Characteristics of chemical components in PM<Subscript>2.5</Subscript> at a plateau city,South-west China

A sampling campaign including summer, autumn and winter of 2014 and spring of 2015 was accomplished to obtain the characteristic of chemical components in PM_2.5 at three sites of Kunming, a plateau city in South-west China. Nine kinds of water-soluble inorganic ions (WSI), organic and element carbon (OC and EC) in PM_2.5 were analyzed by ion chromatography and thermal optical reflectance method, respectively. Results showed that the average concentrations of total WSI, OC and EC were 22.85±10.95 µg·m^-3, 17.83±9.57 µg·m^-3 and 5.11±4.29 µg·m^-3, respectively. They totally accounted for 53.0% of PM_2.5. Secondary organic and inorganic aerosols (SOA and SIA) were also assessed by the minimum ratio of OC/EC, nitrogen and sulfur oxidation ratios. The annual average concentrations of SOA and SIA totally accounted for 28.3% of the PM_2.5 concentration. The low proportion suggested the primary emission was the main source of PM_2.5 in Kunming. However, secondary pollution in the plateau city should also not be ignorable, due to the appropriate temperature and strong solar radiation, which can promote the atmospheric photochemical reactions.

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Characteristics of PM<Subscript>2.5</Subscript>, CO<Subscript>2</Subscript> and particle-number concentration in mass transit railway carriages in Hong Kong

Fine particulate matter (PM_2.5) levels, carbon dioxide (CO₂) levels and particle-number concentrations (PNC) were monitored in train carriages on seven routes of the mass transit railway in Hong Kong between March and May 2014, using real-time monitoring instruments. The 8-h average PM_2.5 levels in carriages on the seven routes ranged from 24.1 to 49.8 µg/m³, higher than levels in Finland and similar to those in New York, and in most cases exceeding the standard set by the World Health Organisation (25 µg/m³). The CO₂ concentration ranged from 714 to 1801 ppm on four of the routes, generally exceeding indoor air quality guidelines (1000 ppm over 8 h) and reaching levels as high as those in Beijing. PNC ranged from 1506 to 11,570 particles/cm³, lower than readings in Sydney and higher than readings in Taipei. Correlation analysis indicated that the number of passengers in a given carriage did not affect the PM_2.5 concentration or PNC in the carriage. However, a significant positive correlation (p < 0.001, R ² = 0.834) was observed between passenger numbers and CO₂ levels, with each passenger contributing approximately 7.7–9.8 ppm of CO₂. The real-time measurements of PM_2.5 and PNC varied considerably, rising when carriage doors opened on arrival at a station and when passengers inside the carriage were more active. This suggests that air pollutants outside the train and passenger movements may contribute to PM_2.5 levels and PNC. Assessment of the risk associated with PM_2.5 exposure revealed that children are most severely affected by PM_2.5 pollution, followed in order by juveniles, adults and the elderly. In addition, females were found to be more vulnerable to PM_2.5 pollution than males (p < 0.001), and different subway lines were associated with different levels of risk.     

Characteristics,sources and health risk assessment of toxic heavy metals in PM<Subscript>2.5</Subscript> at a megacity of southwest China

Twenty trace elements in fine particulate matters (i.e., PM_2.5) at urban Chengdu, a southwest megacity of China, were determined to study the characteristics, sources and human health risk of particulate toxic heavy metals. This work mainly focused on eight toxic heavy metal elements (As, Cd, Cr, Cu, Mn, Ni, Pb and Zn). The average concentration of PM_2.5 was 165.1 ± 84.7 µg m^?3 during the study period, significantly exceeding the National Ambient Air Quality Standard (35 µg m^?3 in annual average). The particulate heavy metal pollution was very serious in which Cd and As concentrations in PM_2.5 significantly surpassed the WHO standard. The enrichment factor values of heavy metals were typically higher than 10, suggesting that they were mainly influenced by anthropogenic sources. More specifically, the Cr, Mn and Ni were slightly enriched, Cu was highly enriched, while As, Cd, Pb and Zn were severely enriched. The results of correlation analysis showed that Cd may come from metallurgy and mechanical manufacturing emissions, and the other metals were predominately influenced by traffic emissions and coal combustion. The results of health risk assessment indicated that As, Mn and Cd would pose a significant non-carcinogenic health risk to both children and adults, while Cr would cause carcinogenic risk. Other toxic heavy metals were within a safe level.     

