Removal of natural organic matter (NOM) and taste and odor problems in drinking water are a sensitive issue in municipal water treatment plants. This study investigated the effectiveness of ozone (O3) + granular activated carbon (GAC), O3 + hydroperoxide (H2O2) + GAC, and GAC processes using a pilot scale plant to remove NOM and geosmin (50–1,000 ng/L), and 2-methylisoborneol (2-MIB: 50–300 ng/L). In the O3 + GAC process, NOM-related parameters showed an average of 52% dissolved organic carbon (DOC) removal from 2 mg/L DOC influent, 99.3% haloacetic acids (HAAs) removal from 0.097 mg/L HAAs influent, and 100% removal from 0.05 mg/L bromide influent. Taste and odor removal rates were 94–100% for geosmin and 87–100% for 2-MIB. The O3 + H2O2 + GAC process removed an average of 55% DOC, 99.7% HAAs, 100% bromate, 94–100% geosmin, and 93–100% 2-MIB. The GAC process removed 46% DOC, 98.3% HAAs, 100% bromate, 83–100% geosmin, and 81–100% 2-MIB. Based on a comparison of the efficiencies and an economic analysis, the O3 + H2O2 + GAC process was determined to be the optimal system for removing NOM and taste and odor compounds.

Microplastic contamination has become a problem, as plastic production has increased worldwide. Microplastics are plastics with particles of less than 5 mm and are absorbed through soil, water, atmosphere, and living organisms and finally affect human health. However, information on the distribution, toxicity, analytical methods, and removal techniques for microplastics is insufficient. For clear microplastic analytical methods and removal technologies, this article includes the following: (1) The distribution and contamination pathways of microplastics worldwide are reviewed. (2) The health effects and toxicity of microplastics were researched. (3) The sampling, pretreatment, and analytical methods of microplastics were all reviewed through various related articles. (4) The various removal techniques of microplastics were categorized by wastewater treatment process, physical treatment, chemical treatment, and biological treatment. This paper will be of great help to microplastic analysis and removal techniques.

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Indoor air quality control becomes a critical role in protecting human life due to a significant increase in indoor living time with industrial development. However, air purifier and ventilation systems are installed in many indoor places, and qualities of air are not guaranteed without effective monitoring systems. In this study, we developed a smart indoor air quality monitoring device, measuring components of PM10, PM2.5, PM1, CO, CO2, VOCs, temperature and humidity. The smart air quality monitoring system is commutated with a developed smartphone application using short and long distance communication modules. The smart application basically provides air quality information (daily, monthly, yearly), air management methods, and emerging environmental issues. For the system verification, we tested the developed air quality monitoring system with other reliable measuring devices. As results, the gaps between our developed system and other reliable measuring devices are PM10 (±4%), PM2.5 (±4%), CO (±1%), CO2 (±1%), VOCs (±2%), temperature (±1%) and humidity (±2%). We found that the developed smart air quality monitoring system is sufficiently reliable comparing to other measuring devices. Therefore, the smart air quality monitoring system would help improve indoor air quality in real time and can be used for future air quality prediction.

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