Treatment Of Tannery Wastewater Research Articles

Treatment of tannery wastewater by electrocoagulation technology

Treatment of tannery wastewater by electrocoagulation (EC) process was investigated in this study. Treatment of the wastewater was carried out by an electrochemical batch reactor equipped with aluminum electrodes, which were connected parallel to each other. The optimum operating conditions were determined and applied to the process. The maximum obtained values for COD, color and turbidity removal efficiencies were 100%, 84%, and 85%, respectively, for an operating time of 21 minutes.The obtained results indicate that EC reactor is the applicable option to treat tannery industry wastewater in terms of removal efficiency and operating cost.

Tratamiento de agua residual procedente de la industria de curtiembres mediante humedales subsuperficiales usando zantedeschia aethiopica

Dos humedales de flujo subsuperficial a escala banco fueron evaluados para la depuración de agua residual de la industria de la curtiembre. Para la construcción de los mismos se usaron tanques de 51 cm de largo, 35 cm de ancho y 30 cm de alto; un sustrato de grava mixta de 25 cm de altura compuesta por dos tipos de granulometría de 9 mm y 12,5 mm fue usado como material de relleno. Uno de los humedales fue plantado con Zantedeschia Aethiopica, mientras el otro se dejó sin plantar como control. Seguimiento de diferentes pará- metros físicos y químicos pH, turbiedad, DQO y Cromo total fue realizado. Los humedales fueron puestos en operación con diferentes diluciones del agua residual; iniciando con una más diluida y finalizando con agua sin diluir a fin de acondicionar el humedal. La operación de los humedales fue en recirculación y se realizó un seguimiento por 26 días. Mejoras significativas en todos los parámetros evaluados fueron obtenidas por el tratamiento con ambos humedales. Sin embargo no hubo diferencias significativas entre el humedal plantado y sin plantar. La acumulación de cromo en las plantas se dio tanto en raíces como en tallo, hojas flores, haciendo de la ideal para procesos de fitoestabilización y fitoremediación.

Green synthesis of TiO2 nanoparticles using leaf extract of Jatropha curcas L. for photocatalytic degradation of tannery wastewater

Green synthesis is a simple, eco-friendly and emerging approach of synthesizing nanoparticles (NPs) and currently, attracting scientific community from around the world. The objective of the present study was to synthesize green titanium dioxide (TiO2) NPs and evaluate its performance for the photocatalytic treatment of TWW after the secondary (biological) treatment process. TiO2 NPs was synthesized using leaf extract of the biodiesel plant, Jatropha curcas L. in a one-step at room temperature to examine its treatability for tannery wastewater (TWW). Moreover, the green synthesized TiO2 NPs was further characterized by UV–Visible spectrophotometer, Field Emission Scanning Electron Microscopy (FESEM), X-ray Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared (FT-IR) spectroscopy, X-ray Diffraction (XRD), Dynamic Light Scattering (DLS), Brunauer-Emmett-Teller (BET) and Barret-Joyner-Halenda (BJH) analysis. Results confirmed the synthesis and anatase phase of the spherical TiO2 NPs and also unfold the presence of phytochemicals in leaf extract, which might involve in the capping/stabilization of NPs. Further, the green synthesized TiO2 NPs was applied for the first time to testify its potential for the simultaneous removal of chemical oxygen demand (COD) and chromium (Cr) from secondary treated TWW. During the photocatalytic treatment of wastewater in a self-designed and fabricated Parabolic Trough Reactor (PTR), 82.26% removal of COD and 76.48% removal of Cr from TWW was achieved upon the treatment with green synthesize TiO2 NPs, and thus, successfully employed for the wastewater treatment. Overall, the green synthesized TiO2 NPs demonstrated the astounding potential for the in-situ treatment of TWW as an alternative clean-green treatment solution.

