Simultaneous visible-light-induced hydrogen production enhancement and antibiotic wastewater degradation using MoS2@ZnxCd1-xS: Solid-solution-assisted photocatalysis

In this study,a ZnxCd1-xS solid solution was successfully synthesized using a hydrothermal method.MoS2 serving as a co-catalyst for hydrogen evolution was also prepared through a one-pot hydrothermal method.The structures,morphology,chemical states,and optical properties were characterized using powder X-ray diffraction,scanning electron microscopy,high-angle annular dark field-scanning transmission electron microscopy,elemental mapping,X-ray photoelectron spectroscopy,and UV-Vis diffuse reflection spectroscopy.Visible-light-driven photocatalytic experiments were conducted to simultaneously achieve hydrogen production and amoxicillin antibiotic wastewater degradation.The results indicated 8%MoS2/ZnxCd1-xS achieves the best photocatalytic performance.The ZnxCd1-xS samples illustrated a superior performance to that of CdS,which can be attributed to a thermodynamic improvement.Based on the results of PL and TRPL analyses,the enhancement of the hydrogen production mechanisms can be ascribed to the prolonged separation process of the photocarriers.Furthermore,the degradation results were analyzed using the HPLC method and the possible degradation pathways were determined through the HPLC-MS techniques.

Pretreatment of apramycin wastewater by catalytic wet air oxidation

The pretreatment technology of wet air oxidation(WAO) and coagulation and acidic hydrolysis for apramycin wastewater was investigated in this paper. The COD, apramycin, NH^+_4 concentration, and the ratio of BOD_5/COD were analyzed, and the color and odor of the effluent were observed. WAO of apramycin wastewater, without catalyst and with RuO_2/Al_2O_3 and RuO_2-CeO_2/Al_2O_3 catalysts, was carried out at degradation temperature of 200℃ and the total pressure of 4 MPa in a 1 L batch reactor. The result showed that the apramycin removals were respectively 50 2% and 55 0%, COD removals were 40 0% and 46 0%, and the ratio of BOD_5/COD was increased to 0 49 and 0 54 with RuO_2/Al_2O_3 and RuO_2-CeO_2/Al_2O_3 catalysts in catylytic wet air oxidation(CWAO) after the reaction of 150 min. With the pretreatment of coagulation and acidic hydrolysis, COD and apramycin removals were slight decreased, and the ratio of BOD_5/COD was increased to 0 45, and the effluents was not suitable to biological treatment. The color and odor of the wastewater were effectively controlled and the reaction time was obviously shortened with WAO. HO_2· may promote organic compounds oxidized in WAO of the apramycin wastewater. The addition of CeO_2 could promote the activity and stability of RuO_2/Al_2O_3 in WAO of apramycin wastewater.

Effects of Influencing Factors on Fenton Oxidation of Antibiotic Pharmaceutical Wastewater by a Statistical Design Approach

A series of batch-scale experiments were completed to investigate the effects of operational parameters on chemical oxygen demand (COD) removal by Fenton reagent for antibiotic pharmaceutical wastewater (APW). The significance of five operational factors including the mass ratio of H2O2/COD (g/g), the mole ratio of H2O2/Fe2+ (mol/mol), initial pH, oxidation temperature T, and reaction time t were evaluated statistically by Box-Behnken design (BBD). It was found that the five parameters were all significant to the COD removal efficiency by t-test, as well as the interactions between mass ratio/reaction time and oxidation temperature/reaction. The optimal COD removal efficiency (89.50%) was achieved when the mass ratio of H2O2/COD and the mole ratio of H2O2/Fe2+ were 3.00 and 5.00 respectively, with pH value of 3.68 at 298K for 72min reaction. A quadratic regression model with 0.9907 regression coefficient (R2) was developed which had good agreement to the experimental data.

Screening of an Effective Degrading Strain for Treatment of Antibiotic Pharmaceutical Wastewater and Determination of Its Biological Properties

In this study,an effective antibiotic-degrading strain NG3 was isolated from activated sludge of antibiotic wastewater treatment.According to the results of morphological,physiological and biochemical identification and phylogenetical analysis of 16S r DNA sequence,the isolated strain belonged to Acinetobacter sp.,which was named Acinetobacter sp.NG3.Moreover,biological properties of the isolated strain were analyzed preliminarily,which provided a basis for the application of Acinetobacter sp.NG3 strain in efficient treatment of antibiotic industrial wastewater.

