Abstract Although converting carbonaceous components in sewage sludge into value-added esters via pyrolysis presents significant resource recovery potential, the complex temperature-dependent interconversion and the limited molecular resolution of conventional analytical techniques have impeded mechanistic elucidation and selective regulation. Here, an integrated approach combining Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), paired mass distance (PMD) network analysis, interpretable machine learning, and density functional theory (DFT) calculations was employed to elucidate the transformation network of organooxygen species (OOSs) during sludge pyrolysis and enabled the proposal of a cascade pathway governing ester enrichment. Esters, unsaturated acids, saturated acids, and peptides/amides accounted for over 95.7% of total OOSs. Ester content decreased at 300–400 °C and regenerated at 400–500 °C, consistent with hydrolysis-esterification interconversion, defining a highly reactive temperature window. Within this interval, dominant interconversion pathways of peptides/amides ⇌ acids ⇌ esters were proposed, suggesting a cascade transformation pathway of peptides/amides → unsaturated acids → saturated acids → esters. The process yielded an additional net benefit of 164.6–474.6 CNY/t over conventional sludge disposal, with a carbon mitigation potential of 776.7 kg CO2e/t. These findings provide a molecular-scale basis for engineering-directed process optimization of pyrolysis systems targeting selective ester production from organic solid wastes.

Eliminating highly toxic and extremely stable heavy metal complexes (HMCs) has been a top priority in wastewater treatment. Conventional microscale zero-valent iron (mZVI) can remove HMCs, but is constrained by limited decomplexation reactivity, re-mobilization of liberated metals, and re-complexation from residual ligands. Here we modulate the lattice strain and interfacial properties of mZVI by N, S-co-doping to form N-S-mZVI, which synergistically accelerates mass transport and electron transfer, thereby efficiently removing organic chelated heavy metals (Cd, Pb, Zn, Cu). N-S-mZVI achieves a 165 times faster removal rate for Cd(II)-EDTA than unmodified mZVI together with a 65-fold higher removal capacity, due to intraparticle encapsulation of released Cd(II). Compared with mZVI, this co-modification accelerates dissolution of lattice iron (Fe), producing Fe ions for replacement decomplexation, and the resulting lattice vacancies facilitate inward diffusion and immobilization of heavy metals. The presence of low-resistance FeS and FexN at the interface forms electron transfer channels, directing electron flow toward O2. Surface Lewis base sites (pyridinic-N) enhance O2 adsorption, generating reactive oxygen species that oxidatively degrade ligands, and prevent re-complexation. N-S-mZVI effectively treats HMCs involving various ligands (EDTA, oxalate, tartrate and humate) and performs well in practical wastewater treatment. Our study provides insight into the synergistic regulatory mechanisms of N, S-co-doping in enhancing the mZVI reactivity and the stability of removed HMCs in environmental applications.

Dissolved organic matter (DOM) plays a key role in influencing the environmental behavior of heavy metals in lake ecosystems. Through mechanisms such as complexation, ion exchange, and physical adsorption, DOM regulates the speciation, transport, and bioavailability of heavy metals, thereby shaping their ecological risks and fate. Here, we provide a comprehensive review of the sources and molecular composition of lake DOM, with particular attention to humic substances, proteins, and polysaccharides, and highlight the importance of functional groups such as carboxyl group and phenolic hydroxyl group in metal binding. The mechanisms of DOM-heavy metal interactions are discussed in detail. These include σ-ligand bonding, which relies on the donation of lone pair electrons from O/N-containing functional groups to metal orbitals. Also covered are π–d electron interactions, often initiated by photoexcitation of aromatic moieties in DOM to facilitate electron transfer, and multi-site adsorption, a process governed by the combined effects of electrostatic attraction, hydrogen bonding, and the porous structure of DOM. Additionally, the effects of environmental factors (temperature, pH, and light) and biological factors (microbial activity and aquatic plant decomposition) on DOM-heavy metal dynamics are examined. Although substantial progress has been made, key challenges remain in understanding the microscale mechanisms, capturing real-time changes in natural waters, and assessing long-term ecological impacts. Future research should prioritize multi-scale approaches. This entails employing advanced techniques like Fourier-transform ion cyclotron resonance mass spectrometry to elucidate molecular mechanisms, while also advancing in situ monitoring technologies and establishing long-term observation networks to resolve real-time dynamics and assess cumulative ecological impacts. This review provides a theoretical basis for understanding DOM-heavy metal interactions and supports future efforts in ecological risk assessment and the sustainable management of lake environments.

