Removal Of Multiple Pollutants Research Articles

An efficient CuO-γFe2O3 composite activates persulfate for organic pollutants removal: Performance, advantages and mechanism.

CuO-γFe2O3 was fabricated as a novel and effective persulfate (PS) catalyst to remove bio-refractory organic pollutants. Characterization results showed that CuO-γFe2O3 possessed a relatively large surface area among transition metal oxides which provided favorable adsorption and activation sites for PS to degrade pollutants. There was an obvious synergy between CuO and γFe2O3 in the composite, which played 84.7% role in Acid orange 7 (AO7) removal. Under the optimal conditions (CuO-γFe2O3 dosage = 0.6 g L-1, PS dosage = 0.8 g L-1, unadjusted solution pH), almost complete AO7 was rapidly eliminated in 5 min. Moreover, the wide workable pH range (2-13), good stability (0.82 mg L-1 Cu leached, almost no Fe leached) and reusability (4 times) were the significant virtues of CuO-γFe2O3 for wastewater treatment. Besides, the reaction mechanism mainly based on the interaction among Cu(II/III) and Fe(II/III) species for sulfate radical (SO4-) generation was emphatically elucidated by the analyses of radicals, PS utilization, TOC removal and metal chemical states. Finally, CuO-γFe2O3+PS system displayed desirable removal of multiple organic pollutants with different molecular structures. In light of the prominent advantages of CuO-γFe2O3+PS, this work extended activated PS process in treating refractory organic wastewater.

Performance and microbial community of simultaneous removal of NO3−-N, Cd2+ and Ca2+ in MBBR

A moving-bed biofilm reactor (MBBR) containing immobilized Acinetobacter sp.CN86 was operated to investigate the simultaneous denitrification, bio-mineralization and cadmium removal performance. Effects of hydraulic residence time (HRT) (4 h, 6 h and 8 h), pH (6.0, 7.0 and 8.0) and influent Cd2+ concentrations (10 mg/L, 30 mg/L and 50 mg/L) were assessed on the simultaneous removal of nitrate, Cd2+ and Ca2+. Results indicate that the highest pollutant removal efficiency (98.33% (1.866 mg/L·h) for NO3−-N; 99.36% (1.242 mg/L·h) for Cd2+; 68.80% (15.480 mg/L·h) for Ca2+) was achieved under the conditions of a hydraulic residence time of 8 h, pH of 7.0 and initial Cd2+ concentration of 10 mg/L. Analyses of microbial distribution and community structures showed that Acinetobacter sp.CN86 was the main contributor (occupy 15.3% at the species level) to the effective removal of multiple pollutants in the MBBR. In addition, the main gas and precipitation components in the biofilm reactor were identified by gas chromatography, scanning electron microscope, and X-ray diffraction analyses.

Hg0 oxidation and SO3, Pb0, PbO, PbCl2 and As2O3 adsorption by graphene-based bimetallic catalyst ((Fe,Co)@N-GN): A DFT study

As important parts of simultaneous removal of multiple pollutants in flue gas, catalytic oxidation of Hg0 and adsorption removal of SO3, Pb species and As2O3 on the surface of (Fe,Co)@N-GN catalyst were systematically investigated in this work, using density functional theory. As a result, we found (Fe,Co)@N-GN not only showed great performance on Hg0 oxidation, but also exhibited outstanding removal capacity for SO3, Pb species and As2O3 molecules. Besides, PDOS and EDD analysis were carried out and the result indicated that electron transfer and orbit hybridization played key roles in gas adsorption. In addition, thermodynamics analysis further evidenced (Fe,Co)@N-GN was a qualified sorbent under 550 K, and competitive analysis suggested that the adsorption order of pollution gas was determined by adsorption energy, rather than the volume fraction of corresponding gases in flue gas. We hoped this work can not only lay a foundation for theoretical investigation of Hg0 oxidation, but also provide an important guideline for simultaneous removal of multiple pollutants released from coal-fired power plants.

Study on the denitrification performance of FexLayOz/activated coke for NH3-SCR and the effect of CO escaped from activated coke at mid-high temperature on catalytic activity.

