Fenton oxidation system for treating petroleum-contaminated solid waste: Advances and prospects.

Both normal activities and accidental spills in the petroleum industry generate solid waste that contain petroleum-contaminated pollutants (referred to as "petroleum-contaminated solid waste"), which mainly include petroleum-contaminated soil, petroleum sludge, and petroleum-based drill cuttings. At present, most relevant studies focus solely on the treatment effects of the Fenton system alone in treating a specific type of petroleum-contaminated solid waste, and systematic studies on the influencing factors, degradation pathways, and applicability of the system are lacking. For this reason, this paper reviews the application and development of the Fenton system to treat petroleum-contaminated solid waste in the period from 2010 to 2021 and summarizes its basic properties. It also compares the influencing factors (e.g., Fenton reagent dosage, initial pH, and catalyst properties), degradation mechanisms, and reagent costs of conventional Fenton, heterogeneous Fenton, chelate-modified Fenton, and electro-Fenton systems for the treatment of petroleum-contaminated solid waste. In addition, the main degradation pathways and intermediate toxicities of typical petroleum hydrocarbons in Fenton systems are analyzed and evaluated, and development directions for the further application of Fenton systems in treating petroleum-contaminated solid waste are proposed.

The success rate of cannulation of needle-knife precut is superior to continuing wire-guided after difficult biliary cannulation with pancreatic stent placement.

BACKGROUND: Difficult biliary cannulation and unintended pancreatic cannulation exist in biliary interventions during endoscopic retrograde cholangiopancreatography. Wire-guided cannulation over a pancreatic stent (PS-WGC) and needle-knife precut over a pancreatic stent (PS-NKP) may facilitate biliary cannulation. This study aimed to compare the outcomes of PS-NKP and PS-WGC following guidewire passage into the pancreatic duct. METHODS: A total of 304 patients who inserted a pancreatic stent and continued cannulation using wire-guided (PS-WGC) or needle-knife precut (PS-NKP) from October 2018 to November 2021 in three centers were ultimately enrolled in this study. The success rate of cannulation and incidence of complications were compared between the two groups. RESULTS: Results of the success rate of cannulation in the PS-NKP (n = 98) group were significantly higher compared with the PS-WGC (n = 206) group (96.9% vs. 89.8%; P < 0.05). The overall adverse events were 10.2% (31/304), and PS-NKP had lower (PEP) rates compared with the PS-WGC (3.1% vs. 10.7%, P < 0.05). CONCLUSION: The PS-NKP group is superior to the PS-WGC group in terms of the effectiveness and safety of continued cannulation. Using needle-knife precut, especially early use, over the pancreatic stent to continue cannulation reduced PEP compared with PS-WGC.

Research on the influencing factors and mechanism of single-phase microemulsion cleaning of shale gas oil-based cuttings.

Oil-based cuttings (OBCs) produced by shale gas exploitation are classified as hazardous waste. Their appropriate utilization and disposal is a key issue that urgently needs to be resolved. A single-phase microemulsion (SPM) has ultra-low interfacial tension and strong solubilization ability. In view of this, based on an analysis of the characteristics of OBCs, SPMs have been selected for their cleaning. The effects of microemulsion components and other conditions on the cleaning efficacy have been explored, as well as the deoiling mechanism and the recycling efficiency of the SPM. Our results have shown that sodium dodecylbenzene sulfonate (SDBS), n-butanol, water, and white oil in appropriate proportions can form an effective SPM. The oil content (OC) of OBCs after cleaning was reduced from 11.89% (±0.32%) to 1.13% (±0.02%) when the proportions of the aforementioned components of the SPM were 14.3%, 14.3%, 66.6%, and 4.8%, respectively. The OC of the residue further decreased to 0.28% (±0.05%) after a second cleaning with an alkaline solution. The optimum SPM conditions for cleaning OBCs were identified as a stirring speed of 200 rpm, a temperature of 30 °C, a cleaning time of 30 min, and a solid to liquid mass to volume ratio of 1:4. The main mechanism whereby the SPM cleans the OBCs is that the former reduces the combined work and adhesion work required for the removal of oil droplets from the cuttings, so that the adhesive oil is easily gathered up. Furthermore, the gathered oil phase is solubilized by the SPM.

