Plasticizers are plastic additives used to enhance the physical properties of plastic and are ubiquitous in the environment. A class of plasticizer compounds called phthalate esters that are not fully eliminated in wastewater treatment facilities are relevant to the ecological health of downstream ecosystems and urban areas due to their ecotoxicity, tendency for soil accumulation, and the emerging concern about their effects on public health. However, plasticizer concentrations in a constructed wetland environment have rarely been studied in the United States, prompting the need for a method of plasticizer quantification in the Tres Rios Constructed Wetlands which are sustained by the effluent of the 91st Avenue Wastewater Treatment Plant in Phoenix, Arizona. The concentrations of four common plasticizer compounds (dimethyl: DMP, diethyl: DEP, di-n-butyl: DnBP, and bis(2-ethylhexyl): DEHP phthalate) at five sites across the wetland surface water were quantified using solid-phase extraction followed by gas chromatography coupled with mass spectrometry (GC/MS). The sampling period included four sample sets taken from March 2022 to September 2022, which gave temporal data in addition to spatial concentration data. Quantification and quality control were performed using internal standard calibration, replicate samples, and laboratory blanks. Higher molecular weight phthalates accumulated in the wetland surface water at significantly higher average concentrations than those of lower molecular weight at a 95% confidence level, ranging from 8 ng/L to 7349 ng/L and 4 ng/L to 27876 ng/L for DnBP and DEHP, respectively. Concentrations for dimethyl phthalate and diethyl phthalate were typically less than 50 ng/L and were often below the method detection limit. Average concentrations of DnBP and DEHP were significantly higher during periods of high temperatures and arid conditions. The spatial distribution of phthalates was analyzed. Most importantly, a method for successful ultra-trace quantification of plasticizers at Tres Rios was established. These results confirm the presence of plasticizers at Tres Rios and a significant seasonal increase in their surface water concentrations. The developed analytical procedure provides a solid foundation for the Wetlands Environmental Ecology Lab at ASU to further investigate plasticizers and contaminants of emerging concern and determine their ultimate fate through volatilization, sorption, photodegradation, hydrolysis, microbial biodegradation, and phytoremediation studies.

This paper outlines the issue of end-of-life management in small scale solar systems deployed generally in Sub-Saharan Africa, known as PAYGos (Pay-as-you-go). Research and interviews were conducted in order to determine the current state of the industry and plans in terms of waste management. Considering the current capabilities and technology of PV recycling, the future of the industry was analyzed. It is important to provide the highest quality of service to the customer and minimize issues with environmental hazards. Therefore, it is recommended here that PAYGo companies create contracts with recycling companies before the issue of solar waste increases drastically.

The cosmetic industry utilizes plastic for most of its packaging, as it is a cheap option that produces packaging that is highly durable and resistant to many chemicals. Polyethylene terephthalate (PET) is the most commonly used plastic in cosmetic packaging, and is an ideal candidate for recycling due to their short lifespan and low diffusion coefficient. However, cosmetic packaging is often not recycled properly due to its small size, contributing to the growing global plastic waste problem. If a sustainable closed-loop system was created where cosmetic packaging was created using purely recycled PET, then the amount of plastic produced could be reduced. By examining the mechanical properties of recycled composite PET from the cosmetic industry, conclusions can be drawn about its applicability in cosmetic packaging. The water absorption, UV-visible absorbance, and tensile strength was tested for recycled composite PET to predict how the material would perform if it was used in cosmetic packaging. It was found that the recycled composite PET did not perform as well as virgin PET in terms of water absorption and tensile strength, but performed similarly in reference to UV-visible absorbance. More research needs to be done to further characterize the mechanical properties of recycled composite PET before it can be used in cosmetic packaging, but this study analyzes three of the most prominent aspects found in cosmetic packaging.