Removal Rate Of Cd2 Research Articles

Highly efficient adsorption and removal of Cd(II) from wastewater by mass synthesis of magnetically functionalized UiO-66 based on its high coordination advantage

The development of heavy metal adsorbent materials that combine high yield and high adsorption capacity is a challenging problem. In this study, we report a novel magnetic adsorbent (Fe3O4@UiO-66-Lcys) for the efficient removal of cadmium from wastewater. Among them, UiO-66 was loaded on the Fe3O4 core by solvothermal method, followed by loading a large amount of L-cysteine (Lcys) on its surface by amidation reaction. The material innovatively achieves a large and uniform loading of functionalized groups on the magnetic core, which is a strategy for targeted removal of heavy metals. The successful synthesis of the materials was confirmed by structural characterization such as FTIR, TGA, and XRD. Excitingly, the composite has excellent adsorption performance, with the maximum adsorption of Cd2+ by Fe3O4@UiO-66-Lcys of 430.89 mg/g at the temperature of 298 K, which is more than five times that of Fe3O4@UiO-66. According to the mechanism analysis, the large amount of –COOH on UiO-66 provided enough sites for the stable grafting of L-cysteine, which exposed a large number of –NH2, –COOH, and −SH groups on the surface of the material, and provided abundant adsorption sites for Cd2+ chelation. In addition, the structure of the adsorbed material remained stable, and the removal rate of Cd2+ was still above 90 % after five times of reuse. Therefore, Fe3O4@UiO-66-Lcys is a good adsorbent for the removal of Cd2+ from wastewater, which provides an idea for the development and creation of high-yield, high-efficiency, and reusable green adsorbents.

Process optimization of Cd2+ removal with Tetradesmus Obliquus-immobilized Algal Beads

In this study, calcium alginate-immobilized microalgae beads were utilized for treating Cd2+-containing wastewater by optimizing the algal species, the preparation conditions of immobilized beads, and the Cd2+ treatment conditions to enhance treatment efficiency. The results revealed that under optimal preparation conditions with a CaCl2 concentration of 3 % and a sodium alginate concentration of 2 %, the removal rate of Cd2+ reached 94.99 % after 3 h of adsorption when 4 g of immobilized Tetradesmus obliquus algal beads were added to a 20 mg/L Cd2+ solution. Additionally, under optimal removal conditions at pH=6, with immobilized Tetradesmus obliquus algal beads as the adsorbent and a dosage of 6 g of immobilized algal beads added to a solution with an initial Cd2+ concentration of 15 mg/L, the Cd2+ removal rate reached 99.85 % after 4 h of adsorption, surpassing that of suspended microalgae and blank algal beads. The adsorption process followed the pseudo-second-order kinetic model and the Langmuir adsorption isotherm model. FTIR analysis indicated that functional groups such as O-H, CO, C-O, C-N, among others, might play a role in the adsorption process. After five adsorption-desorption cycles, the adsorption capacity decreased by only 10 %. This study demonstrated that immobilized Tetradesmus obliquus algal beads is an efficient and renewable and recyclable adsorbent.

Effects of Alkali Activation of the Cotton Straw Biochar on the Adsorption Performance for Cd2.

In this study, a single factor exploration method was adopted to optimize the cotton shell-based activated carbon adsorption reaction time, temperature, pH value, initial concentration of cadmium ion, and other conditions. The experimental results showed that under the conditions of Cd2+ solution pH = 8, initial concentration of 100 mg/L, adsorption reaction time of 180 min, adsorption temperature of 45 °C, cotton shell-based activated carbon dosage of about 0.1 g, the removal rate of Cd2+ was 94.03%, the adsorption capacity was 51.95 mg/g, and the error was only 0.05%. The adsorption kinetic analysis of this study conforms to the quasi-second-order kinetic model, the adsorption isotherm analysis conforms to the Langmuir adsorption isothermal model, and the Gibbs free energy of the adsorption process is negative; the above simulation analysis also proves the spontaneity and feasibility of the adsorption process.

