Organic Pollutants In Industrial Wastewater Research Articles

Influence of aeration-induced air–water interfaces on pollutant degradation in water treatment: A theoretical and experimental study

Advanced oxidation processes (AOPs) based on hydroxyl radicals (OH)-dominant pathway are the most important technologies for the removal of bio-recalcitrant organic pollutants in industrial wastewater. Air–water interface formed by aeration is one of the factors that affect the removal efficiency of pollutants in AOPs. In this work, the mechanistic and kinetic insights into the roles of air–water interface on the hydroxylation of three chlorophenols (CPs) in UV/H2O2 process have been investigated via theoretical calculation and experimental methods. Results show that CPs is more prone to accumulate at the air–water interface as the number of chlorine substituents increases. Consequently, the hydration reaction of CPs occurring at the interfacial influence the electron transfer associated with OH, leading to the non-oxidative consumption of OH. This interfacial reaction diminishes degradation efficiency, resulting in the formation of persistent organic pollutants. Herein, in UV/H2O2 degradation of 2,4,6-TCPs, persistent free radical (PFRs), as well as 1,3,7,9-TCDD and 2,3,6-Trichloro-4-(2,4,6-trichlorophenoxy)phenol, were identified using EPR spectroscopy and LC-Q-TOF-MS mass spectrometry, respectively. Altogether, this work provides a comprehensive understanding of the roles of aeration on OH-initiated degradation behavior of chlorinated phenol pollutants.

Effective visible light-driven binary ZnO catalyst decorated on layered double hydroxides for simultaneous photocatalytic degradation of Ciprofloxacin and Ampicillin

BackgroundThe direct use of clean solar energy to convert organic pollutants in industrial wastewater into harmful products is a viable tactic and a hot topic to save water bodies and avoid water pollution. Pharmaceutical wastewater is complicated and contains a variety of contaminants, making its treatment difficult. MethodThis study focuses on the simultaneous degradation of an aqueous solution containing a combination of contaminants, Ampicillin (AMP) and Ciprofloxacin (CIP). Using hydrothermal process, we successfully fabricated a ZnO-NiCoMn layered double hydroxide (LDH) sheet. The prepared catalyst was examined using a range of surface analytical optical techniques. Significant findingsThe ZnO-NiCoMn LDH demonstrates exceptional photocatalytic performance, as demonstrated by the maximal CIP and AMP degradation rates of 96 % and 94 % in 100 min under visible light, respectively, according to the data. ZnO-adorned NiCoMn LDH sheets exhibited a rod-like structure, as demonstrated by FE-SEM and HR-TEM. Because of the highest charge separation and superior electron (e−) transport between ZnO and NiCoMn LDH material, the binary catalyst degraded CIP and AMP by 96 % and 94 % in 100 min, respectively, more than the bare catalyst. The binary ZnO-NiCoMn LDH catalyst could withstand up to five CIP and AMP degradation cycles.

Compound Similarity Network as a Novel Data Mining Strategy for High-Throughput Investigation of Degradation Pathways of Organic Pollutants in Industrial Wastewater Treatment.

Identification of degradation products and pathways is crucial for investigating emerging pollutants and evaluation of wastewater treatment methods. Nontargeted analysis is a powerful tool to comprehensively investigate the degradation pathways of organic pollutants in real-world wastewater samples but often generates large data sets, making it difficult to effectively locate the exact information on interests. Herein, to efficiently establish the linkages among compounds in the same degradation pathways, we introduce a compound similarity network (CSN) as a novel data mining strategy for LC-MS-based nontargeted analysis of complex wastewater samples. Different from molecular networks that cluster compounds based on MS/MS spectra similarity, our CSN strategy harnesses molecular fingerprints to establish linkages among compounds and thus is spectra-independent. The effectiveness of CSN was demonstrated by nontargeted identification of degradation pathways and products of organic pollutants in leather industrial wastewater that underwent laboratory-scale activated carbon adsorption (ACD) and ozonation treatments. Utilizing CSN in interpreting nontargeted data, we tentatively annotated 4324 compounds in the untreated leather industrial wastewater, 3246 after ACD, and 3777 after ACD/ozonation. We located 145 potential degradation pathways of organic pollutants in the ACD/ozonation process using CSN and validated 7 pathways with 15 chemical standards. CSN also revealed 5 clusters of emerging pollutants, from which 3 compounds were selected for in vitro cytotoxicity study to evaluate their potential biohazards as new pollutants. As CSN offers an efficient way to connect massive compounds and to find multiple degradation pathways in a high-throughput manner, we anticipate that it will find wide applications in nontargeted analysis of diverse environmental samples.

