Poly- and perfluorinated alkyl substances (PFASs) are groups of persistent toxic substances that have been commonly detected in wastewater treatment plants (WWTPs). In some cases, the activated sludge (AS) in WWTPs will encounter special wastewaters containing PFASs up to tens of milligram per liter (mg L⁻¹). However, under this condition, the potential impacts of PFASs on AS process remain unclear. In the present research, a lab-scale sequencing batch reactor was continuously exposed to perfluorooctanoic acid (PFOA), used as a representation for PFASs, at 20 mg L⁻¹ to mimic the extreme condition. The objective is to explore the impact of PFOA on AS process in terms of its wastewater treatment performance and evolution of microbial communities. The results indicate that PFOA restrained the microbial growth and affected the dissolved organic carbon removal. These negative impacts could be recovered after long-term adaptation. Besides, 20 mg L⁻¹ PFOA shows limited inhibition on nitrification and denitrification, suggesting a safe exposure level of PFOA for nitrogen removal. For microbial evolution, PFOA induced changes of communities during long-term exposure. The high abundance of Bacteroidetes, Proteobacteria, and Acidobacteria maintained over time reveals their tolerance towards PFOA. The occurrences of PFOA-resistant species are also observed. The present research provides new insight into the possible impacts of typical PFAS at high concentrations on AS process.

A radish and a grass species were grown in identical substrates either unpolluted or polluted by tungsten (W) at 1, 5, and 10 μg/g levels of watering solutions during 1 month under controlled laboratory conditions. Initially, at 4.1 μg/g, the W content in grass leaves reached 16 μg/g at the highest rate of W supply to the substrate. For radish, the content of W reached 22 and 29 μg/g in the leaves and roots, respectively. The overall W pollution increased significantly the mobility of major elements from substrate to grass leaves, especially at the 5 μg/g pollution level, whereas the W impact on radish leaves resulted in an increase of most contents, only Mn remaining unaffected. The roots from polluted radishes were enriched in Si by 21% and Al by 42% at low pollution, and in Si by 15% at high supply, whereas the uptake of the other elements remained unchanged. It looks like the W pollution at the levels chosen does not impact the transfer of the major and trace elements from roots to leaves of Raphanus sativus. Alternatively, metallic trace elements (Ba, Ni, Cr, Zn, W, Co) of the Raphanus sativus and Chloris gayana leaves outline similar content changes depending on the amount of W pollution. The total rare-earth element contents of the leaves of Raphanus sativus grown in the polluted substrates are lower than those of the leaves from unpolluted substrate. Their normalization in the leaves and roots of Raphanus sativus from the polluted substrates to those of the radish from non-polluted substrate provides flat patterns for both with a positive Eu anomaly for leaves, as for those of the grass and a negative Gd anomaly for roots. Also, addition of soluble W to the substrates induced an increase in the bacterial activity of the soil.

Municipal biosolids in end-of-life lagoons can release phosphorus (P) to floodwater and contribute to P enrichment of receiving waters if the floodwater is released. Phosphorus release to floodwater is well-documented in agricultural and wetland soils, but information on flooding depth and timing effects on P release from flooded biosolids in end-of life municipal lagoons is currently lacking. This 42-day experiment utilized intact, cattail-(Typha latifolia L.) vegetated biosolids cores (45.7-cm diameter by 60-cm height) to investigate the effects of flooding depth (5, 15, and 25 cm) on P release from biosolids and on P fractionation in pore water, floodwater, and biosolids upon flooding of municipal biosolids. Averaged across flooding depths, TP rapidly increased from the onset of flooding (0.45 mg L⁻¹) to day 14 (1.8 mg L⁻¹) and remained relatively constant thereafter (1.8–1.9 mg L⁻¹). Dissolved reactive P was the major fraction of P in pore water and floodwater. Flooding for more than 3 days resulted in the release of > 0.5 mg L⁻¹ dissolved reactive P (DRP) to floodwater. Phosphorus release was positively correlated with Fe and Mn concentrations in pore water and with water-extractable inorganic P, labile inorganic P, and Fe/Al-bound organic P concentrations in biosolids. Results indicate that P release to floodwater; hence, risk to receiving water bodies, is minimal during the first 3 days of flooding. This suggests that release of floodwater from the lagoon presents minimal adverse impact to receiving surface waters if done during the early stages (< 3 days) of flooding.

