Comprehensive evaluation of antibiotics pollution the Yangtze River basin, China: Emission, multimedia fate and risk assessment.

Antibiotics have attracted global attention because of their potential ecological and health risks. The emission, multimedia fate and risk of 18 selected antibiotics in the entire Yangtze River basin were evaluated by using a level Ⅳ fugacity model. High antibiotic emissions were found in the middle and lower reaches of the Yangtze River basin. The total antibiotic emissions in the Yangtze River basin exceeded 1600 tons per year between 2013 and 2021. The spatial distribution of antibiotics concentration was the upper Yangtze River > middle Yangtze River > lower Yangtze River, which is positively correlated with animal husbandry size in the basin. Temperature and precipitation increases may decrease the antibiotic concentrations in the environment. Transfer fluxes showed that source emission inputs, advection processes, and degradation fluxes contributed more to the total input and output. High ecological risks in the water environment were found in 2018, 2019, 2020, and 2021. The comprehensive health risk assessment through drinking water and fish consumption routes showed that a small part of the Yangtze River basin is at medium risk, and children have a relatively high degree of health risk. This study provides a scientific basis for the pollution control of antibiotics at the basin scale.

[Seasonal Variation Characteristics and Pollution Assessment of Heavy Metals in Water and Sediment of Taipu River].

Taipu River is a river spanning two provinces and one city in a demonstration area in the Yangtze River Delta on an ecologically friendly developmentand an important water source in the upper reaches of the Huangpu River in Shanghai. To understand the multi-media distribution characteristics, pollution status, and ecological risk of heavy metals in the Taipu River, the contents of heavy metals (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sb, and Zn) in the sediments of Taipu River were analyzed, and the pollution status and potential ecological risk were evaluated using the Nemerow comprehensive pollution index, geo-accumulation index, and potential ecological risk index methods. In addition, the health risk assessment model was used to assess the health risk of heavy metals in surface water of Taipu River. The results showed that the concentrations of Cd, Cr, Mn, and Ni in the surface water of Taipu River exceeded the class Ⅲ water limit at the upstream point in spring; the concentrations of Sb exceeded the class Ⅲ water limit at all points in winter; the average value of As exceeded the class Ⅲ water limit in overlying water during the wet season; and the average values of As and Cd exceeded the class Ⅲ water limit in pore water during the wet season. The health risk assessment of surface water implied that both adults and children had higher health risk in spring and lower health risk in other seasons. The health risk of children was significantly higher than that of adults, and it mainly came from chemical carcinogenic heavy metal elements As, Cd, and Cr. The average contents of Co, Mn, Sb, and Zn in Taipu River sediments in the four seasons all exceeded the Shanghai soil baseline; the average contents of As, Cr, and Cu in summer, autumn, and winter exceeded the Shanghai soil baseline; and the average contents of Cd, Ni, and Pb in summer and winter exceeded the Shanghai soil baseline. The evaluation results of the Nemerow comprehensive pollution index and geo-accumulation index showed that the pollution degree of the middle reaches of Taipu River was higher than that of the upper and lower reaches, and the Sb pollution was more serious. The potential ecological risk index method revealed that the Taipu River sediment was at a low risk. Cd had a high contribution in both the wet and dry seasons and could be regarded as the main heavy metal of potential ecological risk in the Taipu River sediment.

Seasonal heavy metal speciation in sediment and source tracking via Cu isotopic composition in Huangpu River, Shanghai, China.

The present study systematically analyzed and evaluated the variations in chemical speciation, pollution assessment, and source identification of heavy metals in sediments of Huangpu River. The methods employed included heavy metal concentration, chemical speciation and Cu isotopic compositions analysis. Results showed that the chemical speciation of sediment-bound heavy metals, characterized by significant seasonal variation, shifted from non-residual fractions dominating in spring and summer to residual fractions dominating in autumn and winter. Precipitation was identified as an important factor influencing the chemical speciation of sediment-bound heavy metals. Furthermore, ratio of the secondary phase to the primary phase, RSP (=Cnon-residual/Cresidual) values in Huangpu River sediments were higher than 1 in spring and summer, indicating that sediment-bound heavy metals in Huangpu River were mainly composed of non-residual fractions and could potentially be released into the river water. Principal component analysis (PCA) revealed that navigation, traffic, agricultural, and industrial activities could be the potential sources of heavy metal pollution. Notably, the δ65Cu values in Huangpu River sediments were observed to be isotopically lighter (from -0.37 to +0.18 ‰), suggesting that navigation might be the primary pollution source. These results will not only provide guidance in reducing heavy metal concentrations, but also serve as a crucial basis for policy making regarding heavy metal control.