The application of microscale zero-valent iron (mZVI) for in-situ remediation of contaminated groundwater remains constrained by its limited reactivity and poor mobility. Although silicification has been shown to modulate the reactivity or mobility of mZVI in saturated porous media, achieving an optimal balance between these properties continues to pose a significant challenge. In this study, a series of silicified mZVI (Si-mZVIBM) were synthesized via mechanical co-ball milling of mZVI with layered sodium disilicate. Compared to unmodified mZVI, mechanochemical silicification significantly improved chloramphenicol (CAP) removal efficiency (up to 78.4-fold) and expanded the in-situ reactive zone area by 2.6 times. Characterization of active species revealed that mechanochemical silicification facilitates outward electron transfer from mZVI, thereby enhancing its reductive capacity for CAP degradation. Furthermore, silicates with high proton affinity confine free protons at the ZVI surface. These protons accept electrons released by ZVI to form confined active hydrogen (*H), which further contributes to CAP reduction. Magnetic and zeta potential characterization indicated that silicification reduces the magnetism of mZVI while increasing its surface electronegativity and dispersion stability, resulting in improved mobility within porous media. The optimized Si-mZVIBM (Si/Fe = 0.16) exhibited broad pH adaptability (pH 3-11), achieving over 98 % CAP removal ratios under all tested conditions. These findings demonstrate the promising potential of Si-mZVIBM for effective remediation of CAP-contaminated groundwater.

Magnetite (Fe3O4) is a desirable Fenton-like activator, but its catalytic peroxydisulfate (PDS) activity remains to be improved. Here we report that, by supporting Fe3O4 on graphene oxide (Fe3O4-GO), the PDS activation process can be altered into a Fe(II)-coordinated nonradical pathway (i.e. surface electron-transfer), affording efficient and sustainable phenol degradation in a wide pH range of 3-9. Neither hydroxyl and sulfate radicals, singlet oxygen, nor high valent iron were identified as the major reactive species for phenol degradation through experiments of reactive species quenching, electron paramagnetic resonance, and chemical probe. The C--C sp2 carbon species in GO behaved as electron mediation for the sustainable regeneration of Fe(II) in Fe3O4 (i.e., catalyst regeneration), which behaved as active site for PDS activation through forming an inner-sphere complex to directly capture electron from organic (i.e., degradation). Our study reveals that the selective degradation of organic contaminants by PDS activation depends on the electron-donating capability of the organics. Overall, the study provides new insights into PDS activation by iron-loaded catalysts to selectively degrade pollutants via nonradical pathways.

Metal salts-modified sewage sludge (SS) biochar is increasingly used in agricultural soil remediation, although its effects on available phosphorus (P) species, plant growth and microbial communities remain unclear. This study prepared CaO, CaCl2, MgO and MgCl2-modified hydrochars derived from SS at 260 °C for 2 h. Then the available P characteristics of the hydrochars and their effects on the growth of Vigna radiata (mung bean) and soil microorganisms were comprehensively evaluated by chemical extraction, pot experiments and the diffusive gradients in thin-films (DGT) technique. Results indicated that Ca-based hydrochars contained more slow-release apatite P (AP) compounds (e.g., Ca5(PO4)3OH, Ca5(PO4)3Cl and Ca2PO4Cl), with a 48.6 • Ca/Mg salts promoted the transformation of P from Al-P and Fe–P to Mg-P and Ca-P. • Mg-based hydrochars offer rapid uptake P and boost P-solubilizing bacterial activity. • Ca-based hydrochars provide long-term available P and enhance soil bacterial communities for P mineralization. • Mg-modified hydrochars are more effective for promoting mung bean growth.

