The purpose of this study is to analyze the correlation between ecotoxicity and water quality items using Daphnia magna in public sewage treatment plant process and to obtain operational data to control ecotoxicity through research on removal efficiency. The average value of ecotoxicity was 1.39 TU in the influent, 1.50 TU in the grit chamber, and 0.84 TU in the primary settling tank and it was found that most organic matters, nitrogen, and phosphorus were removed through biological treatment in the bioreactor. Using Pearson’s correlation analysis, the positive correlation was confirmed in the order of ecotoxicity and water quality items TOC, BOD, T-N, NH3-N, SS, EC, and Cu. As a result of conducting a multilinear regression analysis with items representing positive correlation as independent variables, the regression model was found to be statistically significant, and the explanatory power of the regression model was about 81.6%. TOC was found to have a significant effect on ecotoxicity with B=0.009 (p<.001) and Cu with B=16.670 (p<.001), and since the B sign is positive (+), an increase of 1 in TOC increases the value of ecotoxicity by 0.009 and an increase in Cu by 1 increases the value of ecotoxicity by 16.670. TOC (β=0.789, p<.001) and Cu (β=0.209, p<.001) were found to have a significant positive effect on ecotoxicity. TOC and Cu have a great effect on ecotoxicity in the sewage treatment plant process, and it is judged that TOC and Cu should be considered preferentially and controlled in order to efficiently control ecotoxicity.

This study examines the effects of learning conditions (implicit learning condition and explicit learning condition) and task types (comprehension and production task) on the learning of an easy rule (subject-verb inversion in the sentence with location adverbial) and a hard rule (pseudo-cleft clause). One hundred thirty first-year university EFL students with low proficiency were divided into four groups based on the combination of learning conditions and task types. After that, pre-and post-test data on the grammaticality judgement test and controlled written test were analyzed by using the two-way Multiple Analysis of Covariance (MANCOVA). Results showed that the effects of learning conditions are not statistically different on the comprehension of easy and hard grammatical rules whereas the explicit learning condition has more effects on producing easy and hard rules than the implicit learning condition does. They also revealed that the effects of task types are statistically different on the learning of an easy and a hard rule. In addition, production task has more effects on the learning of both an easy and a hard rule than the comprehension task. It could be suggested that the results of this study could be applied in designing more effective instructional condition for the EFL adult learners with low proficiency.