English

Most of the leather industries in Ethiopia discharge their effluent partially or without any treatment to the nearby water bodies. This creates a serious effect on aquatic biota and surrounding environment due to its high organic loading and chromium content. To minimize the effect, tannery wastewater should be treated before the effluent is discharged to the environment. Therefore, the main objective of the study was to use a two stage laboratory scale Anaerobic Sequence Batch Digester (Reactor) in order to investigate the potential of composite tannery wastewater to produce biogas. Two Stage Anaerobic Sequence Batch Digester was used because it has a conducive environment for micro-organisms at different temperature. The present study characterized composite tannery wastewater with respect to biogas production parameters. Four sets of conditions were investigated: Mesophilic to mesophilic; thermophilic to thermophilic; mesophilic to thermophilic and thermophilic to mesophilic in the hydrolysis/acidification and methanogenesis stages (reactors), respectively. The Organic Loading Rate (OLR) was ranged between 9.58 and 10.28 kg COD/m3 day throughout the study. The highest volume of biogas (7232 ml) and content of methane (69.75%) was in the thermophilic‑thermophilic phase. The removal efficiency of total solid (TS) and volatile solids (VS) of all digesters were in the range of 52 to 69 and 58 to 81%, respectively, treatment of composite tannery wastewater by a two stage Anaerobic Sequence Batch Digester (Reactor) (ASBR) produces high amount of methane at thermophilic - thermophilic phase and the lowest produced in mesophlic- mesophlic phase. Digesters in mesophilic-thermophilic (D3) produced higher biogas and biogas quality than digesters with thermophilic- mesophlic (D4) ones. Key words: Anaerobic sequential batch reactor, wastewater to energy, tannery wastewater management.

Investigation of electrodialysis anti-fouling configuration for desalting and treating tannery unhairing wastewater: Feasibility of by-products recovery and water recycling

The desalination and treatment of tannery unhairing wastewater by electrodialysis (ED) is investigated in this research in order to separate, concentrate, recover and reuse low molecular weight charged species (S2−, HS−, OH−, Cl−, Ca2+, Na+ and amino acids), and to separate proteins and recycle treated water. Therefore, a novel electrodialysis membrane configuration was proposed. This was based on a double anti–fouling membrane. The ED anion exchange membrane (AEM), which is very sensitive to organic fouling, was protected by an ultra filtration membrane impermeable to the negatively charged proteins that could not reach the AEM surface. The experimental results were quite promising, and in spite of only one desalination compartment ED cell; the demineralization efficiency was 56 ± 1.25% (5.5–2.4 mS/cm), with a sensitive removal of sulphide, calcium and chloride. The organic matter (protein, peptides…) was isolated in the dilute compartment. The most important result was the total absence of membrane fouling.The experimental results remarkably proved the initial hypothesis, and suggested promising solutions for industrial pollution, where the membrane processes have never been successful.

Treatment of Tannery Wastewater Using Polymerization and Biosorption Technologies

In Egypt, the tannery wastewater is discharged directly to the main domestic sewage pipeline which adds difficulties to the sewer system and to the wastewater treatment plants. Therefore, the removal of the chromium content of these wastewaters and other toxic constituents is necessary for environmental protection and economic reasons. The purpose of this study was to determine the use of alginate as polymer to prepare metal sorbing beads and determine the ability of sodium hydroxide treated Aspergillusniger (immobilized biomass) to remove toxic constituents from tannery wastewater from chromium stage Elmontaza tannery – Ein Elsira, Cairo, Egypt. Batch sorption experiments were carried out at room temperature 25 ± 3oC, pH 5.0 ± 0.2 and 250 rpm for two hours of contacts. Results obtained show that, adsorption efficiencies of Aspergillusniger (immobilized biomass) and Ca-alginate respectively, for chromium (15%, 43.5 %), cadmium (70.97%, 51.6 %), copper (91.9%, 67.4%), lead (79.9%, 57.8%), nickel (93.8%, 73.02%), iron (58.3%, 51.02%) and manganese ions (87.6%, 74.8%). Also, Results showed decrease in color absorbance and organic loads from tannery wastewater. It can be concluded that the immobilized biomass had gained several advantages over the polymer; it was more effective in decreasing all toxic constituents from tannery wastewater.

Integrated tannery wastewater treatment for effluent reuse for irrigation: Encouraging water efficiency and sustainable development in developing countries