A combined evaluation of the characteristics and antibiotic resistance induction potential of antibiotic wastewater during the treatment process

Antibiotic wastewater contains a variety of pollutant stressors that can induce and promote antibiotic resistance(AR)when released into the environment.Although these substances are mostly in concentrations lower than those known to induce AR individually,it is possible that antibiotic wastewater discharge might still promote the AR transmission risk via additive or synergistic effects.However,the comprehensive effect of antibiotic wastewater on AR development has rarely been evaluated,and its treatment efficiency remains unknown.Here,samples were collected from different stages of a cephalosporin production wastewater treatment plant,and the potential AR induction effect of their chemical mixtures was explored through the exposure of the antibiotic-sensitive Escherichia coli K12 strain.Incubation with raw cephalosporin production wastewater significantly promoted mutation rates(3.6×10^(3)-9.3×10^(3)-fold)and minimum inhibition concentrations(6.0-6.7-fold)of E.coli against ampicillin and chloramphenicol.This may be attributed to the inhibition effect and oxidative stress of cephalosporin wastewater on E.coli.The AR induction effect of cephalosporin wastewater decreased after the coagulation sedimentation treatment and was completely removed after the full treatment process.A Pearson correlation analysis revealed that the reduction in the AR induction effect had a strong positive correlation with the removal of organics and biological toxicity.This indicates that the antibiotic wastewater treatment had a collaborative processing effect of conventional pollutants,toxicity,and the AR induction effect.This study illustrates the potential AR transmission risk of antibiotic wastewater and highlights the need for its adequate treatment.

Preparation of Bi_(2)O_(3)/BiOI Step-scheme Heterojunction Photocatalysts and Their Degradation Mechanism of Methylene Blue

Bi_(2)O_(3)/BiOI step-scheme(S-scheme) heterojunction photocatalyst was synthesized by green calcination method, its degradation ability of methylene blue was investigated, and the photocatalytic performance of the Bi_(2)O_(3)/BiOI heterojunction, Bi_(2)O_(3) and BiOI was compared. The structure and morphology of the samples were characterized by X-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), and UV-vis diffuse reflection spectrum (UV-vis DRS). The degradation rate of methylene blue was analysised by spectrophotometry, and the calculation result showed that the degradation rate of methylene blue was 97.8% in 150 minutes. The first order kinetic rate constant of 10%Bi_(2)O_(3)/BiOI is 0.021 8 min^(-1), which are2.37 and 2.68 times of BiOI(0.009 18 min^(-1)) and Bi_(2)O_(3) (0.008 03 min^(-1)) respectively. The calculation result shows that the work function of Bi_(2)O_(3) and BiOI are 3.0 e V and 6.0 e V, respectively, by density functional theory(DFT). When this S-scheme heterojunction is used as a photocatalyst, the weaker electrons in the conduction band of BiOI will be combined with the weaker holes in the Bi_(2)O_(3) valence band under combined effect with built-in electric field and band bending, which will retain stronger photoelectrons and holes between Bi_(2)O_(3) and BiOI. This may be the internal reason for the efficient degradation of tetracycline by Bi_(2)O_(3)/BiOI S-scheme heterostructures.

Occurrence of veterinary antibiotics in struvite recovery from swine wastewater by using a fluidized bed

Recovering phosphorus from livestock wastewater has gained extensive attention. The residue of veterinary antibiotics in the wastewater may be present in the recovered products, thereby posing pharmacological threats to the agricultural planting and human health. This study investigated antibiotic occurrence in the struvite particles recovered from swine wastewater by using a fluidized bed. Results revealed that tetracyclines possessed significant residues in the struvite granules, with the values ranging from 195.2μg.kg^-1 to 1995.0 μg.kg^-1. As for fluoroquinolones, their concentrations varied from 0.4μg·kg^-1 to 1104.0 μg·kg^-1. Struvite particles were of various sizes and. shapes and displayed different antibiotic adsorption capacities. The data also showed that the smaller granules contained much more antibiotics than the larger ones, indicating that the fluidized granulation process of struvite crystals plays an important role on the accumulation of antibiotics. For tetracyclines, organic matters and struvite adsorption exerted significant impacts on tetracyclines migration. The outcomes underscore the need to consider the residues of antibiotics in resource recovery from wastewater because they exert pharmacological impacts on the utilization of recovered products.

