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The Huashandong W deposit (7.7 Mt @ 0.26% WO3) is a newly discovered Neoproterozoic scheelite-dominated deposit in the world-class Jiangnan tungsten belt, South China. It occurs largely in metasedimentary rocks near the western margin of the Neoproterozoic Jiuling batholith and mainly consists of W-bearing exogreisen, hydrothermal breccias, and quartz veins. Two episodes of Neoproterozoic granite magmatism are identified with zircon U-Pb ages of ca. 830–823 and 807–804 Ma, respectively. According to cross-cutting relationships and mineral assemblages, two periods of hydrothermal alteration and W mineralization, corresponding to the two episodes of granite magmatism, are recognized in the Huashandong deposit. The early period is dominated by greisenization and associated scheelite mineralization whereas the late period is characterized by sericitization, hydrothermal brecciation, quartz veining, and associated scheelite and minor wolframite mineralization. Molybdenite Re-Os dating indicates that the early- and late-period W mineralization took place at ca. 828 and 800 Ma, respectively. Zircon trace element characteristics suggest that the Jiuling granite crystallized from reduced granitic magmas and has the potential for W mineralization. The petrologic and geochemical features of the Jiuling granite, coupled with the zircon U-Pb ages and Hf isotopic signatures and molybdenite Re-Os ages, imply that the Huashandong W deposit is genetically related to two phases of evolved granodiorites in the Jiuling batholith. The magmatic-hydrothermal nature of both metallogenic events is confirmed by H-O isotopes on hydrothermal quartz. [ABSTRACT FROM AUTHOR]

A bimetallic Fe-Cu catalyst was applied as a catalyst for heterogeneous Fenton reaction. Fluidized-bed crystallization of bimetallic catalyst supported by a silica seed (FeIII 0.66 CuI 0.33 @SiO 2) was conducted at specific hydraulic conditions. The deposited state of copper and iron of FeIII 0.66 CuI 0.33 @SiO 2 were identified as Cu(I) and Fe(III), which could effectively catalyze H 2 O 2 to form hydroxyls radical for the abatement and mineralization of benzoic acid under blue light irradiation (436 nm). The cupric species as an electron donor enabled the reductive dissolution of the deposited iron to drive a Fenton reaction. The blue light irradiation promoted the regeneration of Fe(III) to Fe(II) through the photoreduction mechanism. Operating parameters included Fe to Cu ratio (0.5–4), dose of H 2 O 2 (0–4 mM), initial pH (3–7) and light intensity (0–10 mW/cm2). The photo Fenton process using FeIII 0.66 CuI 0.33 @SiO 2 catalyst resulted in 86% of benzoic acid mineralization in 3 h. [Display omitted] [ABSTRACT FROM AUTHOR]

The imidacloprid was mineralized by heterogeneous photo-Fenton process in a three-phase fluidized bed reactor using waste iron oxide as catalyst. The effects of catalyst loading, dosage of H2O2 and pH were investigated to determine the optimal experiments conditions. The results revealed that TOC removal efficiency increases with an increase in H2O2 dosage of up to 105.0 mM, an increase in catalyst dosage from 1.0 to 5.0 g L−1, and a decrease in pH from 5.0 to 3.5. Under the optimal conditions, 97.7% TOC removal was achieved in 6 h under 254-nm UV irradiation. Moreover, recycling experiments indicated that the waste iron oxide had a good stability and the TOC removal of pesticide yielded more than 80% under the fourth recycles. [ABSTRACT FROM AUTHOR]

A waste iron oxide (labelled as BT4), which was a by-product of the fluidized-bed Fenton treatment of the bio-treated tannery wastewater, was utilized as the catalyst for the mineralization of bisphenol A (BPA) by a heterogeneous photo-Fenton process in a three-phase fluidized bed reactor. The main constituent of BT4 was identified as α-FeOOH, while BT4 exhibited higher catalytic activity than pure α-FeOOH. The effects of catalyst loading, H 2 O 2 concentration and initial pH on the mineralization of BPA were elucidated. With 2 g/L catalyst loading, 0.74 mmol/L H 2 O 2 and initial pH 3, 90% TOC of 0.05 mmol/L BPA was removed after 180 min reaction. The result of the catalyst reuse experiment indicated that BT4 showed a good stability. [ABSTRACT FROM AUTHOR]