Due to the high conductivity and chromium toxicity of tannery effluents, wastewater reuse can be possible only by implementing integrated process of sustainable wastewater treatments. The objective of the present study was to evaluate the suitability of treated tannery effluent for vegetable growth. An integrated treatment technology [hydrolysis-anaerobic-Sequence Batch Reactor (SBR) integrated with a constructed wetland] was used to treat tannery wastewater. Randomized block design for field and pot experiment was used for vegetable growth. Treated effluent, soil and vegetable samples were analyzed for nutrient, physicochemical, Cr and microbial parameters using standard methods (APHA). The removal efficiency of the innovative integrated treatment system ranges from 82 to 99.9%. The treated effluent concentrations for BOD, COD, TN, NO3–N, and NH3–N were 56 ± 18, 170 ± 26, 50 ± 13, 22.75 ± 20 and 7.1 ± 6 mg/L, respectively. Similarly, the concentration of EC, S2−, SO42− and Cl− were 2.23 ± 0.17 mS/cm, 0.4 ± 0.4, 88 ± 42 and 450 ± 150 mg/L, respectively; with a 99.9% TCF removal. The effluent meets the permissible discharge limits; possibly reuse for irrigation. Cr was found to accumulate the most in all vegetable samples and significantly higher in the field than pot treatments. Cr, Cd, Pb and Ni concentrations in all the pot experiment were found below the FAO/WHO guidelines. The target hazard quotients (THQs) estimation suggests that Cr concentration in all the pot treatment vegetable has no potential health risk.

Performance evaluation of membrane bioreactor (MBR) coupled with activated carbon on tannery wastewater treatment

This study evaluates the performance of membrane bioreactor (MBR) coupled with a modified walnut shell granular activated carbon (WSGAC) for tannery wastewater treatment. For this purpose, a pilot with overall volume of 80L and 12 hours hydraulic retention time (HRT) is operated in three scenarios. Here, the chemical oxidation demand (COD) of wastewater is reduced more than 98% in both C:N ratios of 13 (S1) and 6.5 (S2). This performance also remains intact when alkalinity depletes and pH reduces below 6 (S3). The ammonium removal ranges between 99% (S2) and 70% (S3). The reliability of system in different operating conditions is due to high solids retention time and larger flocs formation in MBR. The average breakthrough periods of WSGAC are determined between 15 minutes (S2) and 25 minutes (S1). In this period, the overall nitrate removal of MBR-WSGAC exceeds 95%. It is also realized that adding no chemicals for alkalinity stabilization and consequently pH reduction of MBR effluent (S3) can slightly lengthen the breakthrough from 15 to 20 minutes. Consequently, MBR can successfully remove the organic content of tannery wastewater even in adverse operational conditions and provide proper influent for WSGAC.

Design of Experiments for the Optimization of Biochemical Treatment of Tannery Wastewater

The present work is concerned with the finding of the optimum conditions for biochemical wastewater treatment for a local tannery The water samples were taken from outline areas the wastewater of the chrome and vegetable tannery in equal volumes and subjected to sedimentation biological treatment chemical and natural sedimentation treatment The Box Wilson method of experimental design was adopted to establish relationships between three operating variables that affect the treatment processes temperature aeration period and phosphate concentration and the Biochemical Oxygen Demand BOD The experimental data collected by this method were successfully fitted to a second order polynomial mathematical model The most favorable operating conditions for the treatment were a temperature C hours aeration period and phosphate concentration of mg L On using the optimum conditions a mathematical model simulating the operation for the treatment was obtained

Defatted microalgal biomass as biosorbent for the removal of Acid Blue 161 dye from tannery effluent

The present study investigates the use of defatted microalgal biomass – DAB (waste from microalgal biofuel) as an alternative proposal adsorbent of leather dyes. The biomass was characterized by analytical techniques of Zeta Potential, FTIR, SEM, BET and BJH. The sorption experiments were performed using aqueous dye solutions of Acid Blue 161 (AB-161) and the equilibrium studies were carried out by variation in different parameters, i.e., pH (2–11), biosorbent dosage (0.005–0.040g), contact time (0–540min), temperature (25–40°C) and dye concentration (200–1500mgL−1). In the evaluation of the kinetic mechanism that controls the adsorption process examined at 200 and 400mgL−1, it was observed that data fitted quite well with general order kinetic model. Freundlich isotherm model showed the best fit of the equilibrium data at boths experimental temperatures. The maximum amounts of AB-161 dye adsorbed were 75.78mgg−1 at 25°C and 83.2mgg−1 at 40°C. For treatment of real tannery wastewater, the results show that DMB significantly reduced the dye concentration (76.65%), TOC (50.78%) and TN (19.80%). From the thermodynamic parameters for the adsorption of AB-161 with DMB indicated a spontaneous endothermic process with a physical reaction by electrostatic interaction. Therefore, defatted microalgal biomass showed to be a promising material for adsorption of dye from tannery effluent.