Enhanced Solubilization and Biodegradation of HMW-PAHs in Water with a Pseudomonas mosselii-Released Biosurfactant.

The treatment and reuse of wastewater are crucial for the effective utilization and protection of global water resources. Polycyclic aromatic hydrocarbons (PAHs), as one of the most common organic pollutants in industrial wastewater, are difficult to remove due to their relatively low solubility and bioavailability in the water environment. However, biosurfactants with both hydrophilic and hydrophobic groups are effective in overcoming these difficulties. Therefore, a biosurfactant-producing strain Pseudomonas mosselii MP-6 was isolated in this study to enhance the bioavailability and biodegradation of PAHs, especially high-molecular-weight PAHs (HMW-PAHs). FTIR and LC-MS analysis showed that the MP-6 surfactant belongs to rhamnolipids, a type of biopolymer, which can reduce the water surface tension from 73.20 mN/m to 30.61 mN/m at a critical micelle concentration (CMC = 93.17 mg/L). The enhanced solubilization and biodegradation of PAHs, particularly HMW-PAHs (when MP-6 was introduced), were also demonstrated in experiments. Furthermore, comprehensive environmental stress tolerance tests were conducted to confirm the robustness of the MP-6 biosurfactant, which signifies the potential adaptability and applicability of this biosurfactant in diverse environmental remediation scenarios. The results of this study, therefore, have significant implications for future applications in the treatment of wastewater containing HMW-PAHs, such as coking wastewater.

Metagenomic analysis reveals the distribution, function, and bacterial hosts of degradation genes in activated sludge from industrial wastewater treatment plants

For comprehensive insights into the bacterial community and its functions during industrial wastewater treatment, with a particular emphasis on its pivotal role in the bioremediation of organic pollutants, this study utilized municipal samples as a control group for metagenomic analysis. This approach allowed us to investigate the distribution, function, and bacterial hosts of biodegradation genes (BDGs) and organic degradation genes (ODGs), as well as the dynamics of bacterial communities during the industrial wastewater bioprocess. The results revealed that BDGs and ODGs associated with the degradation of benzoates, biphenyls, triazines, nitrotoluenes, and chlorinated aromatics were notably more abundant in the industrial samples. Specially, genes like clcD, linC, catE, pcaD, hbaB, hcrC, and badK, involved in the peripheral pathways for the catabolism of aromatic compounds, benzoate transport, and central aromatic intermediates, showed a significantly higher abundance of industrial activated sludge (AS) than municipal AS. Additionally, the BDG/ODG co-occurrence contigs in industrial samples exhibited a higher diversity in terms of degradation gene carrying capacity. Functional analysis of Clusters of Orthologous Groups (COGs) indicated that the primary function of bacterial communities in industrial AS was associated with the category of “metabolism”. Furthermore, the presence of organic pollutants in industrial wastewater induced alterations in the bacterial community, particularly impacting the abundance of key hosts harboring BDGs and ODGs (e.g. Bradyrhizobium, Hydrogenophaga, and Mesorhizobium). The specific hosts of BDG/ODG could explain the distribution characteristics of degradation genes. For example, the prevalence of the Adh1 gene, primarily associated with Mesorhizobium, was notably more prevalent in the industrial AS. Overall, this study provides valuable insights into the development of more effective strategies for the industrial wastewater treatment and the mitigation of organic pollutant contamination.

C, F co-doping Ag/TiO2 with visible light photocatalytic performance toward degrading Rhodamine B

