Degradation characteristics and effect mechanisms of estrogens during aerobic composting of chicken manure based on the orthogonal test.

Environmental estrogens are currently a significant research topic, and poultry manure serves as a crucial source. This study investigated the degradation characteristics and effect mechanisms of six estrogens (E1, 17α-E2, 17ß-E2, E3, 17α-EE2, and DES) during the aerobic composting of chicken manure. An orthogonal test comprising four factors (aeration rate, calcium-magnesium-phosphorus fertilizer (Ca-Mg-P fertilizer), coconut shell biochar, initial moisture content) and three levels of aerobic composting was conducted over a 45-day period to monitor the changes in estrogens and basic parameters. The results indicated that the factors influencing the estrogen degradation rate ranked as: initial moisture content (MC) > Ca-Mg-P fertilizer > aeration rate > coconut shell biochar. These factors significantly influenced the abundance of estrogen-degrading genera. Optimal composting conditions for estrogen degradation were identified as the addition of 10% coconut shell biochar, maintaining an initial moisture content of 60%, and using an aeration rate of 0.08 L min-1∙kg-1DM (dry matter), with an average degradation rate of 86.88% for the six estrogens under these conditions. During the composting process under various treatments, five known estrogen-degrading genera were observed with high relative abundance (max 31.08%), and the predominant genera were Staphylococcus and Brachybacterium for 17α-E2, 17ß-E2, E3, 17α-EE2, and DES, and Pusillimonas for E1. The composition of microbial community structure changed significantly, and the dominated environment factors effecting the composition and succession of these genera were carbon to nitrogen ratio (C/N) and MC. The research results can provide both a theoretical basis and practical reference for the effective degradation of estrogens during the composting of chicken manure.

[Research Progress on Pollution Characteristics, Degradation, and Transformation of Typical PPCPs in the Process of Wastewater Treatment].

Pharmaceuticals and personal care products (PPCPs) have received extensive attention as a new type of pollutant inin the 21st century, and the ecological and health risks caused by PPCPs have gradually been recognized by government regulatory agencies. Daily use of PPCPs has led to their frequent detection and high concentrations in the influent, effluent, and sludge of wastewater treatment plants, but traditional wastewater treatment processes can't remove them effectively. Most research about enhancing the removal of PPCPs through microbial degradation, photodegradation, and ozonation is still in the laboratory research stage, and the removal effects are not satisfactory when applied to actual sewage treatment. Therefore, the effective removal of PPCPs from domestic wastewater is a critical technical problem that urgently needs to be studied and solved in the coming years. At present, many scholars do not have a comprehensive understanding about the degradation and transformation behaviors of microbes, ultraviolet, and ozone for typical PPCPs in the wastewater treatment process, so it is necessary to conduct a systematic analysis and discussion. In this study, 16 typical PPCPs frequently detected in sewage treatment plants were selected as research objects through a literature review. The occurrence, removal characteristics, and sludge adsorption properties of typical PPCPs in wastewater treatment plants were analyzed and summarized. The degradation and transformation behavior of typical PPCPs under microbial, ultraviolet, and ozone treatments in the wastewater treatment process were also discussed. Finally, based on current research gaps, some research directions for the removal and transformation of PPCPs in wastewater were proposed:① investigation into the removal characteristics of PPCPs by actual biochemical treatment; ② study on the mechanism of microbial degradation and transformation of typical PPCPs during biochemical treatment; ③ study on the degradation and transformation mechanism of typical PPCPs by UV/ozone in an actual sewage system; and ④ research on the application technology of removing PPCPs from sewage via microbial degradation, photodegradation, ozone oxidation, etc. The relevant results of this study can provide a reference for the pollution control of typical PPCPs in the sewage treatment process.

Effect comparisons of different conditioners and microbial agents on the degradation of estrogens during dairy manure composting.

To investigate the degradation efficiency of conditioners and commercial microbial agents on estrogens (E1, 17α-E2, 17ß-E2, E3, EE2, and DES) in the composting process of dairy manure, seven different treatments (RHB-BF, OSP-BF, SD-BF, MR-BF, MR-FS, MR-EM, and MR-CK) under forced ventilation conditions were composted and monitored regularly for 30 days. The results indicated that the removal rates of estrogens in seven treatments ranged from 95.35% to 99.63%, meanwhile the degradation effect of the composting process on 17ß-Estradiol equivalent (EEQ) was evaluated, and the removal rate of ΣEEQ ranged from 96.42% to 99.72%. With the combined addition of rice husk biochar (RHB) or oyster shell powder (OSP) and bio-bacterial fertilizer starter cultures (BF), namely RHB-BF and OSP-BF obviously promoted the rapid degradation of estrogens. 17ß-E2 was completely degraded on the fifth day of composting in OSP-BF. Microbial agents have some promotional effect and enhances the microbial degradation of synthetic estrogen (EE2, DES). According to the results of RDA, pH and EC were the main environmental factors affecting on the composition and succession of estrogen-related degrading bacteria in composting system. As predominant estrogens-degrading genera, Acinetobacter, Bacillus, and Pseudomonas effected obviously on the change of estrogens contents. The research results provide a practical reference for effective composting of dairy manure to enhancing estrogens removal and decreasing ecological risk.

[Sorption Characteristics and Site Energy Distribution Theory of Typical Estrogens on Microplastics].

Microplastics (MPs) and estrogens are high-profile emerging contaminants at present, and MPs might become the carrier of estrogens in the environment and induce combined pollution. To study the adsorption behavior of polyethylene (PE) microplastics to typical estrogens, the adsorption isothermal properties of the six estrogens[estrone (E1), 17α-estradiol (17α-E2), 17ß-estradiol (17ß-E2), estriol (E3), diethylstilbestrol (DES), and ethinylestradiol (17α-EE2)] in single-solute and mixed-solute systems were studied through batch equilibrium adsorption experiments, in which the PE microplastics before and after adsorption were characterized by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Then, the site energy distribution theory of the adsorption of six estrogens on PE microplastics was further analyzed based on the Freundlich model. The results showed that the adsorption process of selected estrogens with two concentrations (100 µg·L-1 and 1000 µg·L-1) on PE were more consistent with the pseudo-second order kinetic model. The increase in initial concentration reduced the equilibrium time of adsorption and increased the adsorbing capacity of estrogens on PE. In the single system (one estrogen) or mixed system (six estrogens) with different concentrations (10 µg·L-1-2000 µg·L-1), the Freundlich model showed the best fitting effect for the adsorption isotherm data (R2>0.94). The results of isothermal adsorption experiments and XPS and FTIR spectra showed that the adsorption of estrogens on PE in the two systems was heterogeneous adsorption, and hydrophobic distribution and van der Waals forces were the principal factors in the process of adsorption. The occurrence of C-O-C (in only the DES and 17α-EE2 systems) and O-C[FY=,1]O (in only the 17α-EE2 system) indicated that the adsorption of synthetic estrogens on PE was affected slightly by chemical bonding function, but no obvious effects were observed for natural estrogens. The results of site energy distribution analysis showed that, compared with the single system, the adsorption site energy of each estrogen shifted to the high-energy region in its entirety in the mixed system, and the site energy increased by 2.15%-40.98%. The energy change in DES was the most significant among all of the estrogens, indicating its competitive advantage in the mixed system. The above results of this study can provide some reference for the study of adsorption behavior, mechanism of action, and environmental risks under the coexisting condition of organic pollutants and MPs.