Anaerobic treatment of tannery wastewater using ASBR for methane recovery and greenhouse gas emission mitigation

The objective of this study was to develop and optimize a pilot scale Anaerobic Sequencing Batch Reactor (ASBR) for the treatment tannery wastewater and reduction of greenhouse gas emission. The performance of the pilot scale ASBR was evaluated at the OLRs of 1.03, 1.23, 1.52 and 2.21kgm−3d−1 under mesophilic condition (31°C). The removal efficiencies of COD and methane yield in the pilot scale ASBR were in the range of 69–85% and 0.17±0.2–0.30±0.02m3/kg COD removed, respectively. The optimum COD removal and methane yield were obtained at OLR of 1.03kgm−3d−1 (HRT of 4days) in the stepwise feeding mode. The maximum amount of COD (83.3±3.6%) converted to methane was also obtained in the same loading rate. At this OLR, the volumetric methane production would be 148,190m3 per year when the digester will be operated at full scale level. The total amount of GHG emission reduction from factory is estimated in the range between 1500 and 3032tons CO2-eq per year. Generally, the results of this study showed that ASBR is efficient on generating biogas and reducing green house gas emission while treating high strength wastewater such as tannery. Hence, a full scale ASBR should be developed and used to treat the wastewater generated in the tanning industries.

Combined electrocoagulation/electrooxidation process for the COD removal and recovery of tannery industry wastewater

The efficiencies of electrooxidation (EO), electrocoagulation (EC) and combined EC/EO processes for the treatment and recovery of tannery wastewater were investigated. In this way, not only the effect of retention time and current density on the COD and color removal was investigated, but also, the recovery of effluent was investigated to provide a standard quality for effluent disposal and supply for agricultural and industrial uses. The results showed that the EO process was able to eliminate COD and color by 98.9 and 99.0%, respectively. The EC process at optimum conditions had the removal efficiencies of 82.2 and 68.3% for COD and color, respectively, which could not treat the effluent completely. While the EC process produces a wastewater with COD of 1620 mg/L that needs extra treatment for agriculture and reuse, the process of EO produces a wastewater with COD of about 92 mg/L, whose its organic loading is suitable for agricultural purposes but not appropriate for industrial uses. The combined EC/EO process can produce an effluent with COD ≤ 5 mg/L that has standard quality for disposal and use for agricultural needs as well as for reuse in tannery process. Moreover, the EC/EO process has low energy consumption of 18.2 kWh/m3 as compared with EO process with energy consumption of 60 kWh/m3. The combined EC/EO process is useful for the treatment of tannery wastewater so that the effluent can be used for industrial purposes. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 637–644, 2018

Synthesis of zeolite A using raw kaolin from Ethiopia and its application in removal of Cr(III) from tannery wastewater

AbstractBACKGROUNDThe commercial production of zeolite A mainly involves costly synthetic chemicals. However, cheaper raw materials such as clay minerals, coal ashes, natural zeolites, solid wastes and industrial sludge have been tested. Based on this, the objective of the present study is synthesis of zeolite A from two sources of raw kaolins (Ansho and Bombowha) from Ethiopia and evaluation of its application in tannery wastewater treatment.RESULTSThe synthesis result indicated high crystallinity (>90%) of zeolite A using Ansho kaolin. Lower grade Bombowha kaolin yielded zeolite A with crystallinity of 80%. In the tannery wastewater treatment study, a real sample having chromium concentration of 2036 mg L−1 was treated, obtaining 99.8% removal and about 200 mg g−1 adsorption capacity of Cr(III) using 100 g L−1 and 5 g L−1 adsorbent dose, respectively. This indicated that the synthesized zeolite A has great potential for Cr(III) removal from tannery wastewater.CONCLUSIONIn this study, zeolite A has been synthesized from two sources of kaolin from Ethiopia and has been evaluated in tannery wastewater treatment. The synthesis result indicated the formation of crystals of zeolite A with optimum crystallinity of 91% and the material exhibited chromium removal efficiency of 99.8%. © 2017 Society of Chemical Industry