The organic pollutants in industrial wastewater continuously endanger human health. Therefore, effective treatment of organic pollutants is very urgent. Photocatalytic degradation technology is an excellent solution to remove it. TiO2 photocatalysts are easy to prepare and have high catalytic activity, unfortunately, TiO2 only absorbs ultraviolet light limiting its utilization of visible light. In this study, a facile environmentally friendly synthesis of Ag-coated on micro-wrinkled TiO2-based catalysts in order to extend the absorption of Visible light. Firstly, a fluorinated titanium dioxide precursor was prepared by a one-step solvothermal method, and the precursor was calcined at high temperature in a nitrogen atmosphere to form a carbon dopant, and then a surface silver-deposited carbon/fluorine co-doped TiO2 photocatalyst C/F–Ag–TiO2 was prepared by a hydrothermal method The results showed that the Ag was coated on the wrinkled TiO2 layer and C/F–Ag–TiO2 photocatalyst was synthetized successfully. Benefit from the synergistic effect of doped carbon and fluorine atoms in combination with the quantum size effect of the surface silver nanoparticles, the band gap energy of C/F–Ag–TiO2 (2.56 eV) is obviously lower than anatase (3.2eV). The photocatalyst achieved an impressive degradation rate of 84.2% for Rhodamine B in 4 h, with a degradation rate constant of 0.367 h−1, which was 17 times higher than that of P25 under visible light. Therefore, the C/F–Ag–TiO2 composite is a promising candidate as a highly efficient photocatalyst for environmental remediation.

Preparation of an ultra-long-life porous bilayer Ti/Sb-SnO2 electrode modified by nano-TiC for degradation of phenol

Electrochemical advanced oxidation technology produces hydroxyl radicals and has no secondary pollution, making it one of the most promising technologies for treating organic pollutants in industrial wastewater. Nevertheless, low energy efficiency and short lifetime are the key issues hindering the widespread application of electrodes. In this study, TiC nanoparticles were uniformly dispersed in the deposition solution, and the Ti/Sb-SnO2 electrode was prepared by sol electrodeposition, after calcination, a porous double-layer structure was formed, which improved the catalytic performance and effectively delayed the penetration of industrial wastewater into the electrode. Compared with the Ti/Sb-SnO2 electrode, the electrode life is increased by nearly 6 times, the phenol removal rate reaches 90.64 % (2000 mA/cm2, 1 mol/L H2SO4), the oxygen evolution potential of 2.13 V, a current density of 0.096 A/cm2, a charge transfer resistance of 2.245 Ω. The results show that the porous structure is conducive to providing a larger specific surface area and contact area for the reaction, maximizing the utilization of catalytic active sites, shortens the mass transfer distance between the hydroxyl radicals and pollutants, increases the degradation rate, reduces the corrosion rate of the electrode materials, and improves electrode stability. The unique double-layer structure is obviously different from traditional electrodes, adding a layer of protective barrier, which provides a new idea for prolonging the life of electrodes. The electrode prepared in this study has a simple process, a greatly improved lifespan and an excellent energy utilization rate, which is suitable for industrial application.

Influence of iron content in Fe-based amorphous alloy catalysts on degradation of azo dyes by fenton-like process

Degradation of organic pollutants in industrial wastewater has become one of the biggest problems that are threatening the environment, and correspondingly it is a priority for scientists to find a solution. In this work, we study the effect of the iron content in Fe-based amorphous ribbon catalysts (Fe78+xSi9B13-x, x = 0, 1 and 2) in degradation of Direct Blue 6 (DB 6) azo dye by Fenton-like process. We evaluated the catalytic efficiency by changing experimental conditions with the aim to optimize the degradation performance. The amorphous Fe80Si9B11 ribbon showed the highest catalytic activity with its ability to degrade DB 6 by 94.65% within 15 min Fe80Si9B11 ribbon provides more reactive sites than what generates the most hydroxyl radicals (. OH) and thus increases the degradation reaction. Degradation efficiency can be improved by increasing the reaction temperature and ribbons dosage, a correct amount of H2O2 but decreases with increasing initial pH value and concentration of DB 6. Fe80Si9B11 amorphous ribbons can be reused up to 12 times in optimal conditions, which confirms a good reusability. The excellent performance in catalytic activity and reusability of Fe-based amorphous alloy catalysts will contribute to wastewater treatment.