Fenton technologies for wastewater treatment have demonstrated their effectiveness in eliminating toxic compounds. This study examines how hydrogen peroxide concentration and ultraviolet (UV) light affects oxidation processes. However, total mineralization through these Fenton technologies is expensive compared with biological technologies. Therefore, partial chemical oxidation of toxic wastewaters with Fenton processes followed by biological units may increase the application range of Fenton technologies. Using 2,6-dimethylaniline (2,6-DMA) as the target compound, this study also investigates oxidation intermediates and their biodegradable efficiencies after treatment by Fenton, electro-Fenton and photoelectron-Fenton processes. Analytical results show that the UV light-promoting efficiency, rPE-F/rE-F, was 2.02, 2.55 and 2.67 with initial hydrogen peroxide concentrations of 15, 20 and 25 mM, respectively. We conclude that UV irradiation promoted 2,6-DMA degradation significantly. The same tendency was observed for biochemical oxygen demand/total organic carbon (BOD5/TOC) ratios for each process, meaning that 2,6-DMA can be successfully detoxified using the electro-Fenton and photoelectro-Fenton processes. Some organic intermediates aminobenzene, nitrobenzene, 2,6-dimethylphenol, phenol and oxalic acid-were detected in different oxidation processes. [ABSTRACT FROM AUTHOR]

Abstract: In this study, phenol was degraded by the photo-Fenton process at pH 3, 5mg/L Fe(III), 1080mg/L H2O2 using 3 UV lamps (365nm). In the UV/H2O2 system, the degradation of phenol is inefficient, and only around 25% of the phenol is degraded in 1h. The efficiency of the photo-Fenton system considerably exceeded that in UV/H2O2 and Fenton-like systems. The removal efficiency of COD by the photo-Fenton process was 98% respectively, but only 63% in the Fenton-like system. The effect of oxalate on the degradation of phenol was also investigated. The removal efficiency of phenol was highest at a molar concentration ratio of oxalic acid to ferric ions ([Ox]/[Fe3+]) of 2. Increasing the amount of dissolved oxygen promoted the degradation of phenol. Even when concentration of added ferric ions in the photo-Fenton system was low, the COD removal efficiency was still satisfactory. The intermediate organic acids during the degradation of phenol were formic acid, acetic acid, oxalic acid and succinic acid. The pathway of phenol degradation in the photo-Fenton process is proposed from experimental results and the literature. [ABSTRACT FROM AUTHOR]

This study investigated the degradation and mineralization of Bisphenol A (BPA) at pH 7, taken as a model compound in the presence of the trace metal-ions, Co2+, and peroxymonosulfate (Oxone: PMS). We took advantage of the high oxidation–reduction potential of hydroxyl and sulfite radicals transformed from PMS as the oxidants to oxidize BPA to less complex compounds (stoichiometric ratio: [PMS]0/[BPA]0 =2). Afterwards, the expected radicals were used to mineralize those compounds more efficiently (TOC removal ∼40%) as compared to the 1% removal demonstrated in the UV/persulfate system in our previous study. To the best of our knowledge, this is the first attempt to evidence that the dominant behavior of radicals in a (bi)sulfite process is very different from that in a persulfate process. Additionally, the utilization of extremely small amounts of activator and oxidant for the complete degradation of BPA was achieved. The BPA degradation in this Co2+/PMS process formulated a pseudo-first-order kinetic model well over a practicable range of 25–45°C. The activation energy (ΔE =57.6kJmol−1) was calculated under different conditions, and the detailed discussion indicates that the activity of BPA degradation is not obviously dependent on the PMS concentration, but rather is related to Co2+ dosage. Possible BPA side-chain oxidative metabolic pathways are suggested based on experimental results incorporating the evidence from EPR (electron paramagnetic resonance) and analysis from GC–MS (gas chromatography–mass spectrometry). [Copyright &y& Elsevier]

