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Although enhancing the catalytic oxidation activity is a hotspot in thermal-driven catalytic disposal of persistent organic pollutants, few studies have managed to improve catalysts' water-resistance properties. Herein, we developed Fe2-xMnxO3 perovskite to boost the catalytic oxidation of hexabromocyclododecane under humidity by modulating its super-exchange interaction (SEI, Fe3+ + Mn3+ â Fe2+ + Mn4+). Fe0.4Mn1.6O3, with the strongest SEI, exhibits the biggest oxidation rate-constant, which is 3 times higher than that of commonly used Fe2O3 without SEI. Notably, unlike Fe2O3 which deactivates at a relative humidity of 5 %. Fe0.4Mn1.6O3 maintains its activity and is even boosted by 22 % compared to dry conditions. Mechanistic insights reveal that SEI between Fe and Mn enhances the reactivity of Mn4+- linked Olatt by lowering the reductive temperature from Mn4+ to Mn3+. Meanwhile, SEI promotes the adsorption of the associatively adsorbed H2O (HOH-type water) by reducing adsorption energy, thereby facilitating the formation of hydroxyl species, which are crucial for the oxidation process under humidity.
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Urban wastewater treatment plants (WWTPs) and drinking water treatment plants (DWTPs) play vital roles in the urban water cycle, ensuring access to safe drinking water and maintaining aquatic ecosystems. This study comprehensively assessed the occurrence and risks of pharmaceuticals and personal care products (PPCPs) in urban WWTPs and DWTPs. Our findings revealed widespread PPCPs presence, with concentrations ranging from <1 ng/L to several thousand ng/L. Significant regional disparities in occurrence and composition were observed linked to population types and economic structures. Furthermore, strong correlations were observed between DWTPs and WWTPs indicating consistent transport and transformation patterns of PPCPs within the urban water cycle. Approximately two-thirds of PPCPs were degraded post-WWTP treatment, with about one-tenth persisting in drinking water following surface water dilution and purification processes. Thus, we suggested that controlling the total concentration of the five priority PPCPs in the effluent from the WWTP to <1100 ng/L have potential to reduce the environmental and health risk of PPCPs. Additionally, this research identified influential water quality parameters, such as pH, dissolved oxygen, and temperature, through redundancy analysis. This research underscores the importance of establishing emission standards to mitigate PPCP-related risks and supports sustainable urban water system advancement.
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Risk assessment and source identification of multi-pollutants are essential for accurate control of soil contamination. However, complexity in pollutant properties and diversity in source types raise challenges to the target. Therefore, this study constructed a hierarchical ecological risk quantification method combined with risk ranking, risk of single pollutant using potential affected fraction (PAF), and joint risk of multi-pollutants employing msPAF. Taking regional contamination in South China as a case, the risk ranking was determined, while single and joint effects showed msPAF reaching 79.4 %, with risk as heavy metals (HMs) > per- and polyfluoroalkyl substances (PFASs) > polycyclic aromatic hydrocarbons (PAHs). Meanwhile, an integrated source apportionment method was established from three layers by principal component analysis to classify source types, multiple linear regression of distance to identify key sources, and positive matrix factorization to track omitted sources. Consequently, key sources were captured, with 80.8 %-93.2 % contribution of farmland and electroplating to three main HMs, 52.2 %-69.4 % contribution of roads to three main PAHs, and 71.1 %-73.2 % contribution of electroplating to two main PFASs. Further, omitted sources were tracked with contribution of 31.2 %-84.1 % to eight pollutants. The established methods can identify control targets, including high-risk pollutants and their key sources.
