Phosphorus recovery from phosphate tailings through a two-stage leaching-precipitation process: Toward the harmless and reduction treatment of P-bearing wastes.

To achieve highly efficient extraction of phosphorus (P) and comprehensive utilization of phosphate tailings, a two-stage leaching-precipitation method was proposed. Phosphate tailings primarily consisted of dolomite, fluorapatite, and quartz. During the first-stage leaching, the large majority of dolomite was selectively dissolved and the leaching efficiency of Mg reached 93.1 % at pH 2.0 and 60 °C. The subsequent second-stage leaching of fluorapatite was performed and the P leaching efficiency was 98.8 % at pH 1.5 and 20 °C, while the quartz remained in the residue. Through two-stage leaching, a stepwise leaching of dolomite and fluorapatite was achieved. After chemical precipitation, calcium phosphate with a high purity of 97.9 % was obtained; and the total recovery efficiency of P exceeded 98 %. The obtained calcium phosphate can be a raw material in the phosphorus chemical industry, while the Mg-rich leachate and the final quartz-rich residue have the potential for Mg extraction and the production of mortars or geopolymers, respectively. The two-stage leaching-precipitation process could significantly reduce the leaching costs, and enhance the reaction rates. It is expected to realize a volume reduction and efficient resource utilization of the phosphate tailings by using this sustainable and promising solution.

The association between waist-to-height ratio and cognitive function in older adults.

OBJECTIVES: The waist-to-height ratio (WHtR) is a simple, practical, and effective tool used to assess central obesity. Despite its usefulness, few studies have investigated the association between WHtR and cognitive function among older adults in the United States. This study aims to investigate the associations between WHtR and cognitive function. METHODS: The study sample comprised adults who participated in the National Health and Nutrition Examination Survey (NHANES) between 2011 and 2014. WHtR was calculated from measured waist circumference and height. Cognitive function was assessed using the digit symbol substitution test. A weighted multiple linear regression analysis was performed to evaluate the association between WHtR and cognitive function, with smooth curve fitting applied to detect non-linearities. RESULTS: Our analysis included 1709 participants over the age of 65. After adjusting for potential confounders, WHtR was found to have a negative association with cognitive function (ß = -36.91, 95% CI: -54.54 to -19.29, P < 0.001). Subgroup analyzes stratified by sex and race showed that the negative correlation of WHtR with cognitive function remained in both men and women, as well as in non-Hispanic white and other races. Among women, the association between WHtR and cognitive function followed an inverted U-shaped curve, with an inflection point of 0.68. CONCLUSION: This study provides evidence of a negative association between WHtR and cognitive function in older adults. These findings suggest that in advanced age, central obesity may have negative implications for cognitive function.

Stereoelectroencephalography-guided radiofrequency thermocoagulation of the epileptogenic zone: a potential treatment and prognostic indicator for subsequent excision surgery.

PURPOSE: To evaluate the safety and efficacy of stereoelectroencephalography (SEEG)-guided radiofrequency thermocoagulation (RFTC) for drug-resistant focal epilepsy and investigate the relationship between post-RFTC remission duration and delayed excision surgery effectiveness. METHODS: We conducted a retrospective analysis of 43 patients with drug-resistant focal epilepsy who underwent RFTC via SEEG electrodes. After excluding three, the remaining 40 were classified into subgroups based on procedures and outcomes. Twenty-four patients (60%) underwent a secondary excision surgery. We determined the predictive value of RFTC outcome upon subsequent surgical outcome by categorizing the delayed secondary surgery outcome as success (Engel I/II) versus failure (Engel III/IV). Demographic information, epilepsy characteristics, and the duration of seizure freedom after RFTC were assessed. RESULTS: Among 40 patients, 20% achieved Engel class I with RFTC alone, while 24 underwent delayed secondary excision surgery. Overall, 41.7% attained Engel class I, with a 66.7% success rate combining RFTC with delayed surgery. Seizure freedom duration was significantly longer in the success group (mean 4.9 months, SD = 2.7) versus the failure group (mean 1.9 months, SD = 1.1; P = 0.007). A higher proportion of RFTC-only and delayed surgical success group patients had preoperative lesional findings (p = 0.01), correlating with a longer time to seizure recurrence (p < 0.05). Transient postoperative complications occurred in 10%, resolving within a year. CONCLUSION: This study demonstrates that SEEG-guided RFTC is a safe and potential treatment option for patients with drug-resistant focal epilepsy. A prolonged duration of seizure freedom following RFTC may serve as a predictive marker for the success of subsequent excision surgery.