The valorization of chlorinated organic pollutants in water, such as 1,2-dichloroethane (1,2-DCA), into value-added products, such as ethylene, offers a sustainable remediation strategy but is limited by low efficiency and selectivity. Here we present a bioinspired system, consisting of cobalamin (vitamin B12) cofactor and microscale zero-valent iron (mZVI), that dechlorinates 1,2-DCA to ethylene with a rate constant of 0.066 h-1 and near-100% selectivity. mZVI creates a moderately reducing environment that reduces cob(III)alamin (the original B12 species) to cob(II)alamin, which forms an organocobalt-1,2-DCA complex and drives proton-independent dihaloelimination, avoiding unwanted hydrogenation and ethylene over-reduction. The strategy is effective for various chlorinated alkanes, alkenes and aromatics, high concentrations of 1,2-DCA in wastewater and mixed pollutants in groundwater. Mechanochemically anchoring B12 onto mZVI enables assembly in a column reactor for continuous 1,2-DCA removal, achieving a more than tenfold reduction in costs compared with conventional redox processes. This work demonstrates a cost-effective approach to pollutant remediation and resource recovery through the rational modulation of B12 redox chemistry.

The characteristics of dissolved organic matter (DOM) serve as indicators of nitrate pollution in groundwater. However, the specific DOM components associated with nitrate in groundwater systems remain unclear. In this study, dual isotopes of nitrate, three-dimensional Excitation emission matrices (EEMs) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) were utilized to uncover the sources of nitrate and their associations with DOM characteristics. The predominant nitrate in the targeted aquifer was derived from soil organic nitrogen (mean 46.0%) and manure &sewage (mean 34.3%). The DOM in nitrate-contaminated groundwater (nitrate-nitrogen >20 mg/L) exhibited evident exogenous characteristics, with a bioavailable content 2.58 times greater than that of uncontaminated groundwater. Regarding the molecular characteristics, DOM molecules characterized by CHO + 3N, featuring lower molecular weights and H/C ratios, indicated potential for mineralization, while CHONS formulas indicated the exogenous features, providing the potential for accurate traceability. These findings provided insights at the molecular level into the characterization of DOM in nitrate-contaminated groundwater and offer scientific guidance for decision-making regarding the remediation of groundwater nitrate pollution.

Durango City, Mexico, is one of the richest sources of gem-quality fluorapatite. In previous studies, Mexican apatite was mainly used as a reference material for geochronology and mineralogy, with few gemological and spectroscopic materials. As a kind of natural luminescent material, early scholars mainly used laser-induced photoluminescence spectra to study apatite from unknown origin, but lacked 3D fluorescence spectra. In this paper, nine apatite samples from Durango City, Mexico, were systematically examined by using basic gemological tests, LA-ICP-MS chemical analysis, FTIR spectroscopy, Raman spectroscopy, UV-Vis-NIR absorption spectroscopy and 3D fluorescence spectroscopy, aiming to enrich thedata of spectrum of Mexican apatite and to provide the scientific information for origin determination. Chemical research shows apatite is rich in rare earth elements (REE), with high contents of La, Ce, Pr, Nd, and Sm, with average contents of 3 956, 5 430, 472, 1 596, and 213 mu g center dot g(-1), respectively, which shows the characteristics of obvious enrichment of light REE and deficit of heavy REE. The average value of delta Eu is 0.29, with significant Eu negative anomaly, and the Ca/P molar ratio is close to the standard value of 1.68 of magmatic apatite, which indicate that Mexican apatite is the product of magmatism and the forming magma is in a moderately reductive state. FTIR spectroscopy shows that the intensity of the absorption peaks at 606 and 575 cm(-1) in the fingerprint region has obvious directionalregularity, which can provide a basis for crystal orientation. The functional group region shows absorption peaks of 3 482, 3 538, and 3 556 cm-1 of structure water. In the UV-Vis-NIR absorption spectrum, the single peak at 528 nm and the double peaks at 578 and 585 nm caused by Nd3+ generate the obvious transmission window in the yellow-green region. Therefore, it is speculated that Nd3+ causes the yellow-green color of apatite. In the UV region, the absorption peak at 298 nm is responsible for the absorption edge in the visible violet region, presumably caused by Ce3+. Studies on the 3D fluorescence spectrum showthe strongest fluorescence peak (lambda(ex) 300 nm/lambda(em) 356 nm), caused by the electron leap of Ce3+. In addition, the emission peaks at 603 and 647 nm in the red region are caused by the electron leap of Pr3+ and Sm3+, corresponding to the dark red fluorescence phenomenon observed under the UV lamp. Therefore, the dark red fluorescence is presumed to be caused by Pr3+ and Sm3+. The systematic spectroscopic features in this study enrich the spectroscopic data of apatite of Mexico and provide a scientific basis for origin determination.