Treatment of Cadmium-Contaminated Water Systems Using Modified Phosphate Rock Powder: Contaminant Uptake, Adsorption Ability, and Mechanisms

Cadmium (Cd) water pollution threatens environmental systems and human health. Adsorption is the preferred method for purifying water bodies polluted by Cd, and the development of effective adsorption materials is critical. The performance of original phosphate rock powder (PRP) as an adsorption medium for purifying water bodies polluted by Cd was compared with that of phosphate rock powder modified with fulvic acid, chitosan, MnO2, and sulfhydryl, respectively, and their appearance and adsorption properties were investigated. The surface structures of all modified powders were rougher than the original, and their functional groups were richer. The greatest Cd2+ adsorption capacity, 1.88 mg g−1, was achieved with chitosan-modified PRP (CMPRP). This was 106.59% greater than that of PRP. The capacities of fulvic acid and MnO2 were 15.38% and 4.40% greater than that of the original, respectively. When the fulvic acid-modified PRP, CMPRP, and manganese dioxide PRP reached adsorption equilibrium, the removal rates of Cd2+ were 51.86%, 93.26%, and 46.70%, respectively. Moreover, the removal rate of Cd2+ by CMPRP was 104.43% higher than that of PRP. The main Cd2+ adsorption mechanisms for the MPRPs were electrostatic interactions, ion exchange, co-precipitation, and complexation. Moreover, the processing of the phosphate rock powder was straightforward, harmless to the environment, and could be effectively used for the removal of Cd. These results show that CMPRP is promising as a new adsorption material to treat Cd-contaminated water.

Improved Cadmium Removal Induced by Interaction of Nanoscale Zero-Valent Iron and Microplastics Debris

Nanoscale zero-valent iron (nZVI) is one of the most prevalently used engineered nanomaterials for heavy metals removal. Microplastics (MPs) have been detected extensively in the environment, such as soil, surface water, groundwater, and water treatment plant. PVC MPs and Cd coexist in a variety of environment, and Cd compounds are often used as stabilizers in PVC production, which increases the likelihood of their coexistence. In this work, the influence of aged PVC MPs on Cd2+ removal with nZVI was evaluated. Spent nZVI after reaction with Cd2+ with and without MPs was characterized with scanning transmission electron microscopy (STEM), energy-dispersive spectroscopy (EDS), scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrometer (FTIR), and Brunauer-Emmett-Teller (BET). The results showed that when MPs coexisted, the removal rate of Cd2+ with nZVI increased by up to 73.4%. Spent nZVI has more extensive oxidation, and has looser structure and higher specific surface area in a mixed contamination solution with trace MPs, resulting in high removal efficiency of Cd2+. Interaction between PVC MPs and nZVI shows positive promotion toward removal of Cd2+ with nZVI; thus, nZVI may have great potential for remediation of Cd in the water environment rich in PVC MPs.

Cd2+ tolerance and removal mechanisms of Serratia marcescens KMR-3

Heavy metal contamination is a global issue, with cadmium (Cd2+) and its treatment becoming major environmental challenge that could be solved by microbial restoration, an eco-friendly technique. Serratia marcescens KMR-3 exhibits high tolerance and removal rate of Cd2+ (≤500 mg/L). Here, we aimed to explore mechanisms underlying tolerance to and removal of Cd2+ by KMR-3. Scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectrometry were conducted to analyze characteristics of the KMR-3 biofilm and Cd2+ combined forms. The results revealed varying degrees of cell adhesion, membrane thickening, and shrinkage on the surface of the bacteria. The binding elements, electronic binding energy, and functional groups on the surface of the bacteria exhibited changes. Furthermore, the biofilm amount following treatment with Cd2+ was 1.5–3 times higher than that in the controls, treatment with Cd2+ substantially enhanced biofilm generation and increased Cd2+ adsorption. Cd2+ adsorption by its own secondary metabolite prodigiosin produced by KMR-3 was enhanced by 19.5 % compared with that observed without prodigiosin. Through transcriptome sequencing and RT-qPCR, we observed that Znu protein-chelating system regulated gene expression (znuA, znuB, and znuC), and the efflux mechanism of the P-type ATPase regulated the expression of genes (zntA, zntB, and zntR), which were significantly enhanced. Through the combined action of various strategies, KMR-3 demonstrated a high tolerance and removal ability of Cd2+, providing a theoretical basis to treat Cd2+ pollution.