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Co-combustion of industrial and municipal solid wastes has emerged as the most promising disposal technology, yet its effect on unknown contaminants generation remains rarely revealed due to waste complexity. Hence, six batches of large-scale engineering experiments were designed in an incinerator of 650 t/d, which overcame the inauthenticity and deviation of laboratory tests. 953-1772 non-targeted compounds were screened in fly ash. Targeting the impact of co-combustion, a pseudo-component matrix model was innovatively integrated to quantitatively extract nine components from complex wastes grouped into biomass and plastic. Thus, the influence was evaluated across eight dimensions, covering molecular characteristics and toxicity. The effect of co-combustion with biomass pseudo-components was insignificant. However, co-combustion with high ratios of plastic pseudo-components induced higher potential risks, significantly promoting the formation of unsaturated hydrocarbons, highly unsaturated compounds (DBE≥15), and cyclic compounds by 19 %- 49 %, 17 %- 31 %, and 7 %- 27 %, respectively. Especially, blending with high ratios of PET plastic pseudo-components produced more species of contaminants. Unique 2 Level I toxicants, bromomethyl benzene and benzofuran-2-carbaldehyde, as well as 4 Level II toxicants, were locked, receiving no concern in previous combustion. The results highlighted risks during high proportion plastics co-combustion, which can help pollution reduction by tuning source wastes to enable healthy co-combustion.
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Incineración , Ceniza del Carbón , Plásticos/química , Biomasa , Residuos Sólidos/análisis , Contaminantes Atmosféricos/análisisRESUMEN
Per- and polyfluoroalkyl substances (PFASs) are widely used due to their unique structure and excellent performance, while also posing threats on ecosystem, especially long-chain perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). As the control of conventional PFASs, fluoroalkylether substances (ether-PFASs) as alternatives are constantly emerging. Subsequently, the three representative ether-PFASs, chlorinated polyfluoroalkyl ether sulfonic acid (F-53B), hexafluoropropylene oxide-dimer acid (HFPO-DA), and 4,8-Dioxa-3H-perfluorononanoicacid (ADONA) are discovered and have received more attention in the environment and ecosystem. But their security is now also being challenged. This review systematically assesses their security from six dimensions including environmental occurrence in water, soil and atmosphere, as well as bioaccumulation and risk in plants, animals and humans. High substitution level is observed for F-53B, whether in environment or living things. Like PFOS or even more extreme, F-53B exhibits high biomagnification ability, transmission efficiency from maternal to infant, and various biological toxicity effects. HFPO-DA still has a relatively low substitution level for PFOA, but its use has emerged in Europe. Although it is less detected in human bodies and has a higher metabolic rate than PFOA, the strong migration ability of HFPO-DA in plants may pose dietary safety concerns for humans. Research on ADONA is limited, and currently, it is detected in Germany frequently while remaining at trace levels globally. Evidently, F-53B has shown increasing risk both in occurrence and toxicity compared to PFOS, and HFPO-DA is relatively safe based on available data. There are still knowledge gaps on security of alternatives that need to be addressed.
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Ácidos Alcanesulfónicos , Caprilatos , Fluorocarburos , Propionatos , Contaminantes Químicos del Agua , Animales , Humanos , Bioacumulación , Ecosistema , Fluorocarburos/análisis , Éteres , Éteres de Etila , Contaminantes Químicos del Agua/análisis , China , Monitoreo del AmbienteRESUMEN
Developing industrially moldable catalysts with harmonized redox performance and acidity is of great significance for the efficient disposal of chlorinated volatile organic compounds (CVOCs) in actual exhaust gasses. Here, commercial TiO2, typically used for molding catalysts, was chosen as the carrier to fabricate a series of Ce0.02Mn0-0.24TiOx materials with different Mn doping ratios and employed for chlorobenzene (CB) destruction. The introduction of Mn remarkedly facilitated the synergistic effect of each element via the electron transfer processes: Ce3++Mn4+/3+âCe4++Mn3+/2+ and Mn4+/3++Ti4+âMn3+/2++Ti3+. These synergistic interactions in Ce0.02Mn0.04-0.24TiOx, especially Ce0.02Mn0.16TiOx, significantly elevated the active oxygen species, oxygen vacancies and redox properties, endowing the superior catalytic oxidation of CB. When the Mn doping amount increased to 0.24, a separate Mn3O4 phase appeared, which in turn might weaken the synergistic effect. Furthermore, the acidity of Ce0.02Mn0.04-0.24TiOx was decreased with the Mn doping, regulating the balance of redox property and acidity. Notably, Ce0.02Mn0.16TiOx featured relatively abundant B-acid sites. Its coordinating redox ability and moderate acidity promoted the deep oxidation of CB and RCOOH- intermediates, as well as the rapid desorption of Cl species, thus obtaining sustainable reactivity. In comparison, CeTiOx owned the strongest acidity, however, its poor redox property was not sufficient for the timely oxidative decomposition of the easier adsorbed CB, resulting in its rapid deactivation. This finding provides a promising strategy for the construction of efficient commercial molding catalysts to decompose the industrial-scale CVOCs.
