Photocatalytic Degradation of the Herbicide Erioglaucine in the Presence of Nanosized Titanium Dioxide: Comparison and Modeling of Reaction Kinetics

The present work mainly deals with photocatalytic degradation of a herbicide, erioglaucine, in water in the presence of TiO₂ nanoparticles (Degussa P-25) under ultraviolet (UV) light illumination (30 W). The degradation rate of erioglaucine was not so high when the photolysis was carried out in the absence of TiO₂ and it was negligible in the absence of UV light. We have studied the influence of the basic photocatalytic parameters such as pH of the solution, amount of TiO₂, irradiation time and initial concentration of erioglaucine on the photodegradation efficiency of erioglaucine. A kinetic model is applied for the photocatalytic oxidation by the UV/TiO₂ system. Experimental results indicated that the photocatalytic degradation process could be explained in terms of the Langmuir–Hinshelwood kinetic model. The values of the adsorption equilibrium constant, K, and the second order kinetic rate constant, k, were 0.116 ppm^{? 1} and 0.984 ppm min^{? 1}, respectively. In this work, we also compared the reactivity between the commercial TiO₂ Degussa P-25 and a rutile TiO₂. The photocatalytic activities of both photocatalysts were tested using the herbicide solution. We have noticed that photodegradation efficiency was different between both of them. The higher photoactivity of Degussa P-25 compared to that of rutile TiO₂ for the photodegradation of erioglaucine may be due to higher hydroxyl content, higher surface area, nano-size and crystallinity of the Degussa P-25. Our results also showed that the UV/TiO₂ process with Degussa P-25 as photocatalyst was appropriate as the effective treatment method for removal of erioglaucine from a real wastewater. The electrical energy consumption per order of magnitude for photocatalytic degradation of erioglaucine was lower with Degussa P-25 than in the presence of rutile TiO₂.     

Mechanisms of chromium and arsenite adsorption by amino-functionalized SBA-15

The adsorption of Cr(VI) and As(III) by amino-functionalized SBA-15 (NH₂-SBA-15) from single and binary systems were investigated in this work. The effects of pH and temperature on the adsorption of NH₂-SBA-15 were studied. Adsorption kinetics, isotherm model, and thermodynamics were studied to analyze the experimental data. pH 2 was the optimum condition for the adsorption of Cr(VI) and pH 4 for As(III) adsorption. Increasing temperature had a positive effect on the removal of both Cr(VI) and As(III). The Freundlich isotherm model can depict the adsorption process best. The pseudo-second-order kinetic model fitted well with the kinetic data of Cr(VI) and As(III) in the single-component system. In the binary system, the adsorption of As(III) by NH₂-SBA-15 was slightly enhanced with the presence of Cr(VI); however, As(III) had no obvious effect on the removal of Cr(VI). Regeneration experiments indicated that 0.1 mol/L NaHCO₃ was an efficient desorbent for the recovery of Cr(VI) and As(III) from NH₂-SBA-15; the desorption rates for Cr(VI) and As(III) were 91.6 and 33.59 %, respectively. After five recycling cycles, the removal rates were 88 and 7 % for Cr(VI) and As(III) adsorption by NH₂-SBA-15, respectively.     

汉沙黄/TiO_2光催化剂的制备及其光催化活性

采用溶剂热合成法制备了一种新型的汉沙黄/TiO2复合物光催化剂,利用多种手段SEM、XRD、FT-IR对催化剂的样品形貌、结构进行表征。分别以罗丹明B、亚甲基蓝、中性红为目标降解物,考察了可见光下溶液pH值对催化剂的吸附性能和催化活性的影响。结果表明,敏化后的TiO2对光的响应由紫外区扩展到可见区,催化活性优于纯TiO2,对上述3种染料的吸附率分别为19.2%、29.2%和43.2%,降解率分别为98.6%、92.5%和97.8%。制备的汉沙黄/TiO2光催化剂稳定性好,重复使用率高,在印染废水处理中具有很好的应用前景。     

Photocatalytic degradation of the herbicide pendimethalin using nanoparticles of BaTiO3/TiO2 prepared by gel to crystalline conversion method: A kinetic approach