[Distribution Characteristics, Source Analysis, and Pollution Evaluation of Organic Matter in Surface Sediments of Qingpu District, Yangtze River Delta Integration Demonstration Area].

The surface sediments were collected from 25 sampling points in the Qingpu District of the Yangtze River Delta integration demonstration area, and the total organic carbon (TOC), total nitrogen (TN), organic carbon isotope (δ13C), and nitrogen isotope (δ15N) content in the samples were analyzed. The distribution characteristics and potential sources of organic matter in the surface sediments were discussed in detail, and the organic pollution index was also evaluated. The results showed that the ω(TOC) in the surface sediments of 31 sampling points in Qingpu District was 0.21%-3.55%, with an average value of 1.18%; ω(TN) ranged from 0.02% to 0.23%, with an average value of 0.09%. The δ13C ranged from -28.04‰ to -10.80 ‰, with an average of -22.28‰, and the δ15N ranged from 2.28‰ to 11.19‰, with an average of 5.76‰. The TOC content was significantly correlated with the TN content. Source analysis showed that the organic matter in the surface sediments of the study area was mainly affected by soil organic matter, sewage organic matter, and terrestrial plants. The calculation results of the contribution rate based on IsoSource software showed that the relative contribution rate of soil organic matter was relatively high (0.3%-96.8%), and domestic sewage had a certain contribution to the organic matter source of most sampling points. In addition, the selected end-member substances had certain differences in the contribution of organic matter sources in samples of different land use types. The evaluation index of organic pollution in the surface sediments of the study area ranged from 0.006-0.745, with an average value of 0.163, indicating that the organic pollution of the study area was considered lightly polluted. Among them, the pollution of sampling points around the Jinze Reservoir was more serious than that in other areas, indicating that there was a potential risk of eutrophication in this area, which requires certain attention.

Adsorptive behavior of thallium using Fe3O4-kaolin composite synthesized by a room temperature ferrite process.

Thallium (Tl) contaminants pose serious threats to the ecological environment and human health due to its acute/chronic poisoning on the health of most organisms even at low concentrations. To find a rapid and efficient technology in removing Tl from waters thus becomes a crucial issue. A magnetic Fe3O4-kaolin composite (denoted by FKC) with high specific surface area (133.7 m2/g) was successfully synthesized via a simple and low-cost technique for Tl(I) removing from various water media. The HRTEM images confirmed the existence of lattice fingers Fe3O4 and displayed that a large number of Fe3O4 nanoparticles dispersed on the surface of kaolin sheets. Compared with kaolin or Fe3O4 alone, FKC enhanced obviously the adsorption rate and capacity of Tl(I) over a wide pH range (4.5-9.0). The maximum adsorption capacity of FKC for Tl(I) was 19,347 mg/kg (calculated by Langmuir model), which was almost one hundred times and two times higher than those of kaolin and Fe3O4, respectively. Importantly, FKC was observed to have a great potential in removing Tl(I) from surface water, groundwater, and tap water in more alkaline conditions. By applying the external magnetic field, FKC could be recovered efficiently (99%) and rapidly (20 s). Moreover, Tl L3-edge XANES spectra revealed that Tl(I) was adsorbed on the FKC and would not be converted to more toxic Tl(III). The cations (CaCl2, NaCl, and KCl) and the ionic strength with concentrations of 0.001-1.0 mol/L showed a great influence on the adsorption of Tl(I) by FKC, implying that this adsorption was dominated by outer-sphere surface complexation at investigated pH values. The information provided is essential for designing a rapid and effective scavenger for removing Tl in various natural waters.

Multimedia fate model and risk assessment of typical antibiotics in the integrated demonstration zone of the Yangtze River Delta, China.