Leaching of phosphorus from phosphate tailings and extraction of calcium phosphates: Toward comprehensive utilization of tailing resources.

Phosphate tailing is an extremely fine by-product during phosphate ore flotation. Due to the large quantities and relatively higher P2O5 content, the phosphate tailings have been considered as a potential P resource, compared to other P-bearing wastes. Besides, phosphate tailings also contain a large amount of available components, such as Ca, Mg, and Si. To explore a low-cost and efficient process for the utilization of phosphate tailings, the hydrochloric acid leaching-precipitation method was employed to recover phosphorus. The P in phosphate tailings can be selectively dissolved into leaching liquor, followed by the precipitation of calcium phosphates from the leaching liquor through pH adjustment. The results showed that P was predominantly concentrated in fluorapatite and its dissolution ratio increased with the decrease in pH. At pH 1.0, the P dissolution efficiency from phosphate tailings reached 96.3%, along with the majority of Mg and Ca. However, Si was hardly dissolved. It demonstrated that almost all the fluorapatite and dolomite were dissolved while the quartz was difficult to dissolve. Dolomite was more preferentially dissolved than fluorapatite. Increasing temperature contributed to the dissolution of dolomite while suppressing fluorapatite dissolution. The residue containing 87.9% SiO2 (quartz) and only 0.25% P2O5 has the potential as a building material. As the pH increased to 7.0, the collected precipitate consisted of 34.18% P2O5 and 56.10% CaO, which can serve as a source of a slow-released phosphate fertilizer. The highly efficient utilization of phosphate tailings was achieved via this process.

Topological edge states controlled by next-nearest-neighbor coupling and Peierls phase in a P T-symmetric trimerized lattice.

We study the topological features in a trimerized lattice of parity-time symmetry with comparable nearest-neighbor (NN) and next-nearest-neighbor (NNN) couplings as well as a Peierls phase. Eigen energies of four edge states in two bandgaps, of topological origin verified by the quantized total Zak phase, are surprisingly independent of the NNN coupling and the Peierls phase. Topological regions with respect to the intercell NN coupling, as the intracell NN coupling is fixed, can be extended with reinforced localization strengths for one pair of edge states but reduced with weakened localization strengths for the other pair of edge states, by increasing the NNN coupling. The partial overlapping between extended and reduced topological regions promises then a two-step phase transition of 'zero - two - four' edge states, viable to be periodically modulated by the Peierls phase.

N-Fluorobenzenesulfonimide as a highly effective Ag(i)-catalyst attenuator for tryptamine-derived ynesulfonamide cycloisomerization.

N-Fluorobenzenesulfonimide (NFSI) was identified for the first time as a highly effective Ag(i)-catalyst attenuator in the annulation of a tryptamine-derived ynesulfonamide to azepino[4,5-b]indole derivatives. Substrate tolerances were examined thoroughly and a plausible mechanism was proposed. The interaction between the Ag(i) catalyst and NFSI was probed by density functional theory (DFT) calculations. This study provided a highly efficient method to synthesize azepino[4,5-b]indole derivatives.

A Monte Carlo model for self-assembly of polytetrafluoroethylene nanoparticle films via repulsive electrostatic interactions.

