Potentially toxic elements in weathered waste-rocks of Fushun western opencast mine: distribution, source identification, and contamination assessment.

To understand the current status of the contamination of potentially toxic elements (PTEs) after closing the Fushun Western Opencast Mine, this study has focused on the concentration, contamination assessment, and source identification of eight PTEs in weathered waste-rocks in four distinct areas of the mine. The mean concentrations of Ni, Cr, Zn, Cu, Pb, Hg, Cd, and As were 79.4, 86.3, 126, 64.8, 16.9, 1.04, 1.94, and 6.27 mg kg-1, respectively. The results demonstrated that Ni, Cr, Zn, Cu, Pb, Hg, Cd, and As were contaminated to different extents in different weathered waste-rocks and waste-rocks, among which there was considerable Cd contamination. Coal gangue area (CGA) exhibited the most polluted weathered waste-rocks, which can be attributed to severe pollution and moderate ecological hazards. Self-combustion gangue (SCG) contamination of waste-rocks was considerably serious and caused severe pollution and considerable ecological harm. Health risk assessments demonstrated that Hg had the highest non-carcinogenic risk. Ingestion of PTEs was found to be a primary route of exposure, while dermal and inhalation exposure was negligible. Principal component analysis (PCA) demonstrated that there were roughly three sources of PTEs in the weathered waste-rocks of the mine, natural sources related to the weathering of parent rocks, and human sources, including industrial emissions, mining activities, and atmospheric dust deposition and resuspension. This study advances our knowledge of PTEs in mines and provides policymakers with a reference for designing strategies to protect mine-based ecosystems.

Atomic Modulation Triggering Improved Performance of MoO3 Nanobelts for Fiber-Shaped Supercapacitors.

Asymmetric supercapacitors (ASCs) are emerging as a new class of energy storage devices that could potentially meet the increasing power and energy demand for next-generation portable and flexible electronics. Yet, the energy density of ASC is severely limited by the low capacitance of the anode side, which commonly uses the carbon-based nanomaterials. Here, the demonstration of sulfur-doped MoO3- x nanobelts (denoted as S-MoO3- x ) as the anode for high-performance fiber-shaped ASC are reported. The Mo sites in MoO3 are intentionally modulated at the atomic level through sulfur doping, where sulfur could be introduced into the MoO6 octahedron to intrinsically tune the covalency character of bonds around Mo sites and thus boost the charge storage kinetics of S-MoO3- x . Moreover, the oxygen defects are occurring along with sulfur-doping in MoO3 , enabling efficient electron transport. As expected, the fiber-shaped S-MoO3- x achieves outstanding capacitance with good rate capability and long cycling life. More impressively, the fiber-shaped ASC based on S-MoO3- x anode delivers extremely high volumetric capacitance of 6.19 F cm-3 at 0.5 mA cm-1 , which makes it promising as one of the most attractive candidates of anode materials for high-performance fiber-shaped ASCs.

Preparation of a novel CSM@ZIF-67 composite microsphere to facilitate Congo red adsorption from dyeing wastewater.

ABSTRACTChitosan (CS) is commonly used as an adsorbent for wastewater treatment because of its low cost, strong adsorption properties, and high availability of raw materials required for its production. However, CS exhibits limited adaptability to pH, poor mechanical properties, and high swelling in aqueous media; these limitations restrict its widespread use. To address these issues, herein, zeolitic imidazolate framework-67 (ZIF-67) is loaded onto crosslinked CS microspheres (CSM) to prepare CSM@ZIF-67, a composite adsorbent. Next, the CSM@ZIF-67 is applied to the treatment of Congo red (CR) dye, which is typically present in printing and dyeing wastewater. The results demonstrate that the in situ synthesis of metal-organic frameworks (MOFs) on CSM improve the dispersion of MOFs and preserve the morphology of the MOFs. The adsorption equilibrium of CSM@ZIF-67 is reached within 150 min, and its adsorption capacity is as high as 538.4 mg/g at a pH of 9 and temperature of 25 °C. The CR adsorption process is consistent with the pseudo-second-order kinetic and Langmuir isotherm models, thus revealing that chemisorption is the primary rate-limiting step, and the pollutants are adsorbed on the adsorbent surface in a monolayer. Experiments on material cycling and regeneration performance reveal that the removal efficiency of CSM@ZIF-67 remains above 90%, even after five rounds of adsorption. CSM@ZIF-67 has abundant functional groups and adsorption sites and can efficiently remove CR through mutual interactions between the metal coordination effect, π-π conjugation, hydrogen bonding, and electrostatic interactions.