Due to the widespread consumption of antibiotics by humans and animals, antibiotic residues from human and animal excrements are released into the environment through domestic sewage and breeding wastewater, which ultimately affect the ecological environment and human health. In this study, the concentrations of 10 antibiotics in the air, water, soil, and sediment from 2013 to 2019 in Qingpu District of the integrated demonstration zone of the Yangtze River Delta were predicated by developing a dynamic Level IV fugacity model. The influence of seasonal environmental factors (e.g., temperature, rainfall) on the distribution and migration of antibiotics in multi-media was also explored. The simulation results show that the 10 antibiotics mainly existed in water and sediment. The concentrations of antibiotics in air, water, soil, and sediment were 0-7.629 × 10-14 ng/L, 1.187 × 10-10-16.793 ng/L, 1.042 × 10-14-3.500 × 10-11 ng/g and 8.015 × 10-12-14.188 ng/g, respectively. It was also found that the increase in temperature and rainfall can reduce the migration rate of some antibiotics into the water and sediment phases. The flux analysis of the cross-media migration and transformation of antibiotics in Qingpu District shows that advection was the prime input and output paths of antibiotics in the water. Moreover, the prime input and output paths of antibiotics in sediment were sedimentation from water to sediment and degradation. Sensitivity analysis shows that the characteristics of antibiotic emission, degradation rate, and Koc were the most influential parameters for target chemicals. The results of risk assessment based on Monte Carlo method reveal that the overall risk level of antibiotics in sediment was relatively risk-free, and the risk of antibiotics in water decreased in the order of tetracyclines > ß-lactams > fluoroquinolones > macrolides > sulfonamides.

Synthesis and evaluation of Fe3O4-impregnated activated carbon for dioxin removal.

Polychlorinated dibenzo-p-dioxins and -furans (PCDD/PCDFs) are highly toxic organic pollutants in soils and sediments which persist over timescales that extend from decades to centuries. There is a growing need to develop effective technologies for remediating PCDD/Fs-contaminated soils and sediments to protect human and ecosystem health. The use of sorbent amendments to sequester PCDD/Fs has emerged as one promising technology. A synthesis method is described here to create a magnetic activated carbon composite (AC-Fe3O4) for dioxin removal and sampling that could be recovered from soils using magnetic separation. Six AC-Fe3O4 composites were evaluated (five granular ACs (GACs) and one fine-textured powder AC(PAC)) for their magnetization and ability to sequester dibenzo-p-dioxin (DD). Both GAC/PAC and GAC/PAC-Fe3O4 composites effectively removed DD from aqueous solution. The sorption affinity of DD for GAC-Fe3O4 was slightly reduced compared to GAC alone, which is attributed to the blocking of sorption sites. The magnetization of a GAC-Fe3O4 composite reached 5.38 emu/g based on SQUID results, allowing the adsorbent to be easily separated from aqueous solution using an external magnetic field. Similarly, a fine-textured PAC-Fe3O4 composite was synthesized with a magnetization of 9.3 emu/g.

Pharmaceuticals and personal care products in a drinking water resource of Yangtze River Delta Ecology and Greenery Integration Development Demonstration Zone in China: Occurrence and human health risk assessment.

The occurrence, partition, and human health risk of thirteen pharmaceuticals and personal care products (PPCPs) have been investigated in surface water, overlying water, pore water and sediment samples from Dianshan Lake of Yangtze River Delta Ecology and Greenery Integration Development Demonstration Zone in China. PPCPs were ubiquitous in aqueous phase and sediments from Dianshan Lake. Sulfamethazine (SMZ) was dominated in surface water and overlying water, while ketoprofen (KPF) was rich in sediment. The total concentration of PPCPs ranged from 0.38-85.27 ng/L, 24.26-130.03 ng/L and 5.39-149.84 µg/kg in surface water, overlying water and sediment, respectively, which were in middle levels compared with these reported in other aquatic environment in China. Naproxen (NPX), sulfadimethoxine (SDM), sulfamethoxazole (SMX) and sulfamethazine (SMZ) in surface water showed a relatively higher level in lake side than those in lake center suggesting that a mixed containment source of human- and animal-derived from the areas around lake. The significant season variations of most PPCPs were mainly attributed to their usage, water temperature and dilution effect. The partition behaviors of PPCPs in sediment-overlying water and sediment-pore water system were mainly affected by their logKow values, and showed weak correlation with total organic carbon (TOC) content in sediment and molecular weights of PPCPs. Preliminary results indicated that PPCPs in Dianshan Lake have not posed a high risk to human health by exposure to drinking water for all age groups. Nevertheless, their potential to cause the mixture toxicity and resistance genes cannot be neglected. This work will contribute to the clear picture of PPCPs contamination in drinking water source in the Demonstration Zone, and provide reliable and simple-to-use information to regulators on the exposure and risk levels of PPCPs, as well as recommendations for future research.