Construction of CdS-Tetrahymena thermophila hybrid system by efficient cadmium adsorption for dye removal under light irradiation

The water pollution caused by heavy metals and dyes emitted by industries has become a worldwide problem. These pollutants are difficult to be biodegraded. Even at low concentrations, they are toxic and at last threaten human health. Herein, while using Tetrahymena thermophila, a single-celled ciliate protozoa, to enrich and remove the heavy metal Cd2+ from water, CdS nanoparticle-Tetrahymena thermophila hybrid system (CdS-T. thermophila) for dye pollution remediation under light irradiation was developed. The conditions of Cd2+ enrichment and removal by T. thermophila, construction of efficient CdS-T. thermophila, and decolorization of Congo red using CdS-T. thermophila were investigated. In the presence of cysteine ethyl ester, the removal rate of Cd2+ by T. thermophila was 94% at low Cd2+ concentration of 1 mg L−1. The adsorption capacity of T. thermophila to Cd2+ reached 43 mg g−1 at Cd2+ concentration of 80 mg L−1. Using 0.1 g L−1 constructed CdS-T. thermophila, the decolorization rate of 50 mg L−1 Congo red solution reached 95% in 60 min under light irradiation. This study provides a new insight to effective removing Cd2+ from water by T. thermophila to construct the CdS-T. thermophila and using it to remediate dye pollution in the environment.

Nitrilotriacetic acid modified magnetic Prussian blue for efficient removal of cadmium from wastewater

Novel and environmentally-friendly magnetic adsorbent (Fe3O4@PB@NTA) was prepared for the removal of cadmium (Cd2+) from wastewater. The magnetic Prussian blue (Fe3O4@PB) was synthesized by hydrochloric acid etching method, so that Prussian blue was grown on the surface of Fe3O4. Then, nitrilotriacetic acid (NTA) was used as a chelating agent for surface modification of Fe3O4@PB. The successful loading of NTA was confirmed by structural characterizations such as FTIR, TGA, BET, etc. The adsorption isotherm model analysis was consistent with the Langmuir model, and the maximum adsorption capacity of Fe3O4@PB@NTA for Cd2+ was 310.56 mg/g. Fe3O4@PB@NTA has excellent regeneration and reusable performance, the removal rate of Cd2+ still reached by 93.12% after 5 times of regeneration. According to FTIR and XPS analysis, partial -C≡N of Prussian blue might be hydrolyzed to the amide groups. The adsorption mechanism involved the formation of N-Cd coordination bonds by sharing electron pairs due to the presence of O=C-NH and -C≡N on the Fe3O4@PB@NTA, and the C=O provided by nitrilotriacetic acid could combine with Cd to form the O-Cd complex compound, the electrostatic attraction between COO− and Cd2+ also existed. Therefore, Fe3O4@PB@NTA is a promising adsorbent for the treatment of cadmium-containing wastewater.

Adsorption Mechanism of Cadmium by Superparamagnetic Nano-Fe3 O4@SiO2 Functionalized Materials

The treatment of cadmium-containing wastewater is of great significance for the emission control of the heavy metal cadmium. Here, a superparamagnetic nano-Fe3O4@SiO2 functionalized material (MFS) was prepared via a co-precipitation method, and the adsorption thermodynamic and kinetic characteristics of Cd2+ were studied by isothermal adsorption tests and kinetic experiments. The adsorption process and mechanism of MFS with respect to Cd2+ were also studied using BET, XRD, and SEM. The Langmuir equation well described the isothermal adsorption characteristics of MFS, and the maximum adsorption capacity was 69.49 mg·g-1. The standard free energy (ΔG), enthalpy (ΔH), and entropy changes (ΔS) showed that the adsorption reaction was a spontaneous, endothermic, and entropic process. The optimal initial pH of the adsorption reaction was 7. The four interfering ions (Mg2+, SO42-, Ca2+, and NO3-) in the solution had a certain inhibitory effect on the adsorption reaction. The pseudo-second-order kinetic model showed that the adsorption process of Cd2+ was divided into two stages, namely a rapid external diffusion stage and a slow internal diffusion stage. The removal rate of Cd2+ was still>73% after using the MFS three times. The BET, XRD, FTIR, and VSM analyses showed that SiO2 was successfully modified on the Fe3O4 surface. MFS is mainly spherical in structure with an average particle size of 38.7 nm and has a saturated magnetic intensity of 85.38 emu·g-1. The XRD, EDS, and XPS analyses revealed that Cd2+ was successfully adsorbed by the material, and the main mechanism was the coordination reaction between Cd2+ and -OH on the surface of the material.