Abstract: A batch photo-fluidized bed reactor (photo-FBR) is designed for the mineralization of phenol and the minimization of iron species leached from an active immobilized iron oxide (denoted as SiG2). The hydroxyl radical (h is produced from the reaction of hydrogen peroxide (H2O2) and SiG2 under irradiation by a 400-W Hg-vapor lamp, was confirmed by electron paramagnetic resonance signals of 5,5-DIMETHYL-1-pyrroline-N-oxide (DMPO)-us solution). The mineralization of phenol was more efficient in the presence of light. In general, a decrease of solution pH is commonly ascribed to the formation of carboxylic acids (acetic acid, oxalic acid, formic acid etc.) during the degradation of phenol. However, in this study, an interesting phenomenon was observed. The solution pH first decreased and then rose during the reaction in the presence of light. Also, in this case, the variation of solution pH reflected the degree of mineralization in this study. The approximately 98% mineralization of phenol led to fewer iron species being leached from SiG2 in the photo-FBR. A savings of more than 40% of the H2O2 dosage required for the phenol mineralization process was confirmed. In a batch photo-FBR, the system loading reflects the ratio of catalyst weight to the reaction volume. About 96%, 86% and 11% of the total organic carbons were removed after 180min, resulting in catalyst weight to reaction volume ratios of 30:1, 20:1 and 13:1, respectively. The activity of SiG2 did not decline after six reactions. The reactions for photo-assisted SiG2 in the presence of hydrogen peroxide and phenol were summarized. [Copyright &y& Elsevier]

A two-stage oxidation (UV-Na2S2O8/H2O2-Fe(II,III)) process was applied to mineralize bisphenol A (BPA) at pHi (initial pH) 7. We take advantage of the high oxidation potential of sulfate radicals and use persulfate as the 1st-stage oxidant to oxidize BPA to less complex compounds (stoichiometric ratio: [S2O8 2−]0/[BPA]0 =1). Afterwards, the traditional photo-Fenton process was used to mineralize those compounds to CO2. To the best of our knowledge, this is the first attempt to utilize the two processes in conjunction for the complete degradation of BPA. During the 2nd-stage reaction, other oxidants (H2O2 and Iron alone) were also employed to observe the extent of enhancement of photo-Fenton. Further, qualitative identification of both hydroxyl and sulfate radicals was performed to evaluate their dominance under different conditions. The BPA degradation in this UV/persulfate process formulated a pseudo-first-order kinetic model well, with a rate constant of approximately 0.038min−1 (25°C), 0.057min−1 (35°C), and 0.087min−1 (50°C), respectively. The much lower activation energy (ΔE =26kJmol−1) was further calculated to clarify that the thermal-effect of an illuminated system differs from single heat-assisted systems described in other research. Final total organic carbon (TOC) removal levels of BPA by the use of such two-stage oxidation processes were 25–34%, 25%, and 87–91% for additional Fe(II,III) activation, H2O2 promotion, and Fe(II,III)/H2O2 promotions, respectively. [Copyright &y& Elsevier]

Abstract: This study makes a comparison between photo-Fenton and a novel electro-Fenton called Fered–Fenton to study the mineralization of 10,000mg/L of dye-Reactive Black B (RBB) aqueous solution, which was chosen as the model dye contaminant. Results indicate that the traditional Fenton process only yields 70% mineralization. This result can be improved by using Fered–Fenton to yield 93% mineralization resulting from the action of ferrous ion regenerated on the cathode. Furthermore, photo-Fenton allows a fast and more complete destruction of dye solutions and as a result of the action of ferrous ion regenerated by UV irradiation yields more than 98% mineralization. In all treatments, the RBB is rapidly decayed to some carboxylic acid intermediates. The major intermediates found are formic acid and oxalic acid. This study finds that formic acid can be completely mineralized by photo-Fenton, but its destruction is problematic using the Fenton method. Oxalic acid is much more difficult to treat than other organic acids. It could get further mineralization with the use of the Fered–Fenton process. [Copyright &y& Elsevier]

