Reusing by-products such as cow bones in agriculture can be achieved thorough pyrolysis. The potential of bone-derived biochar as a promising material for metals immobilization in contaminated mining soils has not yet been sufficiently explored. Therefore, cow bones were used as biochar feedstock were pyrolyzed at 500 °C (CBL) and 800 °C (CBH) and. The two biochars were applied to a mine contaminated soil at 0 (control), 2.5, 5 and 10%, w/w, dosages; then, the soils were incubated and cultivated by maize in the greenhouse. Cadmium (Cd) and zinc (Zn) bioavailability and their sequentially extracted fractions (acid soluble, reducible, oxidizable, and residual fraction), soil microbial function, and plant health attributes were analyzed after maize harvesting. Bone-derived biochar enhanced the content of dissolved organic carbon (up to 74%), total nitrogen (up to 26%), and total phosphorus (up to 27%) in the soil and improved the plant growth up to 55%, as compared to the control. The addition of CBL altered the acid soluble fraction of both metals to the residual fraction and, thus, reduced the content of Zn (55 and 40%) and Cd (57 and 67%) in the maize roots and shoots, respectively as compared to the control. The CBL enhanced the β-glucosidase (51%) and alkaline phosphatase activities (71%) at the lower doses (2.5–5%) as compared to control, while the activities of these enzymes decreased with the higher application doses. Also, CBL improved the antioxidants activity and maize growth at the 2.5–5% application rate. However, the activity of the dehydrogenase significantly decreased (77%), particularly with CBH. We conclude that CBL, applied at 2.5–5% dose, can be utilized as a potential low cost and environmental friendly amendment for stabilization of toxic metals in contaminated mining soils and producing food/feed/biofuel crops with lower metal content.

Algal organic matter (AOM) is an important source for the dissolved organic matter (DOM) pool in aquatic systems, particularly in eutrophic waters. In this study, we reported the dynamic pattern of AOM hydrophobicity during the growth cycle of Microcystis aeruginosa using the partition coefficients of AOM in the aqueous two-phase system (KATPS) as a simple quantitative measure. AOM hydrophobicity had significant and non-monotonic changes during the growth cycle. It increased in the lag and early exponential phases, then decreased in the late exponential and stationary phases, and rebounded in the decline phase. AOM hydrophobicity determined using the resin fractionation, SUVA₂₅₄, and nuclear magnetic resonance methods shared similar non-monotonic pattern. Nevertheless, the correlations among these indicators were poor. The partition behavior of polycyclic aromatic hydrocarbons and chlorobenzenes to AOM was assessed based the KATPS dataset and the two-phase system (TPS) model. The TPS model showed good prediction power for the partition behavior of AOM with an RMSE of 0.23, suggesting that it was applicable to AOM from Microcystis aeruginosa. Our results indicate that algae activity will influence the overall hydrophobicity of the DOM pool depending on the growth phase, resulting in changes in the bioavailability of hydrophobic organic compounds in aquatic systems.

Tissue distribution of legacy and emerging per-and polyfluoroalkyl substances (PFASs) in several kinds of edible fishes collected from Meiliang bay of Taihu Lake, China were investigated and the related human health risks were assessed. Perfluorooctanesulfonate (PFOS), perfluorooctanesulfonamide (PFOSA) and 6:2 fluorotelomer phosphate diester (6:2 diPAP) were the most abundant legacy perfluoroalkyl acid (PFAA), PFOS related precursor (PreFOS), and the emerging PFASs in all fish tissues, respectively. Similar to the legacy PFAAs, 6:2 diPAP and 6:6 perfluorophosphinate (6:6 PFPiA) had the highest levels in the fish liver, whereas the highest level of PFOSA was in kidney, which might be due to its intensive transformation in fish liver. The concentrations of PFASs were generally positively correlated with the trophic levels. The profiles of PFASs were significantly different among bitterling, crucian and other fish, which might be related to their different metabolic capacities. Bioaccumulation factors (BAFs) of PreFOSs, 6:2 diPAP, and 6:6 PFPiA were lower than those of PFAAs with the same number of perfluorinated carbons. The calculated hazard ratios (HR) of PFOS (Range: 0.0100–0.655) and perfluorooctanoic acid (PFOA) (<0.00200) in all fish muscles were less than 1.0. However, the HR of the ∑PFASs in crucian muscle was 1.04, which implied that frequent consumption of crucian collected from Meiliang Bay might pose potential risks to human health.