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Óxidos , Compuestos Orgánicos Volátiles , Titanio , Manganeso , Oxidación-Reducción , CatálisisRESUMEN
As the third pole of the world and Asia's water tower, the Tibetan Plateau experiences daily release of pharmaceutical and personal care products (PPCPs) due to increasing human activity. This study aimed to explore the potential relationship between the concentration and composition of PPCPs and human activity, by assessing the occurrence of PPCPs in areas of typical human activity on the Qinghai-Tibet Plateau and evaluating their ecological risk. The results indicate that 28 out of 30 substances were detected in concentrations ranging from less than 1 ng/L to hundreds of ng/L, with the average concentration of most PPCPs in the Tibet Autonomous Region being higher than that in Qinghai Province. Among the detected substances, CAF, NOR, CTC, CIP, TCN, OTC, AZN, and DOX accounted for over 90% of the total concentration. The emission sources of PPCPs were identified by analyzing the correlation coefficients of soil and water samples, with excess PPCPs used by livestock breeding discharged directly into soil and then into surface water through leaching or runoff. By comparing the concentration and composition of PPCPs with those in other regions, this study found that CIP, ENR, LOM, NOR, CTC, DOX, OTC, and TCN were the most commonly used PPCPs in the Qinghai-Tibet Plateau. To assess the ecological risk of PPCPs, organisms at different trophic levels, including algae, crustaceans, fish, and insects, were selected. The prediction of the no effect concentration of each PPCP showed that NOR, CTC, TCN, CAF, and CBZ may have deleterious effects on water biota. This study can assist in identifying the emission characteristics of PPCPs from different types and intensities of human activities, as well as their occurrence and fate during the natural decay of aquatic systems.
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Cosméticos , Contaminantes Químicos del Agua , Animales , Humanos , Tibet , Clima Frío , Monitoreo del Ambiente/métodos , Agua , Cosméticos/análisis , Suelo , Contaminantes Químicos del Agua/análisis , Preparaciones Farmacéuticas , ChinaRESUMEN
EPFRs (Environmentally Persistent Free Radicals) are a class of pollutants that have been identified as potential environmental contaminants due to their persistence and ability to generate reactive oxygen species (ROS) that can cause oxidative stress in living organisms. However, no study has comprehensively summarized the production conditions, influencing factors and toxic mechanisms of EPFRs, impeding exposure toxicity assessments and risk prevention strategies. To bridge the gap between theoretical research and practical application, a thorough literature review to summarize the formation, environmental effects, and biotoxicity of EPFRs are conducted. A total of 470 relevant papers were screened in Web of Science Core collection databases. The transfer of electrons between interfaces and the cleavage of covalent bonds of persistent organic pollutants is crucial to the generation of EPFRs, which is induced by external sources of energy, including thermal energy, light energy, transition metal ions, and others. In the thermal system, the stable covalent bond of organic matter can be destroyed by heat energy at low temperature to form EPFRs, while the formed EPFRs can be destroyed at high temperature. Light can also accelerate the production of free radicals and promote the degradation of organic matter. The persistence and stability of EPFRs are synergistically influenced by individual environmental factors such as environmental humidity, oxygen content, organic matter content, and environmental pH. Studying the formation mechanism of EPFRs and their biotoxicity is essential for fully understanding the hazards posed by these emerging environmental contaminants.
