Ecotoxicological evaluation of sewage sludge using bioluminescent marine bacteria and rotifer

Abstract

− Bioassay using the marine bacteria, Vibrio fischeri and rotifer, Brachionus plicatilis, and chemical analyses were conducted to assess the toxicity of the various sewage sludges, one of the major ocean dumped materials in the Yellow Sea of Korea. Sludge elutriates extracted by filtered seawater were used to estimate the ecotoxicity of the sludge. Chemical characterization included the analyses of organic contents, heavy metals, and persistent organic pollutants in sludge. Bacterial bioluminescent inhibition (15 min), rotifer mortality (24 hr) and rotifer population growth inhibition (48 hr) assay were conducted to estimate the sludge toxicity. EC50 15 min (inhibition concentration of bioluminescence after 15 minutes exposed) values by Microtox® bioassay clearly revealed different toxicity levels depending on the sludge sources. Highest toxicity for the bacteria was found with the sludge extract from dyeing waste and followed by industrial waste, livestock waste, and leather processing waste. Clear toxic effects on the bacteria were not found in the sludge extract from filtration bed sludge and rural sewage sludge. Consistent with Microtox® results, rotifer neonate mortality and population growth inhibition test also showed highest toxicity in dyeing waste and low in filtration bed and rural sewage sludge. High concentrations of persistent organic pollutants (POPs) and heavy metals were measured in the samples from the industrial wastes, leather processing plant waste sludge, and urban sewage sludge. However, there was no significant correlation between pollutant concentration levels and the toxicity values of the sludge. This suggests that the ecotoxicity in addition to the chemical analyses of various sludge samples must be estimated before release of potential harmful waste in the natural environment as part of an ecological risk assessment.

The Use of Methods of Environmental Analysis and Ecotoxicological Tests in the Evaluation of Wastewater

“…Bioassays could give answer on following questions: -interaction between the substances (additive, synergistic, antagonistic etc) -toxic effect after degradation and transformation of products -quantity of the bioavailable chemicals -effects on biota. Testing system is exposed to various concentration of tested substance at exactly defined conditions (Park, et al, 2005). Contrary of the chemical analysis the tests are not able to identify the xenobiotics in the environment, on the other hand their advantage consist in prediction of effect on testing biological material.…”

“…In 21TH century analysis of these matrices is not target only for selected traditional analytes but new xenobiotics as pharmaceuticals and musk compounds in sewage sludge are reported (Herren & Berset 2000;Zorita et al, 2009;McClellan & Halde, 2010). Ecotoxicological evaluation of sewage sludge as integral part of environmental analysis started to appear in this century sparsely (Park et al 2005, Domene et al, 2008. Chemicals analysis is integral part of water quality evaluation but to predict effect of this water or used sewage sludge on environment is necessary to use some other possibilities.…”

Sediment Toxicity of Industrialized Coastal Areas of Korea Using Bioluminescent Marine Bacteria

“…It is sensitive, reproducible, cost effective, and simple to conduct. Furthermore, it does not entail ethical problems, and requires only 5-30 min for toxicity prediction (Park et al, 2005;Parvez et al, 2006;Ocampo-Duque et al, 2008). Its results have been compared with those of other conventional bioassays, with good correlation in many cases (Guerra, 2001;Abbondanzi et al, 2003;Parvez et al, 2006).…”

“…Its results have been compared with those of other conventional bioassays, with good correlation in many cases (Guerra, 2001;Abbondanzi et al, 2003;Parvez et al, 2006). Among several other bioassays, the bacterial bioluminescence bioassay has proven to be the most *Corresponding author: jyu@nfrdi.go.kr sensitive to contaminated marine sediments, in comparison to several other bioassays (Long et al, 1996;Beg et al, 2001;Long et al, 2002;Park et al, 2005;Narracci et al, 2009). It uses re-hydrated freeze-dried luminescent bacteria (Vibrio fischeri) and measures inhibition of luminescence under defined conditions.…”

“…In Korea, it has been standardized by MOMAF (2005). Until now, the quality assessment using the bacterial bioluminescence bioassay has been limited to examining the toxicity of sewage sludge (Park et al, 2005), soils treated with sewage sludge (Nam et al, 2004;Park et al, 2006), effluent from the dye industry , and trace metals (Lee and Bae, 2005). To our knowledge, the present study is the first report on the use of the bioluminescence inhibition test for assessing the quality of marine sediments from Korean coastal waters.…”