Herein, we report an oxygen vacancies (OVs)-rich micro zero-valent iron (mZVI) interface for selective and efficient H2O2 degradation by mechanical chloride (Cl) doping. With the contribution of OVs, electron transfer process was sped up due to the charge unbalance of mZVI, and abundant adsorbed ferrous was produced. The resultant Cl-ZVIBM/H2O2 system increased the yield of center dot OH for threefold, without a significant increase in the subordinate reactive oxygen species, and the degradation rate for sulfamethazine was enhanced by 13 folds. The catalytic reactivity of as-prepared material was maintained for more than 230 days in dry air. The performance of as-prepared catalyst to practical water remediation was evaluated, and it demonstrated excellent results. The study shed light to improve the utilization efficiency of H2O2 by an OVs-rich iron-based catalyst using a simple mechanochemistry method of doping halogen elements.

为了了解包气带土壤中溶解性有机质(DOM)的来源和组成结构,探索其对硝酸盐向地下水迁移转化可能作用过程的影响,对张家口市宣化区包气带土壤DOM进行了光谱分析.结果表明,包气带土壤中DOM受陆源和微生物源共同影响,主要组分为类腐殖质,占比达77％～85％.随着土壤深度的增加,类腐殖质不断被微生物分解转化为反硝化作用提供了充足的碳源,促进了包气带反硝化作用的发生,导致DOM的芳香性和腐殖化程度整体减小.此外,地下水中硝酸盐氮氧同位素(δ15N-NO3-、δ18O-NO3-)组成特征(δ18O∶δ15N=0.59)进一步证明了研究区包气带-地下水中硝酸盐的迁移转化主要受反硝化作用的影响.上述研究有助于了解包气带土壤中DOM的动态变化及其在自然环境中的生物地球化学效应,为进一步研究地下水硝酸盐污染提供基础参考.

Urbanization has dramatically changed the quality and quantity of dissolved organic matter (DOM) fluxes in rivers, thereby affecting the diversity and lifestyle strategies of microbial communities. However, relationships between DOM molecular composition and microbial lifestyle strategies in effluent-dominated rivers are poorly understood. Herein, we investigated the variations in DOM structure and composition of an effluent-dominated river and further revealed how these changes alter the abundance and lifestyle strategies of microbial communities. Results demonstrated that macromolecular (MW > 35 kDa) humic-like substances constituted the major components of effluent-dominated riverine DOM. Also, due to the degradation of humic-like substances, the accumulation of protein-like substances was observed from upstream to downstream areas, corresponding to an apparent decrease in overall aromaticity. The abundance of bacterial, Actinobacteria, and eukaryotic was higher in the upstream and midstream areas but relatively lower in the downstream area. The response of bacterial and Actinobacteria communities to the changes in DOM composition was more prominent as compared to that of eukaryotic. Based on multivariate statistical analysis, the decrease in aromatic components (MW > 35 kDa) was mainly attributed to the degradation of Proteobacteria and Actinobacteria (K-strategists), resulting in a decrease in their relative abundance along the river course. Proteins and polysaccharides (15 kDa < MW < 35 kDa, MW < 6 kDa) were more easily utilized by Firmicutes and Bacteroidetes (r-strategists), leading to an increase in their relative abundance. With the decrease of macromolecular humic-like substances and the increase of protein-like substances, river microbial communities shifted from K-strategists to r-strategists. This work unveils the evolution of DOM in an effluent-dominated river and the influence of the degradation of macromolecular humic-like substances on r/K-strategists.