Self-assembly of polytetrafluoroethylene (PTFE) nanoparticle films on an aluminum alloy substrate under repulsive electrostatic interactions has been achieved experimentally. However, a theoretical framework which is able to accurately predict the self-assembly kinetics based on their underlying mechanisms is not yet available. In this work, we formulate a Monte Carlo model to make predictions on the formation of close-packed monolayer and multilayer PTFE nanoparticle films during repulsive electrostatic self-assembly. In the model, the parameters are obtained from experimental measurements. Our simulation results demonstrate that the layer number of close-packed PTFE nanoparticle films on the aluminum alloy substrate increases with an increase of nanoparticle concentration and an increase of deposition time, which match well with the experimental observations. Beyond this, the underlying mechanism in which the close-packed PTFE nanoparticle film cannot be formed on the Cu substrate was also revealed, which is attributed to the decrease of the substrate repulsive interaction. Hence, the present work not only unveils the self-assembly kinetics of nanoparticle films, but also provides useful guidelines to controllable self-assembly of nanoparticle films with a desired number of layers.

Lewis Acid Assisted Electrophilic Fluorine-Catalyzed Pinacol Rearrangement of Hydrobenzoin Substrates: One-Pot Synthesis of (±)-Latifine and (±)-Cherylline.

A microwave-irradiated solvent-free pinacol rearrangement of hydrobenzoin substrates catalyzed by a combination of N-fluorobenzenesulfonimide and FeCl3·6H2O was developed. Its selectivity was first investigated by density functional theory (DFT) calculations. Then the functional group tolerance was examined by synthesizing a series of substrates designed based on the insight provided by the DFT calculations. The application of the methodology was demonstrated by the efficient one-pot synthesis of (±)-latifine and (±)-cherylline, both are 4-aryltetrahydroisoquinoline alkaloids isolated from Amaryllidacecae plants.

Thymol inhibits bladder cancer cell proliferation via inducing cell cycle arrest and apoptosis.

Thymol is a phenolic compound with various pharmacological activities such as anti-inflammatory, anti-bacterial and anti-tumor effects. However, the effect of thymol on bladder cancer cell growth is still elusive. The purpose of this study is to investigate the efficacy of thymol in bladder cancer cells and its underlying mechanism. Thymol inhibited bladder cancer cell proliferation in a dose and time-dependent manner. We also observed cell cycle arrest at the G2/M phase after the treatment of thymol. Moreover, thymol could induce apoptosis in bladder cancer cells via the intrinsic pathway along with caspase-3/9 activation, release of cytochrome c and down-regulation of anti-apoptotic Bcl-2 family proteins. The activation of JNK and p38 was also critical for thymol-induced apoptosis since it was abrogated by the treatment of JNK inhibitor (SP600125), and p38 inhibitor (SB203580) but not ERK inhibitor (SCH772984). Furthermore, the generation of ROS (reactive oxygen species) was detected after the treatment of thymol. ROS scavenger NAC (N-acetyl cysteine) could block the thymol-triggered apoptosis and activation of MAPKs. These findings offer a novel therapeutic approach for bladder cancer.

Collective Syntheses of 2-(3-Methylbenzofuran-2-yl)phenol-Derived Natural Products by a Cascade [3,3]-Sigmatropic Rearrangement/Aromatization Strategy.

A cascade [3,3]-sigmatropic rearrangement/aromatization strategy to the synthesis of 2-(3-methylbenzofuran-2-yl)phenol derivatives was developed and applied to the collective syntheses of seven 2-arylbenzofuran-containing natural products, namely glycybenzofuran, glycyuralin E, lespedezol A1, puerariafuran, 7,2',4'-trihydroxy-3-benzofurancarboxylic acid, coumestrol, and 4'-O-methylcoumestrol. Among them, the total syntheses of glycybenzofuran, glycyuralin E, puerariafuran, 7,2',4'-trihydroxy-3-benzofurancarboxylic acid, and 4'-O-methylcoumestrol were reported for the first time. The practicality of this novel strategy in preparation of the key intermediates was demonstrated by performing the reaction on gram scale and by synthesizing a series of natural products with 2-(3-methylbenzofuran-2-yl)phenol scaffolds in a common strategy.

