17α-ethynylestradiol and its two main conjugates in seven municipal wastewater treatment plants: Analytical method, their occurrence, removal and risk evaluation.

This work shows the existence of both 17-ethinylestradiol-3-sulfate (EE2-3S) and 17-ethinylestradiol-3-glucuronide (EE2-3G) in seven municipal WWTPs with substantial concentrations (n.d-50.10 ng/L). The calculated removal efficiencies of 17-ethinylestradiol (EE2) in the seven municipal WWTPs ranged from 40.8%-100% with an average removal efficiency of 83.3%. However, upon the inclusion of EE2 concentration transformed from EE2-3S and EE2-3G, the corresponding removal efficiencies were increased to 91.4%-100% with an average removal efficiency of 97.3%. This work is the first to clearly illustrate that EE2 conjugates in raw wastewater could greatly underestimate the removal effectiveness of municipal WWTPs on EE2, indicating the importance of the EE2 conjugates in municipal wastewater having been hardly paid with attention. The EE2-derived estrogen equivalence (EEQ) values in the effluents of seven WWTPs ranged from 0 to 0.98 ng E2/L having an average level of 0.45 ng E2/L, which were relatively low. However, upon the inclusion of EE2 transformable from EE2-3S and EE2-3G in effluents, the EE2-derived EEQ values in effluents would be increased to 0.77-4.85 ng E2/L having an average level of 2.71 ng E2/L, which clearly suggested that ignorance of EE2 conjugates in effluent would largely underestimate EE2's environmental risk to receiving water bodies.

[Relationships Between Microplastic and Surrounding Soil in an E-Waste Zone of China].

Microplastic pollution is ubiquitous and has attracted significant public attention. Recent research on microplastic has focused on aquatic environments, but its impacts on soil ecosystems remain poorly understood, especially in e-waste dismantling zones. The objective of this study was to investigate the relationships between microplastic and surrounding soil in abandoned e-waste disassembling plots with different dismantling methods focusing on ecotoxicology and microbiology in Guiyu, Shantou District, Guangdong Province. The surface morphology of collected microplastics showed signs of aging and degradation, possibly due to their long-term exposure in the soil and the original disassembling methods. In addition, there were diverse metal elements at different surface positions of the same microplastic sample based on SEM-EDS analyses, indicating that some metal elements carried by microplastics are derived from the surrounding soil rather than being inherent to the microplastic. Moreover, seven heavy metals (Pb, Cd, Cr, As, Ba, Co, and Ni) inherent in microplastic were identified using ICP-OES, revealing that the concentrations varied in different sampling plots were typically higher than in the surrounding soil. In particular, the concentration of Ba in microplastic was 103 orders of magnitude higher than in soil. Indeed, Ba in the form of BaSO4 is widely used as a filler in numerous plastics. Furthermore, microplastic-associated microorganisms were examined using 16S rRNA sequencing, and the relationships between the top 50 genera of microplastic-bound bacteria and soil environmental factors were analyzed using the Spearman's rank correlation coefficient. Microorganisms primarily originated from the surroundings of microplastics; therefore, environmental factors could directly affect the microbial communities associated with this type of pollutant. Importantly, different dismantling methods were associated with distinct soil environmental factors, and their correlations with microplastic-associated microorganisms also varied.