Currently, activated coke is widely used in the removal of multiple pollutants from industrial flue gas. In this paper, a series of novel FexLayOz/AC catalysts was prepared by the incipient wetness impregnation for NH3-SCR denitrification reaction. The introduction of Fe-La bimetal oxides significantly improved the denitrification performance of activated coke at mid-high temperature, and 4% Fe0.3La0.7O1.5/AC exhibited a superior NOx conversion efficiency of 90.1% at 400°C. The catalysts were further characterized by BET, SEM, XRD, Raman, EPR, XPS, FTIR, NH3-TPD, H2-TPR, et al., whose results showed that the perovskite-type oxide of LaFeO3 and oxygen vacancies were produced on the catalysts' surfaces during roasting. Fe-La doping enhanced the amount of acid sites (mainly Lewis and other stronger acid sites) and the content of multifarious oxygen species, which were beneficial for NOx removal at mid-high temperature. Moreover, it was investigated that the effect of released CO from activated coke at mid-high temperature on the NOx removal through the lifetime test, in which it was found that a large amount of CO produced by pyrolysis of activated coke could promote the NOx removal, and long-term escaping of CO on the activated coke carrier did not have a significant negative impact on catalytic performance. The results of the TG-IR test showed that volatile matter is released from the activated coke while TG results showed that the weight loss rate of 4% Fe0.3La0.7O1.5/AC only was 0.0015~0.007%/min at 300-400°C. Hence, 4% Fe0.3La0.7O1.5/AC had excellent thermal stability and denitrification performance to be continuously used at mid-high temperature. Finally, the mechanisms were proposed on the basis of experiments and characterization results.

Bacterial cellulose derived paper-like purifier with multifunctionality for water decontamination

Contaminated water contains various types of pollutants, the removal of which requires two or more technologies. It is imperative but challenging to develop water purifier for simultaneous removal of multiple pollutants for the sake of easy operation, low cost, and etc. Previously reported multifunctional purifiers are normally nanoparticles which require caution during use. Here, we describe a design of paper-like multifunctional purifier, which has biomass-based structure by grafting polyethylenimine derived quaternary ammonium compounds onto three-dimensional bacterial cellulose substrate. Compared to similar materials reported previously, our product exhibited strikingly higher adsorption capacities towards various metal ions including Pb2+, Cu2+, and Cr6+, anionic organic dyes including congo red, methyl orange and methyl red, and excellent disinfection efficiency towards both Gram-negative and Gram-positive bacteria. Remarkably, this purifier also demonstrated effective removal of the three contaminative species simultaneously from both simulated and local polluted water. With more virtues of superior reusability and extreme handy convenience, we hope our molecular design could inspire further efforts on the rational construction of multifunctional water purifier with easy operation. We reckon our material to have strong potential for the possible use in water treatment, especially in regions that are short of environmental infrastructures.

Preparation of graphene oxide-montmorillonite nanocomposite and its application in multiple-pollutants removal from aqueous solutions.

It is of interest to develop a novel fabrication method of a mineral adsorbent for wastewater treatment to remove the combination of heavy metal ions and refractory organic contaminants. The crosslinking agent stearyl trimethyl ammonium chloride was added into a suspension of montmorillonite and graphene oxide to implement their recombination to fabricated graphene oxide-montmorillonite nanocomposite (GMN). The fabricated nanocomposite was characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller analysis and zeta potential. Results indicated that GMN exhibited a honeycomb texture, providing the chemical reaction site for the simultaneous adsorption of Pb2+ and p-nitrophenol (PNP). Factors including pH value, contact time, contact temperature and GMN dosage in the adsorption process were crucial for both Pb2+ adsorption and PNP adsorption. The optimum adsorption capacities of Pb2+ and PNP onto GMN were 19.39 mg·g-1 and 14.90 mg·g-1 under the condition of pH = 6, contact temperature 55 °C, contact time 60 min and GMN dosage 0.10 g, respectively. Data from experimental studies on simultaneous adsorption was well described by the pseudo-second-order model. The implementation of this work shows that GMN is a promising material for application in the simultaneous removal of heavy metal ions and refractory organic contaminants.