Abstract: A novel supported iron oxide, prepared using a fluidized-bed reactor (FBR), was utilized as a catalyst of the heterogeneous photoassisted Fenton degradation of azo-dye Reactive Black 5 (RB5). This catalyst is much cheaper than Nafion-based catalysts, and can markedly accelerate the degradation of RB5 under irradiation by UVA (λ =365nm). The effects of the molar concentration of H2O2, the pH of the solution and the catalyst loading on the degradation of RB5 are elucidated. A simplified mechanism of RB5 decomposition that is consistent with the experimental findings for a solution with a pH of up to 7.0 is proposed. About 70% decolorization was measured and 45% of the total organic carbon was eliminated on the surface of the iron oxide at pH 7.0 after 480min in the presence of 0.055mM RB5, 5.0g iron oxide/L, 29.4mM H2O2, under 15W UVA. [Copyright &y& Elsevier]

• We have identified hydrothermal zircons from the Xiadian gold deposit, Jiaodong. • They show homogeneous low CL-response image and have high U with low Th/U. • Direct LA-ICP-MS U-Pb dating shows the Paleocene gold mineralization. • In-situ Hf isotopes suggest lithospheric mantle-derived ore-forming fluids. The eastern North China Craton is characteristic of Mesozoic cratonic destruction and largescale gold mineralization. Previous geochronological studies by 40Ar–39Ar dating on alteration minerals such as sericite and K-feldspar and Rb–Sr and 40Ar–39Ar dating on quartz and pyrite suggested that the gold mineralization occurred in Early Cretaceous. We have identified hydrothermal zircons from the orebody and alterated rocks in the Xiadian gold deposit, Jiaodong Peninsula. These zircons contain two phase (vapor-liquid) fluid inclusions or enclose hydrothermal alteration minerals such as sericite. They show homogeneous low CL-response image and have high U with low Th/U, and also show enriched and flatter normalized LREE pattern with high La and low (Sm/La) N and Ce/Ce* relative to magmatic zircons. Their petrographical, textural and compositional features strongly suggest that they mainly crystallized from the hydrothermal fluids during the pyrite–sericite–quartz alteration that was closely related to the gold mineralization. Direct LA-ICP-MS U-Pb dating on such hydrothermal zircons indicates that the gold mineralization in the Xiadian deposit mainly occurred during the Paleocene and underwent a prolonged metallogenic process (68.7–56.7 Ma), most likely commenced at the end of Cretaceous and lasted at the end of Paleocene. In-situ Hf isotopic compositions of the hydrothermal and inherited zircons suggest that the ore-forming fluids might have been derived from an enriched lithospheric mantle, followed by interacting with Archean metamorphic basement during ascent. Such a gold mineralization event might have been associated with the early Cenozoic uppermost lithospheric thinning in eastern North China Craton. It has important implications for further understanding the geneses and the geodynamics of gold deposits in the whole eastern North China Craton. [ABSTRACT FROM AUTHOR]