Efficient adsorption of Cd2+ from aqueous solution using metakaolin geopolymers.

In this study, geopolymers were prepared using metakaolin (MK) raw material under different alkali activator moduli (SiO2/Na2O = 0.8, 1.2, 1.6, 2.0M ratio) in order to analyze their capacity and mechanism for adsorbing cadmium (Cd2+) from solution. Instrumental analyses including X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy(XPS), Fourier transform infrared (FTIR), and Brunauer-Emmett-Teller (BET) were performed to examine the mineralogical features of the MK and geopolymers before and after Cd2+ adsorption. The effect of initial pH, temperature, contact time, and initial concentration on Cd adsorption performance was studied to obtain the equilibrium isotherm. Kinetic data of the geopolymers fitted the pseudo-second-order kinetic model well. Moreover, the adsorption equilibrium data of Cd2+ adsorbed by the geopolymers fitted the Langmuir model better than the Freundlich model. The result shows that chemisorption dominates Cd2+ adsorption by geopolymers and that the adsorption capacity differs when prepared using different alkali-activated modulus agents. The geopolymer prepared using an alkali activator modulus of 0.8M (molar ratio) exhibited the best Cd2+ adsorption performance with a maximum adsorption capacity of 70.3mgg-1. The removal rate of Cd2+ by geopolymer still remained above 85% after five round of recycling.

Removal of Dyes and Cd2+ in Water by Kaolin/Calcium Alginate Filtration Membrane

Kaolin/calcium alginate (kaolin/CaAlg) free-standing membranes were prepared by adding different amounts of Kaolin into the sodium alginate (NaAlg) casting solution and crosslinked by Ca2+ using urea as porogen agent. The morphology of the kaolin/CaAlg filtration membrane was characterized by scanning electron microscope (SEM). Then the kaolin/CaAlg membrane was used for the removal of dyes and Cd2+. The kaolin significantly improved the mechanical behavior and flux of the kaolin/CaAlg membrane. The flux reached 17.53 L/m2·h at 0.1 MPa and when the content of Kaolin in NaAlg was 70 wt.%. The filtration of BSA solution and oil-water emulsion indicated that the kaolin/CaAlg composite filtration membrane exhibited good anti-fouling properties. The rejection of Brilliant Blue G250, Congo red, and methylene blue by the kaolin/CaAlg filtration membrane was 100%, 95.22%, and 62.86%, respectively. The removal rate of Cd2+ reached 99.69%, with a flux of 17.06 L/m2·h at 0.1 MPa.

Physiological Responses of Ryegrass in Cadmium-Nonylphenol Co-contaminated Water and the Phytoremediation Effects

Physiological responses of ryegrass in cadmium-nonylphenol (Cd-NP) co-contaminated water, as well as the phytoremediation effect were studied under laboratory conditions. The experiment revealed that the biomass and chlorophyll content of ryegrass significantly declined at high concentrations of Cd2+(10 mg·L-1), while POD and PPO activities significantly increased. No significant changes to the biomass, chlorophyll content and MDA of ryegrass were observed in the presence of NP. POD activities significantly increased at high concentrations of NP (5 mg·L-1). The addition of high NP concentrate reduced the inhibition of Cd under co-contaminated stress, the MDA content and PPO activities both reduced. The experiment also revealed that the removal rate of Cd2+ by ryegrass reached 55.3% after 12 h. The absorption efficiency was improved by high NP concentration. Absorption efficiency of Cd2+ by the subterranean part of the plant significantly increased in presence of NP, and the absorption efficiency increased with the increase of NP concentration. The absorption rate of NP was 44.6% after 24 h at NP concentration of 5 mg·L-1. The removal rate was slightly influenced at low concentrations of Cd2+, but significant inhibition of absorption and degradation was observed at high concentrations of Cd2+.

