms of microbial community using...

Humification of effluent organic matters through a surface-flow constructed wetland.

Dominant fractions of wastewater effluent organic matter (EfOM) were changed from polysaccharides (PS) to polyhydroxyaromatics (PHA), throughout the constructed treatment wetland connected to a wastewater treatment plant, as measured using pyrolysis gas chromatography-mass spectrometry (Py-GC/MS). The changes in the fractions were also identified, with respect to molecular weight (MW) distributions of the effluent organic matters, as measured using high performance size exclusion chromatography equipped with both UV and fluorescence detectors, for aromatic/hydrophobic and protein-like organic substances, respectively; organic matter, with MWs of approximately 2,500 and 20,000 Da, and approximately 38,000 Da, as measured by the UV and fluorescence detectors, respectively, were newly formed after the wetlands, especially for the samples of the Typha wetland in June and August against in December. Thus, with the above two different analyses, the humification type of transformation of EfOM through the treatment wetland, was believed to occur, probably due to biological transformation (from the comparison of results in June and August with those in December). It was anticipated that the humification of EfOM could reduce biodegradable organic portions of wastewater effluents even though total organic carbon levels were not reduced that much after the treatment wetland.

Role of a constructed wetland to humify effluent organic matter from a wastewater treatment plant

AbstractThe degree of aromaticity or hydrophobicity in wastewater effluent organic matter (EfOM) increases during flow-through constructed wetlands connected directly to a wastewater treatment plant (WWTP), as identified using fractionation followed by analysis methods, with respect to major biopolymers (polysaccharides, amino sugars, protein, polyhydroxy aromatics, and lignins). In this study, WWTP effluent and wetland EfOM were fractionated using preparative high-performance liquid chromatography (prep-HPLC) with both UV and RI detectors, and then, their physical and chemical properties were characterized using UV/Vis, high-performance size exclusion chromatography (HPSEC), 3D fluorescence, and pyrolysis-GC/MS (Py-GC/MS). WWTP and wetland EfOM were separated into three fractions (peak #1–3), using prep-HPLC, through C-18 and size exclusion mechanisms. Results of specific UV absorbance (SUVA), 3D fluorescence, and Py-GC/MS analyses indicate that relative aromaticity/hydrophobicity of organic matter are i...