Photocatalytic degradation of the herbicide, pendimethalin (PM) was investigated with BaTiO₃/TiO₂ UV light system in the presence of peroxide and persulphate species in aqueous medium. The nanoparticles of BaTiO₃ and TiO₂ were obtained by gel to crystallite conversion method. These photo catalysts are characterized by energy dispersive x-ray analysis (EDX), scanning electron microscope (SEM), x-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) adsorption isotherm and reflectance spectral studies. The quantum yields for TiO₂ and BaTiO₃ for the degradation reactions are 3.166 Einstein m^?2 s^?1 and 2.729 Einstein m^?2 s^?1 and catalytic efficiencies are 6.0444 × 10^?7 mg^?2h^?1L² and 5.403 × 10^?7 mg^?2h^?1L², respectively as calculated from experimental results. BaTiO₃ exhibited comparable photocatalytic efficiency in the degradation of pendimethalin as the most widely used TiO₂ photocatalyst. The persulphate played an important role in enhancing the rate of degradation of pendimethalin when compared to hydrogen peroxide. The degradation process of pendimethalin followed the first-order kinetics and it is in agreement with Langmuir-Hinshelwood model of surface mechanism. The reason for high stability of pendimethalin for UV-degradation even in the presence of catalyst and oxidizing agents were explored. The higher rate of degradation was observed in alkaline medium at pH 11. The degradation process was monitored by spectroscopic techniques such as ultra violet-visible (UV-Vis), infrared (IR) and gas chromatography mass spectroscopy (GC-MS). The major intermediate products identified were: N-propyl-2-nitro-6-amino-3, 4-xylidine, (2, 3-dimethyl-5-nitro-6-hydroxy amine) phenol and N-Propyl-3, 4-dimethyl-2, 6-dinitroaniline by GC-MS analysis and the probable reaction mechanism has been proposed based on these products.     

CdS-TiO_2/MWCNTs结构表征及其光催化性能

采用溶胶-凝胶法,制备了多壁碳纳米管(MWCNTs)负载的双组分复合半导体光催化剂CdS-TiO2/MWCNTs。通过透射电镜(TEM)、比表面分析(BET)、X射线衍射(XRD)和紫外-可见吸收光谱(UV-vis)等分析方法对光催化剂进行了结构表征,并考察了CdS-TiO2/MWCNTs对甲苯降解的光催化性能。结果表明:纳米活性粒子CdS-TiO2均匀负载于MWCNTs上,比表面积、光吸收阈值和强度增大,活性粒子间以及活性粒子与载体之间具有协同作用,有利于光催化性能的提高,CdS-TiO2/MWCNTs在主波长为254 nm紫外光照射下对甲苯的降解效果较好,去除率可达55.3%。     

Photodegradation of gaseous acetaldehyde and methylene blue in aqueous solution with titanium dioxide-loaded activated carbon fiber polymer materials and aquatic plant ecotoxicity tests

TiO₂-supported activated carbon felts (TiO₂–ACFTs) were prepared by dip coating of felts composed of activated carbon fibers (ACFs) with either polyester fibers (PS-A20) and/or a polyethylene pulp (PE-W15) in a TiO₂ aqueous suspension followed by calcination at 250 °C for 1 h. The as-prepared TiO₂–ACFTs with 29–35 wt.% TiO₂ were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and N₂ adsorption. The TiO₂–ACFT(PS-A20) samples with 0 and 29 wt.% TiO₂ were microporous with specific surface areas (S _BET) of 996 and 738 m²/g, respectively, whereas the TiO₂–ACFT(PE-W15) samples with 0 and 35 wt.% TiO₂ were mesoporous with S _BET of 826 and 586 m²/g, respectively. Adsorption and photocatalytic activity of the as-prepared samples were evaluated by measuring adsorption in the dark and photodegradation of gaseous acetaldehyde (AcH) and methylene blue (MB) in aqueous solution under UV light. The TiO₂ loading caused a considerable decrease in the S _BET and MB adsorption capacity along with an increase in MB photodegradation and AcH mineralization. Lemna minor was chosen as a representative aquatic plant for ecotoxicity tests measuring detoxification of water obtained from the MB photodegradation reaction with the TiO₂–ACFT samples under UV light.     

Enhanced bioaccumulation of cadmium in carp in the presence of titanium dioxide nanoparticles

In this study adsorption of Cd onto TiO2 nanoparticles and natural sediment particles (SP) were studied and the facilitated transports of Cd into carp by TiO2 nanoparticles and SP were assessed by bioaccumulation tests exposing carp (Cyprinus carpio) to Cd contaminated water in the presence of TiO2 and SP respectively. The results show that TiO2 nanoparticles had a significantly stronger adsorption capacity for Cd than SP. The presence of SP did not have significant influence on the accumulation of Cd in carp during the 25 d of exposure. However, the presence of TiO2 nanoparticles greatly enhanced the accumulation of Cd in carp. After 25 d of exposure Cd concentration in carp increased by 146%, and the value was 22.3 and 9.07 microg/g, respectively. And there is a positive correlation between Cd and TiO2 concentration. Considerable Cd and TiO2 accumulated in viscera and gills of the fish.     