Single modular flow-electrode capacitive deionization using modified Prussian blue analogues as cation intercalation electrode for continuous water desalination.

Ion back-diffusion hinders the practical application of conventional flow-electrode capacitive deionization (FCDI) under long-term operational conditions. To address this challenge, the present study integrated cation intercalation deionization (CID) with FCDI. A novel PFCDI-CID system was developed by utilizing a modified Prussian blue analogues owing to their enhanced rheological and electrochemical properties. The PFCDI-CID system achieved a high charge efficiency of 89.77% and an energy-normalized removal salt of 0.69 mol kJ-1 in single-cycle (SC) mode with the flow electrodes mass fraction of 2% and a desalinized water chamber-to-concentrated saline water chamber ratio of 2:1. Furthermore, under continuous operation for 12 h in SC mode, the PFCDI-CID system maintained stable desalination performance within the first 2 h. Over an extended duration, the average charge efficiency of the PFCDI-CID system was maintained at 88.44%, with an average energy-normalized removal salt of 0.65 mol kJ-1. The mechanism revealed that the desalination process involving the Prussian blue analogues primarily involves Na+ intercalation, accompanied by a small amount of electro-sorption process. This system exhibits the characteristics of conventional FCDI while enabling desalination and concentration of simulated saline water during brine discharge, thereby mitigating the impact of ion back-diffusion and broadening the application scope of FCDI.

A novel quantitative method for the determination of 10B-carrier boronophenylalanine in rat plasma by UHPLC-MS/MS and comparison with ICP-MS.

L-Boronophenylalanine (BPA), a widely used 10B carrier for clinical boron neutron capture therapy (BNCT), was quantified in rat plasma through a simple, effective and stable ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method. Chromatographic separation was performed on an ACQUITY UPLC HSS T3 (100 mm × 2.1 mm, 1.8 µm) column with the mobile phase of 0.5 % formic acid aqueous solution and acetonitrile. For the detector, the m/z ion pairs used for quantification were 209.1→120.1 for BPA and 210.1→120.1 for internal standard in a positive mode by electrospray ionization (ESI) using multiple reaction monitoring (MRM). The method is specific and robust with rare affection by endogenous substances in the matrix. A good linear relationship was observed over 80-80000 ng/mL (r2 = 0.9993). The values of inter- and intra-day accuracy and precision were within the acceptance criteria of ±15 %. BPA was found to be stable under different experimental conditions. This developed method was successfully applied on a pharmacokinetic experiment on Sprague-Dawley rats (intravenous injection, 125 mg/kg) and a comparation between UHPLC-MS/MS and ICP-MS for BPA was carried out.

Enhancement of humic acid on plant growth in a Cd-contaminated matrix: performance, kinetics, and mechanism.

Phytoremediation of heavy metal-contaminated sites has been widely used. Nonetheless, the destruction of chloroplasts and plant growth enzymes by heavy metals leads to a low germination rate and high mortality of plants. To address these issues, an experiment was conducted in which plants were grown with (SHC) and without humic acid (SC) in actual Cd-contaminated soil from the site of an industrial pollution source. The results showed that the average germination rates of SC and SHC samples were 94.17% and 98.33%, respectively, and the plant heights were approximately 5 and 7 cm after 42 days of planting, respectively. It was discovered that humic acid (HA) enhanced plant growth by increasing urease and invertase content of the soil. The Shannon index and Venn diagram revealed that SHC had the richer population diversity. High-throughput analysis demonstrated that HA increased the content of plant growth-promoting bacteria in the soil from 5.01 to 34.27%. The experimental results revealed that HA increased microbial activity and diversity, thereby providing a favorable environment for plants to thrive. This study develops an effective method to enhance the phytoremediation performance of heavy metal-contaminated soils.

From micro to macro: The role of seawater in maintaining structural integrity and bioactivity of granules in treating antibiotic-laden mariculture wastewater.