Today, widespread growth in the world is intertwined with multichannel monitoring systems based on remote sensing. Such systems allow for the collection of operational information that focuses on the environmental status of marine systems on different scales. The technique of identifying real-time abnormal phenomena in the marine environment requires the presence of algorithmic remote sensing measurements and appropriate software. The present study presents a new monitoring system for remotely sensed anomalies on the marine surface, equipped with a “spotting” model based on empirical data. The experimental verification of the efficiency of the system and the algorithms developed was based on data from the Cosmos-1500 satellite for several seas. Finally, it is stressed that the proposed system, in addition to water, can also be used to detect abnormal phenomena in both air and soil.

Microbial food webs tolerate toxic compounds depending on individualistic species resistance and their ability of using alternate food sources. Soil polluted with low-molecular weight volatile organics, such as hexane, diminishes bacterial and fungal communities despite its short residence time. Survival of microbial species depends on perturbation intensity, which in turn restricts resources for amoebae survival in polluted soil. Soil functional recovery from anthropogenic perturbations depends on microbial organic matter (OM) metabolization of pollutants. However, reconfiguration of amoebae community after soil exposure remains largely unknown. A microcosms study was carried out to determine the effects of hexane on the community structure of soil amoebae as well as the importance of Medicago sativa on amoebae community recovering. Hexane had a negative impact on species richness and structure of the amoebae community 24 h after pollution. There was a significant increase in species richness and number of amoebae 30 days after contamination. These two parameters further increased after 60 days from contamination. After 30 days of the initial trophozoites extinction caused by Hexane, M. sativa’s. Root zone showed a significant increase of both species richness and number of individuals. This recovery trend was kept after 60 days when the highest values in species richness and abundance of individuals were shown in both polluted and non-polluted microcosms. In conclusion, M. sativa’s root zone speeds up recovery of the amoebae community structure after pollution exposure.

This work has been performed to investigate the use of lime mud filtrate (LMF) pretreatment to enhance hydrogen (H₂) evolution from sewage sludge (SS). The SS samples were pretreated with LMF (pH 8.0–11.0) at 55 °C for 48 h, prior to the H₂ fermentation. The maximum H₂ yield of 38.30 ml/g-VS (volatile solid) was obtained from the SS pretreated by LMF pH of 10.0, with the corresponding lag time of 3.10 h, which was well described by the modified Gompertz model. Adequate pH of LMF facilitated the solubilization of SS and the release of organic matters, providing adequate substrates for subsequent bio-H₂ evolution. The soluble chemical oxygen demand was increased from 25.0 to 91.7%, as compared with the control test without LMF soak. However, further increase in pH of LMF could decrease the concentration of available substrate, thus reducing the H₂ yield. This technique revealed sustainable waste management and energy recovery.

This study presents the development of a sensitive and accurate dispersive liquid-liquid microextraction method using binary solvents for the simultaneous determination of endocrine disruptive compounds by GC-MS. Optimum binary solvent and dispersive solvent amounts were determined using an experimental design. The main effects of these parameters and their interaction effects were assessed using analysis of variance. The detection limits of the analytes under optimal experimental conditions ranged between 0.16–1.5 ng/mL. All analytes exhibited good linearity over broad calibration ranges, and high precision (%RSD < 8.0%) was obtained for six repeated readings of the lowest concentrations of the calibration plots. The method’s applicability and accuracy were tested on two municipal wastewater samples spiked at 10, 50, and 100 ng/mL. The recovery results obtained ranged between 82 and 108%, indicating that the method can be used to quantify the analytes in wastewater matrix with substantial accuracy. In addition, matrix matching calibration method was used to improve the percent recovery (≈ 100%) for a waste sludge sample spiked at 50 ng/mL.