High-Voltage Dye-Sensitized Solar Cells Mediated by [Co(2,2'-bipyrimidine)3]z.

The cobalt complex [Co(2,2'-bipyrimidine)3](PF6)2 (Co-bpm) was tested as a redox mediator in the dye-sensitized solar cell. The measured photovoltages for the cells were in excess of 1 V, which is approximately 3-fold greater than that measured for devices where [Co(2,2'-bipyridine)3](PF6)2 (Co-bpy) was used as the redox mediator under the same experimental conditions. The root cause of this voltage enhancement is the CoIII/CoII redox potential for Co-bpm being positively shifted by 0.50 V relative to the Co-bpy mediator. This result highlights how the number and position of the N atoms in aromatic ligands can have a profound effect on the measured photovoltage.

Halogen Bonding Promotes Higher Dye-Sensitized Solar Cell Photovoltages.

We report here an enhancement in photovoltage for dye-sensitized solar cells (DSSCs) where halogen-bonding interactions exist between a nucleophilic electrolyte species (I(-)) and a photo-oxidized dye immobilized on a TiO2 surface. The triarylamine-based dyes under investigation showed larger rate constants for dye regeneration (kreg) by the nucleophilic electrolyte species when heavier halogen substituents were positioned on the dye. The open-circuit voltages (VOC) tracked these kreg values. This analysis of a homologous series of dyes that differ only in the identity of two halogen substituents provides compelling evidence that the DSSC photovoltage is sensitive to kreg. This study also provides the first direct evidence that halogen-bonding interactions between the dye and the electrolyte can bolster DSSC performance.

[Transurethral resection of the prostate versus transurethral holmium laser enucleation of the prostate for benign prostatic hyperplasia with bladder detrusor overactivity].

OBJECTIVE: To compare and analyze the effects of transurethral resection of the prostate (TURP) and transurethral holmium laser enucleation of the prostate (HoLEP) in the treatment of benign prostatic hyperplasia (BPH) with bladder detrusor overactivity. METHODS: his study included 51 cases of BPH with bladder detrusor overactivity treated by TURP and another 58 treated by HoLEP. We evaluated the urination of the two groups of patients during the recovery period and at 3 and 6 months postoperatively. RESULTS: There were no statistically significant differences in such baseline data as the blood PSA level, prostate volume, International Prostate Symptom Score (IPSS), and quality of life (QOL) between the two groups of patients, except in effective bladder capacity, which was higher in the TURP than in the HoLEP group (ï¼»315±59ï¼½ vs ï¼»287±76ï¼½ ml, P<0.05). Urine storage symptoms were obviously improved in both of the groups postoperatively, with the storage symptoms score significantly decreased from 12.6±4.9 preoperatively to 7.5±3.9 at 3 months and 6.1±4.2 at 6 months after surgery in the TURP group (P<0.01) and from 13.7±5.7 to 7.9±4.2 and 7.0±5.1 in the HoLEP group (P<0.01). HoLEP manifested significant advantages over TURP in the postoperative urethral catheterization time (ï¼»2.7±0.8ï¼½ vs ï¼»5.1±1.2ï¼½ d, P<0.05), postoperative bladder contracture time (ï¼»4.1±1.9ï¼½ vs ï¼»5.8±2.4ï¼½ d, P<0.05), postoperative hospital stay (ï¼»4.4±1.8ï¼½ vs ï¼»5.9±2.5ï¼½ d, P<0.05), and improvement of the maximum urinary flow rate, which was increased from (7.9±3.7) ml/s preoperatively to (16.8±4.3) ml/s at 3 months after surgery in the HoLEP group and from (8.6±3.2) ml/s to (14.6±4.3) ml/s in the TURP group (P<0.05). CONCLUSIONS: Both TURP and HoLEP can improve bladder function and detrusor overactivity in BPH patients, with similar effects in improving urination at 3 to 6 months after surgery. However, HoLEP has more advantages over TURP during the period of postoperative recovery.