Rhodonite is a characteristic pink single-chain silicate mineral. As the gem-quality transparent rhodonite is rare, rhodonite is often produced as dense massive aggregate, which is usually classified as common jade in the gem trade. Monocrystal rhodonite is represented by the Broken Hill mining area in Australia and the Minas Gerais mining area in Brazil. In this paper, 10 samples of monocrystal rhodonite from Brazil are used for the LA-ICP-MS test, Raman spectroscopy test, infrared absorption spectroscopy test and UV-Vis absorption spectroscopy test, aiming to explore the chemical composition and spectroscopic characterization of rhodonite and provide basic data for the identification, optimization and origin identification of rhodonite. According to the results of LA-ICP-MS, the average crystal structure chemical formula of the samples is (Mn0.763Ca0.106Fe0.070 Mg-0.061)(1.00)SiO3. The main elements are rich Mn and Ca-Fe-Mg, similar to the monocrystal rhodonite composition produced in Minas Gerais, Brazil. The Raman shift of the sample is mainly composed of 666 cm(-1) strongest peak, 972, 997 cm(-1) double-peak, and several weak peaks. Which are related to the stretching and bending vibration of [SiO4] tetrahedral groups and the stretching vibration of octahedral coordination cations. Infrared test results show that the absorption peak of rhodonite in the fingerprint region is mainly due to the stretching and bending vibration of SiO. The structure of rhodonite determines that there are five absorption peaks in the band of 750 similar to 550 cm(-1), which distinguishespyroxenes and pyroxenoids minerals. There is an obvious absorption peak at 3 631 cm(-1) in the near-infrared region, which is a typical OH stretching vibration band indicating that the sample contains a small amount of structural water. UV-Vis absorption spectra show that rhodonite is a typical self-colored mineral, mainly attributed to the dd electronic transition of octahedral coordination Mn2+. The absorption peak is located at the purple and yellow-green regions, which is the main reason for the orange-pink color of the samples.

Remediation of chromium-contaminated groundwater remainsa significantenvironmental challenge around the world. Herein, we synthesized silicifiedmicroscale zerovalent iron (Si-mZVI(bm)) using a mechanochemicalmethod and demonstrated that the silicate modification could significantlyimprove the Cr(VI) removal efficiency (up to 37.5-fold) compared withits un-silicified counterpart. Results of atomic force microscopy,scanning transmission electron microscopy, and positron annihilationmeasurements revealed that silicate acted as a milling lubricant toboost strain within zerovalent iron particles, inducing more plasticdeformation and surface defects. The defect-rich silicified surfaceaccelerates the electron transfer and subsequent in situ generationof Fe(II). More importantly, the surface-modified silicate can actas a ligand to coordinate leached Fe(II) ions, thus strengtheningthe reduction of Cr(VI) via surface-bound Fe(II) and favoring subsequentco-precipitation of Cr(III) and Fe(III) species on Si-mZVI(bm) surfaces. During column experiments using real Cr-contaminated groundwater,Si-mZVI(bm) (4 wt % in sand) was able to reduce the Cr(VI)concentration from 2 to 0.05 mg L-1, the World HealthOrganization drinking water standard for up to 1720 bed volumes withan empty-bed contact time of 5.1 min. These results demonstrate thepotential field applicability of Si-mZVI(bm) in real contaminatedgroundwater remediation.

Microscale zero-valent iron (mZVI) is used as a catalyst for peroxide activation and, has attracted considerable attention for the degradation of organic contaminants. However, surface inherent oxide films impedes electron transfer in mZVI and decrease its activation efficiency. Herein, the mZVI surface was modified by sodium disilicate (Si-mZVIbm) using a mechanical ball-milling approach. The mechanochemically silicified mZVI enhanced the sulfamethazine removal rate by 2.9–23.8 fold in relation to unmodified ZVI; this rate increased with the Si/Fe molar ratio (0–8%). Reactive intermediates, including radicals and non-radicals, were efficiently generated via peroxydisulfate (PDS) activation over Si-mZVIbm both SO4•- and Fe(IV) contributed toward sulfamethazine removal. The excellent performance of PDS activation over Si-mZVIbm particles was attributed to the continuous generation of ferrous ions, which was due to the accelerated iron release and more effective Fe3+/Fe2+ cycles in the Si-mZVIbm/PDS system after silicification.

Accidental oil leaks and spills can often result in severe soil and groundwater pollution. In situ chemical oxidation (ISCO) is a powerful and efficient remediation technology. In this review, the applications and recent advances of three commonly applied in-situ oxidants (hydrogen peroxide, persulfate, and permanganate), and the gap in remediation efficiency between lab-scale and field-scale applications is critically assessed. Feasible improvements for these measures, especially solutions for the 'rebound effect', are discussed. The removal efficiencies reported in 108 research articles related to petroleum-contaminated soil and groundwater were analyzed. The average remediation efficiency of groundwater (82.7%) by the three oxidants was higher than that of soil (65.8%). A number of factors, including non-aqueous phase liquids, adsorption effect, the aging process of contaminants, low-permeability zones, and vapor migration resulted in a decrease in the remediation efficiency and caused the residual contaminants to rebound from 19.1% of the original content to 57.7%. However, the average remediation efficiency of ISCO can be increased from 40.9% to 75.5% when combined with other techniques. In the future, improving the utilization efficiency of reactive species and enhancing the contact efficiency between oxidants and petroleum contaminants will be worthy of attention. Multi-technical combinations, such as the ISCO coupled with phase-transfer, viscosity control, controlled release or natural attenuation, can be effective methods to solve the rebound problem.