Multiple Pollutants Removal from Industrial Wastewaters Using a Novel Bioflocculant Produced by Bacillus licheniformis NJ3

This study deals with the potential of bioflocculant for the treatment of various industrial wastewaters. Bioflocculant (BFBl) produced by Bacillus licheniformis NJ3, showed 97% flocculating activity in primary screening (kaolin assay). The characteristics of the BFBl such as temperature and pH stability, cation‐independency makes the flocculation process more economic as harmful coagulants and stabilizers are not required. BFBl efficiently treated synthetic wastewaters as compared to alum by reducing turbidity (69–87%), chemical oxygen demand (50–80%) and oil (87%). Further BFBl was used to treat pesticide, petroleum, pharmaceutical and starch processing industrial wastewaters having diversified pH. It reduced total suspended solids (61.9–80%), turbidity (54–94%), total dissolved solids (11–54%), oil and grease (75%) and heavy metals (62–100%) from wastewaters in the absence of cations without altering the temperature and pH. Additionally, Sludge settling process in the presence of BFBl was three times faster as compared to alum. Thus, BFBl successfully treats various wastewaters reducing multiple pollution indices. BFBl was a glycoprotein with 92% polysaccharide and 7% protein contents providing biodegradable nature. As a result, BFBl emerged as environment‐friendly and economical alternative for the bioremediation of various industrial wastewaters. © 2018 American Institute of Chemical Engineers Environ Prog, 38: S306–S314, 2019

Simultaneous Adsorption of Heavy Metals from Roadway Stormwater Runoff Using Different Filter Media in Column Studies

Stormwater runoff from roadways often contains a variety of contaminants such as heavy metals, which can adversely impact receiving waters. The filter media in stormwater filtration/infiltration systems play a significant role in the simultaneous removal of multiple pollutants. In this study, the capacity of five filter media—natural quartz sand (QS), sandy soil (SS) and three mineral-based technical filter media (TF-I, TF-II and TF-III)—to adsorb heavy metals (Cu, Pb and Zn) frequently detected in stormwater, as well as remobilization due to de-icing salt (NaCl), were evaluated in column experiments. The column breakthrough data were used to predict lifespan of the filter media. Column experiment operated under high hydraulic load showed that all technical filters and sandy soil achieved >97%, 94% and >80% of Pb, Cu and Zn load removals, respectively, while natural quartz sand (QS) showed very poor performance. Furthermore, treatment of synthetic stormwater by the soil and technical filter media met the requirements of the Austrian regulation regarding maximum effluent concentrations and minimum removal efficiencies for groundwater protection. The results showed that application of NaCl had only a minor impact on the remobilization of heavy metals from the soil and technical filter media, while the largest release of metals was observed from the QS column. Breakthrough analysis indicated that load removal efficiencies at column exhaustion (SS, TF-I, TF-II and TF-III) were >95% for Cu and Pb and 80–97% for Zn. Based on the adsorption capacities, filtration systems could be sized to 0.4 to 1% (TF-I, TF-II and TF-III) and 3.5% (SS) of their impervious catchment area and predicated lifespan of each filter media was at least 35, 36, 41 and 29 years for SS, TF-I, TF-II and TF-III, respectively. The findings of this study demonstrate that soil—based and technical filter media are effective in removing heavy metals and can be utilized in full-stormwater filtration systems.

Synthesis of graphene oxide dots coated biomatrices and its application for the removal of multiple pollutants present in wastewater

Synthesis of a suitable adsorbent with multiple pollutants removal capacity could be a perfect solution to all water related pollution. This article presents a promising case, where graphene oxide dots (GOD) had been used to coat two different biomatrices and used to remove pollutants like dyes, fluoride, biomolecules and bacteria. The results indicated that after GOD coating the dyes and fluoride removal efficiency for both the biomatrices enhanced around 2–3 times than their untreated counterparts. Also protein removal efficiency of jute enhanced from 10% to around 70% after GOD coating. Similarly, bacteria removal efficiency of both the jute and chitin biomatrices enhanced more than 75%. Also, it was noticed that the preparation of GOD coated biomatrices were cost-effective and technically sound than the GO and GOD based alternatives. However, further study in detail is essential to establish the usability of the materials in multiple pollutants removal from water in large scale.