Development of source profiles and their application in source apportionment of PM<Subscript>2.5</Subscript> in Xiamen,China

Ambient PM_2.5 samples were collected at four sites in Xiamen, including Gulangyu (GLY), Hongwen (HW), Huli (HL) and Jimei (JM) during January, April, July and October 2013. Local source samples were obtained from coal burning power plants, industries, motor vehicles, biomass burning, fugitive dust, and sea salt for the source apportionment studies. The highest value of PM_2.5 mass concentration and species related to human activities (SO₄ ^2–, NO₃ ^–, Pb, Ni, V, Cu, Cd, organic carbon (OC) and elemental carbon (EC)) were found in the ambient samples from HL, and the highest and lowest loadings of PM_2.5 and its components occurred in winter and summer, respectively. The reconstructed mass balance indicated that ambient PM_2.5 consisted of 24% OM (organic matter), 23% sulfate, 14% nitrate, 9% ammonium, 9% geological material, 6% sea salt, 5% EC and 10% others. For the source profiles, the dominant components were OC for coal burning, motor vehicle, biomass burning and sea salt; SO₄ ^2– for industry; and crustal elements for fugitive dust. Source contributions were calculated using a chemical mass balance (CMB) model based on ambient PM_2.5 concentrations and the source profiles. GLY was characterized by high contributions from secondary sulfate and cooking, while HL and JM were most strongly affected by motor vehicle emissions, and biomass burning and fugitive dust, respectively. The CMB results indicated that PM_2.5 from Xiamen is composed of 27.4% secondary inorganic components, 20.8% motor vehicle emissions, 11.7% fugitive dust, 9.9% sea salt, 9.3% coal burning, 5.0% biomass burning, 3.1% industry and 6.8% others.

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PM<Subscript>10</Subscript> emissions from industrial coal-fired chain-grate boilers

Industrial coal-fired boiler is an important air pollutant emission source in China. The chain-grate boiler is the most extensively used type of industrial coal-fired boiler. An electrical low-pressure impactor, and a Dekati® Low Pressure Impactor were applied to determine mass and number size distributions of PM₁₀ at the inlet and the outlet of the particulate emission control devices at six coalfired chain-grate boilers. The mass size distribution of PM₁₀ generated from coal-fired chain-grate boilers generally displays a bimodal distribution that contains a submicron mode and a coarse mode. The PM in the submicron mode for burning with raw coal contributes to 33% ± 10 % of PM₁₀ emissions, much higher than those for pulverized boilers. And the PM in the submicron mode for burning with briquette contributes up to 86 % of PM₁₀ emissions. Multiclones and scrubbers are not efficient for controlling PM10 emission. Their average collection efficiencies for sub-micron particle and super-micron particle are 34% and 78%, respectively. Operating conditions of industrial steam boilers have influence on PM generation. Peak of the submicron mode during normal operation period is larger than the start-up period.

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Trace element concentration in fine particulate matter (PM<Subscript>2.5</Subscript>) and their bioavailability in different microenvironments in Agra,India: a case study

Exposure to airborne particulate matter results in the deposition of millions of particle in the lung; consequently, there is need for monitoring them particularly in indoor environments. Case study was conducted in three different microenvironments, i.e., urban, rural and roadside to examine the elemental bioavailability in fine particulate matter and its potential health risk. The samples were collected on polytetrafluoroethylene filter paper with the help of fine particulate sampler during August–September, 2012. The average mass concentration of PM_2.5 was 71.23 µg m^?3 (rural), 45.33 µg m^?3 (urban) and 36.71 µg m^?3 (roadside). Elements in PM_2.5 were analyzed by inductively coupled plasma atomic emission spectroscopy. Percentage bioavailability was determined to know the amount of soluble fraction that is actually taken across the cell membrane through inhalation pathway. Cadmium and lead were found to have cancer risk in a risk evaluation using an Integrated Risk Information system.     