Bisphenol AF exposure causes fasting hyperglycemia in zebrafish (Danio rerio) by interfering with glycometabolic networks.

Bisphenol AF (BPAF), one of the main alternatives to bisphenol A, has been frequently detected in various environmental media, including the human body, and is an emerging contaminant. Epidemiological investigations have recently shown the implications of exposure to BPAF in the incidence of diabetes mellitus in humans, indicating that BPAF may be a potential diabetogenic endocrine disruptor. However, the effects of BPAF exposure on glucose homeostasis and their underlying mechanisms in animals remain largely unknown, which may limit our understanding of the health risks of BPAF. To this end, zebrafish (Danio rerio), an emerging and valuable model in studying animal glycometabolism and diabetes, were exposed to environmentally relevant concentrations (5 and 50 µg/L) and 500 µg/L BPAF for 28 d. Several key toxicity endpoints of blood glucose metabolism were detected in our study, and the results showed significantly increased fasting blood glucose levels, hepatic glycogen contents and hepatosomatic indexes and decreased muscular glycogen contents in the BPAF-exposed zebrafish. The results of quantitative real-time PCR showed the abnormal expression of genes involved in glycometabolic networks, which might promote hepatic gluconeogenesis and inhibit glycogenesis and glycolysis in the muscle and/or liver. Furthermore, the failure of insulin regulation, including plasma insulin deficiency and impaired insulin signaling pathways in target tissues, may be a potential mechanism underlying BPAF-induced dysfunctional glycometabolism. In summary, our results provide novel in vivo evidence that BPAF can cause fasting hyperglycemia by interfering with glycometabolic networks, which emphasizes the potential health risks of environmental exposure to BPAF in inducing diabetes mellitus.

CHFR­mediated epithelial­to­mesenchymal transition promotes metastasis in human breast cancer cells.

Checkpoint with FHA and RING finger domains (CHFR) is a G2 phase/mitosis checkpoint. Several studies have reported that CHFR is downregulated in multiple cancer types and serves a tumor suppressor role. However, the biological function of CHFR in breast cancer (BRCA), particularly regarding metastasis, are yet to be elucidated. In the present study, it was revealed that CHFR is upregulated in BRCA compared with normal tissues, according to The Cancer Genome Atlas database. In addition, subgroup analysis of BRCA revealed that CHFR was upregulated in both human epidermal growth factor receptor 2­positive and triple­negative BRCA. Meanwhile, patients with high expression levels of CHFR exhibited poorer overall survival rates. Furthermore, the present data revealed that the overexpression of CHFR in SKBR3 cells resulted in enhanced cell migration and invasiveness, and also significantly upregulated mesenchymal markers, such as N­cadherin, vimentin, transcription factor Slug and tight junction protein claudin­1. Furthermore, knockdown of CHFR in MDA­MB­231 cells significantly inhibited cell migration and invasiveness, and also downregulated mesenchymal markers, such as N­cadherin, vimentin and tight junction protein claudin­1. In conclusion, the current results indicated that CHFR expression was associated with cell metastasis in BRCA by mediating epithelial­to­mesenchymal transition.

Morphology and molecules support the new monotypic genus Fenghwaia (Rhamnaceae) from south China.

Fenghwaia, a new monotypic genus, along with the new species Fenghwaia gardeniicarpa, is described from Guangdong Province, China. The combined features of inferior ovary, cylindrical drupaceous fruits and orbicular and dorsiventrally-compressed seeds with an elongate and pronounced basal appendage make the new genus significantly different from other genera of the family. In addition, its pollen morphology also showed great similarity to other species of this stenopalynous family. The molecular phylogenetic analysis, based on nuclear ribosomal internal transcribed spacer (ITS) and plastid trnL-F intron spacer (trnL-F) DNA sequence data from the new genus and the other 375 species representing 58 genera of Rhamnaceae, indicates that Fenghwaia is nested within the 'rhamnoid' group and sister to the tribe Rhamneae and then both sister to the tribe Maesopsideae. A taxonomic classification key to the 'rhamnoid' group is provided, based on morphological characters. A global conservation assessment is also performed and classifies Fenghwaia gardeniicarpa as Near Threatened (NT).