Advanced oxidation processes for the treatment of tannery wastewater

This study has focused on the treatment of real tannery effluent using different advanced oxidation processes in lab and pilot scale studies. Periodic monitoring was conducted for five months to identify the performance at different stages of treatment in the CETP. Monthly monitoring analysis shows that ratio of biochemical oxygen demand (BOD) and chemical oxygen demand (COD) were about 0.1–0.25. It was observed that even after physicochemical treatment the sample had a low biodegradability index (BDI). For this reason, more efficient methods of advanced oxidation processes like Fenton, Ozonation have been experimented with primary settling tank (PST) effluent to improve the biodegradation in the successive activated sludge process and secondary settling tank (SST) effluent to remove the residual inorganics. Sample collection and analysis were performed using standard methods of analysis. Pollutant removal efficiency was measured in terms of reduction in COD and Total Organic Carbon (TOC). The purification effect obtained by Advanced Oxidation Processes (AOPs) was better in Ozone when compared to Fenton. A three step process of (coagulation+aeration+O3) resulted in 80–90% reduction of COD. Coagulation, extended aeration followed by ozonation was recognized as the best method of treatment of tannery wastewater. Lab scale and pilot scale studies were done with real tannery wastewater effluents and the economics of the treatment processes were evaluated.

Sequential oxic-anoxic bio reactor for the treatment of tannery saline wastewater using halophilic and filamentous bacteria

The present investigation was focused on the removal of dissolved organics and suspended solids from tannery saline wastewater [TSWW]Raw, known as soak liquor, by sequential oxic-anoxic bio reactor (SOAR) using halophilic bacteria 3and filamentous bacteria (FB). The high concentration of Sodium Chloride (NaCl) in tannery wastewater retards biodegradation of dissolved organics. The aim of this study was to cultivate halophilic bacteria and facultative bacteria from tannery soil supported sewage culture using soak liquor nutrient, for the degradation of organics in [TSWW]Raw. SOAR was used for the maximum removal of proteins, 47.4%; carbohydrates, 44.8% and lipids, 70.4% from [TSWW]Raw at optimum HRT of 12h. The Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD) and suspended solids were removed by 36.8%, 31.2% and 72.6% respectively from [TSWW]Raw containing total dissolved solids (TDS) concentration of 6–7% (w/v) without the addition of any coagulants. The degradation of proteins (albumin and globulin) in [TSWW]Raw was evaluated and confirmed through circular dichroism (CD) studies. Further, the removal of organic compounds was characterized by UV–vis spectroscopy and fluorescence spectroscopy, TGA-DSC and FT-IR studies. The presence of filamentous bacteria was confirmed through SEM analysis.

Carbon and energy footprint analysis of tannery wastewater treatment: A Global overview

In this study the carbon footprint and power demand of tannery wastewater treatment processes for the largest bovine leather producing regions were quantified and analysed. Moreover, we present a case in which we benchmarked the carbon footprint and energy demand analysis of tannery wastewater treatment to municipal wastewater treatment. We quantified the greenhouse gas direct and indirect emissions from tannery wastewater treatment facilities. Our results show that the total CO2-equivalent emission for tannery wastewater treatment is 1.49 103 tCO2,eqd−1. Moreover, the energy intensity of tannery wastewater treatment processes are evaluated at 3.9kWhkg−1bCOD,removed, compared to 1.4kWhkg−1bCOD,removed of municipal wastewater treatment processes. Based on this work in the field of tannery wastewater treatment, an effort to innovate suitable treatment trains and technologies has the strong potential to reduce the carbon footprint.

Novel bioflocculant produced by salt-tolerant, alkaliphilic strain Oceanobacillus polygoni HG6 and its application in tannery wastewater treatment.

The optimized production of MBF-HG6, which is a novel salt-tolerant alkaliphilic bioflocculant produced by Oceanobacillus polygoni with its application in tannery wastewater treatment was investigated in this study. It was found the optimal carbon source, nitrogen source, cation, and initial pH of the medium for bioflocculant production were starch, urea, Fe2+, and pH 9.0, respectively. The best stability in the temperature range was from 0 to 80°C and the purified MBF-HG6 contained polysaccharides of 81.53% and proteins of 9.98%. The carboxyl, hydroxyl, and amino groups were determined in bioflocculants, while the optimized bioflocculating activity was observed as 90.25% for the dosages of 6.96mL MBF-HG6, 4.77mL CaCl2 (1%, m/v), and 19.24g/L NaCl using response surface methodology. In addition, SS and turbidity removal rates of the tannery wastewater (4g/L MBF-HG6) could, respectively, reach 46.49% and 91.08%, indicating that the great potential was emerged in enhancement of tannery wastewater treatment by MBF-HG6.