Granular sludge (GS) has superior antibiotic removal ability to flocs, due to GS's layered structure and rich extracellular polymeric substances. However, prolonged exposure to antibiotics degrades the performance and stability of GS. This study investigated how a seawater matrix might help maintain the structural integrity and bioactivity of granules. The results demonstrated that GS had better sulfadiazine (SDZ) removal efficiency in a seawater matrix (85.6 %) than in a freshwater matrix (57.6 %); the multiple ions in seawater enhanced boundary layer diffusion (kiR1 = 0.0805 mg·g-1·min-1/2 and kiR2 = 0.1112 mg·g-1·min-1/2) and improved adsorption performance by 15 % (0.123 mg/g-SS freshwater vs. 0.141 mg/g-SS seawater). Moreover, multiple hydrogen bonds (1-3) formed between each SDZ and lipid bilayer fortified the adsorption. Beyond S-N and S-C bond hydrolyses that took place in freshwater systems, there was an additional biodegradation pathway for GS to be cultivated in a saltwater system that involved sulfur dioxide extrusion. This additional pathway was attributable to the greater microbial diversity and larger presence of sulfadiazine-degrading bacteria containing SadAC genes, such as Leucobacter and Arthrobacter, in saltwater wastewater. The findings of this study elucidate how seawater influences GS properties and antibiotic removal ability.

Achieving tetracycline removal enhancement with granules in marine matrices: Performance, adaptation, and mechanism studies.

Using the aerobic granular sludge (AGS) to improve tetracycline (TET) removal in the treatment of mariculture wastewater was investigated in the present study. The AGS rapidly adapted to and was sustained in seawater matrices with a robust granule strength (k = 0.0014) and a more stable sludge yield than the activated sludge (AS) (0.14 vs 0.11 g-VSS/g-CODrem). The compact structure provided the AGS with an anoxic environment, which favored the growth of N (37.3 %) and P removal bacteria (30.4 %) and the expression of functional genes (nos, nor, and nar), resulting in more than 62 % TN and TP removals, respectively. Similar abundances of aromatic compound-degrading bacteria (∼34 %) in both reactors (AGS and AS) led to comparable TET biodegradation efficiencies (∼0.045 mg/g-VSS). The greater size and surface area of the AGS expanded the boundary layer diffusion region, leading to 16 % increases in the granule's TET adsorption capacity.

Enhancement strategies of aerobic denitrification for efficient nitrogen removal from low carbon-to-nitrogen ratio shale oil wastewater.

The strategy of high reflux ratio and long solids retention time was adopted to realize efficient nitrogen removal from real shale oil wastewater. This was undertaken with a low chemical oxygen demand to total nitrogen (COD/TN) ratio by strengthening aerobic denitrification in an anoxic/aerobic membrane bioreactor (A/O-MBR). The TN removal load climbed from 22 to 25 g N/(kg MLSS·d) as the COD/TN ratio declined from 8 to 3. The abundance of heterotrophic nitrifying and aerobic denitrifying (HNAD) bacteria increased by 13.8 times to 42.5%, displacing anoxic denitrifying bacteria as the predominant bacteria. The abundance of genes involved in denitrification (napAB, narGHI, norBC, nosZ) increased, however the genes related to assimilatory nitrate reduction (nirA, narB, nasC) decreased. The capacity of the dominant HNAD bacteria in an A/O-MBR to efficiently utilize a carbon source is the key to efficient nitrogen removal from shale oil wastewater with a low COD/TN ratio.

Sensitive electrochemiluminescence detection of c-Myc mRNA in breast cancer cells on a wireless bipolar electrode.