Greenhouse gas emissions from semi-aerobic bioreactor landfills with different vent-pipe diameters.

The emission patterns of three greenhouse gasses (GHGs), viz. CH4, CO2, and N2O from landfills, were examined on a lab scale. Three simulated semi-aerobic bioreactor landfills (SABL1, SABL2, SABL3), with respective vent-pipe inner diameters (φ) of 25, 50, and 75 mm, were used to investigate their effect on the greenhouse effect (GHE) during the municipal solid waste (MSW) stabilization process. We found that the vent-pipe φ influenced both MSW degradation and GHG emissions, increasing the vent-pipe φ which improved the removal of carbon and nitrogen-based pollutants. The GHG emissions were 364, 356, and 309 kg CO2 equivalents per ton of MSW from the SABL2, SABL1, and SABL3, respectively, during the operation of 465 days. Of the three GHGs, CH4 influenced the GHE the most, contributing 72.53%, 79.17%, and 71.42% in SABL1, SABL2, and SABL3, respectively. In the same sequence, CO2 (14.87%, 14.06%, and 21.9%) and N2O (12.6%, 6.77%, and 6.69%) were the second and third contributors to the GHE, respectively. Considering the rapidly MSW stabilization and the mitigation of GHG emissions, a vent pipe with φ of 75 mm in the SABL column (φ of 800 mm) was suggested. Moreover, the GHG mitigation in the SABL should be implemented by prioritizing CH4 collection and oxidation. The results provided a technical guidance for GHG mitigation in MSW management.

The diagnostic value of exosomal miRNAs in human bile of malignant biliary obstructions.

BACKGROUND: Diagnosis of malignant biliary obstruction is complicated and lacks accuracy. Exosomes may be secreted by malignant tumors; intact miRNAs from exosomes might serve as potential biomarkers for the disease. AIM: To identify exosomal microRNAs in human bile among benign and malignant biliary obstructions. METHODS: Bile samples were collected from patients undergoing therapeutic endoscopic retrograde cholangiopancreatography for biliary obstruction. Exosome microRNAs were determined by RNA-sequencing in the discovery cohort, which comprising benign (n = 5) cases and malignant biliary obstruction (n = 5) cases. Then, the diagnostic performance of the two up-regulated microRNAs (mir-483-5p and mir-126-3p) of bile exosomes was verified by analysis of 82 patients with a diagnosis of malignant (n=37) or nonmalignant (n=45) biliary obstruction. RESULTS: In both cohorts, the expressions of mir-483-5p and mir-126-3p were significantly higher in bile exosomes samples from patients with malignant biliary obstructions than controls. In the verification cohort, the two miRNAs can distinguished the benign and malignant groups with high diagnostic accuracy and specificity; the diagnostic values of the two microRNAs were better than serum carbohydrate antigen 19-9 (CA19-9), area under the curve (AUC) were 0.81 and 0.74. CONCLUSION: The expression of exosomal mir-483-5p and mir-126-3p in the bile samples discriminates between patients with malignant and nonmalignant biliary obstructions. CLINICAL TRIAL REGISTRATION NO: NCT03102268.

Physicochemical characteristics of oil-based cuttings from pretreatment in shale gas well sites.

Understanding the physicochemical characteristics of oil-based cuttings (OBCs) is an important foundation for subsequent treatment and management. The macro- and microscopic properties of white oil-based cuttings (WOBCs) and diesel-based cuttings (DBCs) after the different pretreatment steps have been assessed using scanning electron microscopy. The organic and inorganic compositions of OBCs have been analyzed using X-ray diffraction, Fourier-transform infrared spectrometry, and gas chromatography-mass spectrometry. Inorganic matter (SiO2, BaSO4, and CaCO3), alkanes, aromatic compounds, and water were the main components of OBCs. The organic content (26.14%) and alkane content of the WOBCs were higher than that of the DBCs, whereas for the inorganic content (70.87%), the reverse was true. The macro- and micromorphologies of OBCs were quite different because their oil and water contents were different. The oil contents of OBCs decreased in the order A1 (14.64%) > A3 (12.67%) > A2 (11.06%) and B1 (9.19%) > B3 (8.94%) > B2 (4.66%); the water contents decreased in the order A1 (2.99%) > A3 (2.19%) > A2 (1.09%) and B1 (2.30%) > B3 (1.87%) > B2 (1.09%). Moreover, a skid-mounted treatment technology for OBCs was proposed. The results can be a scientific guidance for the treatment and management of OBCs.