Fifteen endophytic isolates were recovered from the phytoremediator plant Phragmites. Phylogenetic analysis revealed they were primarily from the class Sordariomycetes and Dothiodiomycetes. Most of the endophytes in Sordariomycetes were from the orders Diaporthales (six isolates, e.g., Diaporthe, Phomopsis), Hypocreales (two isolates, e.g., Gliomastix, Trichoderma), and Xylariales (one isolate, e.g., Arthrinium), while members from Dothideomycetes were from the order Pleosporales (six isolates, e.g., Bipolaris, Curvularia, Microsphaeropsis, Saccharicola). The endophytes demonstrated varying responses to the metals (Al³⁺, Cu²⁺, Zn²⁺, Pb²⁺, and Cd²⁺) and concentrations (10, 25, 50, 100, and 200 mg L⁻¹) tested, with isolates of Dothideomycetes predominantly more tolerable to metals (80–97% tolerance) than Sordariomycetes (73–90% tolerance). Pb²⁺ was the least harmful towards the endophytes, while Al³⁺ appeared to be highly toxic with mean tolerable range (TR) of > 200 and 25–50 mg L⁻¹, respectively. Endophytes thriving in toxic metals may further be applied for biocontrol, bioremediation, or growth-promoting purposes in metal-contaminated areas.

This study confronts the questionable reliability and accuracy of field test kits distributed globally to determine arsenic in drinking water. Because kits are the primary method of arsenic analysis in the areas most affected, an alternate, nontoxic formulation is needed to provide accurate results. Hypothesizing that introducing silver nitrate as the reagent in test kits could successfully substitute for restricted mercuric bromide, the study found that the reformulated kits provided reliable, precise, and accurate results over a broader range of contamination. Digital image analysis was used to examine the blue color value produced when arsine reacts with silver nitrate impregnated test strips. An optimal concentration of AgNO₃ exhibiting the greatest linearity was determined by graphical comparison and the color intensity of the strips observed to be inversely proportional to the concentration of As (III). Adapted field test kits were then constructed to examine water samples ranging in arsenic contamination from 0 to 50 μg L⁻¹. A series of reactions was completed to demonstrate reproducibility and test for the accuracy of the procedure. Statistical examination of colorimetrically quantified results confirmed the hypothesis that silver nitrate can reliably and precisely expand the kit’s range of detection while maintaining its low cost, quick assessment, and uncomplicated technique. This new method, using 0.4% m/v AgNO₃ as a reagent for the Gutzeit reaction, was able to distinguish between concentrations of 0, 5, 10, 15, and 50 μg L⁻¹ at the 95% confidence level.

Rapid and extensive social and economic development has caused severe soil contamination by heavy metals in China. The spatial distribution, pollution levels, and health risks of metals were identified in an oasis-desert zone of northwest China. The mean concentrations of six heavy metals exceeded their corresponding background contents, and each metal concentration in farmland samples was higher than that in Gobi samples. Moreover, these heavy metals followed a similar spatial pattern and showed significant positive correlations with each other, indicating that they have the same sources. The contamination features of heavy metals and ecological risks were calculated using several quality indicators, and their health risks for population groups were quantified. The results showed that the Gobi and farmland soils were uncontaminated to moderately contaminated by heavy metals, and that farmland pollution was more serious than that of Gobi. The Gobi and farmland soils posed low ecological risks. As a whole, the non-carcinogenic risk which was caused by heavy metals was low for local residents, and the carcinogenic risk was within an acceptable level. Comparatively speaking, children were the more vulnerable population to health risks. The Zn and Cu pollution was relatively serious, and Cr and V were major contributors to health risks. Graphical abstract ᅟ