PM<Subscript>2.5</Subscript> pollution from household solid fuel burning practices in Central India: 2. Application of receptor models for source apportionment

USEPA’s UNMIX, positive matrix factorization (PMF) and effective variance-chemical mass balance (EV-CMB) receptor models were applied to chemically speciated profiles of 125 indoor PM_2.5 measurements, sampled longitudinally during 2012–2013 in low-income group households of Central India which uses solid fuels for cooking practices. Three step source apportionment studies were carried out to generate more confident source characterization. Firstly, UNMIX6.0 extracted initial number of source factors, which were used to execute PMF5.0 to extract source-factor profiles in second step. Finally, factor analog locally derived source profiles were supplemented to EV-CMB8.2 with indoor receptor PM_2.5 chemical profile to evaluate source contribution estimates (SCEs). The results of combined use of three receptor models clearly describe that UNMIX and PMF are useful tool to extract types of source categories within small receptor dataset and EV-CMB can pick those locally derived source profiles for source apportionment which are analog to PMF-extracted source categories. The source apportionment results have also shown three fold higher relative contribution of solid fuel burning emissions to indoor PM_2.5 compared to those measurements reported for normal households with LPG stoves. The previously reported influential source marker species were found to be comparatively similar to those extracted from PMF fingerprint plots. The comparison between PMF and CMB SCEs results were also found to be qualitatively similar. The performance fit measures of all three receptor models were cross-verified and validated and support each other to gain confidence in source apportionment results.     

PM<Subscript>2.5</Subscript> particulates and metallic elements (Ni,Cu, Zn,Cd and Pb) study in a mixed area of summer season in Shalu,Taiwan

PM_2.5 has become an important environmental issue in Taiwan during the past few years. Moreover, electricity increased significantly during the summertime and TTPP generated by coal burning base is the main electricity provider in central Taiwan. Therefore, summer season has become the main research target in this study. The ambient air concentrations of particulate matter PM_2.5 and PM₁₀ collected by using VAPS at a mixed characteristic sampling site were studied in central Taiwan. The results indicated that the average daytime PM_2.5 and PM₁₀ particulate concentrations were occurred in May and they were 44.75 and 57.77 µg/m³ in this study. The results also indicated that the average nighttime PM_2.5 and PM₁₀ particulate concentrations were occurred in June and they were 38.19 and 45.79 µg/m³ in this study. The average PM_2.5/PM₁₀ ratios were 0.7 for daytime, nighttime and 24-h sampling periods in the summer for this study. This value was ranked as the lowest ratios when compared to the other seasons in previous study. Noteworthy, the results further indicated that the metallic element Pb has the mean highest concentrations for 24-h, daytime and nighttime sampling periods when compared to those of the other metallic elements (Ni, Cu, Zn and Cd). The average mean highest metallic Pb concentrations in PM10 were 110.7, 203.0 and 207.2 ng/m³ for 24-h, daytime and nighttime sampling periods in this study. And there were 59.53, 105.2 and 106.6 ng/m³ for Pb in PM2.5 for 24-h, daytime and nighttime sampling periods, respectively. Moreover, the results further indicated that mean metallic element Pb concentrations on PM_2.5 and PM₁₀ were all higher than those of the other elements for 24 h, day and nighttime.     

An assessment of the potential health benefits of realizing the goals for PM<Subscript>10</Subscript> in the updated Chinese Ambient Air Quality Standard

As a response to the severe air quality problems in China, the Chinese Ministry of Environmental Protection in 2012 issued an updated Ambient Air Quality Standard (GB3095-2012), which set a stricter grade II PM₁₀ standard. A successful implementation of this standard will have an impact on human health through reduction of exposure to air pollution in the population. Using the methods of adjusted human capital and value of statistical life, the authors in this article estimate the economic impact of a successful implementation of the updated Ambient Air Quality Standard on human health in China. The key results are: 1) The human health benefits from reaching the updated standard for PM₁₀ would equal CNY 51.1 billion using adjusted human capital, accounting for 18.5% of total human health costs in China, and CNY 83.5 billion using the value of a statistical life; 2) the benefit of reaching the updated standard for PM₁₀ is highest in the east coastal areas and gradually declines for more Western provinces; and 3) the marginal benefit of public health increases as the environmental quality standard PM₁₀ improves. If the annual concentration of PM₁₀ were to be reduced from the target number in the original grade II standard to that in the updated standard, the mortality rate of long-term exposure would be reduced by 6.5% due to reduced chronic exposure. In addition, if the annual concentration were to be reduced further from updated grade II to grade I standard, the mortality rate for long-term exposure would be lowered by 32.8%.     