Quantitative acetylome and phosphorylome analysis reveals Girdin affects pancreatic cancer progression through regulating Cortactin.

The actin-binding protein Girdin is involved in a variety of cellular processes, including pancreatic cancer. The objective of this study is to explore the role and the mechanism of Girdin in pancreatic cancer by quantitative acetylome and phosphorylome analysis. We firstly found that Girdin was overexpressed in pancreatic cancer tissue and increased expression of Girdin was associated with tumor size and stage of patients with pancreatic cancer. We established the shRNA knockdown of Girdin in PANC-1 and Aspc-1 cells, and we found that shGirdin inhibited proliferation, migration and invasion, and promoted apoptosis. Subsequently, we identified and quantified 5,338 phosphorylated sites in 2,263 proteins that changed in response to Girdin knockdown, and identified a similar set of Girdin-responsive acetylome data as well. Additional data revealed that down-regulation of Girdin affected Cortactin phosphorylation and acetylation, suggesting Cortactin as an important regulatory target of Girdin. Moreover, we found that overexpression of Cortactin could rescue the effect of shGirdin on proliferation, apoptosism, migration and invasion of pancreatic cancer cells. In general, our results provided new insights into the mechanisms of Girdin function including cell proliferation, migration and invasion, and offer biomarker candidates for clinical evaluation of Girdin.

Nucleocytoplasmic Trafficking of the Arabidopsis WD40 Repeat Protein XIW1 Regulates ABI5 Stability and Abscisic Acid Responses.

WD40 repeat-containing proteins (WD40 proteins) serve as versatile scaffolds for protein-protein interactions, modulating a variety of cellular processes such as plant stress and hormone responses. Here we report the identification of a WD40 protein, XIW1 (for XPO1-interacting WD40 protein 1), which positively regulates the abscisic acid (ABA) response in Arabidopsis. XIW1 is located in the cytoplasm and nucleus. We found that it interacts with the nuclear transport receptor XPO1 and is exported by XPO1 from the nucleus. Mutation of XIW1 reduces the induction of ABA-responsive genes and the accumulation of ABA Insensitive 5 (ABI5), causing mutant plants with ABA-insensitive phenotypes during seed germination and seedling growth, and decreased drought stress resistance. ABA treatment upregulates the expression of XIW1, and both ABA and abiotic stresses promote XIW1 accumulation in the nucleus, where it interacts with ABI5. Loss of XIW1 function results in rapid proteasomal degradation of ABI5. Taken together, these findings suggest that XIW1 is a nucleocytoplasmic shuttling protein and plays a positive role in ABA responses by interacting with and maintaining the stability of ABI5 in the nucleus.

Impact of leachate recirculation frequency on the conversion of carbon and nitrogen in a semi-aerobic bioreactor landfill.

To study the impact of leachate recirculation frequency on the transformation of carbon and nitrogen pollutants in a semi-aerobic bioreactor landfill (SABL), three laboratory-scale SABLs were investigated, each using a different leachate recirculation frequency (daily, once each 3 days, and once each 5 days). Results showed that degradation of total nitrogen (TN), ammonium nitrogen (NH4+-N), chemical oxygen demand (COD), and total organic carbon (TOC) could be described using a quadratic polynomial-compound index model. Degradation rates of TN, NH4+-N, COD, and TOC slightly increased from 0.01795, 0.01814, 0.01451, and 0.01166 day-1 to 0.02054, 0.01903, 0.01488, and 0.01203 day-1, respectively, when the recirculation frequency increased from once per 5 days to once per 3 days. When recirculation frequency was increased to daily, degradation rates of TN, NH4+-N, COD, and TOC significantly increased to 0.03698, 0.02718, 0.02479, and 0.02872 day-1, respectively. Moreover, when recirculation frequency increased from once per 5 days to once per 3 days, the gasification rate of nitrogenous and carbonaceous pollutants was enhanced between 20.38 and 8.17%, respectively. When the leachate recirculation rate further increased to daily, only a small amount of carbonaceous and nitrogenous pollutants was transformed to the liquid phase. Thus, increasing the leachate recirculation frequency in an SABL benefits the removal of carbonaceous and nitrogenous pollutants from the reactor. In addition, the greater is the recirculation frequency, the lower is the residual carbon and nitrogen in the solid phase, and the higher is the gasification rate. A proper recirculation frequency promotes the stabilization of landfill leachate. This study provides a theoretical reference and experimental evidence for accelerating the stabilization of MSW and contributes to the macro-control of landfills.