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Contaminantes Ambientales , Radicales Libres/química , Especies Reactivas de Oxígeno , Contaminantes Ambientales/toxicidad , Estrés Oxidativo , Contaminantes Orgánicos Persistentes , Material Particulado/análisisRESUMEN
Microplastics (MPs) as emerging contaminants have become a major global concern, however, the distribution and origin of MPs in Qinghai-Tibet Plateau (QTP) and their impacts on ecosystem are poorly known. Hence, we systematically evaluated the profile of MPs on the representative metropolitan locations of Lhasa and Huangshui Rivers and the scenic sites of Namco and Qinghai Lake. The average abundance of MPs in the water samples was 7020 items/m3, which was 34 and 52 times higher than those for the sediment (206.7 items/m3) and soil samples (134.7 items/m3), respectively. Huangshui River had the highest levels, followed by Qinghai Lake, Lhasa River and Namco. Human activities rather than altitude and salinity impacted the distribution of MPs in those areas. Besides the consumption of plastic products by locals and tourists, laundry wastewater and exogenous tributary inputs, the unique prayer flag culture also contributed to the MPs emission in QTP. Notably, the stability and fragment of MPs were crucial for their fate. Multiple assessment models were employed to evaluate the risk of MPs. PERI model took MP concentration, background value and toxicity into account, comprehensively describing the risk differences of each site. The large PVC proportion in Qinghai Lake posed the highest risk. Furthermore, concerns should be raised about PVC, PE and PET in Lhasa and Huangshui Rivers, and PC in Namco Lake. Risk quotient suggested that aged MPs in sediments slowly released biotoxic DEHP and should be cleaned up promptly. The findings offer baseline data of MPs in QTP and ecological risks, providing important support for the prioritization of future control measures.
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Microplásticos , Contaminantes Químicos del Agua , Humanos , Anciano , Tibet , Plásticos , Ecosistema , Sedimentos Geológicos , Monitoreo del Ambiente , Contaminantes Químicos del Agua/análisisRESUMEN
Accurate source apportionment is essential for preventing the contamination of pervasive industrial zones. However, a limitation of traditional receptor models is their negligence of transmission loss, which consequently reduces their accuracy. Herein, chemical mass balance (CMB) and generic environmental model (GEM) was fused into a new method, which was employed to determine the traceability of polycyclic aromatic hydrocarbons (PAHs) in a complex zone containing three coking plants, two steel plants, and one energy plant. Five categories of fingerprints comprising various compounds were established for the six plant sources where seven PAHs with low-high rings were screened as the best. Considering volatilization, dry deposition, and advective and dispersive transport, the GEM model generated 232 "compartments" in multimedia to capture subtle variations of PAHs during transmission. More than 90 % of the transmission of the seven PAHs varied between 0.4 % and 6.0 %. Over pure CMB model, acceptable results and best-fit results improved by 1.6-44.4 % and 0.3-80.8 % in the GEM-CMB model. Additionally, the coking, steel, and energy industries accounted for 36.4-56.1 %, 25.6-41.7 %, and 18.3-23.6 % of PAHs sources at four receptor points, respectively. Furthermore, quantifying contaminant loss rendered the traceability results more realistic, judged by distances and discharge capacities. Accordingly, these outcomes can help in precisely determining soil contamination.
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As hotspots for the dissemination of antibiotic resistance genes (ARGs), wastewater treatment plants (WWTPs) have attracted global attention. However, there lacks a sufficient metagenomic surveillance of antibiotic resistome in the WWTPs located on the Qinghai-Tibet Plateau. Here, metagenomic approaches were used to comprehensively investigate the occurrence, mobility potential, and bacterial hosts of ARGs in influent and effluent of 18 WWTPs located on the Qinghai-Tibet Plateau. The total ARG relative abundances and diversity were significantly decreased from influent to effluent across the WWTPs. Multidrug, bacitracin, sulfonamide, aminoglycoside, and beta-lactam ARGs generally consisted of the main ARG types in effluent samples, which were distinct from influent samples. A group of 72 core ARGs accounting for 61.8-95.8 % of the total ARG abundances were shared by all samples. Clinically relevant ARGs mainly conferring resistance to beta-lactams were detected in influent (277 ARGs) and effluent (178 ARGs). Metagenomic assembly revealed that the genetic location of an ARG on a plasmid or a chromosome was related to its corresponding ARG type, demonstrating the distinction in the mobility potential of different ARG types. The abundance of plasmid-mediated ARGs accounted for a much higher proportion than that of chromosome-mediated ARGs in both influent and effluent. Moreover, the ARGs co-occurring with diverse mobile genetic elements in the effluent exhibited a comparable mobility potential with the influent. Furthermore, 137 metagenome-assembled genomes (MAGs) assigned to 13 bacterial phyla were identified as the ARG hosts, which could be effectively treated in most WWTPs. Notably, 46 MAGs were found to carry multiple ARG types and the potential pathogens frequently exhibited multi-antibiotic resistance. Some ARG types tended to be carried by certain bacteria, showing a specific host-resistance association pattern. This study highlights the necessity for metagenomic surveillance and will facilitate risk assessment and control of antibiotic resistome in WWTPs located on the vulnerable area.