A retrospective study of clinical characteristics of interstitial lung disease associated with rheumatoid arthritis in Chinese patients.

BACKGROUND: Interstitial lung disease (ILD) in rheumatoid arthritis (RA) is associated with a poor prognosis. The purpose of this study was to assess the characteristics of ILD that are associated with RA. MATERIAL AND METHODS: This was a retrospective study of 544 Chinese patients with RA (427 women and 117 men). RA-ILD was diagnosed by high-resolution computed tomography (HRCT). Patients with RA-ILD or with RA alone were compared in terms of age, sex distribution, duration of disease, clinical and laboratory parameters, history of smoking, and medication. RESULTS: Based on HRCT imaging, 83 (15.26%) patients with RA were diagnosed with ILD. ILD was more frequent in older patients (59.60±9.66 vs. 50.54±13.76 years, P<0.001), in those with a longer duration of disease (7.46±7.40 vs. 5.27±6.32 years, P=0.013) and in male patients (34.9% vs. 19.1%, P=0.001). RA-ILD was found to be associated with hepatitis B surface antigen (HBsAg) positivity (odds ratio [OR]=2.56, 95% confidence interval [95% CI] 1.02-6.43) and smoking (OR=3.38, 95% CI 1.65-6.95). Higher levels of C-reactive protein (OR=3.59, 95% CI 1.58-8.15), anti-cyclic citrullinated peptide (CCP) (OR=2.24, 95% CI 2.09-4.13), and rheumatoid factor (OR=3.72, 95% CI 1.56-8.86) were detected in association with RA-ILD. RA-ILD was more frequently observed in patients treated with steroids (OR=1.91, 95% CI 1.18-3.09) or Tripterygium wilfordii (OR=2.56, 95% CI 1.21-5.40). Age (OR=2.20, 95% CI 1.04-4.65), age at RA onset (OR=2.55, 95% CI 1.11-5.90), anti-CCP (OR=2.47, 95% CI 1.19-5.17), and steroid use (OR=1.83, 95% CI 1.04-3.20) were independently associated with RA-ILD in multivariate analysis. CONCLUSIONS: RA-ILD was associated with age, age at RA onset, anti-CCP, and steroid use. Anti-CCP antibodies might be important biomarkers of RA-ILD.

Self-assembly of polytetrafluoroethylene nanoparticle films using repulsive electrostatic interactions.

An approach for manufacturing polytetrafluoroethylene nanoparticle films using repulsive electrostatic interactions was developed. This approach used the strong repulsive force between colloidal nanoparticles and a substrate surface to cause the colloidal nanoparticles to suspend and self-assemble at a near-wall equilibrium position. A suspended monolayer was formed and was subsequently deposited on the substrate surface. A relatively large-area (3 × 3 cm(2)), close-packed unordered monolayer of polytetrafluoroethylene nanoparticles was observed. Multilayer nanoparticle films were also generated by increasing the particle concentration and deposition time. This work confirms the feasibility of nanoparticle self-assembly under repulsive electrostatic interactions and provides new routes for the large-area fabrication of monolayer and multilayer close-packed nanoparticle films.

Distribution Characteristics and Risk Assessment of 57 Pesticides in Farmland Soil and the Surrounding Water.