Development of microsatellite markers for a monotypic and globally endangered species, Glyptostrobus pensilis (Cupressaceae).

PREMISE OF THE STUDY: Microsatellite markers were developed to facilitate studies of genetic diversity and structure in Glyptostrobus pensilis, a critically endangered and monotypic conifer species. METHODS AND RESULTS: Using restriction site-associated DNA sequencing (RAD-Seq), we developed 10 polymorphic and 27 monomorphic microsatellite markers. Polymorphism was characterized using 333 individuals from nine populations. The number of alleles per locus ranged from one to 14 at the population level. The levels of observed and unbiased expected heterozygosities varied from 0.058 to 0.844 and 0.219 to 0.583, respectively. Nine of these 10 polymorphic markers were successfully cross-amplified in Taxodium distichum, the species most closely related to G. pensilis. CONCLUSIONS: These microsatellite markers can be used to reveal the genetic diversity in existing populations of G. pensilis, enabling its conservation and restoration.

Transformation and degradation mechanism of landfill leachates in a combined process of SAARB and ozonation.

Dissolved organic matter (DOM) in mature landfill leachate is significantly different from that in young landfill leachate; the composition of DOM greatly influences both biological treatment and advanced treatment processes. In the present study, the transformation and degradation mechanisms of landfill leachates in a combined semi-aerobic aged refuse biofilter (SAARB) and ozonation process was investigated using organic removal analysis, molecular weight distribution (MWD), 3D-EEM-PARAFAC analysis, UV-Vis spectroscopy, and linear regression. Results revealed that the DOM in mature landfill leachate contained a greater amount of aromatic substances and had higher molecular weight than DOM in young landfill leachate. After the SAARB process, humus contained in the SAARB was discharged with effluent from both mature and young landfill leachate. Due to the differences in composition and structure of organic matter, the COD removal efficiency (17.89%) of SAARB effluent from treating mature landfill leachate (mature SAARB effluent) was much lower than that (45.91%) of SAARB effluent from treating young landfill leachate (young SAARB effluent) under the same operational parameters of the ozonation process. As indicated by PARAFAC analysis, better chemical stability of DOM in mature SAARB effluent resulted in inferior ozone treatment efficiency. Furthermore, the hydrophobicity and the concentration of benzene ring compounds in the mature and young SAARB effluent were reduced significantly by the ozonation process. Therefore, great improvements in the biodegradability of SAARB effluents were achieved in the ozonation process. Overall, the results of this study provide suggestions and guidance for practical applications of these technologies.

Impact of landfill density on transport and hydraulic characteristics of recirculated leachate.

To achieve a uniform water distribution and to promote the stabilization of bioreactor landfills, the effects of different density on the transport and hydraulic characteristics of recirculated leachate were studied in a Li+ tracer experiment. The landfill density was related negatively to the maximum production rate of leachate, the percentage of Li+ tracer solution and the cumulative amount of Li+ that washed out in the first recirculation round. The cumulative amount of Li+ that was washed out accounted for 92.61%, 82.07% and 75.25% of the injection volume in three waste columns (1#, 2# and 3#) with landfill densities of 497.5, 726.4 and 970.1 kg m-3 at the thirtieth recirculation, respectively. The results revealed that a greater landfill density yielded a smaller amount of Li+ that was washed out per recirculation cycle and the cumulative amount of Li+ washed out, and a longer contact time between the waste and leachate. Moreover, waste columns 1#, 2# and 3# are reactors with a high dispersion and obvious retention zones, and their Morrill Dispersion Index (MDI) values were 25.00, 34.51 and 24.55, respectively. A short-flow phenomenon is obvious in the reactor with a low landfill density. Furthermore, the plug-flow effect is relatively better in the reactor with a high landfill density. To achieve a uniform distribution of recirculated leachate in the landfill, the MDI of the reactor should be reduced combined with other measures, such as pre-crushing and different recirculation schemes.

miR­27a promotes human breast cancer cell migration by inducing EMT in a FBXW7­dependent manner.