Highly efficient photocatalytic removal of multiple refractory organic pollutants by BiVO4/CH3COO(BiO) heterostructured nanocomposite

Highly efficient photocatalytic degradation of refractory organic contaminants in wastewater remains a great challenge due to low quantum efficiency and poor solar energy utilization of the currently employed photocatalysts. Herein, a novel BiVO4/CH3COO(BiO) heterojunction photocatalyst is designed and prepared by a simple one-pot solvothermal method, and characterized by various techniques. By using this photocatalyst, degradation efficiency of four kinds of emerging refractory organic pollutants (sulfamethoxazole, bisphenol A, 4‑aminoantipyrine and ibuprofen) in water is investigated under simulated solar irradiation. Then, total organic carbon is measured to determine the mineralization degree, and degradation intermediates of the pollutants are identified to propose their degradation pathway. It is found that under the given conditions, complete degradation of the pollutants is observed within the irradiation of 5–24 h, and 81–96% mineralization degree is achieved in 24 h. Furthermore, it is shown that the degradation kinetics can be described by pseudo-first order model. Based on the detected intermediates during the degradation process of 4‑aminoantipyrine and ibuprofen, the degradation pathways of these two pollutants are suggested to involve cleavage of side chain, heterocyclic ring opening and hydroxylation of aromatic ring. In addition, the application of the BiVO4/CH3COO(BiO) heterojunction photocatalyst in the purification of the spiked real wastewater is also investigated.

Synthesis and Impregnation of Copper Oxide Nanoparticles on Activated Carbon through Green Synthesis for Water Pollutant Removal

In this article was developed a green synthesis of CuO nanoparticles on vegetal activated carbon (VAC), using pomegranate leaf extract as reducing and stabilizing agent in the removal of multiple pollutants. The impregnated carbons with CuO nanoparticles were characterized morphologically and structurally. The SEM and XRD analysis, after carbons modification, showed that the surface structure remained porous with CuO nanoparticles sizes between 40 and 78 nm. As concern to the contaminants atrazine, caffeine and diclofenac, it is observed that the maximum adsorption capacities practically did not suffer interference by the presence of 1.5% Cu nanoparticles, keeping their values very close to those obtained with pure carbon. The nitrate removal was favored by the impregnation of CuO nanoparticles, from 0.93 mg g-1 to 4.09 mg g-1. The results are promising and demonstrate that it is possible to obtain VAC impregnated whit nanoparticles of CuO by a non-polluting and low cost method.

Inhibiting Mercury Re-emission and Enhancing Magnesia Recovery by Cobalt-Loaded Carbon Nanotubes in a Novel Magnesia Desulfurization Process.

Mercury re-emission, because of the reduction of Hg2+ to form Hg0 by sulfite, has become a great concern in the desulfurization process. Lowering the concentrations of Hg2+ and sulfite in the desulfurization slurry can retard the Hg0 formation and, thus, mitigate mercury re-emission. To that end, cobalt-based carbon nanotubes (Co-CNTs) were developed for the simultaneous Hg2+ removal and sulfite oxidation in this work. Furthermore, the thermodynamics and kinetics of the Hg2+ adsorption and effect of Hg2+ adsorption on catalytic activity of Co-CNTs were investigated. Experimental results revealed that the Co-CNTs not only accelerated sulfite oxidation to enable the recovery of desulfurization by-products but also acted as an effective adsorbent of Hg2+ removal. The Hg2+ adsorption rate mainly depended on the structure of the adsorption material regardless of the cobalt loading and morphological distribution. The catalytic activity of the Co-CNTs for sulfite oxidation was not significantly affected due to the Hg2+ adsorption. Additionally, the isothermal adsorption behavior was well-fitted to the Langmuir model with an adsorption capacity of 166.7 mg/g. The mercury mass balance analysis revealed that the Hg0 re-emission was decreased by 156% by adding 2.0 g/L of Co-CNTs. These results can be used as a reference for the simultaneous removal of multiple pollutants in the wet-desulfurization process.

Reply to comments on “CuYb0.5Fe1.5O4 nanoferrite adsorbent structural, morphological and functionalization characteristics for multiple pollutant removal by response surface methodology”

Present short communication is in reply to the comments on published paper “CuYb0.5Fe1.5O4 nanoferrite adsorbent structural, morphological and functionalization characteristics for multiple pollutant removal by response surface methodology” [1].