N‐Methyl‐2‐pyrrolidone (NMP), a commonly used solvent in industries, is treated with zero‐valent iron (Fe0) and hydrogen peroxide (H2O2) under UV irradiation. The reaction is carried out in a three‐phase fluidized bed reactor to ensure the smooth and continuous circulation of the Fe0 powder. The results reveal that NMP can be efficiently mineralized by UV‐assisted Fe0/H2O2 process (advanced photo‐Fenton process) with aeration. The mineralization process is properly fitted with the pseudo‐first order kinetics (R2 > 0.93). To determine the optimum conditions for NMP mineralization, the effects of pH, Fe0 dosage, H2O2 concentration, and initial NMP concentration are investigated. Addition of 0.05 g L−1 Fe0 and 0.1 M H2O2 yields 85.2% total organic carbon removal of NMP (10 mM) in 6 h at pH 4.0 ± 0.2. To explore the changes of the nitrogen species, released NO2−, NO3−, and NH4+ are also monitored during the reaction. The present study provides an effective method for the mineralization of NMP‐containing wastewater. N‐Methyl‐2‐pyrrolidone (NMP), a commonly used nitrogen‐containing organic solvent, often exists in wastewater. The UV/Fe0/H2O2/air process is carried out in a three‐phase fluidized bed reactor to mineralize NMP. The results show that 85.2% mineralization removal efficiency is achieved after 6 h under optimal conditions. Herein, the UV‐assisted advanced Fenton process is shown to be an effective method for the mineralization of NMP. [ABSTRACT FROM AUTHOR]

Abstract: A new approach for promoting ferric reduction efficiency using a different electrochemical cell and the photoelectro-Fenton process has been developed to degrade organic toxic contaminants. The use of UVA light and electric current as electron donors can efficiently initiate the Fenton reaction. 2,6-Dimethylaniline (2,6-DMA) was the target compound in this study. Effects of initial pH (pHi), Fe2+ loading, H2O2 concentration and current density were determined to test and to validate a kinetic model for the oxidation of organic compound by the electro-Fenton process. Kinetic results show evidence of pseudo-first-order degradation. When reaction pH was higher than 2, amorphous Fe(OH)3(s) was generated. Increasing ferrous ion concentration from 1.0 to 1.5mM increased the hydroxyl radicals and then promote the degradation efficiency of 2,6-DMA. The optimal H2O2 concentration for 2,6-DMA degradation in this study was 25mM. The degradation of 2,6-DMA was increased with the increase of current density from 3.5 to 10.6A/m2. Oxalic acid was the major detected intermediate of 2,6-DMA degradation. The final TOC removal efficiencies were 10%, 15%, 60% and 84% using the electrolysis, Fenton, electro-Fenton and photoelectro-Fenton processes, respectively. [Copyright &y& Elsevier]

• Fluidized-bed homogeneous crystallization of iron in wastewater was developed. • 77% of iron was removed as crystallized magnetite granulate. • The recovery of iron oxide was dependent on index of supersaturation in effluent. • RB5 was degraded in three-phase photo reactor using the iron oxide catalyst. • The decolorization and mineralization efficiency reached 98% and 68%, respectively. Iron recovery from wastewater as magnetite (Fe 3 O 4) pellets was performed in a fluidized-bed homogeneous crystallization (FBHC) process. The catalytic effectiveness of magnetite in the heterogeneous degradation of RB5 azo dye was evaluated. The key parameters of FBHC, including effluent pH, cross-section loading (L, kg/m2.h), initial iron concentration ([Fe(II)], mg/L), and inlet supersaturation (S), were optimized to maximize the total iron removal (TR, %) and crystallization ratio (CR, %) from a fluidized-bed reactor. Under the conditions of pH = 8.5–9.5 and [Fe(II)] in = 100 – 500 mg/L, the TR and CR values reached 99% and 77%, respectively. The magnetization and coercivity of the recovered Fe 3 O 4 pellets were analyzed to confirm the magnetic characteristic. A Fenton-like degradation of RB5 azo dye was activated using the Fe 3 O 4 pellets under UVA irradiation, pH = 2.75 – 3.0, initial peroxide concentration of 10 mM, and catalyst loading of 2 g/L. The efficiencies of decolorization and mineralization reached about 98 – 99% and 60 – 68%, respectively. FBHC method benefited the recovery of high-purity metal oxides and the production of a low quantity of sludge. Magnetic pellets transformed from the dissolved iron in wastewater were promising materials to reuse as a photochemical reactant for organic pollutant degradation. [ABSTRACT FROM AUTHOR]