Gas-phase degradation of CCl<Subscript>4</Subscript>, CHCl<Subscript>3</Subscript> and CH<Subscript>2</Subscript>Cl<Subscript>2</Subscript> over metallic Fe

We studied the hydrolysis of gas-phase carbon tetrachloride (CCl₄), chloroform (CHCl₃), and dichloromethane (CH₂Cl₂) over a metallic Fe surface for its application in combination with air stripping and soil vapour extraction. The effects of chlorocarbon concentration, type and preparation of the iron-containing material, humidity, and temperature on process performance are reported. The hydrolysis of chlorinated methane derivatives is catalysed by metallic iron resulting in a noticeable decrease of the reaction temperature. The reaction kinetics were found to be consistent with the Langmuir-Hinshelwood model.     

Preparation of effective TiO<Subscript>2</Subscript>/Bi<Subscript>2</Subscript>O<Subscript>3</Subscript> photocatalysts for water treatment

Photocatalytic oxidation using semiconductors is one of the advanced oxidation processes for degradation of organic pollutants in water and air. TiO₂ is an excellent photocatalyst that can mineralize a large range of organic pollutants such as pesticides and dyes. The main challenge is to improve the efficiency of the TiO₂ photocatalyst and to extend TiO₂ light absorption spectra to the visible region. A potential solution is to couple TiO₂ with a narrow band gap semiconductor possessing a higher conduction band such as bismuth oxide. Therefore, here we prepared Bi₂O₃/TiO₂ heterojunctions by the impregnation method with different Bi/Ti ratio. The prepared composites have been characterized by UV–Vis diffused reflectance spectra and X-ray diffraction. The photocatalytic activity of the heterojunction has been determined from the degradation of orange II under visible and UV light. Results show that Bi₂O₃/TiO₂ heterojunctions are more effective than pure TiO₂-anatase under UV-A irradiation, with an optimum for the Bi/Ti ratio of 5 %, for the photocatalytic degradation of Orange II. However, the photocatalytic activity under irradiation at λ higher than 420 nm is not much improved. Under UV–visible radiation, the two semiconductors are activated. We propose a mechanism explaining why our products are more effective under UV–visible irradiation. In this case the charge separation is enhanced because a part of photogenerated electrons from the conduction band of TiO₂ will go to the conduction band of bismuth oxide. In this composite, titanium dioxide is the main photocatalyst, while bismuth oxide acts as adsorbent photosensitizer under visible light.     

Spectroscopic tools for remote sensing of greenhouse gases CH<Subscript>4</Subscript>, CF<Subscript>4</Subscript> and SF<Subscript>6</Subscript>

Highly symmetrical molecules such as CH₄, CF₄ or SF₆ are known to be atmospheric pollutants and greenhouse gases. High-resolution spectroscopy in the infrared is particularly suitable for the monitoring of gas concentration and radiative transfers in the earth's atmosphere. This technique requires extensive theoretical studies for the modeling of the spectra of such molecules (positions, intensities and shapes of absorption lines). Here, we have developed powerful tools for the analysis and the simulation of absorption spectra of highly symmetrical molecules. These tools have been implemented in the spherical top data system (STDS) and highly-spherical top data system (HTDS) software available at http://www.u-bourgogne.fr/LPUB/shTDS.html. They include a compilation of modeled data obtained during the last 20 years. An overview of our latest results in this domain will be presented. Electronic Publication     

Promotion of transition metal oxides on the NH<Subscript>3</Subscript>-SCR performance of ZrO<Subscript>2</Subscript>-CeO<Subscript>2</Subscript> catalyst

Chromium oxide and manganese oxide promoted ZrO₂-CeO₂ catalysts were prepared by a homogeneous precipitation method for the selective catalytic reduction of NO _x with NH₃. A series of characterization including X-ray diffraction (XRD), high-resolution transmission electron microscope (HR-TEM), Brunauer–Emmett–Teller (BET) surface area analysis, H₂ temperatureprogrammed reduction (H₂-TPR), and X-ray photoelectron spectroscopy (XPS) were used to evaluate the influence of the physicochemical properties on NH₃-SCR activity. Cr-Zr-Ce and Mn-Zr-Ce catalysts are much more active than ZrO₂-CeO₂ binary oxide for the low temperature NH₃-SCR, mainly because of the high specific surface area, more surface oxygen species, improved reducibility derived from synergistic effect among different elements. Mn-Zr-Ce catalyst exhibited high tolerance to SO₂ and H₂O. Cr-Zr-Ce mixed oxide exhibited>80% NO _x conversion at a wide temperature window of 100°C–300°C. In situ DRIFT studies showed that the addition of Cr is beneficial to the formation of Bronsted acid sites and prevents the formation of stable nitrate species because of the presence of Cr^{6 +}. The present mixed oxide can be a candidate for the low temperature abatement of NO _x .