Photocatalytic fuel cell for simultaneous antibiotic wastewater treatment and electricity production by anatase TiO_(2) nanoparticles anchored on Ni foam

Photocatalytic fuel cell (PFC) holds great potential for the sustainable production of electricity and degradation of organic pollutants for solving global energy and environmental problems.However,the efficient photodegradation of organic dyes and antibiotic drugs,such as ciprofloxacin (CIP) and methylene blue(MB),remains challenging.Aiming at improving the separation efficiency of hole and electron for electricity generation in the PFC system,TiO_(2)-NPs@NF-x photoanode was fabricated by a cost-effective and laborsaving hydrothermal approach.The as-fabricated photoanode demonstrated abundant active sites,enhanced light harvesting capacity and photogenerated charge carrier separation.At a CIP-HCl concentration of 10 mg/L and p H value of about 7,85%of CIP-HCl can be efficiently removed after 3 h irradiation by 300 W Xe lamp.TiO_(2)-NPs@NF-20 photoelectrode based PFC system exhibited an impressed ability to simultaneously degrade ciprofloxacin and generate electricity under light irradiation with an open circuit voltage of 1.021 V,short circuit current density and maximum power density of 2.4 mA/cm^(2),0.357 mW/cm^(2),respectively.This work provided a cost-effective method for the treatment of organic waste and generation of electrical power.

Algae-mediated antibiotic wastewater treatment:A critical review

The existence of continually increasing concentrations of antibiotics in the environment is a serious potential hazard due to their toxicity and persistence.Unfortunately,conventional treatment techniques,such as those utilized in wastewater treatment plants,are not efficient for the treatment of wastewater containing antibiotic.Recently,algae-based technologies have been found to be a sustainable and promising technique for antibiotic removal.Therefore,this review aims to provide a critical summary of algae-based technologies and their important role in antibiotic wastewater treatment.Algal removal mechanisms including bioadsorption,bioaccumulation,and biodegradation are discussed in detail,with using algae-bacteria consortia for antibiotic treatment,integration of algae with other microorganisms(fungi and multiple algal species),hybrid algae-based treatment and constructed wetlands,and the factors affecting algal antibiotic degradation comprehensively described and assessed.In addition,the use of algae as a precursor for the production of biochar is highlighted,along with the modification of biochar with other materials to improve its antibiotic removal capacity and hybrid algae-based treatment with advanced oxidation processes.Furthermore,recent novel approaches for enhancing antibiotic removal,such as the use of genetic engineering to enhance the antibiotic degradation capacity of algae and the integration of algal antibiotic removal with bioelectrochemical systems are discussed.Finally,some based on the critical review,key future research perspectives are proposed.Overall,this review systematically presents the current progress in algae-mediated antibiotic removal technologies,providing some novel insights for improved alleviation of antibiotic pollution in aquatic environments。

Effects of hydraulic retention time on net present value and performance in a membrane bioreactor treating antibiotic production wastewater

A cost sensitivity analysis was performed for an industrial membrane bioreactor to quantify the effects of hydraulic retention times and related operational parameters on cost.Different hydraulic retention times(72-24 h)were subjected to a flat-sheet membrane bioreactor updated from an existing 72 h oxidation ditch treating antibiotic production wastewater.Field experimental data from the membrane bioreactor,both full-scale(500 m/d)and pilot(1.0 m3/d),were used to calculate the net present value(NPV),incorporating both capital expenditure(CAPEX)and operating expenditure.The results showed that the tank cost was estimated above membrane cost in the 38.2%,where capital expenditure contributed 24.2%more than operational expenditure.Tank construction cost was decisive in determining the net present value contributed 62.1%to the capital expenditure.The membrane bioreactor has the advantage of a longer lifespan flat-sheet membrane,while flux decline was tolerable.The antibiotics decreased to 1.87±0.33 mg/L in the MBR effluent.The upgrade to the membrane bioreactor also benefited further treatments by 10.1%-44.7%lower direct investment.