This study aims to explore the reusability of wastewater treatment by-product for photo-Fenton process to treat an organic pollutant model. The optimal condition, reactive oxygen species (ROS), and kinetic approach in photo-Fenton process was discussed. The Metal oxide crystal pellets from are a by-product of the Fluidized-Bed Crystallization (FBC) process and can be used as a catalyst in the Photo-Fenton process. Electroplating wastewater containing iron and copper was treated via the FBC process using granulated Al(OH) 3 as carrier seeds. The binary oxide of FeOOH and Cu 2 O on the Al(OH) 3 surface (Fe 0.66 Cu 0.33 @Al(OH) 3) was identified as the FBC by-product after characterization using FTIR and XPS analysis. In the photo-Fenton process, visible light from a fluorescence lamp with a wavelength of 400–610 nm was chosen as an irradiation source. Oxalic acid was added as chelating agent to form photosensitive iron oxalate species and hydrogen peroxide was applied as oxidant to generate active radical to decolorize and mineralize RB5 synthesized solution (100 mg/L). The operating conditions including the oxalic acid to pollutant ratio ([OA] 0 /[RB5] 0) of 4.5–13.0, reaction pH (pHr) of 3–7 and initial to theoretical hydrogen peroxide molar ratio [H 2 O 2 ] 0 /[ H 2 O 2 ] theoretical of 35%–120% were optimized. Under the optimal conditions, pH r = 5.0; [H 2 O 2 ] 0 /[RB5] 0 at 75% stoichiometric and [OA] 0 /[RB5] 0 = 9, the RB5 is almost completely decolorized after 210 min of operation and the mineralization efficiency is 58%. The contribution of •OH, O 2 •-, and O 2 1 to the Photo-Fenton system was determined using ESR analysis with the addition of DMPO and TEMP as spin trap agents. The kinetic analysis reveals the observed rate constants k RB5 , k OA and k R from fitting are 0.0120, 0.0054 and 0.0001 M−1s−1, respectively. [Display omitted] • The binary oxide of by-product from FBC process is useful for organics treatment. • Treatability of azo dye RB5 by visible light-assisted photo-Fenton was investigated. • RB5 was completely degraded and mineralized of 55% using a 75% stoichiometric dosage of H 2 O 2 with the addition of oxalic acid at pH 5. • Up to 55% of TOC was mineralized mainly by O 2 •- and O 2 1. • Rate modeling of RB5 and TOC removal were explained using consecutive kinetics. [ABSTRACT FROM AUTHOR]

Abstract This work reports the use of ferrioxalate complexes to assist solar photo-Fenton treatment of pentachlorophenol (PCP) in aqueous medium at mild pH, which inhibits the precipitation of iron hydroxides and allows working at a low iron dosage. The experimental parameters were optimized by assessing the effect of initial concentrations of H 2 O 2 (0–2.5 mM) and Fe(II) (2–10 mg/L), pH (3.0–9.0) and iron/oxalic acid molar ratios (1:0–1:13.5) on total organic carbon (TOC) removal. Ferrioxalate-assisted solar photo-Fenton achieved 97.5% mineralization in 120 min, clearly outperforming conventional Fenton and solar photo-Fenton. The presence of photosensitive ferrioxalate complexes accounted for the enhancement, as a result of Fe(II) regeneration that accelerated the hydroxyl radical (OH) production. The time course of H 2 O 2 and Fe(II) concentrations was evaluated under different iron/oxalic acid ratios. The five carboxylic acids determined by ion-exclusion HPLC and the eight aromatic by-products identified by GC-MS allowed the proposal of a degradation pathway that included hydroxylation, dechlorination and dimerization steps. Complete chloride ion release was achieved after 90 min of treatment. Highlights • Up to 97.5% mineralization achieved by ferrioxalate-assisted solar photo-Fenton process. • Similar TOC abatement was obtained within pH range 3.0–6.0 • Complete dechlorination of PCP at 90 min using low iron dosage (5 mg/L) at pH 5.0 • Fe(III) was maintained soluble, being efficiently reduced to Fe(II) in the presence of oxalate. • Up to 8 aromatic products found by GC-MS: hydroxylation, dechlorination and dimerization. [ABSTRACT FROM AUTHOR]

