Search

Zn doped CuBi2O4 photocathodes are prepared by using a low‐cost solution‐based spray pyrolysis method. The doping of Zn in CuBi2O4 promotes the separation and migration of carriers and effectively increases the carrier density. Compared with CuBi2O4 alone, the photoelectrochemical activity of the Zn doped CuBi2O4 photoelectrode is improved with the photocurrent density of −0.56 mA/cm2 at 0.4 V vs. RHE. This improvement is due to the lower electronegativity of Zn, which leads to the covalent increase of Cu−O and Bi−O bonds in CuBi2O4, which limits the recombination of photogenerated electrons and holes and improves charge separation and transport. This study presents an innovative approach to enhance the charge separation efficiencies of photocathodes by implementing element doping strategies, which may contribute to further research on photocatalytic water splitting. [ABSTRACT FROM AUTHOR]

Biomineralization has not been widely applied due to the lack of bacterial reusability, which needs to be investigated urgently. In this study, we found Lysinibacillus could immobilize Pb2+ at initial pH ≥ 2.0. Lead ion recovery and cell reutilization could be achieved efficiently at pH = 1.0 (c (HNO3) = 0.1 mol/L). Besides, the strong chelating agent EDTA-2Na (c (EDTA-2Na) = 0.1 mol/L) was used for comparison. The oxidative damaging effect of cells could be reduced by both eluents. Mechanism analysis was conducted through zeta potential measurement, 3D-EEM, cyclic voltammetry, FE-EPMA, XRD, FTIR, and XPS. After the cells were eluted by HNO 3 , the enzyme activity enhanced and the removal efficiency increased continuously. Cells were used to remove Pb2+ repeatedly, and regular-shaped Pb 3 (PO 4) 2 crystals were always formed. After the cells were eluted by EDTA-2Na, cells were more prone to redox reaction and were induced to produce mercaptan (R-SH). The active hydrogen in R-SH could react with peroxide free radicals. New free radicals were formed after the R-SH was stripped of hydrogen, and finally, PbS stable mineral was formed. This research provides a new strategy to realize bacterial reutilization, which is a breakthrough in the field of biomineralization. [Display omitted] • Bacterial reutilization and metal recovery were realized in the field of biomineralization. • The time scale evolution of oxidative damage effect of cells was investigated. • The reutilization mechanism of biomineralization was studied. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cu/γ-Fe 2 O 3 nanoparticles anchored on carbon substrate with strong Cu-Fe interaction were successfully prepared. • The micro-heterojunction of Cu/γ-Fe 2 O 3 induces electron polarization distribution. • SO 4 •- is formed in electron-rich Cu centers, 1O 2 is formed in electron-deficient Fe centers. • Consistent performance could be maintained under typical water parameters. • Cu/γ-Fe 2 O 3 exhibits significantly low metal leaching and excellent long-term stability. The development of the efficient material for peroxymonosulfate (PMS) activation is of great importance for water treatment. Herein, a novel magnetic Cu/γ-Fe 2 O 3 catalyst with a dual reaction center (DRC) and abundant heterojunctions/interfaces was constructed, in which uniform composite Cu/γ-Fe 2 O 3 nanoparticles were anchored on a thin continuous carbon framework. The asymmetric configuration of the Cu/γ-Fe 2 O 3 catalyst significantly promotes the adsorption and activation of PMS by strengthening Fe–OH coordination and reducing the adsorption energy barrier of interfacial Cu sites. The efficient conversion of SO 4 •- and the generation of singlet oxygen (1O 2) were realized in the Cu and γ-Fe 2 O 3 domains, respectively, owing to the electron polarization distribution in Cu/γ-Fe 2 O 3. Through synergetic multi-pathway activation, tetracycline (TC) underwent efficient degradation over a wide pH range (3–11), and the degradation efficiency was not inhibited by common ions. The reaction rate of Cu/γ-Fe 2 O 3 (0.685 min−1) was 5.1 and 9.8 times higher than that of the non-DRC Cu and γ-Fe 2 O 3 catalysts, respectively. Furthermore, the Cu/γ-Fe 2 O 3 + PMS system exhibited excellent stability and significantly low metal leaching. This work provides a possible approach to address the application bottlenecks of metal-based catalysts as well as to develop novel environmental remediation materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bar coating was successfully applied to the preparation of PDA/TFC-BMBC membranes. • BMBC was firstly and successfully introduced into the PDA/TFC membrane. • The PDA/TFC-2 obtained a high permeation flux and a high rejection rate. • The cycle performance of prepared membranes was acceptable. Nowadays, attempts emerge in an endless stream to explore an efficient active interlayer to break the "trade-off" relationship between permeability and rejection of conventional thin-film composite (TFC) membrane. Biochar, which is often used as an economically efficient material in soil remediation and wastewater treatment, however, is usually neglected in the application of TFC membrane. This study fabricated a series of polydopamine (PDA)/TFC membranes incorporated with different concentrations of ball-milled biochar (BMBC) interlayer by the combination of conventional interfacial polymerization and bar coating method and employed them in antibiotics wastewater removal. Results indicated that water permeability of the optimized membrane (PDA/TFC-2) improved nearly two-fold (32 ± 1.8 LMHB (L.m−2·h−1·bar−1) versus 18.6 ± 1.6 LMHB for control membrane), and the rejection rates were also the highest (91.9% for chlortetracycline, 90.3% for tetracycline, 81.8% for Ciprofloxacin and 91.3% for oxytetracycline). Furthermore, the fouled PDA/TFC-2 membrane could be easily regenerated by NaOH washing and remained ~70.6% permeability flux of that of fresh membrane even after five times washing, while the rejection rate was still more than 60%. The findings of our study not only provide a promising material for the separation of antibiotic wastewater but also give a new sight towards the application of biochar in wastewater treatment. [ABSTRACT FROM AUTHOR]