Adsorption of aquatic Cd2+ using a combination of bacteria and modified carbon fiber

Batch experiments were conducted to investigate the capacity and mechanisms for adsorbing Cd2+ from aqueous solutions by the composite material. The composite material was manufactured with Plesiomonas shigelloides strain H5 and modified polyacrylonitrile-based carbon fiber. Experimental results showed that the surface areas of modified polyacrylonitrile-based carbon fiber increased by 58.54% and pore width increased by 40.19% compared with unmodified polyacrylonitrile-based carbon fiber. Boehm’s titration results show the surface acid sites of composite material were increased by 712% compared with unmodified polyacrylonitrile-based carbon fiber. The field emission scanning electron microscope results show P. shigelloides H5 can be grown on the surface of modified polyacrylonitrile-based carbon fiber closely. The equilibrium removal rate and sorption quantity of composite material were 71.56% and 7.126 mg g−1, respectively. With the pH value of aqueous solution increased, the removal rate of Cd2+ ions was also increased, but the change of temperature and ionic strength had no significant effect on the removal rate. Furthermore, the results showed the whole sorption process was a good fit to Lagergren pseudo-second-order model and Freundlich isotherms model. Therefore, the results infer that there was a heterogeneous distribution of active sites, and then the sorption process was chemical adsorption and multilayer adsorption. In a word, microbial composite carbon fiber material can adsorb Cd2+ ions from aqueous solution effectively, which might be helpful in wastewater treatment in the future.

Efficient removal of Cd2+ ion from water by calcium alginate hydrogel filtration membrane.

Calcium alginate (CaAlg) hydrogel filtration membrane was prepared using urea as pore-forming agent. The effects of preparation and operating conditions on the removal rate of Cd2+ were researched. The removal mechanism of Cd2+ and the anti-fouling property of CaAlg membrane were investigated. The removal rate of the CaAlg filtration membrane reached over 99.5% within 120 min when 20 mg/L Cd2+ was used, and the flux was 15.5 L/m2h at 0.1 MPa when the thickness of the membrane was 0.28 ± 0.08 mm. However, the removal rate of Cd2+ was below 10.0% when the same concentration Cd2+ solution was adsorbed by CaAlg membrane with the same size. Energy dispersive spectroscope analysis demonstrated that the removal of Cd2+ depended on the adsorption and ion exchange of Ca2+ by Cd2+. CaAlg membrane exhibited a higher removal rate for Cd2+ (almost 100%). It was the filtration process that promoted the adsorption and ion exchange of Cd2+ in CaAlg hydrogel.

Synthesis of the poly(acrylic acid‐acrylic sodium) bentonite composite and its adsorption of Cd(II)

AbstractIn order to improve the adsorptive properties of bentonite, a new poly(acrylic acid‐acrylic sodium) bentonite composite was prepared by copolymerization reaction. The properties of the bentonite composites were investigated. Based on the amount of acrylic monomers dissolution and Cd2+ ions adsorption as objective functions, the optimal conditions which were determined with single‐factor experiments are as follows: the neutralization degree of acrylic acid, the polymerization temperature, the polymerization time, and the mass ratio of bentonite to acrylic acid monomer unneutralized were 20%, 80 °C, 3 h and 8 : 2, respectively. The bentonite composite was characterized by XRD, IR, and SEM. It was indicated the basic structure of bentonite had not been destroyed when the monomers were intercalated into the bentonite interlayers. The synthetic products had excellent adsorption properties to Cd2+ ions, such as the removal rate of Cd2+ ions reached 99.9% for 100 mL solution with initial Cd2+ ions concentration of 50.0 mg/L by adding 0.5 g sample of the bentonite composite, whose removal rate was significantly superior to calcium bentonite and other modified bentonite reported in literatures. The adsorption process to Cd2+ ions was corresponding with the Lagergren secondary adsorption kinetics equation and the Langmuir isotherm equation. © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.

Study on Sudden Cadmium Pollution Emergency Treatment Tests of Drinking Water Source of Cities

The experiment is based on cadmium pollution of Long River in Hechi Guangxi. The results shows that under existing process condition of water plants, dosing PAC separately can make removal rate of Cd2+ reach about 60%, only ensuring the inflow water containing maximum 0.01 mg/L Cd2+ reach the standard when outflowed. When the inflow water concentration of Cd2+ surpasses 0.01 mg/L, existing technology is needed to be improved. If using combined treatment with sodium carbonate and PAC, in condition the dosing quantity of sodium carbonate is 1.1 times than the theoretical molar ratio, and PAC is 15 mg/L, the removal rate of Cd2+ reach higher than 90%, making the effluent which Cd2+ exceeds the standard by 10 times reach the standard after treated, providing a new idea for emergency treatment on Cd2+ pollution of drinking water.