Cu/La共掺杂TiO2光催化氧化水中的氨氮

采用水解-沉淀法制备了Cu/La共掺杂纳米TiO2催化剂,利用XRD、XPS和BET技术对其进行表征,并考察了在紫外灯下,共掺杂TiO2对氨氮的光催化氧化工艺条件。物相结构和比表面积测试结果表明,共掺杂催化剂具有较好的锐钛矿晶型,孔径分布为4～8 nm,Cu/La共掺杂TiO2La以La3+,Cu是以Cu2+、Cu+的形式掺杂进入TiO2的晶格。光催化实验表明:所得改性光催化剂对氨氮的去除及焦化废水的处理均具有较高的催化活性。     

Cellular uptake and mutagenic potential of metal oxide nanoparticles in bacterial cells

Extensive production and consumption of nanomaterials such as ZnO and TiO₂ has increased their release and disposal into the environment. The accumulation of nanoparticles (NPs) in ecosystem is likely to pose threat to non-specific targets such as bacteria. The present study explored the effect of ZnO and TiO₂ NPs in a model bacterium, Salmonella typhimurium. The uptake of ZnO and TiO₂ bare NPs in nano range without agglomeration was observed in S. typhimurium. TEM analysis demonstrated the internalization and uniform distribution of NPs inside the cells. Flow cytometry data also demonstrates that both ZnO and TiO₂ NPs were significantly internalized in the S. typhimurium cells in a concentration dependent manner. A significant increase in uptake was observed in the S. typhimurium treated even with 8 and 80 ng mL⁻¹ of ZnO and TiO₂ NPs with S9 after 60 min, possibly the formation of micelles or protein coat facilitated entry of NPs. These NPs exhibited weak mutagenic potential in S. typhimurium strains TA98, TA1537 and Escherichia coli (WP2uvrA) of Ames test underscoring the possible carcinogenic potential similar to certain mutagenic chemicals. Our study reiterates the need for re-evaluating environmental toxicity of ZnO and TiO₂ NPs presumably considered safe in environment.     

Remediation of organic and inorganic arsenic contaminated groundwater using a nanocrystalline TiO2-based adsorbent

A nanocrystalline TiO₂-based adsorbent was evaluated for the simultaneous removal of As(V), As(III), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) in contaminated groundwater. Batch experimental results show that As adsorption followed pseudo-second order rate kinetics. The competitive adsorption was described with the charge distribution multi-site surface complexation model (CD-MUSIC). The groundwater containing an average of 329 μg L^?1 As(III), 246 μg L^?1 As(V), 151 μg L^?1 MMA, and 202 μg L^?1 DMA was continuously passed through a TiO₂ filter at an empty bed contact time of 6 min for 4 months. Approximately 11 000, 14 000, and 9900 bed volumes of water had been treated before the As(III), As(V), and MMA concentration in the effluent increased to 10 μg L^?1. However, very little DMA was removed. The EXAFS results demonstrate the existence of a bidentate binuclear As(V) surface complex on spent adsorbent, indicating the oxidation of adsorbed As(III).     

The role of humic acid in the toxicity of arsenite to the diatom Navicula sp.