Source identification of Zn in Erren River, Taiwan: An application of Zn isotopes.

Source identification of environmental pollutants is critical for pollution prevention and controlling. In this work, Zn isotopic compositions and Zn spatial distribution from headwater to estuary of Erren River (ER) catchments (southern Taiwan) were systematically investigated as a potential source tracer for distinguishing natural weathering and anthropogenic activities. Industrial wastewaters/effluents including leather, printed circuit board (PCB), metal surface treatment (MST), semiconductor wafer (SCW), and electroplating (EP) industries were collected and analyzed as the potential sources of Zn isotopic database. Results implied that MST wastewaters/effluents had the lowest δ66Zn values (Zn isotopic composition) in the range of -0.40 to +0.04. Oppositely, high Zn isotopic composition was observed in leather (δ66Zn = +0.41 to +0.71) and EP wastewaters/effluents (δ66Zn = +0.54 to +1.84). Significantly, the plot of δ66Zn versus 1/Zn clearly indicates that riverine Zn isotope in the ER waters (-0.73 to 1.77‰) can be simply explained by at least three end-member mixing which contains EP, MST wastewaters, and natural component. Our data importantly proved that Zn isotopic composition is a powerful tracer for distinguishing different Zn sources of anthropogenic pollution in rivers.

Recycling of neodymium enhanced by functionalized magnetic ferrite.

This study systematically evaluates Neodymium (Nd) recovery from actual seawaters and wastewater using functionalized magnetic ferrite (3-mercaptopropionic acid-tetraethyl orthosilicate ferrite, MPA-TEOS-ferrite). The recovery of Nd by MPA-TEOS-ferrite displayed an L-shaped nonlinear isotherm, suggesting limiting binding sites on the adsorbent surface. At room temperature, a significant recovery of Nd by MPA-TEOS-ferrite increased from 8.99% to 99.99% with increasing pH (2.89-8.16) and an enhanced maxima Nd recovery capacity was observed on MPA-TEOS-ferrite (25.58 mg/g) when compared with pure ferrite (22.27 mg/g). The L3-edge X-ray absorption near-edge structure (XANES) spectra for the adsorbents collected after Nd recovery indicated that Nd(III) was still the predominant oxidation species on the surface of MPA-TEOS-ferrite. Only slightly change in the oxidation state or electronic structure around the Nd ions could be found during the adsorption process. Importantly, no significant change was found on Nd recovery while the NaCl ionic strength increased from 0.01 to 0.5 N. Furthermore, the results also displayed that the synthesized MPA-TEOS-ferrite has a great potential in efficient and rapid recovery of Nd from seawaters and wastewater.

Rapid and efficient removal/recovery of molybdenum onto ZnFe2O4 nanoparticles.

An efficient method for removing and recovering molybdenum (Mo) from water was developed by using ZnFe2O4 nanoparticles. The Mo adsorption displayed a nonlinear isotherm that fitted well with the Langmuir isotherm, showing limited adsorption sites on the surface of ZnFe2O4. The adsorption of Mo(VI) was dependent on solution pH. With increasing pH, the build-up of negative charges of both adsorbent and adsorbate led to enhanced electric repulsion between them. The K-edge XANES spectra for the adsorbents collected after Mo adsorption revealed that Mo(VI) was the predominant oxidation state sorbed on ZnFe2O4, indicating that the reduction of Mo(VI) did not occur on ZnFe2O4. The different peak positions of k-space and R-space shown in K-edge EXAFS spectra demonstrated that the adsorbed Mo could be bound on the surface or be slipped in the vacancy position of the ZnFe2O4 crystal. Importantly, Mo could be efficiently adsorbed from photoelectric industrial wastewater and these adsorbed Mo anions were rapidly replaced by OH(-) ions, implying the potential for Mo removing and recovering in industrial wastewater.

Heterogeneous Degradation of Organic Pollutants by Persulfate Activated by CuO-Fe3O4: Mechanism, Stability, and Effects of pH and Bicarbonate Ions.