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Antibacterianos , Purificación del Agua , Antibacterianos/farmacología , Genes Bacterianos , Metagenoma , Tibet , Aguas Residuales , Bacterias/genéticaRESUMEN
Catalytic combustion of ubiquitous chlorinated volatile organic compounds (CVOCs) encounters bottlenecks regarding catalyst deactivation by chlorine poisoning and generation of toxic polychlorinated byproducts. Herein, Ru, Pd, and Rh were loaded on {001}-TiO2 for thermal catalytic oxidation of chlorobenzene (CB), with Ru/{001}-TiO2 representing superior reactivity, CO2 selectivity, and stability in the 1000 min on-stream test. Interestingly, both acid sites and reactive active oxygen species (ROS) were remarkably promoted via adding NaBH4. But merely enhancing these active sites of the catalyst in CVOC treatment is insufficient. Continuous deep oxidation of CB with effective Cl desorption is also a core issue successfully tackled through the steady Ru0âRu4+ circulation. This circulation was facilitated by the observed higher subnanometer Ru dispersion on {001}-TiO2 than the other two noble metals that was supported by single atom stability DFT calculation. Nearly 88 degradation products in off-gas were detected, with Ru/{001}-TiO2 producing the lowest polychlorinated benzene byproducts. An effective and sustainable CB degradation mechanism boosted by the cooperation of NaBH4 enhanced active sites and Ru circulation was proposed accordingly. Insights gained from this study open a new avenue to the rational design of promising catalysts for the treatment of CVOCs.
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The sight into photoconversion of toluene, a ubiquitous typical pollutant, attentively by the involvement of PM2.5 in the real air environment is crucial for controlling haze pollution. Compared with the large-size PM2.5 on normal day (PM2.5-ND), the PM2.5 on haze day (PM2.5-HD) formed of small particle agglomerates featured greater oxidation capability, evidenced by the valence distribution of sulfur species. Notably, PM2.5-HD had abundant O2-⢠and â¢OH and participated in the photochemical reaction of toluene, giving it a greater toluene conversion with a first-order kinetic rate constant of 0.4 d-1 on haze day than on normal day (0.2 d-1). During the toluene photoconversion, isotopic labelling traced small molecules including benzene and newfound pentane, ethylbenzene, 1,3,8-p-menthatriene and 4-methyl-1-pentanone benzene that could be formed by methyl breakage, ring opening, fragmentation reforming and addition reaction of toluene. Given ADMET properties, 1,3,8-p-menthatriene was assigned high priority since it had poor metabolism, low excretion and severe toxicity, while benzene and 4-methyl-1-pentanone benzene should also be noticeable. FT-ICR MS results indicated that toluene could create multiple macromolecular products that are more sensitive to SOA generation in haze air matrix with broader carbon number and O/C, more oxygenated substitution with CHO/CHON occupying by 81.4%, lower DBEaverage at 4.66 and higher OSCâ¾ at -1.60 than normal air matrix. Accordingly, a photochemical reaction mechanism for toluene in real air atmosphere was proposed. The stronger oxidation property of PM2.5 not only facilitated toluene to generate small molecules but also boosted the conversion of intermediates to oxygenated macromolecular products, contributing to the formation of SOA.