The NWW-striking North Qilian Orogenic Belt records the Paleozoic accretion–collision processes in NW China, and hosts Paleozoic Cu–Pb–Zn mineralization that was temporally and spatially related to the closure of the Paleo Qilian-Qinling Ocean. The Wangdian Cu deposit is located in the eastern part of the North Qilian Orogenic Belt, NW China. Copper mineralization is spatially associated with an altered early Paleozoic porphyritic granodiorite, which intruded tonalites and volcaniclastic rocks. Alteration zones surrounding the mineralization progress outward from a potassic to a feldspar-destructive phyllic assemblage. Mineralization consists mainly of quartz-sulfide stockworks and disseminated sulfides, with ore minerals chalcopyrite, pyrite, molybdenite, and minor galena and sphalerite. Gangue minerals include quartz, orthoclase, biotite, sericite, and K-feldspar. Zircon LA-ICPMS U–Pb dating of the ore-bearing porphyritic granodiorite yielded a mean 206 Pb/ 238 U age of 444.6 ± 7.8 Ma, with a group of inherited zircons yielding a mean U–Pb age of 485 ± 12 Ma, consistent with the emplacement age (485.3 ± 6.2 Ma) of the barren precursor tonalite. Rhenium and osmium analyses of molybdenite grains returned model ages of 442.9 ± 6.8 Ma and 443.3 ± 6.2 Ma, indicating mineralization was coeval with the emplacement of the host porphyritic granodiorite. Rhenium concentrations in molybdenite (208.9–213.2 ppm) suggest a mantle Re source. The tonalities are medium-K calc-alkaline. They are characterized by enrichment of light rare-earth elements (LREEs) and large-ion lithophile elements (LILEs), depletion of heavy rare-earth elements (HREEs) and high-field-strength elements (HFSEs), and minor negative Eu anomalies. They have ε Hf ( t ) values in the range of +3.6 to +11.1, with two-stage Hf model ages of 0.67–1.13 Ga, suggesting that the ca. 485 Ma barren tonalites were products of arc magmatism incorporating melts from the mantle wedge and the lithosphere. In contrast, the 40-m.y.-younger ore-bearing porphyritic granodiorite is sub-alkaline and peraluminous. They are enriched in LREEs and LILEs, depleted in HFSEs, and show weak negative Eu anomalies. They display ε Hf ( t ) values of captured or inherited zircons in the range of +8.5 to +10.0, and younger two-stage Hf model ages of 0.78 Ga and 0.86 Ga, similar to those of ca. 485 Ma tonalite. The ca. 445 Ma zircons have ε Hf ( t ) values of −2.1 to +9.9, with two-stage Hf model ages of 0.75–1.27 Ga. Moreover, they have relatively high oxygen fugacity than that of the precursor barren tonalite. The ca. 445 Ma magmas at Wangdian thus formed in a subduction setting, and incorporated melts from the subduction-modified lithosphere that had previously been enriched by additions of chalcophile and siderophile element-rich materials by the earlier magmatism and metasomatism during the Paleo Qilian-Qinling Ocean subduction event. [ABSTRACT FROM AUTHOR]

