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The main source of natural estrogens to municipal wastewater is human excretions via urine or feces, thus their concentrations in raw wastewater should show positive linear relationship with their human excretions. This study mainly focused on their concentration relationship in raw wastewater. Based on comparison between chemical analyses and predictions through human excretion rates, the observed concentrations of estriol ( E) in municipal wastewater were found to be noticeably lower than the predicted values. The main cause for the disparity is that substantial conjugated E also exists in raw wastewater. This work suggested that monitoring both E and its conjugates is necessary to get more accurate E removal performance of wastewater treatment plants (WWTPs). [ABSTRACT FROM AUTHOR]

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 10 3 orders of magnitude higher than in soil. Indeed, Ba in the form of BaSO 4 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.

This study employed BiOI-deposited TiO 2 nanotube arrays (BiOI-TNTAs) electrode in a photoelectrochemical (PEC) system to oxidize Ibuprofen and generate hydrogen in the anodic and cathodic chamber, respectively. FESEM results revealed the diameter of TiO 2 nanotubes was 90-110nm. According to the XRD analysis, the BiOI-TNTAs were dominated by the anatase phase and tetragonal structure of BiOI. XPS results confirmed the coexistence of BiOI in the BiOI-TNTAs associated with Bi (33.76%) and I (8.81%). UV-vis absorption spectra illustrated BiOI-TNTAs exhibit strong absorptions in the visible light region. The PEC method showed the best degradation efficiency for Ibuprofen is a rate constant of 3.21×10 -2 min -1 . The results of the Nyquist plot revealed the recombination of photogenerated electron-hole pairs was inhibited as the bias potential was applied. Furthermore, the Bode plot demonstrated the lifetime (τ el ) of photoexcited electrons of BiOI-TNTAs was 1.8 and 4.1 times longer than that of BiOI-Ti and TNTAs, respectively. In the cathodic chamber, the amount of hydrogen generation reached 219.94μM/cm 2 after 3h of reaction time., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Crude e-waste dismantling activities have caused a series of environmental pollution problems, and the pollutants released from the dismantling activities would finally pose high risks to human health by means of the accumulation through food chains. To explore the contamination status of heavy metals to the surrounding farmland soils in Longtang and Shijiao Town, Qingyuan, Guangdong, China, 22 farmland soil samples were collected and analyzed for the contents, spatial distributions and chemical forms of 6 heavy metals (Pb, Cu, Cd, Zn, Cr and Ni). The results showed that the 6 heavy metals exhibited obvious accumulations when compared to the corresponding background values in Guangdong Province. According to farmland environmental quality evaluation standard for edible agricultural products HJ 332-2006, the pollution severity of heavy metals was evaluated by monomial pollution index and Nemerow synthetic pollution index methods, the results indicated that 72. 7% of the soil samples contained one or more kinds of heavy metals with higher concentrations than the corresponding standard values, Cd, Cu, Pb and Zn were the main metals in the polluted soils, and for the proportion of contaminated soil samples in all the 22 samples, Cd was the highest, followed by Cu, and finally Pb and Zn. Nemerow synthetic pollution index further revealed that 68. 2% of soil samples were contaminated, and among them 53. 3% of samples were heavily contaminated. Most of the heavy metals were well correlated with each other at the 0. 05 or 0. 01 level, which indicated that primitive e-waste recycling activities were an important source of the heavy metal contamination in Longtang and Shijiao Town. The contents of Cd, Pb, Cu and Zn in surface soils were higher than those of other soil layers, and the contents of these 4 metals in deep soils (20- 100 cm) did not show significant decreases with the increasing depths. The contents of Cr and Ni maintained constant, and exhibited no statistical differences with the sampling depths. Sequential leaching tests showed that the active fractions of Pb, Cu and Cd ranged from 36. 9% to 90. 6%, 39. 6% to 93. 9% and 43. 7% to 99. 6%, with mean values of 61. 3% 65. 3% and 80. 7%, respectively. The active fractions of these three metals in most samples accounted for more than half of their own total contents, which would cause a high ecological risk.

The first step of biodegradation is the contact of microorganism and pollutants, in order to examine the influence of phenanthrene on Sphingomonas sp. GY2B's surface properties during its degrading process, the bacteria was cultivated at different conditions, and detected by flow cytometry combined with fluorescent dyes for its surface changes. The results indicated that, the membrane structure had been certainly damaged during the degrading process, leading to an increased membrane permeability. Moreover, the destruction of bacteria membrane integrity became more serious with a higher pollutant concentration. At the concentration of 300 mg x L(-1), the ratio of stained bacterial cells/unstained cells was 12.44 after cultured for 60 h, while at 100 mg x L(-1) and 1.2 mg x L(-1), the ratios were 1.95 and 1.11, respectively. The results of fourier transform infrared (FT-IR) absorbance spectroscopy detection, the discrimination of death, injured and intact cells, and Zeta potential detection further verified the bacterial cell surface permeability changes. Flow cytometry combined with fluorescent dye propidium iodide was used to monitor the changes of bacterial membrane integrity on single-cell level which exhibited a good potential for exploring the changes of bacterial surface properties during the degrading progress and more deeply for investigating the degradation mechanism.

This study described the development of a method based on Soxhlet extraction combining high performance liquid chromatography (Soxhlet-HPLC) for the accurate detection of BDE-209 in soils. The solvent effect of working standard solutions in HPLC was discussed. Results showed that 1:1 of methanol and acetone was the optimal condition which could totally dissolve the BDE-209 in environmental samples and avoid the decrease of the peak area and the peak deformation difference of BDE-209 in HPLC. The preliminary experiment was conducted on the configured grassland (1 μ g/g) to validate the method feasibility. The method produced reliable reproducibility, simulated soils (n = 4) RSD 1.0%, and was further verified by the analysis e-waste contaminated soils, RSD range 5.9-11.4%. The contamination level of BDE-209 in burning site was consistent with the previous study of Longtang town but lower than Guiyu town, and higher concentration of BDE-209 in paddy field mainly resulted from the long-standing disassembling area nearby. This accurate and fast method was successfully developed to extract and analyze BDE-209 in soil samples, showing its potential use for replacing GC to determinate BDE-209 in soil samples.

The effect of rhamnolipids on pyrene degradation by Pseudomonas sp. GP3A was investigated to explore the interrelationships of biosurfactant, hydrophobic substrate and degrading bacteria. The cell surface hydrophobicity, lipopolysaccharide, hydrogen bond, bacterial biomass and pyrene degradation were determined. The results showed that the apparent solubility of pyrene was enhanced significantly when the concentration of rhamnolipids was higher than critical micelle concentration (CMC) of 60 mg x L(-1). Biosurfactant can increase the cell surface hydrophobicity by releasing the component of the cell wall-lipopolysaccharide; With the increase of cell surface hydrophobicity from 12% to 55%, bacterial biomass increased from 4.4 x 10(6) CFU x mL(-1) to 1.2 x 10(7) CFU x mL(-1), corresponding with the increase of pyrene degradation from 16% to 44%. Meanwhile, hydrogen bond was formed between biosurfactant and bacteria, which was beneficial to hydrophobic substrate degradation. The half-life of pyrene was shorten significantly. The average residual rate of pyrene in 10 days was 81% without rhamnolipids, but decreased to 57%, 41%, 33% and 26%, respectively with the addition of 20, 50, 200 and 500 mg x L(-1) of rhamnolipids.