Chemical characterization and source attribution of organic pollutants in industrial wastewaters from a Chinese chemical industrial park

Accelerated urbanization and industrialization have led to an alarming increase in the generation of wastewater with complex chemical contents. Industrial wastewaters are often a primary source of water contamination. The chemical characterization of different industrial wastewater types is an essential task to interpret the chemical fingerprints of wastewater to identify pollution sources and develop efficient water treatment strategies. In this study, we conduct a non-target chemical analysis for the source characterization of different industrial wastewater samples collected from a chemical industrial park (CIP) located in southeast China. The chemical screening identified volatile and semi-volatile organic compounds that included dibutyl phthalate at a maximum concentration of 13.4 μg/L and phthalic anhydride at 35.9 μg/L. Persistent, mobile, and toxic (PMT) substances among the detected organic compounds were identified and prioritized as high-concern contaminants given their impact on drinking water resources. Moreover, a source analysis of the wastewater collected from the wastewater outlet station indicated that the dye production industry contributed the largest quantities of toxic contaminates (62.6%), and this result was consistent with the ordinary least squares and heatmap results. Thus, our study utilized a combined approach of a non-target chemical analysis, a pollution source identification method, and a PMT assessment of different industrial wastewater samples collected from the CIP. The results of the chemical fingerprints of different industrial wastewater types as well as the results of the PMT assessment benefit risk-based wastewater management and source reduction strategies.

Heterogeneous Catalytic and Non-Catalytic Supercritical Water Oxidation of Organic Pollutants in Industrial Wastewaters Effect of Operational Parameters

This work reports supercritical water oxidation (SCWO) of organic pollutants in industrial wastewater in the absence and presence of catalysts. To increase the efficiency of the oxidation process, the SCWO of organic compounds in industrial wastewater was performed in the presence of various iron- and manganese-containing heterogeneous catalysts (Fe-Ac, Fe-OH, and Mn-Al). The catalytic and non-catalytic SCWO of organic compounds in wastewater from PJSC “Nizhnekamskneftekhim”, generated from the epoxidation of propylene with ethylbenzene hydroperoxide in the process of producing propylene oxide and styrene (PO/SM), was performed. The effect of operational parameters (temperature, pressure, residence time, type of catalysts, oxygen excess ratio, etc.) on the efficiency of the process of oxidation of organic compounds in the wastewater was studied. SCWO was studied in a flow reactor with induction heating under different temperatures (between 673.15 and 873.15 K) and at a pressure of 22.5 MPa. The reaction time ranged from 1.8 to 4.83 min. Compressed air was used as an oxidizing agent (oxidant) with an oxidant ratio of two to four. A pseudo-first-order model expressed the kinetics of the SCWO processes, and the rate constants were evaluated. In the present work, in order to optimize the operation parameters of the SCWO process, we used the thermodynamic properties of near- and supercritical water by taking into account the asymmetric behavior of the liquid–vapor coexistence curve.

Visible light photocatalytic degradation of organic pollutants in industrial wastewater by engineered TiO2 nanoparticles

Visible light photocatalytic degradation of organic pollutants in industrial wastewater by engineered TiO2 nanoparticles

Continuous Flow Photooxidative Degradation of Azo Dyes with Biomass‐Derived Carbon Dots

AbstractThe presence of persistent organic pollutants in industrial wastewaters is becoming a problem of major concern. In the present study we explored the degradation of azo dyes, well‐known common hazardous contaminants, by a green and efficient procedure using continuous flow photooxidative degradation. In particular, carbon dots synthesized from fishery waste (bass‐CDs) were used as a cheap and readily available photocatalyst in combination with oxygen and UV light. Methyl orange, acid red 18, amaranth, sunset yellow and chromotrope were chosen as model substrates and their degradation was studied both in batch and in continuous flow conditions. All the azo dyes were fully degraded with both techniques highlighting the suitability of bass‐CDs for the decontamination of wastewater. The main advantages are of using a “disposable” photocatalyst, in aqueous solvent and in continuous flow. In particular, continuous flow operation allowed faster decompositions: circa 2 min versus 1–3 hours needed in batch.

Gas-liquid flow pattern identification and bubble characteristics analysis in a static mixer based HiPOxTM reactor

The multiphase flow in HiPOxTM reactor are the criteria for the mass transfer of ozone at the gas–liquid interface, determining the degradation rate of the refractory organic pollutant in industrial wastewater. In this work, the gas–liquid flow patterns and their transitions in a static mixer-based HiPOxTM reactor were investigated systematically by a high-speed camera. Six types of flow patterns were identified under the conditions of inlet liquid Re ranging from 8,000 to 160,000 and gas fraction from 3.23% to 86.96%. Three composite flow patterns are involved, and a flow pattern map was demonstrated. The effect of liquid inlet flow rate on the bubble groups is much more significant than that of gas phase in the bubble flow. If the liquid flow rate increases twice, the Sauter mean diameter is expected to fall to 65%, which was only reduced by 28% when the gas flow rate even drops 8 times.