Microplastic pollution is a growing concern worldwide. Despite numerous studies showing the occurrence of microplastics in low-trophic level aquatic organisms, microplastic ingestion and contamination in cetaceans, especially those from Asian waters, has been rarely recorded. Here, we investigated stomach microplastic pollution in twelve Indo-Pacific humpback dolphins stranded along the Pearl River Estuary (PRE), China. We also compared microplastic abundances in dolphins stranded near populated urban areas (ZH, n = 6) with those stranded near rural areas (JM, n = 6). Microplastics were detected in all samples, with abundance ranging widely from 11 to 145 items individual⁻¹ (mean ± SD, 53 ± 35.2). Major microplastics were polypropylene and polyethylene fibers, with the size mostly ranging from 1 to 5 mm and the dominant colors of white or transparent. Humpback dolphins from ZH (73 ± 36.8 items individual⁻¹) exhibited a significantly higher average microplastic abundance than those from JM (33 ± 18.3 items individual⁻¹, p < 0.05). In particular, the highest microplastic concentration was identified in the dolphin (SC-ZH01) stranded near the mouth of the Pearl River, whereas the dolphin (SC-JM04) collected at the rural site contained the lowest concentration of microplastics, suggesting the important influence of land-based human activities on the accumulation of microplastics in the PRE. The identification of varied microplastic polymers indicated their complex source scenarios. This study suggests that, as one of top predators in the potential microplastic food chains, this cetacean species could likely serve as an endpoint biomonitoring species of microplastic pollution in the PRE or other similar estuarine ecosystems. Our results highlight the need for more studies towards better understanding the potential impacts of microplastics on this endangered species.

In this work, valorisation pathways of brewers’ spent grains (BSG) towards biofuels production under the biorefinery concept were studied utilizing experimental data that provide a common base for straightforward comparison. The dehydration and the recovery of used oil, bioethanol and biogas from BSG were studied. The process units involved were thoroughly investigated and optimized. The oil extraction efficiency reached up to 70% using solid-liquid extraction process with hexane as solvent. The optimal ethanol yield achieved was 45% after the application of acid pretreatment, enzymatic hydrolysis with CellicCTec2 and fermentation with S. Cerevisiae. As far as biogas potential is concerned, the raw BSG, defatted BSG and stillage presented values equal to 379 ± 19, 235 ± 21 and 168 ± 39 mL biogas/g for respectively. Through the combination of the proposed schemes, three biorefinery scenarios were set up able to produce biodiesel, bioethanol and/or biogas. Material flow diagrams were set up in order to assess these schemes. Given that BSG could ensure ‘green’ energy production in the range of 4.5–7.0 million MJ/y if the European BSG potential is fully valorised, BSG could substantially contribute to the biofuel energy strategy.

Metal pollution is a great concern worldwide and the development of new technologies for more sustainable extraction methods as well as for the remediation of polluted sites is essential. Extremophilic microorganisms are attractive for this purpose since they have poly-resistance mechanisms which make them versatile. In this work, we sampled an acidic river and a hot spring of Caviahue-Copahue volcanic environment. The indigenous microbial communities were exposed to five heavy metals (Cd, Co, Cu, Ni and Zn) in batch-cultures favouring different metabolisms of biotechnological interest. Remarkably, high tolerance values were reached in all the cultures, even though most of the metals studied were not present in the environmental sample. Particularly, outstanding tolerances were exhibited by acidophiles, which grew at concentrations as high as 400 mM of Zn and Ni. High-throughput amplicon sequencing of 16S rRNA gene was used to study the indigenous communities and the resistant consortia. We took three approaches for the analysis: phylotypes, OTUs and amplicon sequence variants (ASVs). Interestingly, similar conclusions were drawn in all three cases. Analysing the phylogenetic structure and functional potential of the adapted consortia, we found that the strongest selection was exerted by the culture media. Notably, there was a poor correlation between alpha diversity and metal stress; furthermore, metal stress did not seem to harm the functional potential of the consortia. All these results reveal a great adaptability and versatility. At the end, 25 metal-resistant extremophilic consortia with potential uses in bioremediation, bioleaching or biomonitoring processes were obtained.