The strong oxidant, persulfate (PS, S 2 O 8 2−), was applied to treat the synthetic wastewater of benzoic acid (BA) under UV irradiation. UVC light initiated a chain reaction that derived the sulfate radical (SO 4 •-) and hydroxyl radical (HO•) from S 2 O 8 2− ion. The experiment parameters, including light irradiation (UVA and UVC), pH, dose ratio ([PS] 0 /[BA] 0), initial concentration ([BA] 0 , mg/L), was optimized based on degradation efficiency and total organic carbon (TOC) removal of BA, which reached up to 100% and 96%, respectively, under pH 3.0. The best dose ratio was close to equivalent stoichiometry (and [PS] 0 /[BA] 0 = 15) for the treatment of 100 mg-BA/L, suggesting that UV/S 2 O 8 2− was able to completely convert BA to carbon dioxide and water. The scavenging test showed that SO 4 •- contributed to about 60% of degradation rate, which the HO• predominated the mineralization rate, i.e., TOC removal. A consecutive kinetic model was proposed to clarify the reaction sequence and rate-determining factor of photo-persulfate oxidation for benzoic acid. [Display omitted] • The UVC-persulfate oxidation of benzoic acid was investigated. • Up to 100% of Benzoic acid was degraded within 1 h. • Up to 96% of TOC was mineralized within 1 h. • Sulfate radical is the predominant agent in benzoic acid mineralization. [ABSTRACT FROM AUTHOR]

• The Jurassic porphyries at Chuankeng were formed at intra-plate extensional setting. • Magma source are Neoproterozoic juvenile crust with minor Paleoproterozoic ancient crust. • More contributions of ancient crust, lower oxygen fugacity and water contents reduce Cu fertility. • Nd-Hf isotopes, zircon Ce4+/Ce3+and T ti-zr can be used together to assess the potential of Cu mineralization. Large-scale Jurassic porphyry–skarn Cu mineralization in the Qin-Hang metallogenic belt of South China has attracted much attention, but comparative studies of porphyries in large- and small-scale deposits are lacking. In this paper, we present new zircon U–Pb ages, trace element composition and Hf isotopic composition as well as whole-rock geochemical and Sr–Nd isotopic compositions for the porphyries associated with mineralization in the small-scale Chuankeng Cu deposit. Drawing on our data for the Chuankeng deposit and existing data for the nearby giant Dexing Cu deposit, we aim to identify factors controlling the mineralization potential of both deposits. Granodiorite porphyries of Chuankeng deposit were emplaced at ca. 161–158 Ma. They have moderate SiO 2 contents of 61.9–66.1 wt% and high Sr/Y (59–135) and (La/Yb) N (4–14) ratios. Their high MgO contents (0.2–2.9 wt%), lack of negative Eu anomaly, depletion in Y and Yb, relatively high initial 86Sr/87Sr ratios (0.7076–0.7078), and low ε Nd (t) values (−4.5 to −4.9), indicating that the Chuankeng porphyries were derived from partial melting of delaminated lower crust. The Middle–Late Jurassic Chuankeng porphyries are considered to have been formed in a localized intra-continental extension environment along the Jiangshao Fault in response to far-field stress from Paleo-Pacific Plate subduction. Although no Middle–Late Jurassic magmatic arc rocks have been found in the study area, the Chuankeng porphyries display similar characteristics to arc rocks. On the basis of their zircon ε Hf (t) values (−2.6 to +0.9), two-stage Hf model ages (1.4–1.1 Ga), and regional geological history, we infer that magma source of Chuankeng porphyries were mainly Neoproterozoic juvenile crust with the involvement of Paleoproterozoic ancient crust. Thus their arc-like features were inherited from the Neoproterozoic juvenile crust that formed by subduction of oceanic crust during the Jiangnan orogeny. Chuankeng porphyries have lower zircon Ce4+/Ce3+ and higher Ti-in-zircon temperatures and lower whole rock ε Nd and zircon ε Hf values than the Dexing porphyries, indicating they are less oxidized and less hydrous and with more involvement of the ancient crustal material in the magma source, which could explain the relatively small-scale Cu mineralization in Chuankeng. This study highlights the values of integrated studies of whole rock Nd and zircon trace element and Hf isotopic compositions in assessing the potential for Cu mineralization. [ABSTRACT FROM AUTHOR]