To investigate the effect of pesticide use on surface water, the concentration and distribution characteristics of 57 pesticides and 3 degradation products were analyzed in the farmland soil and surface water in the Xingkai Lake area, including water from paddy fields, drainages and the Xingkai Lake, in Heilongjiang Province, China. Forty-three pesticides and three degradation products were detected in farmland soil. In dry field (corn and soybean field) soil, the main detected pesticides were atrazine and acetochlor with mean concentrations of 26.09 ng·g-1 and 49.08 ng·g-1, respectively. In paddy field soil, oxadiazon, mefenacet and chlorpyrifos were the main detected pesticides with mean concentrations of 14.32 ng·g-1, 78.60 ng·g-1 and 20.03 ng·g-1, respectively. In the surrounding water, including water from paddy fields, drainages and Xingkai Lake, the total concentrations of contaminants detected in the water samples ranged from 71.19 ng·L-1 to 10,145.76 ng·L-1. Of the three sampling periods, the mean concentration of contaminants in the water exhibited its peak during the vegetative period. In the analysis of the drainage water, the primary pesticides detected were atrazine, acetochlor and buprofezin with mean concentrations of 354.83 ng·L-1, 109.09 ng·L-1 and 254.56 ng·L-1, respectively. Atrazine, simetryn, buprofezin and isoprothiolane were the main pesticides detected in Xingkai Lake water, with the mean concentrations of 222.35 ng·L-1, 112.76 ng·L-1, 301.87 ng·L-1 and 138.02 ng·L-1, respectively. The concentrations of contaminants could be correlated with drainage, Da Xingkai Lake and Xiao Xingkai Lake water (ρ > 0.8) suggested that the source of these contaminants in drainage and Xingkai Lake water could be the same. The maximum potentially affected fraction (PAF) values of atrazine, chlorpyrifos and prometryn were higher than 5% in Xingkai Lake water, resulting in high ecological risks.

Variations in serum low-density lipoprotein and sST2 among heart failure patients with different ejection fraction groups and their clinical significance.

OBJECTIVE: This study aimed to examine the changes in serum Low Density Lipoprotein Cholesterol (LDL-C) and Soluble Growth Stimulating Expressed Gene 2 Protein (sST2) among Heart Failure (HF) patients with varying ejection fractions and their clinical significance, providing a reference for the clinical assessment of HF severity. METHODS: A total of 238 HF patients treated in our hospital's cardiology department from September 2019 to December 2021 were selected; 68 patients hospitalized in the same period were selected as the control group. General information, LDL-C and echocardiographic results of admitted patients were collected. According to LVEF results and the latest European Society of Cardiology standards in 2021, HF patients were categorized into those with HFpEF (n = 95), HFmrEF (n = 60), and HFrEF (n = 83). Meanwhile, venous blood was collected to determine sST2 and NT-proBNP to compare and analyze the changes and clinical significance of sST2 and LDL-C across the groups. RESULTS: Compared to the control group, the HF group showed significant differences in age, gender, heart rate, smoking history, history of atrial fibrillation, history of diabetes, LVEDD, LVEF, sST2, and NT-proBNP levels (P < .05), but not in LDL-C levels. Significant differences (P < .05) were also found among the 3 HF groups in terms of age, gender, history of atrial fibrillation, LVEDD, LVEF, LDL-C, sST2, and NT-proBNP levels, with an increase in LVEDD, LDL-C, sST2, and NT-proBNP values as the ejection fraction decreased. ROC curve analysis indicated that the area under the curve (AUC) for sST2 in diagnosing HF was 0.915 (P < .05), with an optimal cutoff value of 23.71 ng/mL, a sensitivity of 76.5%, and a specificity of 95.6%; LDL-C was not a significant diagnostic marker for HF (P > .05). Coronary artery disease, NT-proBNP, and sST2 were identified as risk factors for HF. With each unit increase in coronary artery disease, the risk of HF increased by 36.3%; for NT-proBNP, the risk increased by 1.3% per unit; and for sST2, it increased by 18.3% per unit. CONCLUSION: As the ejection fraction decreases in HF patients, serum sST2 and LDL-C values progressively increase, which is clinically significant for predicting the severity of HF. sST2 is an independent risk factor for HF and can enhance the diagnostic accuracy for HF.

The Association Between Trajectory-Skull Angle and Accuracy of Stereoelectroencephalography Electrode Implantation in Drug-Resistant Epilepsy.

