Identification of multi-concentration aromatic fragrances with electronic nose technology using a support vector machine.

Due to the concentration effect, there is a major challenge for the electronic nose system to identify different odor samples with multiple concentrations. The development of artificial intelligence provides new ways to solve such problems. This article attempts to use support vector machine (SVM) technology to distinguish four fragrance samples with three concentrations, including roman chamomile, jasmine, lavender, and orange.

Degradation effect of ultraviolet-induced advanced oxidation of chlorine, chlorine dioxide, and hydrogen peroxide and its impact on coagulation of extracellular organic matter produced by Microcystis aeruginosa.

Implementation of an ultraviolet (UV)-induced advanced oxidation process (AOP) before coagulation was found to enhance the removal of algae cells. However, the effect of UV-induced AOPs on extracellular cellular organic matter (EOM) and on its coagulation and removal was neglected. This study investigated the impact of UV-induced AOPs (UV/Cl, UV/ClO, and UV/HO) on EOM from Microcystis aeruginosa, and its coagulation and removal by a conventional gravity system (CGS), dissolved air flotation, and a low-energy flash-pressurized flotation (FPF) process.

Characterization of marine dissolved organic matter and its effect on ozonation.

As the marine industry develops, the importance of seawater treatment process is increasing. To treat seawater, oxidation processes have primarily been used, such as ballast water treatment systems, aquaculture farm operations, aquarium management, and seawater desalination. However, dissolved organic matter in seawater, whose characteristics vary spatially and seasonally, affects the efficiency of oxidation processes.

Evaluating membrane fouling potentials of dissolved organic matter in brackish water.

Isolating dissolved organic matter (DOM) is a preliminary step that improves the accuracy of its characterization. In this study, DOM in brackish water was clearly separated and evaluated by multiple characterization analyses. The sample was divided into three fractions by preparative high-performance liquid chromatography (preparative HPLC) according to molecular size.

Operating cost reduction of UF membrane filtration process for drinking water treatment attributed to chemical cleaning optimization.

This study investigated the cost and CO emission reduced as a result of optimizing operating conditions for chemical cleaning in a membrane filtration process used for water treatment. A new protocol was proposed and operating conditions for chemical cleaning of a pilot-scale membrane filtration process were optimized. The critical flux for irreversibility was identified as the permeate flux using a modified flux-step method, and was 100 l m h, 20 l m h higher than the vendor recommended permeate flux.

Characteristics of intracellular algogenic organic matter and its reactivity with hydroxyl radicals.

The aim of this study was to investigate the reactivity of intracellular algogenic organic matter (IOM) with hydroxyl radicals (·OH), a key reaction species in advanced oxidation processes. IOM was extracted from two green algae, Chlamydomonas reinhardtii and Scenedesmus sp., and two blue-green algae, Anabaena sp.

Characteristics and fate of natural organic matter during UV oxidation processes.

Advanced oxidation processes (AOPs) are widely used in water treatments. During oxidation processes, natural organic matter (NOM) is modified and broken down into smaller compounds that affect the characteristics of the oxidized NOM by AOPs. In this study, NOM was characterized and monitored in the UV/hydrogen peroxide (HO) and UV/persulfate (PS) processes using a liquid chromatography-organic carbon detector (LC-OCD) technique, and a combination of excitation-emission matrices (EEM) and parallel factor analysis (PARAFAC).

Coupling effects of abiotic and biotic factors on molecular composition of dissolved organic matter in a freshwater wetland.

In this study, temporal and spatial variations in five defined molecular size fractions of dissolved organic matter (DOM) were examined for a well preserved wetland (Upo Wetland) and its surrounding areas, and the influencing factors were explored with many biotic and abioic parameters. For each DOM sample, the five size fractions were determined by size-exclusion chromatography coupled with organic carbon detector (SEC-OCD). For 2-year long monthly monitoring, bio-polymers (BP), humic substances (HS), building blocks (BB), low molecular-weight (LMW) neutrals, and LMW acids displayed the median values of 264, 1884, 1070, 1090, and 11 μg-CL(-1), respectively, accounting for 6.

Tracking the monthly changes of dissolved organic matter composition in a newly constructed reservoir and its tributaries during the initial impounding period.

Understanding the roles of inland reservoirs becomes increasingly important with respect to global carbon cycling as well as water resource management due to the unprecedented demand for construction in recent decades. In this study, the dissolved organic matter (DOM) quantity and quality in a newly constructed dam reservoir and its tributaries were monitored monthly during the initial impounding period (July to November 2014) using a size exclusion chromatography (SEC) with online organic carbon detector (OCD). The highest values were observed in the month of August with the highest precipitation for the bulk dissolved organic carbon (DOC), specific UV absorbance (SUVA), and most of the assigned size fractions (except for biopolymers) in the tributaries, indicating that allochthonous sources of DOM were dominant in the feeding stream waters of the reservoir.

Tracking the behavior of different size fractions of dissolved organic matter in a full-scale advanced drinking water treatment plant.

In this study, five different dissolved organic matter (DOM) fractions, defined based on a size exclusion chromatography with simultaneous detection of organic carbon (OCD) and ultraviolet (UVD), were quantitatively tracked with a treatment train of coagulation/flocculation-sand filtration-ozonation-granular activated carbon (GAC) filtration in a full-scale advanced drinking water treatment plant (DWTP). Five DOM samples including raw water were taken after each treatment process in the DWTP every month over the period of three years. A higher abundance of biopolymer (BP) fraction was found in the raw water during spring and winter than in the other seasons, suggesting an influence of algal bloom and/or meltwater on DOM composition.

Presence, molecular characteristics and geosmin producing ability of actinomycetes isolated from South Korean terrestrial and aquatic environments.

The unpleasant odor of drinking water is one of the major problems in many water utilities in the world. Actinomycetes have long been associated with odorous compounds. Considering the paucity of research on Actinomycetes producing odorous compounds in South Korea, presence of Actinomycetes, their molecular characteristics and ability to produce odorous compounds were investigated in this study.

Estrogen enhances angiogenesis through a pathway involving platelet-activating factor-mediated nuclear factor-kappaB activation.

In this study, we investigated the molecular events involved in estrogen-induced angiogenesis. Treatment of the human endometrial adenocarcinoma cells, HEC-1A, with estrogen up-regulated mRNA expression and protein synthesis of various angiogenic factors such as tumor necrosis factor-alpha, interleukin-1, basic fibroblast growth factor, and vascular endothelial growth factor. The estrogen-dependent induction of the expression was blocked by the platelet-activating factor (PAF) antagonists, WEB 2170.

Nuclear factor kappaB dependency of platelet-activating factor-induced angiogenesis.

This study investigated the mechanisms of platelet-activating factor (PAF)-induced angiogenesis in a mouse model of Matrigel implantation. PAF induced a dose- and time-dependent angiogenic response. Inhibitors of nuclear factor (NF) kappaB expression or action, including antisense oligonucleotides to the p65 subunit of NFkappaB (p65 antisense) and antioxidants such as alpha-tocopherol and N-acetyl-L-cysteine, significantly reduced PAF-induced angiogenesis.