Dissolved organic matter (DOM) affects arsenite [As(III)] toxicity by altering its sorption equilibrium at the cell wall interface. A better understanding of such mechanism is of great importance to assess As(III) ecotoxicity in aquatic systems. Batch experiments were conducted to study the effects of DOM on the regulation of As(III) sorption and toxicity in the diatom Navicula sp. The influence of humic acid (HA) on As(III) toxicity was assessed by measuring algal growth, chlorophyll a, and reactive oxygen species (ROS), whereas As(III) mobility across the cell wall was estimated by determining the concentration of intracellular, cell-wall-bound, and free As(III) ions in cell media. Results showed that the effects of HA on arsenite toxicity varied depending on various combinations of As(III)-HA concentrations. EC₅₀ had an approximate threefold increase from 8.32 (HA-free control) to 22.39 μM (at 20 mg L^?1 HA) when Navicula sp. was exposed to 1.0–100.0 μM of As(III), compared to an overall low complexation ratio of HA-As(III) in a range of 0.91–6.00 %. The cell wall-bound and intracellular arsenic content decreased by 19.8 and 20.3 %, respectively, despite the lower arsenite complexation (2.10?±?0.16 % of the total As). Meanwhile, intracellular ROS was decreased by 12.6 % in response to 10.0 μM As(III) and 10 mg L^?1 HA vs. the HA-free control. The significant contrast indicated that complexation alone could not explain the HA-induced reduction in arsenite toxicity and other factors including HA–cell surface interactions may come into play. Isotherms describing adsorption of HA to the Navicula sp. cells combined with morphological data by scanning electron microscopy revealed a protective HA floccule coating on the cell walls. Additional Fourier transform infrared spectroscopic data suggested the involvement of carboxylic groups during the adsorption of both HA and As(III) on the Navicula sp. cell surface. Collective data from this study suggest that cell wall-bound HA can moderate As(III) toxicity through the formation of a protective floccule coating occupying As(III) sorption sites and decreased effective functional groups capable of binding As(III). Our findings imply that As(III) toxicity can be alleviated due to the increased hindrance to cellular internalization of As(III) in the presence of naturally abundant DOM in water.     

Enhanced bioaccumulation of pentachlorophenol in carp in the presence of multi-walled carbon nanotubes

The impact of suspended particles on the bioavailability of pollutants has long been a controversial topic. In this study, adsorption of pentachlorophenol (PCP) onto a natural suspended particulate matter (SPM) and multi-walled carbon nanotubes (MWCNTs) was studied. Facilitated transports of PCP into carp by SPM and MWCNTs were evaluated by bioaccumulation tests exposing carp (Carassius auratus red var.) to PCP-contaminated water in the presence of SPM and MWCNTs, respectively. Desorption of PCP on SPM and MWCNTs in simulated digested fluids was also investigated. The results demonstrate that MWCNTs (K _F?=?7.99?×?10⁴) had a significantly stronger adsorption capacity for PCP than the SPM (K _F?=?19.0). The presence of SPM and MWCNTs both improved PCP accumulation in the carp during the 21 days of exposure, and the 21 days PCP concentration in the carp was enhanced by 25.9 and 12.8 % than that without particles, respectively. The enhancement in bioaccumulation by MWCNTs was less than that by the SPM. Considerably more PCP was accumulated in the viscera of the fish (BCF?=?519495 for SPM and 148955 for MWCNTs), and the difference in PCP concentrations between different tissues became greater with particles. PCP desorption in the simulated digestive fluids was faster than that in the background solution. Compared to MWCNTs-bound PCP, more SPM-bound PCP was desorbed, and K _F of desorption for SPM was at least 4 orders of magnitude higher than that for MWCNTs, which can explain the greater enhancement in bioaccumulation in the presence of SPM. Particle-bound pollutants might pose more risk than pollutants alone.     

Direct and indirect photolysis of two quinolinecarboxylic herbicides in aqueous systems

The photodegradation of two quinolinecarboxylic herbicides, 7-chloro-3-methylquinoline-8-carboxylic acid (QMe) and 3,7-dichloroquinoline-8-carboxylic acid (QCl), was studied in aqueous solution at different irradiation wavelengths. The effect of sunlight irradiation was investigated also in the presence of titanium dioxide (TiO₂). UV irradiation degraded rapidly QMe affording 7-chloro-3-methylquinoline (MeQ) through a decarboxylation reaction. The reaction rate was lower in the presence of dissolved organic carbon (DOC) because of the adsorption of the herbicide on the organic components. Instead, QCl was stable under both UV light and sunlight irradiation. The irradiation of QMe or QCl solutions with simulated sunlight in the presence of TiO₂ produced the complete mineralization of the two herbicides.     