Treatment of tannery saline wastewater by using effective immobilized protease catalyst produced from salt tolerant Enterococcus feacalis

In this present investigation, the saline tolerant organism Enterococcus faecalis was isolated for the degradation of protein content of soak liquor discharged from tanneries. The optimized conditions for the growth of organism were fermentation time, 96h, pH, 9 and temperature, 40°C. The protease activity of the enzyme was determined to be 310U/mg. The enzyme was stable and retained its maximum activity at pH 7–9, temperature 30–40°C and Total dissolved solids (TDS) upto 40000mg/L. The activity of protease in different solvent systems (polar & non polar), organic matter (lipids), metal ions and surfactants were evaluated. The effect of time, pH and temperature for maximum immobilization of protease on functionalized nano porous activated carbon (f-NPAC) was optimized and it was confirmed through SEM and XRD analysis. The protein content of soak liquor was degraded by the protease immobilized functionalized nano porous activated carbon (Pr-NPAC) and the optimum conditions were studied. The degradation was achieved by 91% and it was confirmed through instrumental analysis such as FTIR, UV–vis and UV-Fluorescence spectroscopic studies.

Chemical toxicity and ecotoxicity evaluation of tannery sludge stabilized with ladle furnace slag

In this study, the stabilization of tannery sludge, which produced during the physico-chemical treatment of tannery wastewaters, was examined by the addition of ladle furnace slag. Moreover, the simultaneous addition of organoclay and ladle furnace slag for the stabilization of tannery sludge was also examined. Chromium and dissolved organic carbon in the leachate of raw tannery sludge, using the EN 12457-2 standard leaching test, were found to exceed the limit values for disposal in non-hazardous and even in hazardous waste landfills, according to the EU Decision 2003/33/EC. Tannery waste (air-dried sludge) was mixed with ladle furnace slag and water or ladle furnace slag, organoclay and water at different ratios, in order to study the stabilization of chromium and organic compounds. The mixtures were left for one week aging and then they were subjected to the standard leaching test EN 12457-2. The leachate of tannery waste stabilized with ladle furnace slag showed Cr concentrations below the respective regulation limit value for disposal in non-hazardous waste landfills; however, the dissolved organic carbon cannot meet the respective limit value. On the other hand, the leachate of tannery waste stabilized with a mixture of ladle furnace slag and organoclay, using 30:50:20 mass ratio, presented both Cr and dissolved organic carbon concentrations below the regulation limit values for disposal in non-hazardous waste landfills. Moreover, this leachate was further subjected to ecotoxicity test, using the Vibrio fischeri photo-bacterium. The leachate of stabilized tannery waste showed reduced ecotoxicity, in comparison with the toxicity effect of the leachate of the untreated tannery waste.

Microwave-assisted solvothermal synthesis of hierarchical TiO2 microspheres for efficient electro-field-assisted-photocatalytic removal of tributyltin in tannery wastewater

Organotin compounds have been widely used in recent decades, however, the residential tributyltin (TBT) in environment has potential harmful effects on human health due to the disruption of endocrine system even at trace level. Herein, this work reports on an effective electro-field-assisted-photocatalytic technique for removal of TBT by applying an electric field to photocatalysis of as-prepared hierarchical TiO2 microspheres. The synthesis of catalytic materials is based on a self-assembly process induced by microwave-assisted solvothermal reaction. Hierarchical TiO2 microspheres consisting of nanowires can be obtained in short time with this facile method and possess high surface area and superior optical properties. As the catalyst, it was found that the reaction rate constant of electro-field-assisted-photocatalytic removal (0.0488 min−1) of TBT exhibited almost a 9 fold improvement as compared to that of photocatalysis (0.0052 min−1). The proposed mechanism of electro-field-assisted-photocatalytic removal of TBT was verified by using 117Sn-enriched TBT spike solution as an isotopic tracer. In addition, varying impacts from some key reaction conditions, such as voltage of potential, pH value and the presence of Cr and formaldehyde were also discussed. The overall satisfactory TBT removal performance of the proposed electro-field-assisted-photocatalysis procedure with hierarchical TiO2 microspheres, which was validated using actual tannery wastewater samples from three different kinds of tanning procedures. These attributes suggest that this electro-field-assisted-photocatalysis may have broad applications for the treatment of tannery wastewater.