Release efficiencies of potassium permanganate controlled-release biodegradable polymer (CRBP) pellets embedded in polyvinyl acetate (CRBP-PVAc) and polyethylene oxide (CRBP- PEO) for groundwater treatment.

In-situ chemical oxidation (ISCO) is a commonly used method for the remediation of environmental contaminants in groundwater systems. However, traditional ISCO methods are associated with several limitations, including safety and handling concerns, rebound of groundwater contaminants, and difficulty in reaching all areas of contamination. To overcome these limitations, novel Controlled-Release Biodegradable Polymer (CRBP) pellets containing the oxidant KMnO4 were designed and tested. The CRBP pellets were encapsulated in Polyvinyl Acetate (CRBP-PVAc) and Polyethylene Oxide (CRBP-PEO) at different weight percentages, baking temperatures, and time. Their release efficiency was tested in water, soil, and water and soil mixture media. Results showed that CRBP-PVAc pellets with 60 % KMnO4 and baked at 120 °C for 2 min had the highest release percentage and rate across different conditions tested. Natural organic matter was also found to be an important factor to consider for in-field applications due to its potential reducing effect with MnO4-. Overall, the use of CRBP pellets offers an innovative and sustainable solution to remediate contaminated groundwater systems, with the potential to overcome traditional ISCO limitations. These findings suggest that CRBP pellets could provide sustained and controlled release of the oxidant, reducing the need for multiple injections and minimizing safety and handling concerns. This study represents an important step towards developing a new and effective approach for ISCO remediation.

Quantified Activity Patterns for Young Children in Beach Environments Relevant for Exposure to Contaminants.

In a study to evaluate beach play activities, 120 children were videotaped to observe and quantify factors that could influence their exposure to contaminants in the beach environment. Children aged 1 to 6 years were followed by researchers with video cameras at beaches (two in Miami, Florida and two in Galveston, Texas) for approximately one hour each. Factors evaluated included time spent in various beach locations, various activities engaged in, and various surfaces contacted (including contacts by hand and mouth). Activities recorded in the videos were transcribed to text files to allow for quantitative analyses. Across all sexes, age groups, and beaches, Wading was the most common activity and Seawater was the most common location where children played. The left hand was found to not be in contact with objects most of the time, while the right hand, considered the most dominant hand in most cases, contacted Plastic-Toys the most. Although activity patterns collection through videotaping and videotranslation can be labor-intensive, once collected, they can be widely useful for estimates of exposures to all contaminants in the beach environment (e.g., microorganisms and chemicals) as well as UV exposure, with considerations for whether the contaminants are found in water, sand or both. These activity patterns were collected to potentially look at exposures following the Deepwater Horizon 2010 Spill.

Radioactive waste: A review.

The reviewed papers presented here provide a general overview of worldwide radioactive waste-related studies conducted in 2019. The current review includes studies related to safety assessments, decommission and decontamination of nuclear facilities, fusion facilities, and transportation. Further, the review highlights radioactive wastewater decontamination, management solutions for the final disposal of low- and high-level radioactive wastes (LLRW and HLRW), interim storage and final disposal options for spent fuel (SF), and tritiated wastes, with a focus on environmental impacts due to the mobility of radionuclides in the ecosystem, water and soil along with other research progress made in the management of radioactive waste. PRACTITIONER POINTS: The release of radionuclides and their subsequent fate and transport in the environment poses public health concern and has stimulated recent research on the waste management techniques. Seeking a safe and environmental-friendly solution is the current trend for existing and projected inventories of radioactive waste. Significant progress in the field of geological disposal of radioactive waste has been made in the last two decades.

Textiles wastewater treatment technology: A review.

The following is a review of published literature on textile wastewater in 2019. Presented are the sections described for the review: concise introduction on the textiles wastewater, followed by a review of present textile treatment technologies organized by physicochemical, biological, and combined processes. Lastly, a discussion of the future topics is presented. PRACTITIONER POINTS: The discharge of textile dye wastewater represents a serious environmental problem and public health concern. Effluents from textile manufacturing, dyeing, and finishing processes contain high-concentration recalcitrant chemicals that are resistant to biodegradation. The textile wastewater needs environmental-friendly and cost-effective combined treatment process.