Visible light photocatalytic antibacterial activity of Ni-doped and N-doped TiO<Subscript>2</Subscript> on <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> and <Emphasis Type="Italic">Escherichia coli</Emphasis> bacteria

The Ni-doped and N-doped TiO₂ nanoparticles were investigated for their antibacterial activities on Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacteria. Their morphological features and characteristics such as particle size, surface area, and visible light absorbing capacity were compared and discussed. Scanning electron microscopy, X-ray diffraction, and UV–visible spectrophotometry were used to characterize both materials. The inactivation of E. coli (as an example of Gram-negative bacteria) and S. aureus (as an example of Gram-positive bacteria) with Ni-doped and N-doped TiO₂ was investigated in the absence and presence of visible light. Antibacterial activity tests were conducted using undoped, Ni-doped, and N-doped TiO₂. The N-doped TiO₂ nanoparticles show higher antibacterial activity than Ni-doped TiO₂. The band gap narrowing of N-doped TiO₂ can induce more visible light absorption and leads to the superb antibacterial properties of this material. The complete inactivation time for E. coli at an initial cell concentration of 2.7?×?10⁴ CFU/mL was 420 min which is longer than the 360 min required for S. aureus inactivation. The rate of inactivation of S. aureus using the doped TiO₂ nanoparticles in the presence of visible light is greater than that of E. coli. The median lethal dose (LD50) values of S. aureus and E. coli by antibacterial activity under an 18-W visible light intensity were 80 and 350 mg/ml for N-doped TiO₂, respectively.     

Photoassisted and photocatalytic degradation of sulfur mustard using TiO2 nanoparticles and polyoxometalates

The decomposition of highly toxic chemical warfare agent, sulfur mustard (bis(2-chloroethyl) sulfide or HD), has been studied by homogeneous photolysis and heterogeneous photocatalytic degradation on titania nanoparticles. Direct photolysis degradation of HD with irradiation system was investigated. The photocatalytic degradation of HD was investigated in the presence of TiO₂ nanoparticles and polyoxometalates embedded in titania nanoparticles in liquid phase at room temperature (33?±?2 °C). Degradation products during the treatment were identified by gas chromatography–mass spectrometry. Whereas apparent first-order kinetics of ultraviolet (UV) photolysis were slow (0.0091 min^?1), the highest degradation rate is obtained in the presence of TiO₂ nanoparticles as nanophotocatalyst. Simultaneous photolysis and photocatalysis under the full UV radiation leads to HD complete destruction in 3 h. No degradation products observed in the presence of nanophotocatalyst without irradiation in 3 h. It was found that up to 90 % of agent was decomposed under of UV irradiation without TiO₂, in 6 h. The decontamination mechanisms are often quite complex and multiple mechanisms can be operable such as hydrolysis, oxidation, and elimination. By simultaneously carrying out photolysis and photocatalysis in hexane, we have succeeded in achieving faster HD decontamination after 90 min with low catalyst loading. TiO₂ nanoparticles proved to be a superior photocatalyst under UV irradiation for HD decontamination.     

Decomposition of indoor ammonia with TiO2-loaded cotton woven fabrics prepared by different textile finishing methods

Addition of urea-based antifreeze admixtures during cement mixing in construction of buildings has led to increasing indoor air pollution due to continuous transformation and emission of urea to gaseous ammonia in indoor concrete wall. In order to control ammonia pollution from indoor concrete wall, the aqueous dispersion was firstly prepared with nano-scale TiO₂ photocatalysts and dispersing agent, and then mixed with some textile additives to establish a treating bath or coating paste. Cotton woven fabrics were used as the support materials owing to their large surface area and large number of hydrophilic groups on their cellulose molecules and finished using padding and coating methods, respectively. Two TiO₂-loaded fabrics were obtained and characterized by X-ray diffractometer (XRD) and scanning electron microscopy (SEM). Moreover, a specifically designed ammonia photocatalytic system consisting of a small environmental chamber and a reactor was used for assessing the performance of these TiO₂-loaded fabrics as the wall cloth or curtains used in house rooms in the future and some factors affecting ammonia decomposition are discussed. Furthermore, a design equation of surface catalytic kinetics was developed for describing the decomposition of ammonia in air stream. The results indicated that increasing dosage of the TiO₂ aqueous dispersion in treating bath or coating paste improved the ammonia decomposition. And ammonia was effectively removed at low ammonia concentration or gas flow rate. When relative humidity level was 45%, ammonia decomposition was remarkably enhanced. It is the fact that ammonia could be significantly decomposed in the presence of the TiO₂-padded cotton fabric. Whereas, the TiO₂-coated cotton fabric had the reduced photocatalytic decomposition of ammonia and high adsorption to ammonia owing to their acrylic binder layer. Finally, the reaction rate constant k and the adsorption equilibrium constant K values were determined through a curve-fitting method and the TiO₂-padded cotton fabric had the higher k value and lower K value than the TiO₂-coated cotton fabric.     