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Contaminantes Atmosféricos , Tolueno , Contaminantes Atmosféricos/análisis , Benceno/análisis , Carbono , Material Particulado/análisis , Pentanos , Pentanonas , Azufre , Tolueno/análisisRESUMEN
Environmentally persistent free radicals (EPFRs) are emerging pollutants in contaminated soils and have attracted significant attention. Chinese coke production making a great contribution to the globe is increasingly identified as the non-ignorable source of EPFRs. However, the distribution level, influence factors, and biotoxicity of EPFRs at coking sites remain poorly understood. Herein, a typical coking plant in Tangshan, China, featuring two functional regions (the reconstructed project (RP) and elimination engineering (EE)) was used to study the existence of EPFRs. The spin density of the EPFRs in coking soils was 3.20 × 1020-3.11 × 1021 spins/g with g-factor values of 2.0020-2.0036. The EPFRs presented higher concentrations and g-factor values in RP region than in EE region, and a mixture of carbon-centered radicals and carbon-centered radicals with adjacent oxygen atoms as well as carbon-centered radical was ascertained in the former and the latter, respectively. Correlation analysis and FT-ICR-MS results indicated that polycyclic aromatic hydrocarbons (PAH) together with other unsaturated hydrocarbons and condensed aromatic contaminants, might contribute to the EPFRs formation in the soils of RP region, whereas PAHs were the main source of EPFRs in EE region. Soil components were determined to investigate the influence factors in EPFRs formation. Cu and Fe2O3 were recognized as the markedly positive influence factors, while TOC had a negative impact on EPFR formation. Visible light irradiation can induce the transformation and generation of EPFRs. As representative contaminants, both toluene and 2-chlorophenol can create EPFRs in coking soil under visible light irradiation. The potential biotoxicity tests of Photobacterium phosphoreum T3 spp. showed that EPFRs from the soils diminished bacterial luminescence. Such effect was proven to be induced by the OH based on the quenching experiment. Understanding the influence factors of EPFRs formation and their biotoxicity in coking soils is critical for developing risk assessments and prevention strategies.
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Coque , Hidrocarburos Policíclicos Aromáticos , Carbono , Coque/análisis , Radicales Libres/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/toxicidad , SueloRESUMEN
Volatile organic compounds (VOCs) are toxic to the ecological environment. The emission of VOCs into the atmosphere has already caused attention. However, few studies focus on their regional effects on soil. As a major VOCs source in China, research on the effect of petrochemical industry on the environment is urgent and essential for regional control and industrial layout. This study established national VOCs emission inventory of five petrochemical sub-industries and spatial distribution based on consumption of raw material or products' yield and 28,888 factories. The VOCs emissions showed continuously increasing trend from 2008 to 2019, with cumulative 1.83 × 107 t, wherein these from rapid economic development zones accounted for 66.10%. The detected concentrations of VOCs in various industries combined with meteorological parameters were used in Resistance Model to quantify regional dry deposition. Higher concentrations of 111 VOC species were 238.27, 260.01, 207.54 µg·m-3 from large-scale enterprises for crude oil and natural gas extraction, oil processing, synthetic rubber and resin, leading to higher deposition ratios of 0.81%-0.94%, 0.70%-0.81%, 1.50%-1.75% in rapid economic development zones, respectively. The regional climate condition played a dominant role. Annual VOCs dry deposition amount in rapid economic development zones was calculated to be totally 6.38 × 103 t using obtained deposition ratios and emissions, with 3.21 × 103 t in Bohai Economic Rim (BER), 2.42 × 103 t in Yangtze River Economic Belt (YREB), 748.43 t in Pearl River Delta (PRD). Generally, crude oil and natural gas extraction, oil processing, synthetic rubber and resin contributed 13.09%, 57.77% and 29.14%, respectively. The proportion of synthetic rubber and resin for dry deposition increased by 5.04%-18.81% compared with VOCs emissions in BER and YREB. In contrast, it declined from 45.52% for emission to 29.86% for deposition due to absolute dominance of small-scale enterprises in PRD. Overall, VOCs control from oil processing was significant, especially in BER.