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Interpolation performance of a spatio-temporal model with spatially varying coefficients: application to PM<Subscript>10</Subscript> concentrations in Rio de Janeiro

In this work we present a Bayesian analysis in linear regression models with spatially varying coefficients for modeling and inference in spatio-temporal processes. This kind of model is particularly appealing in situations where the effect of one or more explanatory processes on the response present substantial spatial heterogeneity. We describe for this model how to make inference about the regression coefficients and response processes under two scenarios: when the explanatory processes are known throughout the study region, and when they are known only at the sampling locations. Using a simulation experiment we investigate how parameter inference and interpolation performance are affected by some features of the data and prior distribution that is used. The proposed methodology is used to model the dataset on PM₁₀ levels in the metropolitan region of Rio de Janeiro presented in Paez and Gamerman (2003).     

Unexpected release of HNO<Subscript>3</Subscript> and related species from UV-illuminated TiO<Subscript>2</Subscript> surface into air in photocatalytic oxidation of NO<Subscript>2</Subscript>

We have discovered that HNO₃ and related species are released from the TiO₂ surface into air in the TiO₂ photocatalytic oxidation of NO₂ (1 ppm) under continuous UV light illumination (1 mW cm⁻²) by dehumidifying the outlet gas of the reaction and analyzing the recovered condensate liquid by ion chromatography. The origin of the HNO₃ recovered in the dehumidifier could not be explained by a simple desorption of HNO₃ overproduced on the TiO₂ surface. The produced HNO₃ must be activated on the TiO₂ surface and causing the unidentified reaction.     

Effects of Pd doping on N<Subscript>2</Subscript>O formation over Pt/BaO/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> during NO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> storage and reduction process

N₂O is a powerful greenhouse gas and plays an important role in destructing the ozone layer. This present work investigated the effects of Pd doping on N₂O formation over Pt/BaO/Al₂O₃ catalyst. Three types of catalysts, Pt/BaO/Al₂O₃, Pt/Pd mechanical mixing catalyst (Pt/BaO/Al₂O₃ + Pd/Al₂O₃) and Pt-Pd co-impregnation catalyst (Pt-Pd/BaO/Al₂O₃) were prepared by incipient wetness impregnation method. These catalysts were first evaluated in NSR activity tests using H₂/CO as reductants and then carefully characterized by BET, CO chemisorption, CO-DRIFTs and H2-TPR techniques. In addition, temperature programmed reactions of NO with H2/CO were conducted to obtain further information about N₂O formation mechanism. Compared with Pt/BaO/Al₂O₃, (Pt/BaO/ Al₂O₃ + Pd/Al₂O₃) produced less N₂O and more NH3 during NO _x storage and reduction process, while an opposite trend was found over (Pt-Pd/BaO/Al₂O₃ + Al₂O₃). Temperature programmed reactions of NO with H₂/CO results showed that Pd/Al₂O₃ component in (Pt/BaO/Al₂O₃ + Pd/Al₂O₃) played an important role in NO reduction to NH₃, and the formed NH3 could reduce NO _x to N₂ leading to a decrease in N₂O formation. Most of N₂O formed over (Pt-Pd/BaO/Al₂O₃ + Al₂O₃) was originated from Pd/BaO/Al₂O₃ component. H₂-TPR results indicated Pd-Ba interaction resulted in more difficultto- reduce PdOx species over Pd/BaO/Al₂O₃, which inhibits the NO dissociation and thus drives the selectivity to N₂O in NO reduction.

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Decolorisation of Acid Blue 74 by ultraviolet/H<Subscript>2</Subscript>O<Subscript>2</Subscript>

The photodegradation of Acid blue 74 in aqueous solution employing a H₂O₂/ultraviolet system in a photochemical reactor was investigated. The kinetics of decolorization were studied by application of a kinetic model. The results show that the reaction of decolorization followed pseudo-first order kinetics. We demonstrate that there is an optimum H₂O₂ concentration, at which the rate of the decolorization reaction is maximum. Irradiation at 253.7 nm of the dye solution in the presence of H₂O₂ results in complete discoloration after ten minutes of treatment.     

