Returning Individual Tap Water Testing Results to Research Study Participants after a Wildfire Disaster

After the devastating wildfire that destroyed most of the town of Paradise, California in 2018, volatile organic compounds were found in water distribution pipes. Approximately 11 months after the fire, we collected tap water samples from 136 homes that were still standing and tested for over 100 chemicals. Each participant received a customized report showing the laboratory findings from their sample. Our goal was to communicate individual water results and chemical information rapidly in a way that was understandable, scientifically accurate, and useful to participants. On the basis of this process, we developed a framework to illustrate considerations and priorities that draw from best practices of previous environmental results return research and crisis communication, while also addressing challenges specific to the disaster context. We also conducted a follow-up survey on participants’ perceptions of the results return process. In general, participants found the results return communications to be understandable, and they felt less worried about their drinking water quality after receiving the information. Over one-third of the participants reported taking some kind of action around their water usage habits after receiving their results. Communication with participants is a critical element of environmental disaster research, and it is important to have a strategy to communicate results that achieves the goals of timeliness, clarity, and scientific accuracy, ultimately empowering people toward actions that can reduce exposure.

Cooperative Learning With and About Internet Forums: A Case Study on a Unit on the Consumption and Chemistry of Mineral Water vs. Tap Water

In today’s society, digital media play an increasing role in gathering and exchanging information. A growing part of communication takes place in the Internet and many people are increasingly influenced by information provided via digital and social media. Development of critical media literacy is needed, if the general public is expected to effectively deal with this flood of information and to become able to distinguish between correct and false information sources. Thus, critical media education becomes an important aim of education in general, and of chemistry education in particular when considering questions directly related to chemistry and its associated consumer products or technologies. The article describes a curriculum development case study investigating the integration of media education with chemistry learning along the case of learning with and about Internet forums on the topic of water chemistry. A unit integrating theoretical and practical chemistry learning based on student communication is described, which is built around a digital forum operated by Moodle. The unit design and findings from the implementation are presented.

Rational Design of ICT-Based Fluorescent Probe with AIE and NIR Properties for Hypochlorite Determination

In recent years, the easily synthesized fluorescent probes with good photophysical and sensing properties have attracted widespread attention. Herein, by utilizing the fluorescence regulation effect of electron push-pull effect and the oxidation property of hypochlorite (ClO-) to C=N double bonds, we proposed two intramolecular charge transfer (ICT)-based fluorescent probes with typical aggregation-induced emission (AIE) properties for ClO- detection. The synthesis process of the two probes is very convenient, and both of them can exhibit significant colorimetric and fluorescence changes within 3 min in the presence of ClO-. Moreover, compared with Probe A, the Probe B with near-infrared (NIR) fluorescence centered at 677 nm was successfully applied to ClO- determination in tap water and food samples as well as live cell imaging.

Isotopic and Chemical Composition of the Deep Water of Lake Baikal

Introduction. Due to its natural composition, the deep water of Lake Baikal can be bottled without any conserving agents. The development of large-scale production of bottled Baikal water requires its detailed study in order to protect it from counterfeit and falsification. The purpose of this work was to study the isotopic and chemical composition of the deep water of Lake Baikal and offer indicators for its identification. Study objects and methods. The research included deep water of Lake Baikal, sampled at various points, the water from the Angara River, and the tap water from the cities of Irkutsk and Shelekhov. The tests were performed using a quadrupole ICP-MS mass spectrometer and a Delta V Plus isotope mass spectrometer with a GasBench II module. Results and discussion. All the water samples revealed fresh water with insignificant mineralization. As for salts, the deep water samples had a lower content of sodium and chlorides, as well as a higher content of silicon. As for metals, the deep water samples contained iron, manganese, copper, and zinc; in the tap water samples, these indicators were significantly higher. Unlike that of the Angara water samples, the isotopic profile of the deep water samples was somewhat “lighter”, both in the ratio of oxygen isotopes δ18O – by 0.73‰, and hydrogen δD – by 0.49‰. The tap water samples had a higher deuterium content. The content of oxygen isotopes (δ18O) in the tap water samples was close to that in the Angara samples. Conclusion. The complex physicochemical and isotope analyses expanded the list of identification indicators and made it possible to identify the deep water of Lake Baikal.