Microalgae have become imperative for biological wastewater treatment. Its capability in biological purification of wastewaters from different origins while utilizing wastewater as the substrate for growth has manifest great potentials as a sustainable and economical wastewater treatment method. The wastewater grown microalgae have also been remarked in research to be a significant source of value-added bioproducts and biomaterial. This paper highlights the multifaceted roles of microalgae in wastewater treatment from the extent of microalgal bioremediation function to environmental amelioration with the involvement of microalgal biomass productivity and carbon dioxide fixation. Besides, the uptake mechanism of microalgae in wastewater treatment was discussed in detail with illustrations for a comprehensive understanding of the removal process of undesirable substances. The performance of different microalgae species in the uptake of various substances was studied and summarized in this review. The correlation of microalgal treatment efficacy with various algal strain types and the bioreactors harnessed for cultivation systems was also discussed. Studies on the alternatives to conventional wastewater treatment processes and the integration of microalgae with accordant wastewater treatment methods are presented. Current research on the biological and technical approaches for the modification of algae-based wastewater system and the maximization of biomass production is also reviewed and discussed. The last portion of the review is dedicated to the assertion of challenges and future perspectives on the development of microalgae-based wastewater treatment technology. This review serves as a useful and informative reference for readers regarding the multifaceted roles of microalgae in the application of wastewater biotreatment with detailed discussion on the uptake mechanism.

The current review reports the importance and significance of cattle solid waste in vermicomposting technology concerning biowaste pollution in the environment. Needy increasing population evokes livestock production resulting in the massive generation of livestock wastes, especially cattle dung. Improper disposal and handling of biowastes originating from agriculture, industries, forests, rural and urban areas lead to nutrient loss, environmental pollution and health risks. Among the organic waste disposal methods available, vermicomposting is regarded as an environmentally friendly technology for bioconversion of agricultural, industrial, rural and urban generated organic solid wastes which are serving as reservoirs of environmental pollution. In vermicomposting of organic wastes, cattle dung plays a central role in mineralization, nutrient recovery, earthworm and microbial activity leading to vermifertilizer production. Even though the vermicomposting studies use cattle dung invariably as an amendment material, its importance has not been reviewed to highlight its central role. Hence, the present review mainly emphasizes the key role played by cattle dung in vermicomposting. Vermiconversion of cattle dung alone and in combination with other biowaste materials of environmental concern, mechanisms involved and benefits of vermicompost in sustainable agriculture are the major objectives addressed in the present review. The analysis reveals that cattle dung is indispensable amendment material for vermicomposting technology to ensure agricultural and environmental sustainability by reducing pollution risks associated with biowastes on one hand, and nutrient-rich benign vermifertilizer production on the other hand.

Perfluoroalkyl ether carboxylic acids (PFECAs), including hexafluoropropylene oxide dimer acid (HFPO-DA, GenX), have been widely used as alternatives to perfluorooctanoic acid (PFOA) and subsequently detected in various environmental matrices. Despite this, public information regarding their hepatotoxicity remains limited. Here, to compare the hepatotoxicity of PFECAs and identify better alternatives for GenX, adult male mice were exposed to different concentrations (0.4, 2, and 10 mg/kg/d) of PFOA, GenX, and its analogs (PFMO2HpA and PFMO3NA) for 28 d. Results demonstrated increased hepatomegaly and disturbed fatty acid metabolism with increasing treatment doses. After dimensionality reduction analysis, significant differences were observed in the relative liver weights and liver and serum biochemical parameters among the four clusters. Furthermore, when chemical concentrations in the liver were similar, no differences in the indicators of liver injury associated with fatty acid metabolism were observed among groups in the same clusters. Our results suggest that dimensionality reduction analysis is a useful strategy for analyzing samples exposed to multiple compounds at different doses. Furthermore, PFECAs exhibit similar hepatotoxicities at the same cumulative hepatic concentration in mice with constant body weight, while PFMO2HpA exhibits lower hepatotoxicity compared to GenX at the same dose.

Studies have documented that exposure to organochlorine pesticides (OCPs) is linked with breast cancer, but the underlying biological mechanisms are still unknown. This study included 313 women diagnosed with breast cancer and 313 controls in Wuhan, China, and measured 18 OCPs in serum and 3 oxidative stress biomarkers in urine. Multivariable adjusted regression models were used to evaluate the associations among OCPs, oxidative stress biomarkers, and breast cancer. The mediating effect of oxidative stress was assessed by mediation analysis. We observed that most OCPs were positively associated with risk of breast cancer (all FDR-P values < 0.05 or 0.10). Moreover, we found that p,p'-DDT, p,p'-DDD, dieldrin, heptachlor, and heptachlor epoxide were positively associated with 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA) and 8-iso-prostaglandin F₂α (8-isoPGF₂α), which in turn were positively associated with risk of breast cancer. Mediation analysis indicated that HNE-MA and 8-isoPGF₂ɑ mediated the positive associations between these OCPs and risk of breast cancer, with mediating proportion ranging from 6.23% to 19.9%. Our results suggest that lipid peroxidation may mediate the positive associations between OCP exposures and risk of breast cancer.