Increasingly, evidence has revealed that aberrant microRNA (miRNA) expression is involved in breast cancer carcinogenesis and further progression, including metastasis. miRNA (miR)­27a was previously identified to be abnormally expressed and to serve pro­oncogenic functions in multiple human cancer types, including breast cancer. However, its functions and underlying mechanisms in breast cancer remain poorly understood. In the present study, it was demonstrated that miR­27a was significantly upregulated in breast cancer tissues and cell lines compared with their normal counterparts. Overexpression of miR­27a resulted in enhanced cell migration by inducing epithelial­to­mesenchymal transition, while its knockdown effectively reversed these cellular events. The present study additionally confirmed for the first time, to the best of our knowledge, that F­box and WD repeat domain containing 7 (FBXW7) is a downstream target gene of miR­27a in human breast cancer cells. FBXW7 is underexpressed in breast cancer tissues and cell lines, and is an independent positive factor for the overall survival rate of patients with breast cancer. Notably, the ectopic expression of FBXW7 may effectively suppress the epithelial­to­mesenchymal transition and migratory activity of breast cancer cells, in addition to reversing the cell migration mediated by miR­27a. Altogether, the results of the present study indicated the important function of miR­27a in regulating the metastasis of breast cancer in a FBXW7­dependent manner, and provide evidence for the potential application of miR­27a in breast cancer therapy.

Transgenerational thyroid endocrine disruption induced by bisphenol S affects the early development of zebrafish offspring.

Maternal thyroid hormones (THs) play an essential role in the embryonic and larval development of fish. Previous studies in fish have reported that parental exposure to thyroid disrupting chemicals (TDCs) changed maternal TH levels in the offspring; however, whether this transgenerational thyroid endocrine disruption can further disturb the early development of the offspring still remains largely unknown. Bisphenol S (BPS), a substitute of bisphenol A, has been reported to be a potential TDC. In this study, zebrafish (F0) were exposed to environmentally relevant concentrations (1, 10, and 100 µg/L) of BPS from 2 h post-fertilization to 120 days post-fertilization and then paired to spawn. Plasma levels of thyroxine (T4) were significantly decreased in F0 females while 3,5,3'-triiodothyronine (T3) plasma levels were significantly increased in F0 females and males; moreover, TH content in eggs (F1) spawned by exposed F0 generation exhibited similar changes as the F0 females, with significant decreases in T4 and increases in T3, demonstrating BPS-induced maternal transfer of thyroid endocrine disruption. Further, excessive levels of maternal T3 in the offspring resulted in delayed embryonic development and hatching, swim bladder inflation defect, reduction in motility, developmental neurotoxicity, and lateral stripe hypopigmentation in non-exposed F1 embryos and larvae. These results highlight the adverse effects on the early development of offspring induced by transgenerational thyroid endocrine disruption, which have been ignored by previous studies. Therefore, these results can further improve our understanding of the ecological risks of TDCs.

Impairment of bisphenol F on the glucose metabolism of zebrafish larvae.