“Switch-Off-On” Detection of Fe3+ and F− Ions Based on Fluorescence Silicon Nanoparticles and Their Application to Food Samples

An approach to the detection of F− ions in food samples was developed based on a “switch-off-on” fluorescence probe of silicon nanoparticles (SiNPs). The fluorescence of the synthetic SiNPs was gradually quenched in the presence of Fe3+ ion and slightly recovered with the addition of F− ion owing to the formation of a stable and colorless ferric fluoride. The fluorescence recovery exhibited a good linear relationship (R2 = 0.9992) as the concentration of F− ion increased from 0 to 100 μmol·L−1. The detection limit of the established method of F− ion was 0.05 μmol·L−1. The recovery experiments confirmed the accuracy and reliability of the proposed method. The ultraviolet–visible spectra, fluorescence decays, and zeta potentials evidenced the fluorescence quenching mechanism involving the electron transfer between the SiNPs and Fe3+ ion, while the fluorescence recovery resulted from the formation of ferric fluoride. Finally, SiNPs were successfully applied to detect F− ions in tap water, Antarctic krill, and Antarctic krill powder.

ОЦІНКА ЯКОСТІ ПИТНИХ ВОД З РІЗНИХ ДЖЕРЕЛ ВОДОПОСТАЧАННЯ

Purpose. Monitor different sources of water supply in a particular region of Ukraine. Methodogy. To monitor the drinking water of the selected settlement of Cherkasy region, water from the water supply network (10 samples), water from the pump room (1 sample) and water from wells (26 samples) were selected and analyzed for 20 main chemical indicators in accordance with the requirements of DSanPiN 2.2.4-171-10 and DSTU 7525: 2014. Findings. It was found that tap water has a slight excess of iron and turbidity in 5 samples. The water does not contain aluminum, ammonium ions, nitrates, nitrites, residual amounts of free and bound chlorine and chlorination by-products. The sample of water from the pump room has a slight excess of silicon and salts of general hardness – calcium and magnesium ions. Water from the pump room in chemical composition (pH, dry matter, alkalinity, chlorides, sulfates, sodium) and the content of microcomponents is very similar to tap water, it has a slightly higher "color" and "turbidity", but the content of petroleum products and iron does not exceed drinking standards. water – 0.1 mg / dm3 and 0.2 mg / dm3, respectively. In this case, well water is the most unsuitable for drinking purposes. It was found that the largest excess of normalized values in these waters was observed when determining the dry residue (up to 4 standards), hardness (up to 5 standards), nitrate concentration (up to 9 standards).Originality. Monitoring of drinking water in the selected settlement of Cherkasy region and the analysis of the suitability of tap water, pump room water and well water for drinking needs.Practical value. The peculiarities of the chemical composition of drinking water supply facilities of this settlement have been established, in particular, much attention is paid to the determination of microelements and persistent organic toxicants at the level of their maximum permissible concentrations. The analysis of the obtained results testifies that the quality of tap water and pump room meets the current hygienic standards in terms of organoleptic parameters, general mineralization, hardness, alkalinity, content of organic components, and water in almost all wells does not meet.

Enhancing corrosion resistance of RC pipes using geopolymer mixes when subjected to aggressive environment

The durability of reinforced concrete (RC) pipes depends upon the corrosion resistance of the reinforcing steel and the resistance of concrete mixes against an aggressive environment. This research paper aims to compare the performance of R.C. pipes made of ordinary Portland cement (OPC) concrete mixtures with others made of two different geopolymer concrete mixes based on different ratios of granulated blast furnace slag (GBFS), fly ash (FA), and pulverized red brick (RB) subjected to three different environments, ambient, tap water (TW), and an aggressive environment, and a solution of 10% magnesium sulfates + 5% chloride (MS-CL). An accelerated corrosion setup has been applied to accelerate the corrosion process in the tested samples. The evaluation of change of compressive strength of concrete and microstructure of different mixes was investigated too. Fourier transform infrared (FTIR) spectroscopy has been studied on all pipes. Geopolymer concrete mixes based on 90% GBFS and 10% RB show better results in all cases. Geopolymer concrete mixes based on 63% GBFS, 27% FA, and 10% RB increase the concrete compressive strength in the magnesium sulfate and chloride environment by 5% compared to tap water. It can be concluded that the geopolymer concrete mixes produced of 90% GBFS and 10% RB perform well under all environments, and its microstructure shows stable behavior in an aggressive environment.