Magnetic CuO-Fe3O4 composite was fabricated by a simple hydrothermal method and characterized as a heterogeneous catalyst for phenol degradation. The effects of pH and bicarbonate ions on catalytic activity were extensively evaluated in view of the practical applications. The results indicated that an increase of solution pH and the presence of bicarbonate ions were beneficial for the removal of phenol in the CuO-Fe3O4 coupled with persulfate (PS) process. Almost 100% mineralization of 0.1 mM phenol can be achieved in 120 min by using 0.3 g/L CuO-Fe3O4 and 5.0 mM PS at pH 11.0 or in the presence of 3.0 mM bicarbonate. The positive effect of bicarbonate ion is probably due to the suppression of copper leaching as well as the formation of Cu(III). The reuse of catalyst at pH0 11.0 and 5.6 showed that the catalyst remains a high level of stability at alkaline condition (e.g., pH0 11.0). On the basis of the characterization of catalyst, the results of metal leaching and EPR studies, it is suggested that phenol is mainly destroyed by the surface-adsorbed radicals and Cu(III) resulting from the reaction between PS and Cu(II) on the catalyst. Taking into account the widespread presence of bicarbonate ions in waste streams, the CuO-Fe3O4/PS system may provide some new insights for contaminant removal from wastewater.

Conversion of waste Mn-Zn dry battery as efficient nano-adsorbents for hazardous metals removal.

A novel technique was successfully developed for manufacturing Mn-Zn ferrite nano-particles by acid dissolution and ferrite processes. The powders of waste dry batteries (PWDBs) were used as starting raw materials because the Mn and Zn content inside the PWDBs is potentially high. Our data showed that the most abundant elements inside PWDBs are manganese (41.0%), oxygen (40.6%), zinc (15.3%), and carbon (3.1%). It was found that proper reductant was critical for dissolution where FeSO4 is essential for spinel ferrite formation. Synthesized Mn-Zn ferrite particles reached their saturation magnetization at 63.8 emu/g and were successfully applied for As, Cd, and Pb removal in aqueous solution. Under the conditions of Mn-Zn ferrite 0.005 g, volume 10 mL, temperature 27°C, and contact time 1h, As, Cd, and Pb removal could reach 99.9, 99.7, and 99.8%, respectively. We demonstrate a novel method that can be applied for transforming WDBs into resource materials. This not only reduces the amount of WDBs, but also supports the concept of waste-battery reusable green-energy policy.

XANES evidence of arsenate removal from water with magnetic ferrite.

Arsenic (As) in groundwater and surface water is a worldwide problem possessing a serious threat to public health. In this study, a magnetic ferrite, was synthesized and investigated for its As(V) removal efficiency. The adsorption of As(V) by magnetic ferrite exhibited an L-shaped nonlinear isotherm, suggesting limiting binding sites on the adsorbent surface. The As K-edge X-Ray Absorption Near-Edge Structure (XANES) revealed that the adsorbed As(V) on ferrite was not reduced to more toxic As(III) by Fe(2+) in the ferrite structure. The maximum As adsorption capacity of ferrite was 14 mg/g at pH 3 and decreased with increasing pH due to enhanced electrostatic repulsion between As(V) and the adsorbent surface. Desorption of As(V) using six different acid and salt solutions showed that the desorption rate decreased in an order of H3PO4 > Na3PO4 > H2SO4 > Na2SO4 > HCl > HNO3. These results suggest that magnetic ferrite without surface modification is an effective adsorbent for removing As(V) from water, which was confirmed by the effective removal of As(V) from contaminated groundwater using this material. The used material can then be recovered using a magnet because of its paramagnetism; the adsorbed As(V) on the material can be recovered using H3PO4 or Na3PO4 solutions.

Kinetics and thermodynamics of adsorption for Cd on green manufactured nano-particles.

Magnetic nano-particles CuFe(2)O(4) were successful manufactured from industrial sludge by combination of acid leaching, chemical exchange, and ferrite process. For the first time these recycled nano-particles were used as adsorbent to investigate the kinetics and thermodynamics for adsorption of Cd in aqueous solutions. These experimental results showed that Cd(2+) adsorption efficiency increased from 0.85 to 99.9% when pH increased from 2 to 6. The maximum adsorption capacity of Cd(2+) was found to be 17.54 mg g(-1) under the conditions at pH 6.0, contact time 30 min, and temperature 318 K. The pseudo-second-order kinetic model provides the best correlation with the experimental data compared to the pseudo-first-order model. The Langmuir model yields a better fitting than the Freundlich model for Cd(2+) adsorption on CuFe(2)O(4) nano-particles under investigated temperatures. The thermodynamic constants of the adsorption process were evaluated, ΔG°, ΔH° and ΔS° is -6.05 kJ mol(-1) (at 318 K), 0.71 kJ mol(-1), and 4.53 J mol(-1) K(-1), respectively. These results imply that Cd(2+) adsorption onto CuFe(2)O(4) is feasible, spontaneous and endothermic in nature.