Potential application of MoO3 loaded SBA-15 photo-catalyst for removal of multiple organic pollutants from water environment

A photo-catalyst of mesoporous silicate SBA-15 doped with 15%MoO3 was synthesized by modified sol–gel process and then characterized by SBET, XRD, HRTEM/EDX, TGA and optical techniques. The photo-catalytic performances of 15%Mo/SBA-15 were tested in the photo-remediation of wastewater composed of multi-organic pollutants (i.e., aromatics, phenols, and dyes) at different light sources of visible (400nm), UVB (316nm)and UVC (254nm) irradiation. The photo-catalytic activities of the 15%Mo/SBA-15 were considerably greater under UVC irradiation, which is coincident with 15%Mo/SBA-15 calculated band gap of 3.5eV. Further, wastewater treatment rate was ranked in the order of aromatic>phenolic>dyes with the rate of 95%, 69%, and 14%, respectively after 120min UVC irradiation time. A statistical analysis, using both parametric (one way ANOVA) and nonparametric (Kruskal-Wallis) methodologies, were developed to validate the experimental comparison between neat SBA-15 and 15%Mo/SBA-15 based on structural properties, light intensity and the type of organic contaminants are the key factors influencing the photo-catalytic degradation rate. The kinetic rate of the wastewater photo-catalytic remediation was found to be ranked in the order of benzene>anthracene>pyrene>naphthalene within aromatic contaminants, hydroxyphenyl≈chlorophenols>phenol within the phenolic group, and no significant difference between methyl orange and methyl red within dyes contaminants over 15%Mo/SBA-15. Results suggested that the developed 15%Mo/SBA-15 could be used as efficient photocatalysts for the treatment of petroleum and petrochemical wastewater with aromatic and phenolic hazardous, but not efficient for the treatment of textile wastewater pollutants.

Dual-Functional Ultrafiltration Membrane for Simultaneous Removal of Multiple Pollutants with High Performance.

Simultaneous removal of multiple pollutants from aqueous solution with less energy consumption is crucial in water purification. Here, a novel concept of dual-functional ultrafiltration (DFUF) membrane is demonstrated by entrapment of nanostructured adsorbents into the finger-like pores of ultrafiltration (UF) membrane rather than in the membrane matrix in previous reports of blend membranes, resulting in an exceptionally high active content and simultaneous removal of multiple pollutants from water due to the dual functions of rejection and adsorption. As a demonstration, hollow porous Zr(OH)x nanospheres (HPZNs) were immobilized in poly(ether sulfone) (PES) UF membranes through polydopamine coating with a high content of 68.9 wt %. The decontamination capacity of DFUF membranes toward multiple model pollutants (colloidal gold, polyethylene glycol (PEG), Pb(II)) was evaluated against a blend membrane. Compared to the blend membrane, the DFUF membranes showed 2.1-fold increase in the effective treatment volume for the treatment of Pb(II) contaminated water from 100 ppb to below 10 ppb (WHO drinking water standard). Simultaneously, the DFUF membranes effectively removed the colloidal gold and PEG below instrument detection limit, however the blend membrane only achieved 97.6% and 96.8% rejection for colloidal gold and PEG, respectively. Moreover, the DFUF membranes showed negligible leakage of nanoadsorbents during testing; and the membrane can be easily regenerated and reused. This study sheds new light on the design of high performance multifunction membranes for drinking water purification.

Split, Partial Oxidation and Mixed Absorption: A Novel Process for Synergistic Removal of Multiple Pollutants from Simulated Flue Gas

In this paper, a new method of split, partial oxidation and mixed absorption for the synergistic removal of SO2, NOx, and Hg0 is proposed. Factors that affect the multipollutant removal, such as the flue gas split ratio, NaClO2 concentration, initial pH and temperature of NaClO2 solution in the oxidation reactor, SO2, NO, O2, and CO2 concentrations, gas flow rate, and species of alkali absorbent in the absorption reactor are investigated, with a special focus on NOx removal. Results show that SO2 and Hg0 are removed quite efficiently and are slightly affected by reaction conditions, whereas NOx removal is seriously affected by the above factors, except for O2 and CO2 concentrations. Under the best experimental conditions, the average removal efficiencies of SO2, NOx, and Hg0 reach more than 99, 82, and 95%, respectively. Meanwhile, the mechanism of multipollutant removal is deduced based on related literature, experimental phenomena, and reaction products. The novel process has enormous potential in the r...

Comment on “CuYb0.5Fe1.5O4 nanoferrite adsorbent structural, morphological and functionalization characteristics for multiple pollutant removal by response surface methodology” by M.A. Rehman et al., J. Mol. Liq. 224 (2016) 1256–1265

In late 2016, Rehman et al. reported on the synthesis of Yb doped CuFe2O4 nanoferrite adsorbents, i.e. CuYb0.5Fe1.5O4, and discussed this material´s adsorption performance in dependence on a large variety of parameters such as adsorbent dose, sonication time and concentrations of different pollutants, e.g. methyl orange, safranin, Cr3+ and Pb2+ [1]. Unfortunately, some of the data as presented by the authors are in strong conflict with the authors' data interpretation.