Development of Co-Al LDH/GO composite photocatalyst for enhanced degradation of textile pollutant under visible light irradiation

Industrial wastewater contamination is a severe global issue due to the effective dosage of textile dyes that are directly exiting from the textile industries either without treatment or mild treatment. These dyes contain many organic pollutants severely damaging human beings along with aquatic environment and animals. Methylene blue (MB) dye is a carcinogenic that can cause acute diseases. In this regard, Photocatalysis proves an alluring approach because to its fascinating characteristics over ordinary technologies particularly economical and simple methodology. Layered double hydroxide (LDH) as a photocatalysts are exhibiting their promising performance for the treatment of organic pollutant in industrial wastewater. The present research displays a simple and facile co-precipitation method for the synthesis pure Co-Al LDH and its composite with graphene oxide (GO). A series of composites of GO and Co-Al layered doubled hydroxide with varied content of GO is successfully synthesized that enhanced the photocatalytic performance of Co-Al LDH in terms of MB dye degradation. With the optimized sample, 0.5 g GO loading onto Co-Al LDH termed as 0.5-CAL/GO, the MB dye degradation of 71 % was achieved under white LED light (10 W) irradiation. Synthesized photocatalysts are characterized by several analytical techniques such as (XRD, SEM, FTIR, Raman, UV Visible DRS, Photoluminescence spectroscopy). This research presents the flexible strategy for effective removal of MB dye simulated wastewater, acting as a textile industry wastewater employing a visible light active photocatalyst under white light (LED) illumination.

Coupling photocatalytic water oxidation on decahedron BiVO4 crystals with catalytic wet peroxide oxidation for removing organic pollutions in wastewater

Catalytic wet peroxide oxidation (CWPO) is widely used to remove organic pollutants in industrial wastewater, however, the remained challenges in circulating Fe3+/Fe2+ ions, inevitably forming iron sludge and massively consuming H2O2 limit its applications. Herein, the coupling of CWPO and photocatalytic water oxidation on decahedron BiVO4 crystals was reported to solve the above challenges. Using spatial photogenerated charge separation between different facets of BiVO4, efficiently circulating Fe3+ to Fe2+ was realized with a selectivity of ~100%, which greatly inhibits the formation of iron sludge. Moreover, in-situ formation of H2O2 through two-hole-involved photocatalytic water oxidation on BiVO4 replenishes the H2O2 consuming in the CWPO process. The coupling system exhibits a much higher total organic carbon (TOC) removal than the CWPO process in various pollutants, giving an improvement of rate constant to more than 10 times. This work provides a potential coupling route for advanced degradation of organic pollutants in wastewater treatment.

The Effect of Governance on Industrial Wastewater Pollution in China

Water pollution not only aggravates the deterioration of the ecological environment and endanger human health, but also has a significantly negative impact on economic growth and social development. It is crucial to investigate the relationship between industrial wastewater governance and industrial wastewater pollution on the path to reduce water pollution. In this paper, we studied whether industrial wastewater governance affected industrial wastewater pollution using the panel fixed effect model and system generalized moment estimation model (SYS-GMM) with the panel data of 30 provinces from 2005 to 2020 in China. This is the only empirical analysis of the relationship between industrial wastewater governance and industrial wastewater pollution. We proxied industrial wastewater pollution by organic pollutants and inorganic pollutants and measured the per capita investment in industrial wastewater governance. The results shed light on the positive correlation between the per capita investment in industrial wastewater governance and industrial wastewater pollution. The increase in per capita investment in industrial wastewater governance promoted the increase of pollutant emissions from industrial wastewater. The estimation also indicated that there was an inverted U-shaped relationship between per capita GDP and inorganic /organic pollutants in industrial wastewater. Our empirical research shows that it is necessary to increase investment in industrial wastewater treatment and optimize the investment structure of environmental treatment, so as to pave the way for the comprehensive utilization of a variety of environmental treatment solutions.

A study of highly efficient phenol biodegradation by a versatile Bacillus cereus ZWB3 on aerobic condition.

