Amination of cotton fiber using polyethyleneimine and its application as an adsorbent to directly remove a harmful cyanobacterial species, Microcystis aeruginosa, from an aqueous medium.

In the present study, we applied an adsorption-based strategy for the removal of a harmful cyanobacterial species, Microcystis aeruginosa, using cotton fiber. Considering the negatively charged surface properties of M. aeruginosa cells in aqueous phases, aminated cotton fibers were prepared through polyethyleneimine (PEI) modification on the pristine cotton fibers. The aminated surface properties of PEI-modified cotton fiber (PEI-cotton) were confirmed by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and potentiometric titration analyses. The pristine cotton fiber could not remove the M. aeruginosa cells, but the PEI-cotton could efficiently remove 98.7% of M. aeruginosa cells from the aqueous medium. In addition, removed cells could be observed on the sorbent surface by field emission scanning electron microscopy (FE-SEM) analysis. PEI-cotton fabricated in 3% PEI solution could remove M. aeruginosa cells (97.9%) more efficiently compared to that fabricated in 1% (82.1%) and 2% (86.2%) of PEI solutions. From the toxicity assessment of the PEI-cotton using Daphnia magna, negligible toxicity of PEI-cotton was confirmed. Our results indicate that the application of PEI-cotton fibers for the removal of M. aeruginosa cells could be suggested as a feasible, effective, and eco-friendly method of harmful algal bloom (HAB) control in water resources.

Application of a polyethylenimine-modified polyacrylonitrile-biomass waste composite fiber sorbent for the removal of a harmful cyanobacterial species from an aqueous solution.

Cyanobacterial harmful algal blooms (Cyano-HABs) in water resources involving algal species such as Microcystis aeruginosa have become a serious environmental issue due to their severely negative effects. In the present study, an adsorption-based strategy was employed to control M. aeruginosa, with industrial waste-derived Escherichia coli biomass valorized to produce polyethylenimine-modified polyacrylonitrile-E. coli biomass composite fiber (PEI-PANBF). PEI-PANBF removed approximately 80% of M. aeruginosa cells from an aqueous solution without causing any cell damage. Interestingly, the thickness of PEI-PANBF had a strong influence on the efficiency of M. aeruginosa cell removal. In addition, PEI-PANBF simultaneously removed M. aeruginosa cells and their toxic secondary metabolite, microcystin-LR, from aqueous media. Thus, our proposed fiber represents a feasible utilization method of industrial waste biomass as a biosorbent for the control of Cyano-HABs.

Phosphorus adsorption behavior of industrial waste biomass-based adsorbent, esterified polyethylenimine-coated polysulfone-Escherichia coli biomass composite fibers in aqueous solution.

This study sought to develop a highly efficient adsorbent material for phosphorus (P) removal via valorization of industrial Escherichia coli biomass waste. To ensure an easy and fast recovery after the sorption process, the E. coli biomass waste was immobilized into polysulfone matrix. Additionally, to improve P sorption capacity, the sorbent surface was coated with polyethylenimine (PEI) and further chemically modified. The P uptakes of the developed sorbent (decarboxylated PEI-modified polysulfone-biomass composite fiber, DC-PEI-PEF) were significantly affected by pH. Moreover, the maximum sorption capacity (qmax) of DC-PEI-PEF was estimated as 30.46 ± 1.09 mg/g at neutral pH, as determined by a Langmuir isotherm model. Furthermore, DC-PEI-PEF could reach sorption equilibrium within 5 min and exhibited reusability potential. The partition coefficient of the newly developed material (DC-PEI-PEF) was calculated as 0.387 mg/g⋅µM at 4 mg/L of initial P concentration and decreased as initial P concentrations increased. Therefore, DC-PEI-PEF could be suggested as a promising adsorbent for application in direct phosphorus removal from natural aquatic environments.

[Factors Affecting the Self-Management of Adolescents with Type 1 Diabetes Mellitus based on the Information-Motivation-Behavioral Skills Model]. / ì œ1형 당뇨병 ì²­ì†Œë „ì˜ 자기관리 영향요인: ì •ë³´-동기-í–‰ë™ê¸°ìˆ ëª¨ë¸ì„ 기반으로.

PURPOSE: The purpose of this study was to investigate associations between self-management and diabetes knowledge, diabetesrelated attitudes, family support, and self-efficacy in adolescents with type 1 diabetes mellitus based on the information-motivation- behavior skills model. METHODS: Data collection was conducted between March 18 and September 30, 2018. Patients (N=87) aged 12 to 19 years were recruited from the outpatient clinic of S children's hospital and an online community for patient with type 1 diabetes mellitus. Data were analyzed using descriptive statistics, the independent t-test, one-way ANOVA, Pearsons correlation, and hierarchical multiple linear regression with SPSS IBM 23.0, with the two-tailed level of significance set at 0.05. RESULTS: The mean score of self-management in adolescents with type 1 diabetes mellitus was 61.23±10.00 out of 80. The regression analysis showed that self-efficacy and family support significantly explained 56.9% of the variance in self-management (F=21.38, p<.001). Self-efficacy (ß=.504, p<.001) and family support (ß=.188, p<.001) were significant predictors of self-management. CONCLUSION: It is necessary to develop individual interventions to improve self-efficacy and family support for adolescents with type 1 diabetes mellitus to help them enhance their self-management.