OBJECTIVE: To analyze the relationship between trajectory-skull angle and stereoelectroencephalography electrode implantation accuracy in drug-resistant epilepsy patients, aiming to guide clinical electrode placement and enhance surgical precision and safety. METHODS: We conducted a retrospective analysis of medical records and surgical characteristics of 32 consecutive patients diagnosed with drug-resistant epilepsy, who underwent stereoelectroencephalography procedures at our center from June 2020 to June 2023. To evaluate the accuracy of electrode implantation, we utilized preoperative and postoperative computed tomography scans fused with SinoPlan software-planned trajectories. Entry radial error and target vector error were assessed as measurements of electrode implantation accuracy. RESULTS: After adjusting for confounders, we found a significant positive correlation between trajectory-skull angle and entry radial error (ß = 0.02, 95% CI: 0.01-0.03, P < 0.001). Likewise, a significant positive correlation existed between trajectory-skull angle and target vector error in all three models (ß = 0.03, 95% CI: 0.01-0.04, P < 0.001). Additionally, a U-shaped relationship between trajectory-skull angle and target vector error was identified using smooth curve fitting. This U-shaped pattern persisted in both frame-based and robot-guided stereotactic techniques. According to the two-piecewise linear regression model, the inflection points were 9° in the frame-based group and 16° in the robot-guided group. CONCLUSIONS: This study establishes a significant positive linear correlation between trajectory-skull angle and entry radial error, along with a distinctive U-shaped pattern in the relationship between trajectory-skull angle and target vector error. Our findings suggest that trajectory-skull angles of 9° (frame-based) and 16° (robot-guided) may optimize the accuracy of target vector error.

Contamination and health risks of heavy metals in the soil of a historical landfill in northern China.

Landfill-induced heavy metal (HM) contamination of soils is a widespread and complex problem. The levels and potential hazards of HM contamination in landfills must be evaluated before they can be reused for any purpose. In order to reuse a historical landfill in northern China, 376 sampling sites were selected in 2019 using the checkerboard layout method, and the levels of arsenic (As), mercury (Hg), antimony (Sb), copper (Cu), lead (Pb), cadmium (Cd), nickel (Ni), zinc (Zn), and thallium (Tl) in the soil were measured. Multiple evaluation methods established the HM pollution levels, agricultural suitability, and health risks associated with the sampling sites. In most parts of the study area, the concentrations of all nine HMs exceeded the screening levels and maximum allowable concentrations for agricultural soils. Only the soils in Zones 5 and 6 can be used for agricultural activity. Moreover, the deep soils were heavily contaminated with HMs in certain areas, possibly because of leaching and infiltration in the surface soil and the rise and diffusion of polluted groundwater. The soil HMs in the study area posed a higher carcinogenic risks to both adults and children. The average carcinogenic risk associated with As was 6.12 × 10-4, which was the major contributor to carcinogenic risk at all HM-contaminated sites. The results of this work empirically demonstrated that soil HM pollution is severe and problematic in the study area and remedial measures are urgently required.

A review on the P enrichment and recovery from steelmaking slag: Towards a sustainable P supply and comprehensive utilization of industrial solid wastes.

Phosphorus (P) is one of the desirable nutrient elements for the growing of crops and is a non-renewable resource. The over-exploitation of high-grade phosphate rocks makes finding alternative P sources urgent for a sustainable and stable P supply. Steelmaking slag has been considered a potential P source due to its huge production and the increasing P content in slag with the utilization of low-grade iron ores. If the efficient separation of P from steelmaking slag is achieved, the obtained P can be used as the raw material for phosphate products, and the P-removal steelmaking slag can be reused as a metallurgical flux in steel plants, realizing the comprehensive utilization of steelmaking slag. To better understand the separation method and mechanism of P from steelmaking slag, this paper reviews: (1) the enrichment mechanism of P in steelmaking slag, (2) the methods of the P-rich phase separation from slag and P recovery, and (3) facilitating the enrichment of P in the mineral phase by cooling treatment and modification. Furthermore, some industrial solid wastes were selected as modifiers for steelmaking slag, which not only provided several valuable components but also significantly reduced treatment costs. Hence, a collaborative processing of steelmaking slag and other P-bearing industrial solid wastes is proposed, providing a new solution for P recovery and the comprehensive utilization of industrial solid wastes, achieving the sustainable development of steel and phosphate industries.