Bisphenol F (BPF) is a substitute of bisphenol A in the production of epoxy resin and polycarbonate. Its extensive use in consumer products leads to a wide human exposure at high levels. Although the adverse effects of BPF on animal health are of increasing public concern, its risks on systematic glucose metabolism and blood glucose concentrations still remain largely unknown. Using zebrafish larvae as the model animal, we investigated the disturbance of BPF exposure on glucose metabolism and the underlying mechanisms. Zebrafish larvae at 96 h post fertilization were exposed to 0.1, 1, 10, and 100 µg/L of BPF for 48 h. Compared with the control group, glucose levels of larvae increased significantly in the 10 and 100 µg/L exposure groups, which are associated with enhancement of gluconeogenesis and suppression of glycolysis induced by high doses of BPF. Additionally, both mRNA expressions and protein levels of insulin increased significantly in the 10 and 100 µg/L exposure groups, while transcription levels of genes encoding insulin receptor substrates decreased significantly in these groups, indicating a possibly decreased insulin sensitivity due to impairment of insulin signaling transduction downstream of insulin receptor. Further, compared with BPF alone, co-exposure of larvae to BPF and rosiglitazone, an insulin sensitizer, significantly attenuates increases in both glucose levels and mRNA expressions of a key gluconeogenesis enzyme. Our data therefore indicate impairing insulin signaling transduction may be the main mechanism through which BPF disrupts glucose metabolism and induces hyperglycemia. Results of the present study inform the health risk assessment of BPF and also suggest the use of zebrafish larvae in large-scale screening of chemicals with possible glucose metabolism disturbing effect.

Removal of refractory organic pollutants in reverse-osmosis concentrated leachate by Microwave-Fenton process.

A microwave-Fenton technology was applied to dispose of the reverse-osmosis concentrated leachate. Influential factors on the treatment of concentrated leachate with the pure Fenton and microwave-Fenton method were investigated. For the conventional Fenton process, the removal efficiencies of chemical oxygen demand (CODCr), UV254, and the color number (CN) reached 84%, 87%, and 96%, respectively, with the biodegradability (BOD5/CODCr) increased from 0.13 to 0.51 at an initial pH of 5.0, Fe2+ of 0.04 mol/L, a n(H2O2)/n(Fe2+) ratio of 8 after a reaction time of 3 h. When incorporating the Fenton process with microwave irradiation, a comparative CODCr and UV254, and the CN removal rate of 75%, 83%, and 95%, and a high BOD5/CODCr of 0.62 were achieved under a microwave power of 390 W and an extremely shortened reaction time of only 8 min. Meanwhile, sludge quantity showed a reduction of 24.7%, decreased from 8.50 g/L to 6.40 g/L after the participation of microwave. In addition, molecular-weight fraction (MWF), UV-visible spectrum (UV-vis), and 3D-EEM spectrum tests demonstrated that the macromolecular and complex organic compounds in the wastewater were significantly decomposed into small molecular matters. Our results found that microwave-Fenton is a promising technology for concentrated leachate treatment, with much shorter reaction time, lower sludge production, and enhanced biodegradability, as well as comparative organic matter removal performance.

Investigation of the characteristics of concentrated leachate from six municipal solid waste incineration power plants in China.

The characteristics of concentrated leachate in municipal solid waste (MSW) incineration power plants were analyzed for CODCr, BOD5, the concentration of heavy metals, and spectral characteristics of dissolved organic matter (DOM). We performed correlation-principal component analysis to analyze the data. The samples were collected from leachate treatment plants of six MSW incineration power plants in China, all of which have a typical treatment process. Our study showed that the samples have high content of organic matter with extremely low biodegradability, various heavy metals, and a large amount of negative ions such as Cl-, SO4 2- and PO4 3- in the concentrated leachate. The intense fluorescent absorption peaks in the visible and ultraviolet regions of the ultraviolet-visible spectra and three-dimensional fluorescence spectra suggest that the concentrated leachate contains a large amount of refractory organic matter mainly consisting of fulvic acid. The humification indexes (HIX) of samples ranged from 1.26 to 14.24 when the biodegradability indexes (BIX) ranged from 0.10 to 2.25. Correlation analysis revealed that the concentration of Cl-, PO4 3-, and NO3 - is significantly correlated with the property of the DOM, and the concentration of Ca, Cr, and SO4 2- almost has no correlation with other indicators in the concentrated leachate. The characteristics of the concentrated leachate are reflected by three principal components: PC1 is mainly related to the DOM, which is relatively stable and hardly degrades, this component may reflect the degradability and humification degree of the concentrated leachate. PC2 reflects the degradability of the concentrated leachate; a higher score in its positive direction indicates greater degradability of the concentrated leachate. PC3 has little influence on the characteristics of the concentrated leachate. This research can provide a theoretical basis for the effective treatment of concentrated leachate of MSW incineration power plants.