Combustion of isopropyl alcohol using a green manufactured CuFe2O4.

A green method for manufacturing CuFe(2)O(4) from industrial Cu sludge was successfully developed by a combination of acid leaching, chemical exchange and ferrite process. The CuFe(2)O(4) was applied for combustion of volatile organic compounds (VOCs) derived from isopropyl alcohol (IPA). The results show that IPA was reacted to form intermediate acetone and CO(2) at the temperature range of 110-170°C. When the temperature was increased to 180°C, IPA can be 100% converted into CO(2). The 96-h decay tests indicated that the catalyst has a good thermal stability and durability under the conditions of gas hourly space velocity 30,000 h(-1), oxygen content 21%, IPA inlet concentration 2000 ppm, and reaction temperature 180°C. The results demonstrate great potential that our manufactured CuFe(2)O(4) catalyst can be used in combustion IPA streams to eliminate the emission of IPA.

Treatment of complex heavy metal wastewater using a multi-staged ferrite process.

Complete removal of heavy metal from complex heavy-metal wastewater (CHMW) requires advanced technology. This study investigated the feasibility of a multi-staged ferrite process (MSFP) for treating CHMW, containing Cd, Cu, Pb, Cr, Zn, Ag, Hg, Ni, Sn and Mn. Our experimental results showed that most of the supernatants after conventional single-step ferrite process could conform to the effluent standard of Environmental Protection Administration in Taiwan. However, the sludge could not satisfy the toxicity characteristic leaching procedure (TCLP) limits due to high Cd, Cu, and Pb concentrations. The performance of MSFP in removing heavy metals from wastewater was subsequently investigated and the parameters of three treating steps in MSFP were optimized under 70°C and 90°C at pH 9, and 80°C at pH 10. After the three-staged procedures, all heavy metals in supernatant and sludge could fulfill the contamination levels regulated by law. In addition, the sludge generated from the MSFP was examined by XRD and forms a stable spinel structure, which could be effectively separated by external magnetic field.

trans-Iodido(pyrazinyl-κC(2))bis-(triphenyl-phosphane-κP)palladium(II).

There are two independent mol-ecules with similar configurations in the asymmetric unit of the title complex, [Pd(C(4)H(3)N(2))I(C(18)H(15)P)(2)]. In each mol-ecule, the geometry around the Pd atom is distorted square-planar, with the Pd atom displaced by 0.0549 (12) and 0.0734 (13) Šfrom the least-squares plane of the I-P-P-C atoms. The PPh(3) ligands are in trans positions, with P-Pd-P angles of 173.12 (4) and 170.29 (4)°, while the pyrazinyl ligands and I atoms, also trans to each other, form C-Pd-I angles of 179.38 (12) and 178.44 (12)°. In the crystal, C-H⋯π inter-actions occur, resulting in a three-dimensional supramolecular architecture.

Recycling of Cu powder from industrial sludge by combined acid leaching, chemical exchange and ferrite process.

A method in combination of acid leaching, chemical exchange and ferrite process was applied to recycle copper and confer higher chemical stability to the sludge generated from etching process in printed circuit board industry. Ninety-five percent copper could be recycled in the form of powder from the sludge. Moreover, not only the wastewater after chemical exchange can be treated to fulfill the effluent standard, but also the sludge can satisfy the toxicity characteristic leaching procedure (TCLP) limits made by Taiwan's environmental protection administration.

Incinerating volatile organic compounds with ferrospinel catalyst MnFe2O4: an example with isopropyl alcohol.

This paper concerns the incineration of isopropyl alcohol (IPA) using the ferrospinel catalyst MnFe2O4. It covers the preparation of the ferrospinel catalyst, the screening of catalytic activity, catalytic incineration testing, and 72-hr decay testing of the catalyst. The experimental results of catalyst screening reveal that the Mn/Fe catalyst is the best of five prepared catalysts (chromium/iron [Cr/Fe], manganese/iron [Mn/Fe], zinc/iron [Zn/Fe], nickel/iron [Ni/Fe], and pure magnetite [Fe3O4]). In tests of the catalytic incineration system used to convert IPA, 98% conversion was obtained at a space velocity of 24,000 hr(-1), an oxygen (O2) content of 21%, 1700 ppm of IPA, and a reaction temperature of 200 degrees C.