We report an ultrasensitive wireless electrochemiluminescence (ECL) protocol for the detection of a nucleic acid target in tumor cells on an indium tin oxide bipolar electrode (BPE) in a poly(dimethylsiloxane) microchannel. The approach is based on the modification of the anodic pole of the BPE with antisense DNA as the recognition element, Ru(bpy)(3)(2+)-conjugated silica nanoparticles (RuSi@Ru(bpy)(3)(2+)) as the signal amplification tag, and reporter DNA as a reference standard. It employs the hybridization-induced changes of RuSi@Ru(bpy)(3)(2+) ECL efficiency for the specific detection of reporter DNA released from tumor cells. Prior to ECL detection, tumor cells are transfected with CdSe@ZnS quantum dot (QD)-antisense DNA/reporter DNA conjugates. Upon the selective binding of antisense DNA probes to intracellular target mRNA, reporter DNA will be released from the QDs, which indicates the amount of the target mRNA. The proof of concept is demonstrated using a proto-oncogene c-Myc mRNA in MCF-7 cells (breast cancer cell line) as a model target. The wireless ECL biosensor exhibited excellent ECL signals which showed a good linear range over 2 × 10(-16) to 1 × 10(-11) M toward the reporter DNA detection and could accurately quantify c-Myc mRNA copy numbers in living cells. C-Myc mRNA in each MCF-7 cell and LO2 cell was estimated to be 2203 and 13 copies, respectively. This wireless ECL strategy provides great promise in a miniaturized device and may facilitate the achievement of point of care testing.

Removal of tetracycline by aerobic granular sludge from marine aquaculture wastewater: A molecular dynamics investigation.

Although biological treatment of marine aquaculture wastewater is promising, the fundamental principles driving the adsorption of tetracycline to microbial cell membrane are not well understood. Using a combination of experiments and molecular dynamics (MD) simulations, the mechanism underlying the biological removal of tetracycline from seawater was investigated. More than 90% tetracycline removal was achieved in an aerobic granular sludge system, with degradation accounting for 30% of total removal. A model of the tetracycline-dipalmitoylphosphatidylcholine lipid bilayers was established to elucidate the transport mechanism of tetracycline from bulk solution to microorganisms' cell membrane. 62% of the driving force for tetracycline adsorption on the cell membrane originated from electrostatic attraction. The electrophilic groups on tetracycline (amino and aromatic groups) were attracted to the phosphate groups in the cell membrane. Sodium ions, which are abundant in seawater, decreased the interaction energy between tetracycline and the cell membrane.

Can a compact biological system be used for real hydraulic fracturing wastewater treatment?

Hydraulic fracturing wastewater (HFW), a byproduct of hydraulic fracturing oil extraction, contains a complex mixture of oil, aldehydes, and benzene compounds. Efficient and eco-friendly HFW treatment means are critical for the oil extraction industry, particularly in developing countries. In this study, two biological processes namely an anaerobic/anoxic/moving bed biofilm reactor (A2-MBBR) and an A2-MBBR with a microfiltration membrane (A2-MFMBBR) were established, and assessed for the real HFW treatment. Removal efficiencies of chemical oxygen demand (COD) and NH4+-N were over 92% and 95%, respectively, in both processes with a hydraulic retention time of 72 h. The majority of organic compounds in both systems identified by GC-MS were degraded in the anaerobic units. In comparison, A2-MFMBBR demonstrated higher removal efficiencies for oil, total suspended solids, and complex compounds. The average relative abundances of refractory compound degrading bacteria were 43.4% and 51.6% in the A2-MBBR and A2-MFMBBR, respectively, which was consistent with the COD and oil removal, and suggested that the MBR could maintain a high diversity of microorganisms and contribute to deep recalcitrant organics degradation. This study sheds light on the potential of using a compact biological process for the real HFW treatment.

Toxicity assessment of nine types of decoction pieces from the daughter root of Aconitum carmichaeli (Fuzi) based on the chemical analysis of their diester diterpenoid alkaloids.

Various processed types of FUZI (the daughter roots of the highly toxic plant Aconitum carmichaeli Debx, FZ) decoction pieces (the herbal materials processed according to the specifications of Chinese medicine manuals; " YINPIAN" in Chinese transliteration) are widely used in traditional medicine to treat various diseases, but their toxicities are not known. Nine types of FZ decoction pieces, including one raw slice and eight processed forms, were therefore prepared, each in 7 to 10 batches, to assess for their toxicity. Altogether 84 FZ samples were quantified on the amount of highly toxic diester diterpenoid alkaloids, i.e., aconitine, mesaconitine and hypaconitine by a newly developed HPLC method with HPLC-DAD and LC-MS techniques. The comparison of the processed FZ to raw slices of the root showed that the amount of each analyte in the processed FZ was drastically decreased. The sum of the three toxic compounds in the 8 types of processed FZ was only 3.91-34.80 % of this value in the FZ raw slice. This implies that the toxicity of processed FZ was decreased significantly. The amounts of toxic components in the 8 types of processed FZ varied significantly, often by a power of ten, indicating that the dosage of these herbs, when prescribed for clinical uses, should be cautiously set in order to avoid poisoning incidents.