CuYb0·5Fe1.5O4 nanoferrite adsorbent structural, morphological and functionalization characteristics for multiple pollutant removal by response surface methodology

CuYb0·5Fe1.5O4 nanoferrite adsorbent was prepared and characterized with analytical techniques i.e. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy dispersion spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED). Until now, little information is available on the competition mechanisms to explain the complex multiple pollutant adsorption by ytterbium doped nanoferrites. A central composite design (CCD) was used to optimize the adsorption process variables, adsorbent mass (0.004–0.03g), sonication time (2–6min), initial metal ion concentration (4–30mgL−1) and initial dye concentration (7–20mgL−1). The CCD results were analyzed for the significant variables and interaction effect on the adsorption performance of CuYb0·5Fe1.5O4 nanoferrite adsorbent. The best response of the present adsorption system was achieved at optimum adsorbent dose (0.02g), sonication time (4min), methyl orange (MO) conc. (20mgL−1), safranin O (SO) conc. (10mgL−1), Cr3+ conc. (40mgL−1) and Pb2+ conc. (35mgL−). The results indicate that the R2 values were >0.987, while the adjusted R2 values are in close agreement with R2. The quadratic model optimal conditions for MO, SO, Pb2+ and Cr3+ ions yielded 99.44%, 95.65, 82.5 and 100% removal efficiency respectively.

PH-tunable surface charge of chitosan/graphene oxide composite adsorbent for efficient removal of multiple pollutants from water

A versatile composite adsorbent combination of chitosan and graphene oxide (CS–GO) has been prepared by self-assembly method. This well-obtained adsorbent has amphoteric characteristics that show pH-tunable surface charge and morphology. These vital features result in its flexible and tunable adsorption performance. CS–GO is highly efficient in removing multiple types of pollutants from water, including various dyes and metal ions with different charge properties: cationic [methylene blue (MB) and Cu(II)] and anionic species [methyl orange (MO) and Cr(VI)]. Multiple mechanisms, including electrostatic interaction, π–π stacking, and chelating effects, are involved in the adsorption of the four pollutants for their different structural characteristics and charge properties. Both pollutants can be efficiently removed at suitable pH conditions in MB/Cu(II) and MO/Cr(VI) binary systems. Moreover, CS–GO shows strongly preferential adsorption of MB over Cu(II) at lower pH levels, whereas very slight selectivity of MO over Cr(VI). According to the adsorption kinetics results, the equilibrium time of CS–GO for adsorption of each pollutant is less than 10.0min, which is sufficiently fast and satisfactory for practical use. After saturated adsorption, CS–GO can be efficiently regenerated and reused with little uptake loss. Therefore, CS–GO is a versatile adsorbent that efficiently removes various pollutants from water.

Molecular Insights into Ternary Surface Complexation of Arsenite and Cadmium on TiO2.

Insights from molecular-level mechanisms of arsenite [As(III)] and cadmium (Cd) co-adsorption on TiO2 can further our understanding of their synergistic removal in industrial wastewaters. The motivation for our study is to explore the interfacial interactions of neutrally charged As(III) and cationic Cd(2+) on nanocrystalline TiO2 using multiple complementary techniques. The results of adsorption edge, ζ potential, and surface complexation modeling suggest that coexistence of As(III) and Cd(2+) enhanced their synergistic adsorption on TiO2 and, consequently, resulted in the formation of a ternary surface complex. This ternary surface complex, in turn, inhibited the metal release into the aqueous phase and, therefore, facilitated the immobilization of the heavy metals. Our in situ flow-cell attentuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and extended X-ray absorption fine structure (EXAFS) spectroscopy evidence showed that, regardless of the order of contact, As(III) was preferentially adsorbed on TiO2 rather than Cd. In agreement with our spectroscopic analysis, quantum chemistry calculations also illustrated that the Cd-As(III)-TiO2 ternary surface complex should be formed with the adsorbed As(III) as the bridging molecule. At high As(III) concentrations, the formation of the Cd-As(III)-TiO2 complex is responsible for the Cd removal. The simultaneous removal mechanisms will further our understanding of the removal of multiple pollutants in industrial wastewaters.