Calderonmcneil9166

From a viewpoint of reducing the burden on both human health and the environment, alternative surface modification techniques for preparing highly water-repellent surfaces without the use of environmentally damaging perfluorocarbons are highly desirable. Among them, the development of hydrophilic surfaces showing superior water sliding/removal properties has been scarcely reported. In this study, we have successfully demonstrated the fabrication of smooth, transparent, and hydrophilic pegylated organosilanes (PEGn-Si, CH3O-(C2H4O)n-C3H6-Si(OCH3)3 where n = 3, 6-9, 9-12)-derived hybrid films showing excellent water sliding/removal properties using a simple sol-gel reaction of PEGn-Si and tetraethoxysilane (TEOS, Si(OC2H5)4). The final static/dynamic surface wetting properties of the samples were found to be significantly influenced by both the PEG chain length and their mixing ratios. The use of PEGn-Si with the longest PEG chain (n = 9-12) was found to be effective for improving water sliding/removal properties. Small volume water droplets (5 μL) on the PEG9-12-Si/TEOS hybrid film (static water contact angle (CA) of ∼40°) at a 90°-inclined surface could slide at an average speed of 3.4 mm/sec without pinning and tailing, which was about twice as fast as that on the PEG6-9-Si/TEOS hybrid film surface (1.5 mm/sec, static water CA of ∼40°), in spite of having similar static hydrophilic nature.A systematic study was conducted to investigate the effect of major groundwater ions (i.e., Ca2+, Na+, and HCO3-) on removal of hexavalent chromium (Cr(VI)) by an Fe(II)-phosphate mineral (i.e., vivianite). The batch experiments revealed that the second-order rate constant for Cr(VI) removal by vivianite with Ca2+ + CO32- (0.076-1.90 mM) and Na+ + HCO3- (0.26-6.50 mM) was 1.5-5.2 times lower than that without these ions. The removal kinetics of Cr(VI) by vivianite was abruptly slowed down with the increased ion concentration, which showed their inhibitory effect on the reaction. The results of the geochemical modeling and density functional theory calculations showed that the presence of Ca2+ + HCO3- and Na+ + HCO3- can form less favorable Cr(VI) species (i.e., CaCrO4(aq) and NaCrO4-) on the Fe-B site of vivianite surface, leading to the inhibitory effect observed in this study. Finally, the X-ray absorption spectroscopy results showed that reductive immobilization of Cr(VI) to Cr(III) occurred by structural Fe(II) oxidation of vivianite to amorphous mixed-valence Fe-phosphate via an inner-sphere complexation. The results suggest that the presence of Ca2+, Na+, and HCO3- in phosphorous-enriched iron-reducing environments may lower the remedial efficiency of Cr(VI) removal.This study explores the simultaneous application of fly ash (FA) generated from the thermal treatment of municipal solid waste as a CO2 sequester through aqueous mineral carbonation and as a supplementary cementitious material (SCM) for the development of green construction materials. Two types of FAs are tested, namely an incineration fly ash (IFA) collected from electrostatic precipitator of an incineration plant and a gasification fly ash (GFA) collected from air pollution control unit of a high temperature slagging gasification waste-to-energy (WTE) plant. Ground waste glass (GWG) is used as a tertiary SCM. GFA demonstrates favorable sequestration capacity (87.5 mg/g) and high carbonation degree (74.1 %) while the IFA is found to be inactive during carbonation (3.1 mg/g, 4.6 %). Mortars blended with the wastes have shown delay in the cement hydration but eventually achieve compressive strength comparable to the control specimen. The mixing of GWG and GFA synergistically improves the performance of mortars which highlights the importance of strategic coupling of different waste streams. Most of the hazardous heavy metals, chloride and sulfate in FAs were stabilized in the mortars suggesting the potential for safe re-utilization of carbonated FAs as sustainable SCMs to concurrently close the waste loop and combat climate change.Ultra sensitive detection of mercuric ion (Hg2+) with superior anti-interference capability from natural water is of great significance for food safety, environmental protection, and human health. We herein develop Au ordered nanorod arrays (Au NRAs) as surface-enhanced Raman scattering (SERS) substrates to construct SERS-active and signal-reproducible sensing platforms modified with 4-mercaptophenylboronic acid (4-MBA) as multifunctional SERS reporters. The aqueous Hg2+ can be efficiently trapped by 4-MBA through electrophilic substitution reactions and precisely appraise its concentration based on the collective spectral changes of reporters including peak disappearance, emergence, and Raman shift. Based on this, the optical nanoprobe shows an ultrahigh detection sensitivity of 0.1 nM for Hg2+, which is two orders of magnitude lower than the U.S.A. Pacritinib environmental protection agency (EPA)-required maximum level of drinkable water. It also offers both an exceptional Hg2+ discrimination against other metal ions as well as organic ligands and perfect feasibilities of detecting solutions with ultra-wide pH ranges from 1.0-14.0 at varying temperatures. Moreover, the nanoprobe demonstrates an ability to identify different chemical forms of mercury and has a high repeatability, accuracy and reliability to meet the practical detection requirements in natural environments.The high content of nitrogen in hydrochar produced from hydrothermal carbonization (HTC) of sewage sludge (SS) leads to serious NOx pollution when the hydrochar is used as a solid fuel. Mg-Ga layered double hydroxides (LDHs), Mg-Al LDHs and their calcined samples (layered double oxides, LDO) were prepared. The LDHs and LDO all can notably promote the removal of nitrogen element, in which organic-N was transferred to NH4+-N to cause increasing pH value. Mg-Al LDO showed the highest efficiency for the removal of nitrogen among the catalysts. The thermal decomposition of the N-organic matter with acidic sites in catalyst was the key step to release NH3. The key role of basic sites in Mg-Al LDO was that it can effectively destroy the cell wall and extracellular polymeric substances structure. The lipid-like substance did not participate in the carbonization reaction, but they can be absorbed by the hydrochar. Partial SS floc directly transformed to hydrochar according to "solid-solid" reaction. The reaction pathways of remove nitrogen were proposed.