Traditional sewage treatment technology cannot remove heavy metals, which needs to be improved urgently. Lysinibacillus with the function of bio-mineralization was screened and loaded on granular sludge to form a phosphate-mineralized bacterial consortium, which demonstrated the ability of self-regulating pH and automatic solid-liquid separation. Heavy metals could be fixed on the bacterial consortium to produce stable and harmless phosphate minerals. The highest removal efficiency of Pb(Ⅱ), Cd(Ⅱ), and Ni(Ⅱ) were 97.9%, 70%, and 40%, respectively. Organic matter and other metal ions in actual polluted water had little effect on the Pb(Ⅱ) removal efficiency. Mechanism analysis was conducted through 3D-EEM, XRD, SEM-EDS, XPS, FTIR, and high-throughput sequencing analyses. The bacterial consortium was a multi-species coexistence system, but Lysinibacillus played a major role in removing Pb(Ⅱ). C-O and O-H bonds of tyrosine and phosphorous organics were broken by enzyme catalysis and the metal-oxygen bond (Pb-O) was formed. Mineral crystals in the reactor accumulated, transforming from the initial phase non-crystalline structure to the metaphase Pb 3 (PO 4) 2 and eventually to the Pb 5 (PO 4) 3 OH. This research obtained a promising technique for immobilizing Pb(Ⅱ) or other hazardous metals continuously and efficiently. [Display omitted] • The aerobic granular sludge has been improved to immobilize heavy metals. • Rapid and automatic solid-liquid separation can be realized. • The reactor possessed a strong resistance to the actual polluted wastewater. • The mechanism of Pb(Ⅱ) removal in the reactor was analyzed. [ABSTRACT FROM AUTHOR]

Coupling of adsorption and advanced oxidation processes triggered by metal-free carbocatalysts is an appealing wastewater purification scheme. However, its practical application is challenging due to the unsatisfactory stability of conventional heteroatom-doped systems. Herein, we innovatively developed a simple and scalable biochemical strategy to synthesize selenium and nitrogen co-doped biochar (Se/N-BC) as a bifunctional catalyst of adsorption-oxidation. The Se/N-BC displays the highest efficiency of phenol (PE) degradation (99.2% of PE was removed within 5 min) with the lowest dosage of catalyst (0.1 g L−1) and peroxymonosulfate (PMS, 0.4 g L−1). More importantly, the Se/N-BC is not only universal in a wide pH range of 3.0–11.0 and complex ionic environment, but also possesses an excellent cycling stability. The Se/N co-doping induces a rapid cycle of adsorption-degradation for PE. The Se/N-BC acts as an "electron transfer bridge", guiding rapid electron transfer from PE to PMS to achieve high-efficient degradation. The Se/N co-doping facilitates the formation of graphitic N and unlocks the potential of adjacent C sites for PMS activation, consequently boost oxidation efficiency. In addition, the oxidation of catalyst is prevented due to the antioxidant properties of Se, which has been a primary concern either to regenerate adsorbate or to enhance degradation performance. [Display omitted] • Se/N-BC was fabricated using the bacterial cells contained bio-reduced Se0. • The Se/N co-doping triggered a rapid cycle of adsorption-degradation for PE. • Se/N-BC activated the peroxymonosulfate through a nonradical mechanism. • The activated Se/N-BC-PMS* complex dominated the degradation reaction. • The Se-C-N sites were identified as the primary catalytic sites. [ABSTRACT FROM AUTHOR]