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Contaminantes Atmosféricos , Petróleo , Compuestos Orgánicos Volátiles , Contaminantes Atmosféricos/análisis , China , Elastómeros , Monitoreo del Ambiente , Gas Natural , Suelo , Compuestos Orgánicos Volátiles/análisisRESUMEN
Polycyclic aromatic hydrocarbons (PAHs) are widely present in the environment. The coking industry is an important industrial source of PAHs. Coke production in China accounts for 67.44% of total global coke production. Tangshan, a coastal city on the Bohai Rim, contains the largest cluster of coking plants in China. Extremely high PAH emissions in Tangshan may cause long-distance cross-border pollution problems. In this study, the concentrations and sources of 16 priority PAHs in soil at a coking plant in Tangshan were determined and the risks posed by the PAHs were assessed. The PAH concentrations were generally higher in surface soil than subsurface soil, particularly near the coke oven, crude benzol, and coal blending areas. The dibenz[a,h]anthracene (DBA) concentrations were higher than the risk screening value (1500 ngg-1) but lower than the control value (15,000 ngg-1) for type II land defined in Chinese standard (GB36600-2018). The main sources of PAHs were coal combustion, the coke oven, and traffic. The PAH concentrations were higher in the ammonium sulfate, boiler room, coal blending, and coke oven areas than in the other areas. Toxic equivalent concentrations were calculated to assess the toxic and carcinogenic risks posed by PAHs. The toxic equivalent concentrations were relatively high in the boiler, crude benzol, and coal blending areas, where the toxic equivalent concentrations for the sums of seven highly carcinogenic PAHs contributed 95% of the toxic equivalent concentrations for the sums of the 16 PAHs that were analyzed. The carcinogenic risks posed to humans were therefore assessed using the concentrations of the seven highly carcinogenic PAHs. Dermal contact was found to be an important exposure pathway leading to carcinogenic risks. The carcinogenic risk posed by DBA was > 1 × 10-6 but < 5 × 10-6, indicating that DBA concentrations at the study site monitored closely.
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Coque , Hidrocarburos Policíclicos Aromáticos , Contaminantes del Suelo , China , Coque/análisis , Monitoreo del Ambiente , Humanos , Hidrocarburos Policíclicos Aromáticos/análisis , Medición de Riesgo , Suelo , Contaminantes del Suelo/análisisRESUMEN
With the rapid development of China's economy, volatile organic compounds (VOCs) as the precursor of smog and ozone are of increasing concern, especially in rapidly developing areas. This paper is a systematic analysis of VOCs emissions and distribution trends in 12 typical industrial sectors, garbage and wastewater treatment plants, comprehensive industrial parks, and residential districts in Beijing-Tianjin-Hebei, Yangtze River Delta, and Pearl River Delta Regions. The results show that pharmacy, rubber producing, as well as paint spraying are the top three industries among the 12 typical industries with the highest average VOCs emission concentrations at 541, 499, and 450 mg·m-3, respectively. By comparison, the average emission concentration of VOCs from the pharmaceutical industry in Yangtze River Delta and Beijing-Tianjin-Hebei Region was, respectively, about 112 and 1.00×103 mg·m-3. The paint spraying industry in the Pearl River Delta region has the highest emission rate with an average concentration of 1.04×103 mg·m-3. The investigation pertaining to the distribution of different VOCs categories indicates that highly toxic aromatics and halogenated hydrocarbons account for the highest emissions in paint spraying and pharmaceutical industries, reaching ratios of 55.99% and 26.57%, respectively. Additionally, among the three major economic zones, the VOCs concentration is the lowest in residential areas and comprehensive industrial parks in the Yangtze River Delta but the highest in the Beijing-Tianjin-Hebei Region, which is consistent with the distribution of industrial emissions in each region. Moreover, the research reveals that VOCs concentration in residential districts experienced a fluctuating reduction from 2002 to 2018. The significant reduction since 2016 suggests that formulated policies, laws and standards, along with the performed techniques have made significant contributions to the control of VOCs.