Modification of Reed Alkali Lignin to Adsorption of Heavy Metals

We use reed alkali lignin to extract heavy metal adsorbent with the method of phenol modification. Then we study how the phenols addition amount, reaction temperature and reaction time affect the modified products’ adsorption of heavy metal. The results are as follows. The best adsorption of Pb2+, Cd2+, Cr3+ can be got when phenols addition amount is 4g, the reaction temperature is100°C and the reaction time is 90 min. Compared with alkali lignin, the adsorption rate gets an obvious improvement. The removal rate of Pb2+ rises from 92.4 to 97.8%. The removal rate of Cd2+ rises from 44.5 to 63.8%. The removal rate of Cr3+ rises from 43.4 to 62.5%. Also the adsorption rate improves with the increase of phenolic hydroxyl, which shows that the phenolic hydroxylfacilitates adsorption.

Study of Cadmium Wastewater Treatment with Polymer PHA Containing Hydroxamic Acid Groups

Polymer heavy metal chelating agent containing hydroxamic acid groups (PHA) was made in order to observe its effects on the removal rate of Cd2+. The present study reaches the following results: (1) On conditions that pH value is 8.0, the chelating agent is 60mg•L-1and the reaction time is 60min, the highest chelating capacity of the polymer heavy metal chelating agent PHA can reach 341 mg/g. (2) The existence of common cations: K+, Na+and Mg2+can improve PHA’s ability to remove Cd2+. (3) The existence of common anions Cl-, SO42-and NO3-can improve PHA’s ability to remove Cd2+. (4) Co-existing with the turbidity-causing materials, PHA’s removal abilities of Cd2+and turbidity are mutually promotive. (5) The chelating product, Cd-PHA’s amount of leaching of Cd2+is only 1/11 of that in neutralization titration ,having a relatively higher stability and better environmental safety.

The Study of Cadmium Wastewater Disposal by Heavy Metal Flocculant Polyhydroximic Acid

Polyhydroximic acid (PHA) with the function of heavy metal flocculant was made by compounding polyacrylamide, hydroxylamine hydrochloride and sodium hydroxide, to observe its effects on the cadmium wastewater disposal under different conditions (pH value, different organic complexing agents EDTA, triammonium citrate, glycocoll, humic acids and turbidity). The present study reaches the following results: (1) PHA has good effects on the removal of Cd2+ in wastewater; for the sample wastewater with a concentration of 25 mg•L-1, the removal rate of Cd2+ can reach 94%; (2) The removal rate of Cd2+ rise with the rise of pH values(4-8); (3) EDTA can obviously inhibit PHA’s removal rate of Cd2+; (4) Triammonium citrate can improve PHA’s removing ability of Cd2+. (5) Glycocoll and humic acids can obviously enhance the removing of Cd2+; (6) Turbidity-causing materials can promote the removal of Cd2+ and turbidity.

Study on Preparation of Modified Nano-TiO2 and its Application in Photocatalytic Treatment Wastewater Containing Cd<sup>2+</sup>

Nano-Sn0.25Ti0.75O2 was prepared with hydrothermal method using tetrabutyl titanate as one of the primary raw materials. The products were characterized by XRD and SEM, which revealed that the crystal structure of Sn4+-doped nano-TiO2 is rutile, and the nanoparticles diameter was 14.49nm. Photocatalytic treatment the machining wastewater containing cadmium ions with the UV excitation by Nano-Sn0.25Ti0.75O2 was investigated. The experimental results show that Nano-Sn0.25Ti0.75O2 can be used as photocatalyst to removal Cd2+ from the wastewater effectively with the UV excitation. The wastewater pH value, the initial concentration of Cd2+, the amount of catalyst，the reaction time and other factors affect the efficiency of photocatalytic treatment significantly. The optimization experimental conditions for photocatalytic treatment wastewater containing cadmium ions are as follows, when the concentration of Cd2+ in the wastewater is 20mg/L, amount of Sn0.25Ti0.75O2 is 2g/L, pH in wastewater is 7 and the photocatalytic reaction time is 2h, the removal rate of Cd2+ from the wastewater is up to 98.4%.