As one of the organic pollutants in industrial wastewater, phenol seriously threatens the environment and human health. Among various methods, microbial degradation of phenol possesses the advantages of nontoxicity and no secondary pollution. Therefore, search for microbial resources that can efficiently degrade phenol has become an important issue. In this study, a strain that could efficiently degrade phenol was isolated. The strain was identified as Bacillus cereus based on its morphology, physiological and biochemical features and 16S rRNA sequence analysis. The strain can completely degrade phenol up to 1,500 mg/L within 26 h (57.7 mg·L-1·h-1), under the optimum conditions, faster compared with the known degrading bacteria. The strain could efficiently remove phenol at a wide range of temperatures (22-37 °C) and pH (7-9), and Mn2+ and Zn2+ stress. Interestingly, this strain displayed the potential on microthermal environment, which could degrade 1,200 mg/L phenol within 36 h at 22 °C. Further, the strain had capacity that used a variety of aromatic compounds as the sole carbon source for growth. This study shows a useful biodegradation route on the wastewater treatment under high phenol concentration conditions, providing alternatives for environmental remediation.

Preparation of porous activated carbon with ultra-high specific surface area and its adsorption performance for specific organic pollutants in industrial wastewater

Porous activated carbon particles (GAC-1) with ultra-high specific surface area were prepared from starch by hydrothermal carbonization and high temperature activation. The porous structure and surface morphology of GAC-1 were characterized by N2 adsorption desorption isotherm and SEM. Compared with the commercially available activated carbon with the same particle size, the porous GAC-1 with ultra-high specific surface area shows better adsorption performance for CODCr, pyrazole and chloroform in wastewater. The results show that when the amount of activated carbon in the fixed bed is 160 g/L, the removal rate of CODCr, pyrazole and chloroform is 97.3%, 96.1% and 98.0%, respectively. The effluent meets the reuse requirements of the plant (CODCr ≤ 1500 mg/L). Finally, the activated carbon was regenerated five times by simple thermal regeneration method, and the COD removal rate could still reach 87.9%.

Chemical fingerprinting of organic micropollutants in different industrial treated wastewater effluents and their effluent-receiving river

Industry wastewater is considered one of the worst polluters of our precious water ecologies. However, the types of pollutants present in wastewater from industrial wastewater treatment plants (IWTPs) are still unclear. In this study, a simple and effective chemical fingerprinting method for checking the source-sink relationships among different industrial wastewaters and their effluent-receiving river was established. 107, 228, 155, and 337 chemicals were screened out in wastewater from electronics, steel, textile, and printing and dyeing plants, respectively. Chemical fingerprinting of the detected chemicals was performed, and results showed that aromatic compounds were the most prevalent among the pollutant categories (i.e., 56, 189, and 168 in electronics, iron and steel, and printing and dyeing plants, respectively). The traceability analysis of the chemicals selected in the effluent determined the characteristic pollutants of different industrial enterprises. Sixty-eight compounds were identified as the characteristic pollutants in the different process stages of wastewater of the four IWTPs. Of the 84 effluent-receiving river water signature pollutants, 47.6% (n = 40) were also detected in the effluent from the four IWTPs. Effective screening of organic pollutants in industrial wastewater and determining their sources will help accelerate the improvement of industrial wastewater treatment technology.

Characterization of submicro-sized Ag/ZnO particles generated using the spray pyrolysis method

Environmental issues caused by the rapid industrialization and urbanization of modern society are a serious problem. For example, conventional wastewater treatment technologies such as adsorption, coagulation, and filtration are expensive and cannot completely treat the discharge of organic pollutants in industrial wastewater. A promising alternative is the decomposition treatment of organic pollutants using an eco-friendly metal oxide photocatalyst. However, the rapid recombination of excited electron-holes limits the photolytic activity of semiconductor photocatalysts. This study investigates the inhibition of electron-hole recombination by supporting Ag nanoparticles on a ZnO photocatalyst. Ag/ZnO particles are generated under various conditions using ultrasonic spray pyrolysis. XRD analysis confirms the presence of Ag and ZnO crystal peaks in the generated particles. EDX mapping and STEM images show that Ag nanoparticles are well dispersed in ZnO. The photolysis rate of organic dye (rhodamine-B) is faster than that of ZnO in all Ag/ZnO particles, and particles with a 0.2 mass% silver nitrate supported on ZnO particles exhibit twice the photolysis activity of P25. Additionally, the optimal photolysis activity in 100 mL of 5 mg/L rhodamine-B aqueous solution with 10 mg of Ag/ZnO particles are confirmed and had excellent persistence and stability even during 7 reuses.