Effect of the Sewage and Wastewater Plant Effluent on the Algal Growth Potential in the Nakdong River Basin

doi:2003.18.2.157

Algae > Volume 18(2); 2003 > Article

Algae 2003;18(2): 157-167. doi: https://doi.org/10.4490/ALGAE.2003.18.2.157

Jung-Kwan Seo, Jay-Jung Lee, Sang-Yong Yang, Ik-Kyo Chung

Nakdong River Water Quality Research Laboratory, National Institute of Environmental Research, Division of Earth Environmental system, Pusan National University

ABSTRACT

Effect of the effluent of the Sewage and Wastewater Plants on the algal growth was investigated from the 19 plants located in the Nakdong river basin. Most of the samples showed high values of the algal growth potential (AGP) when they were mixed with natural river water at 20% of final concentration. At 20% of the mixing ratio, the mixed effluents of sewage and wastewater showed 3.5 and 1.8 times higher AGP than those of the natural river water. The higher AGP values are attributable to the high contents of phosphorus and ammonium in the effluent. The mixing ratio of effluents of the discharge/river flow was highest in the Kumho River (42.8%) followed by the middle of Nakdong River (22.7%), Kam Stream (13.9%), Byungsung Stream (13.3%), Yangsan Stream (7.9%), and Young River(5.4%). Comparison of the trophic state of the effluents with natural river water indicated that the effluents showed higher trophic values than natural water. Concentrations of total phoshorus, total nitrogen and conductivity in the effluents were 12.3, 4.9 and 5.3 times higher than the those found in natural river water respectively. The AGP values were highly related with the trophicity of the water especially on the concentrations of phosphate and ammonium. Toxicities of the treated sewage water, wastewater and livestock waste water tested by the luminescent bacteria, Vibrio fischerii were generally low.

Key words: algal growth potential, Nakdong river basin, sewage and waste water plant effluent, Vibrio fischerii