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In this study, a 2018 anthropogenic volatile organic compounds (VOCs) emission inventory in Hubei Province was conducted using the emission factor method based on activity levels of five sources. The emission characteristics and variation trends of process sources from 2009 to 2018 were further analyzed. Total anthropogenic VOCs emissions were 6.52×105 tons in Hubei Province, accounting for about 6.41% of the country's total omissions. The contributions of fossil combustion sources, process sources, solvent sources, mobile sources, and waste disposal sources were 3.26%, 76.39%, 4.54%, 14.72%, and 1.09%, respectively. Process sources involving 45 sub-categories of nine industries accounted for a significant proportion of VOCs emissions, with Wuhan and Yichang recording the highest VOCs emission levels. The VOCs emissions intensity of each city and state were analyzed based the level of economic activity and territorial area. Tianmen and Shennongjia had higher VOCs emissions per unit of GDP, while Wuhan, Ezhou, and Tianmen had higher VOCs emissions per unit area. Regarding process source contributions, VOCs emissions increased progressively to 2.45×105 tons in 2009 and then stabilized between 2015 and 2017 with maximum emissions of 7.01×105 tons. In 2018, VOCs emissions decreased to 4.98×105 tons. This trend was similar to national anthropogenic emissions. Two industrial sectors, namely chemical raw materials and rubber and plastics, were the main driving force with contributions of 33.85%-51.55% and 7.07%-38.13%, respectively. Among them, the production of chemicals and active pesticide and pharmaceutical ingredients played an important role in contributing to VOCs emissions, while emissions during foam plastics production varied greatly, increasing sharply to more than 2.00×104 tons in 2015-2017. Under the guidance of the relevant national and local policies, emissions from key industries were significantly reduced in Hubei Province.
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In order to understand the sources and distribution characteristics of hexachlorobutadiene (HCBD) in the Yangtze River Delta (YRD), Beijing-Tianjin-Hebei (BTH), and Pearl River Delta (PRD), the emission sources, as well as their distribution in water and soil were analyzed based on the production levels of chlorinated hydrocarbons and wastewater discharge in the three regions. The results showed that the by-products of trichloroethylene (TCE) and tetrachloroethylene (PCE) and wastewater treatment plants were the main sources of HCBD in the three regions. In 2018, the total emissions of HCBD from by-products of TCE and PCE in the three regions were 498.46 t, among which the proportion of by-products of TCE was 66.9%. The HCBD emissions of the three regional industrial and domestic wastewater treatment plants were 628.9 kg and 254.6 kg, respectively. The emissions of HCBD from hydrocarbon chlorination production and wastewater treatment plants in YRD were significantly higher at 497.8 t and 648 kg, respectively, while the emissions from the two sources in BTH were 0.37 t and 125 kg, respectively, and in PRD they were 0.29 t and 110.3 kg, respectively. The average concentrations of HCBD in the natural water of YRD, BTH and PRD were 0.35, 0.25, and 0.64 µg·L-1, respectively, and in the drinking water concentrations were 0.16, 0.09, and 0.04 µg·L-1, respectively. The overall level of HCBD in urban drinking water was relatively low. The concentrations of HCBD in industrial soil were significantly higher than in farmland soil, at 9.3-24.6 ng·g-1 and 0.13-2.67 ng·g-1, respectively. Similar to the situation in water bodies, HCBD pollution in the soil of YRD was the most serious, which was related to the fact that HCBD emissions in YRD were significantly higher than in BTH and PRD.
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Persistent organic pollutants (POPs) have gained heightened attentions in recent years owing to their persistent property and hazard influence on wild life and human beings. Removal of POPs using varieties of multifunctional materials have shown a promising prospect compared with conventional treatments. Herein, three main categories, including thermal degradation, electrochemical remediation, as well as photocatalytic degradation with the use of diverse catalytic materials, especially the recently developed prominent ones were comprehensively reviewed. Kinetic analysis and underlying mechanism for various POPs degradation processes were addressed in detail. The review also systematically documented how catalytic performance was dramatically affected by the nature of the material itself, the structure of target pollutants, reaction conditions and treatment techniques. Moreover, the future challenges and prospects of POPs degradation by means of multiple multifunctional materials were outlined accordingly. Knowing this is of immense significance to enhance our understanding of POPs remediation procedures and promote the development of novel multifunctional materials.