Interaction between cadmium,lead and potassium fertilizer (K<Subscript>2</Subscript>SO<Subscript>4</Subscript>) in a soil-plant system

A pot experiment was conducted to examine the influence of potassium (K) fertilizer (K₂SO₄) application on the phytoavailability and speciation distribution of cadmium (Cd) and lead (Pb) in soil. Spring wheat (Triticum aestivum L.) was selected as the test plant. There were seven treatments including single and combined contamination of Cd and Pb. CdCl₂·2.5 H₂O and Pb(NO₃)₂ were added to the soil at the following dosages: Cd + Pb = 0.00 + 0.00, 5.00 + 0.00, 25.0 + 0.00, 0.00 + 500, 0.00 + 1000, 5.00 + 500 and 25.0 + 1000 mg kg⁻¹, denoted by CK, T1, T2, T3, T4, T5 and T6, respectively. The K fertilizer had five levels: 0.00, 50.0, 100, 200 and 400 mg K₂O kg⁻¹ soil, denoted by K0, K1, K2, K3 and K4, respectively. The results showed that the K fertilizer promoted the dry weight (DW) of wheat in all treatments and alleviated the contamination by Cd and Pb. The application of K₂SO₄ reduced the uptake of Cd in different parts including roots, haulms and grains of wheat; the optimum dosage was the K2 level. K supply resulted in a significant (P < 0.05) decrease in the soluble plus exchangeable (SE) fraction of Cd and there was a negative correlation (not significant, P > 0.05) between the levels of K and the SE fraction of Cd in soil. The application of the K fertilizer could obviously restrain the uptake of Pb by wheat and there were significant (P < 0.05) negative correlations between the concentrations of Pb in grains and the levels of K in soil. K supply resulted in a decrease in the SE fraction of Pb (except the K1 level) from the K0 to K4 levels. At the same time, the application of the K fertilizer induced a significant (P < 0.05) decrease in the weakly specifically adsorbed (WSA) fraction of Pb and a significant (P < 0.05) increase in the bound to Fe–Mn oxides (OX) fraction of Pb. At different K levels, the concentration of Pb in the roots, haulms and grains had a positive correlation with the SE (not significant, P > 0.05) and WSA (significant, P < 0.05) fractions of Pb in the soil. All the K application levels in this experiment reduced the phytoavailability of Cd and Pb. Thus, it is feasible to apply K fertilizer (K₂SO₄) to alleviate contamination by Cd and/or Pb in soil. Moreover, the level of K application should be considered to obtain an optimal effect with the minimum dosage.     

Tracing the sources of gaseous components (<Superscript>222</Superscript>Rn,CO<Subscript>2</Subscript> and its carbon isotopes) in soil air under a cool-deciduous stand in Sapporo,Japan

Radon (²²²Rn) and carbon dioxide were monitored simultaneously in soil air under a cool-temperate deciduous stand on the campus of Hokkaido University, Sapporo, Japan. Both ²²²Rn and CO₂ concentrations in soil air varied with atmospheric (soil) temperature in three seasons, except for winter when the temperature in soil air remained constant at 2–3°C at depth of 80 cm. In winter, the gaseous components were influenced by low-pressure region passing through the observation site when the ground surface was covered with snow of ~1 m thickness. Carbon isotopic analyses of CO₂ suggested that CO₂ in soil air may result from mixing of atmospheric air and soil components of different origins, i.e. CO₂ from contemporary soil organic matter and old carbon from deeper source, to varying degrees, depending on seasonal meteorological and thus biological conditions.     

Photocatalytic degradation of organic dyes by Er<Superscript>3+</Superscript>:YAlO<Subscript>3</Subscript>/TiO<Subscript>2</Subscript> composite under solar light

In this work, Er³⁺:YAlO₃/TiO₂ composite was synthesized by a ultrasonic dispersion and liquid boil method. The Er³⁺:YAlO₃/TiO₂ composite and pure TiO₂ powder were characterized by XRD. The degradation of different organic dyes was used to evaluate the photocatalytic activity of the Er³⁺:YAlO₃/TiO₂ composite. It is found that the photocatalytic activity of Er³⁺:YAlO₃/TiO₂ composite is much higher than that for the similar system with only TiO₂. Moreover, this Er³⁺:YAlO₃/TiO₂ composite provides a new way to take advantage of TiO₂ in sewage treatment aspects using solar light.