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In this study, a pilot scale anaerobic-anoxic-oxic (A2O) process with submerged membrane (MBR) in the oxic tank was coupled with thermophilic aerobic digestion (TAD) reactor and was operated for longer than 600 days to treat real domestic wastewater. Regardless of the varying conditions of the system, the A2O-MBR-TAD process removed MLSS, TCOD, BOD, TN, TP, and E. coli about 99%, 96%, 96%, 70%, 83%, and 99%, respectively. The additional TP removal of the system was due to the precipitating agent directly added in the oxic reactor, without which TP removal was about 56%. In the TAD reactor, receiving MLSS from the oxic tank (MBR), about 25% of TSS and VSS were solubilized during 2 days of retention. The effluent of the TAD reactor was recycled into the anoxic tank of A2O-MBR to provide organic carbon for denitrification and cryptic growth. By controlling the flowrate of wasting stream from the MBR, sludge production decreased to almost zero. From these results, it was concluded that the A2O-MBR-TAD process could be a reliable option for excellent effluent quality and near zero-sludge production.

This study aimed to evaluate the discharge characteristics of nonylphenol (NP) and octylphenol (OP) in the effluent of wastewater treatment facilities in the southern Gyeonggi-do. The detection rates of NP and OP were found to be 39.3% and 43.1%, respectively, with median values ranging from 1 to 3 μg/L across all industries. The industries that showed a detection rate of 50% or more were car wash, chemical experiment, fabric leather, paper wood, and plating facilities, with rates ranging from 50% to 75%, while other industries had detection rates of 21.7% to 36.8%. In terms of facility size, small-size establishments such as Type 4 and Type 5 showed higher detection rates in the "Na" region where somewhat relaxed standards are applied on a regional basis. This is because the proportion of Type 4 and Type 5 industries, including various concentration distributions of chemical experiments, research facilities, car washes, petrochemical, and plating industries, is higher than 77.7% overall and concentrated at a rate of 55.6% or higher in the “Na” region. Furthermore, the correlation coefficient (R) between NP and OP exhibited moderate association with values of 0.45 and 0.60 for car washes and plating industries, respectively. Chemical experiments, paper and wood, electrical and electronic, and medicine and hospital facilities showed strong association with correlation coefficients of 0.83, 0.82, 0.82, and 0.79, respectively. The findings in this study can be expected to serve as fundamental data for NP and OP in the establishment of water quality pollutants designation and discharge standards (draft) currently being pursued.

Purpose: This paper reviews popular measurement system indices and proposes a procedure for assessing a measurement system using two parameters with intraclass correlation and a factor for process capability.Methods: Gage Repeatability and Reproducibility(GR&R), precision-to-tolerance ratio(PTR), number of distinct categories, producer's and consumer's risks are employed to assess the measurement capabilities and discuss the relationships between measurement system metrics.Results: Two-dimensional plot by two parameters is presented to assess adequacy of the measurement system and process capability. A numerical example and previously studied case study are provided for illustration. Conclusion:The procedure proposed in this paper using two-dimension parameters provides a valuable procedure and helpful guidelines to quality and production managers in assessing the capabilities of a measurement system and choosing the needed actions to be the most benefit.