Shape-dependent bactericidal activity of TiO2 for the killing of Gram-negative bacteria Agrobacterium tumefaciens under UV torch irradiation

This paper demonstrated the relative bactericidal activity of photoirradiated (6W-UV Torch, λ?>?340 nm and intensity?=?0.64 mW/cm²) P25–TiO₂ nanoparticles, nanorods, and nanotubes for the killing of Gram-negative bacterium Agrobacterium tumefaciens LBA4404 for the first time. TiO₂ nanorod (anatase) with length of 70–100 nm and diameter of 10–12 nm, and TiO₂ nanotube with length of 90–110 nm and diameter of 9–11 nm were prepared from P-25 Degussa TiO₂ (size, 30–50 nm) by hydrothermal method and compared their biocidal activity both in aqueous slurry and thin films. The mode of bacterial cell decomposition was analyzed through transmission electron microscopy (TEM), Fourier transform-infrared (FT-IR), and K⁺ ion leakage. The antimicrobial activity of photoirradiated TiO₂ of different shapes was found to be in the order P25–TiO₂?>?nanorod?>?nanotube which is reverse to their specific surface area as 54?<?79?<?176 m² g^?1, evidencing that the highest activity of P25–TiO₂ nanoparticles is not due to surface area as their crystal structure and surface morphology are entirely different. TiO₂ thin films always exhibited less photoactivity as compared to its aqueous suspension under similar conditions of cell viability test. The changes in the bacterial surface morphology by UV-irradiated P25–TiO₂ nanoparticles was examined by TEM, oxidative degradation of cell components such as proteins, carbohydrates, phospholipids, nucleic acids by FT-IR spectral analysis, and K⁺ ion leakage (2.5 ppm as compared to 0.4 ppm for control culture) as a measure of loss in cell membrane permeability.     

Combined effects of titanium dioxide and humic acid on the bioaccumulation of cadmium in Zebrafish

The combined effects of titanium dioxide (TiO₂) nanoparticles and humic acid (HA) on the bioaccumulation of cadmium (Cd) in Zebrafish were investigated. Experimental data on the equilibrium Cd bioaccumulation suggest that only the dissolved Cd effectively contributed to Cd bioaccumulation in HA solutions whereas both the dissolved and TiO₂ associated Cd were accumulated in TiO₂ or the mixture of HA and TiO₂ solutions, due likely to the additional intestine uptake of the TiO₂-bound Cd. The equilibrium Cd bioaccumulation in the mixed system was comparable to that in the corresponding HA solutions, and significantly lower than that in the corresponding TiO₂ solutions (n = 3, p < 0.05). The presence of either HA or TiO₂ (5-20 mg L⁻¹) in water slightly increased the uptake rate constants of Cd bioaccumulation whereas combining HA and TiO₂ reduced the uptake rate constants.     

Solar CPC pilot plant photocatalytic degradation of bisphenol A in waters and wastewaters using suspended and supported-TiO2. Influence of photogenerated species

Photocatalytic degradation of bisphenol A (BPA) in waters and wastewaters in the presence of titanium dioxide (TiO₂) was performed under different conditions. Suspensions of the TiO₂ were used to compare the degradation efficiency of BPA (20 mg L^?1) in batch and compound parabolic collector (CPC) reactors. A TiO₂ catalyst supported on glass spheres was prepared (sol–gel method) and used in a CPC solar pilot plant for the photodegradation of BPA (100 μg L^?1). The influence of OH·, O₂ ^·?, and h ⁺ on the BPA degradation were evaluated. The radicals OH· and O₂ ^·? were proved to be the main species involved on BPA photodegradation. Total organic carbon (TOC) and carboxylic acids were determined to evaluate the BPA mineralization during the photodegradation process. Some toxicological effects of BPA and its photoproducts on Eisenia andrei earthworms were evaluated. The results show that the optimal concentration of suspended TiO₂ to degrade BPA in batch or CPC reactors was 0.1 g L^?1. According to biological tests, the BPA LC₅₀ in 24 h for E. andrei was of 1.7?×?10^?2 mg cm^?2. The photocatalytic degradation of BPA mediated by TiO₂ supported on glass spheres suffered strong influence of the water matrix. On real municipal wastewater treatment plant (MWWTP) secondary effluent, 30 % of BPA remains in solution; nevertheless, the method has the enormous advantage since it eliminates the need of catalyst removal step, reducing the cost of treatment.