| Title |
A Study on Water Environment and Benthic Macroinvertebrate Community in Reclaimed Wastewater Effluent Dominated Stream |
| Authors |
손정원 ( Jung-won Son ) ; 곽진숙 ( Jin-suk Kwag ) ; 조갑제 ( Gab-je Cho ) ; 류동춘 ( Dong-choon Ryou ) |
| DOI |
https://doi.org/10.15681/KSWE.2021.37.3.190 |
| Keywords |
Benthic macroinvertebrates; Ecological stream health; Effluent discharge; Jwagwang stream |
| Abstract |
Water quality, benthic macroinvertebrate communities, and other factors were investigated to explore the effects of the effluent discharge from a sewage treatment plant into Jwagwang stream in Busan in 2019. During the study period, the flow rate of this stream was in the range of 10,400 ㎥/day to 52,200 ㎥/day except for the discharge of about 24,000 ㎥/day of the effluent. After discharge, the flow velocity increased by about 65% and the water depth increased by about 40%. At sites downstream of the discharge point, BOD, COD, TOC, T-N, T-P, and other water quality values were worse than those of the upstream sites. The periphytic algal chlorophyll-a concentrations in the natural substrata were higher than those of the upstream sites, especially in May and August. However, at sites downstream of the discharge point, the individual numbers of Annelida were decreased and individual numbers of the insecta of arthropoda were increased. Also, species numbers and the diversity and dominance indexes were improved in the sites downstream of the discharge point. The functional feeding groups (FFGs) of collector-filterers were increased and the habitat orientation groups (HOGs) of sprawlers, burrowers, and clingers were especially increased at the sites with additional reclaimed wastewater effluent flow. Regardless of the effluent discharge, BMI, an indicator of ecological stream health using benthic macroinvertebrate species, did not show large gaps between the study points. Although the water quality of the sites downstream of the discharge point was much worse than those upstream, their ecosystem soundness was better than those of the upstream sites from an ecological perspective. |