Determination of sophoricoside in rat plasma by HPLC and its application to pharmacokinetic studies.

A simple, sensitive, selective and reproducible reversed-phase HPLC method was developed for the determination of sophoricoside in rat plasma after intravenous administration. Naringin was successfully used as internal standard (IS) for calibration. The chromatographic separation was accomplished on a reversed-phase C(18) column using acetonitrile-methanol-0.08% phosphoric acid (8:29:63, v/v/v) as mobile phase with a flow rate of 1.0 ml/min, with UV detection at 260 nm. Plasma samples were injected into the HPLC system after precipitating protein directly by methanol. Good linearity was achieved in the range of 0.0240 approximately 48.0 microg/ml (R(2)=0.9989). The limit of detection (LOD) and limit of quantification (LOQ) of this method were 0.0075 microg/ml and 0.0240 microg/ml, respectively. The absolute recoveries of sophoricoside from plasma were 95.8%, 93.2%, 98.0% at concentrations of 0.0240, 1.92, 15.0 microg/ml. The intra-day and inter-day variabilities were 3.39%~5.78% and 2.17%~4.72%, respectively. The developed method was successfully applied to the pharmacokinetic study of sophoricoside after intravenous administration of 2.5, 10 and 20 mg/kg in rats.

Effects of a pulsed electric field on nitrogen removal through the ANAMMOX process at room temperature.

This study explored the effect of a pulsed electric field (PEF) on the anaerobic ammonium oxidation (ANAMMOX) process at room temperature (20 ±â€¯1 °C). The influences of different modes of PEF (R1), a direct current electric field (R2) and a control reactor (R3) were determined through long-term tests. The results showed that R1 shortened the start-up time and led to excellent nitrogen removal. At this stage, the activities of key enzymes of R1 were much higher than those of R3. The high-throughput sequencing results showed that the relative abundance of functional bacteria in R1 was higher than that in R2 and R3. The mechanism by which the PEF enhanced ANAMMOX might be the improvement of the speed of ion and molecular migration that occurred by changing the permeability of the cell membrane under the PEF.

Optimization and validation of a chromatographic method for the simultaneous quantification of six bioactive compounds in Rhizoma et Radix Polygoni Cuspidati.

A reverse-phase HPLC method was developed for simultaneous quantification of six bioactive compounds in Rhizoma et Radix Polygoni Cuspidati. These compounds--polydatin (1), resveratrol (2), rhein (3), emodin (4), chrysophanol (5) and physcion (6)--were analysed from 24 authentic samples of the herb using UV HPLC. Based on the UV absorption characteristics of the six compounds, absorption wavelengths of 306 nm were chosen to quantify compounds 1 and 2, and 290 nm for compounds 3-6. A reliable and reproducible quantitative HPLC method for analysing authentic samples of Rhizoma et Radix Polygoni Cuspidati from different cultivation regions was developed. The results showed that the concentration of compound 1 in samples from Sichuan was almost 2 fold higher than that of samples acquired in Guangxi. Furthermore, compounds 3 and 5 were not found in all the samples tested. Thus, instead of using polydatin (1) and emodin (4) as markers for quality assessment, as in conventional practice, these findings show that compounds 2 and 6 are more suited to act as marker compounds for a more specific assessment of the quality of this herb.

Research on the enhancement of biological nitrogen removal at low temperatures from ammonium-rich wastewater by the bio-electrocoagulation technology in lab-scale systems, pilot-scale systems and a full-scale industrial wastewater treatment plant.

In cold areas, nitrogen removal performance of wastewater treatment plants (WWTP) declines greatly in winter. This paper systematically describes the enhancement effect of a periodic reverse electrocoagulation technology on biological nitrogen removal at low temperatures. The study showed that in the lab-scale systems, the electrocoagulation technology improved the biomass amount, enzyme activity and the amount of nitrogen removal bacteria (Nitrosomonas, Nitrobacter, Paracoccus, Thauera and Enterobacter). This enhanced nitrification and denitrification of activated sludge at low temperatures. In the pilot-scale systems, the electrocoagulation technology increased the relative abundance of cold-adapted microorganisms (Luteimonas and Trueperaceae) at low temperatures. In a full-scale industrial WWTP, comparison of data from winter 2015 and winter 2016 showed that effluent chemical oxygen demand (COD), NH4+-N, and NO3--N reduced by 10.37, 3.84, and 136.43 t, respectively, throughout the winter, after installation of electrocoagulation devices. These results suggest that the electrocoagulation technology is able to improve the performance of activated sludge under low-temperature conditions. This technology provides a new way for upgrading of the performance of WWTPs in cold areas.

Performance and microbial community analysis of bio-electrocoagulation on simultaneous nitrification and denitrification in submerged membrane bioreactor at limited dissolved oxygen.

A pair of Fe-C electrodes was installed in a traditional submerged membrane bioreactor (MBR, Rc), and a novel asynchronous periodic reversal bio-electrocoagulation system (Re) was developed. The simultaneous nitrification and denitrification (SND) performance was discussed under limited dissolved oxygen (DO). Results showed that electrocoagulation enhanced total nitrogen (TN) removal from 59.48% to 75.09% at 1.2 mg/L DO. Additionally, Fe electrode could increase sludge concentration, particle size, and enzyme activities related to nitrogen removal. The enzyme activities of Hydroxylamine oxidoreductase (HAO), Nitrate Reductase (NAR), nitric oxide reductase NOR and nitrous oxide reductase (N2OR) in Re were 38.35%, 21.59%, 89.96% and 38.64% higher than Rc, respectively. Moreover, electrocoagulation was advantageous for nitrite accumulation, indicating partial nitrification and denitrification were more easily achieved in Re. Besides, results from high throughput sequencing analysis revealed that electrocoagulation increased the relative abundance of most genera related to nitrogen removal, including Nitrosomonas, Comamonadaceae_unclassified, Haliangium and Denitratisoma.

Influence of electric field and iron on the denitrification process from nitrogen-rich wastewater in a periodic reversal bio-electrocoagulation system.

This study proposed a periodic reversal bio-electrocoagulation system (PRBES) with Fe-C electrodes and three other control systems and explored their denitrification mechanism. The experimental results illustrated that iron ions contributed to increasing biomass and denitrifying bacteria and that the electric field may enhance the nitrogen transfer rate and enzyme activities. The dominant bacterial genera in the four systems were the Enterobacter (32.75%), Thauera (9.29%), Paracoccus (8.54%), Hyphomicrobium (5.01%) and Saccharibacteria_genera (10.57%). The sum of the relative abundance of the first four bacteria, which were the major microorganisms in the denitrification process in this study, was 64.61%, 55.40%, 61.19% and 47.08%, respectively, in PRBES and the three other control systems at 10 °C. Additionally, compared to the conventional SBR, there was a 65.48% decrease in N2O in PRBES at 10 °C. This study provided a meaningful and significant understanding of denitrification in PRBES when treating nitrogen-rich wastewater.

[Determination of 63 compounds illegally added in tea, substitute tea and beverage foods by ultra-high performance liquid chromatography-tandem mass spectrometry].

A method based on ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of 63 compounds illegally added in tea, substitute tea, and beverage products. The samples were extracted by ultrasonic extraction using methanol, and the analytes were separated on the Thermo Acclaim RSLC C18 chromatographic column (100 mm×2.1 mm, 2.2 µm) by gradient elution using 5 mmol/L ammonium formate solution containing 0.1% (v/v) formic acid and 0.1% (v/v) formic acid acetonitrile as the mobile phase. The electrospray ion source was operated in the positive ion mode using the dynamic multi-reaction monitoring (dMRM) method, and the results were quantified by the external standard method. The correlation coefficients (R2) of the linear calibration curves were greater than 0.99 in the corresponding mass concentration ranges, and the limits of quantification (LOQs) for the analytes were 0.10-2.50 mg/kg. The average recoveries at three spiked levels ranged from 62.4% to 129.4%. The RSDs of the injection precision and the repeatability of samples were in the range 0.3%-9.6% (n=6). Thus, the proposed method is simple, rapid, accurate, reliable, and applicable for the detection of the illegal addition of antipyretic and analgesic affect compounds in tea, substitute tea and beverage food.