为达到水环境承载力和区域经济协调发展的目的,运用系统动力学方法构建了包括17个细化工业类型在内以及受水资源、水污染、水生态多要素约束的白洋淀流域水环境承载力系统动力学模型,通过敏感性分析获得了 32个敏感指标,同时结合当地实际发展需求,通过设置6种适用于白洋淀流域的水环境承载力调控情景,得到2017～2035年白洋淀水环境承载力情景模拟与调控结果:(1)如果维持现状,人口和经济的增长会导致各方面对水资源需求增多、水体污染加剧,2020年以后将出现水资源缺口,并且缺口将进一步增大,2021年以后同时会出现水污染加剧的状况.(2)与现状情景相比,单独采取产业结构调整措施或水环境保护措施可使得未来一段时间内白洋淀流域水环境超载情况改善10.78％或10.42％,GDP增加0.22％或0.26％;如果采取更严格的水环境保护措施,改善效果将更好为34.56％,但是GDP会减少5.06％,经济发展受到较大限制;因此,考虑经济和环境协调发展的可持续发展型情景方案更优,GDP增加0.22％时对水环境超载情况改善更为明显为16.23％.(3)综合以上分析,必须统筹规划,大力发展高端高新产业和服务业,合理调减第一和第二产业规模,控制牲畜养殖规模,抑制纺织业、造纸和纸制品业等高耗水、重污染产业发展规模并采用清洁生产技术对其进行提升和改造,建立多元补水机制,保证淀区水位,减少地下水开采,完善流域水污染治理设施,提高水资源利用率和污水回用率,同时恢复森林和湿地,高标准开展流域污染治理,以使经济、人口和环境协调发展.

The natural attenuation of petroleum hydrocarbons is inseparable from the action of microorganisms, while the degradation methods and ecological strategies of microorganisms in petroleum-contaminated aquifers are still under debate. In the present study, 16 S rRNA sequencing and quantitative real-time polymerase chain reaction were used to assess the potential microbial degradation of petroleum hydrocarbons, and the ecological strategy of microorganisms under petroleum stress was analyzed through a co-occurrence network. The results showed that the microbial community in sediments exhibit higher efficiency and stability and stronger ecological function than that in groundwater. Keystone species coordinated with the community to execute ecosystem processes and tended to choose a K-strategy to survive, with the aquifer sediment being the main site of petroleum hydrocarbon degradation. Under natural conditions, the presence of petroleum hydrocarbons at concentrations higher than 126 μg kg-1 and 5557 μg kg-1 was not conducive to the microbial degradation of polycyclic aromatic hydrocarbons and alkanes, respectively. These results can be used as a reference for an enhanced bioremediation of contaminated groundwater. Overall, these findings provide support to managers for developing environmental management strategies.

为揭示流域社会经济、资源与生态对水环境承载力的影响程度,以白洋淀流域为研究对象,基于频次分析与主成分分析构建白洋淀流域水环境承载力评级指标体系,筛选出研究区水环境承载力指标12个.同时首次结合控制图及流域发展规划方法确定各项指标的阈值区间,建立白洋淀水环境承载力BP神经网络模型.结果表明,研究区2012、2013与2015年处于较弱承载状态,而2014、2016与2017年处于中等承载状态.评价结果与白洋淀流域实际发展趋势吻合,同时也表明未来人均GDP、地下水开采等将会给白洋淀流域水环境承载带来较大的压力.研究表明,结合控制图及流域发展规划方法可更精准地确定水环境承载力指标体系分级标准,同时基于BP神经网络模型可以准确有效地进行流域水环境承载力评价,可为流域的水环境与经济协调发展提供借鉴.

Biopile could improve the remediation efficiency of petroleum-contaminated soil, but the volatilization of petroleum also occurred during the biopile process. To quantitatively estimate the roles of volatilization and microbial degradation during the biopile process, a field-scale greenhouse-enhanced biopile was applied. Four group field trials added cow dung and exogenous microorganism were conducted in greenhouses built in Qingyang, China. Cow dung had little effect on the microbial community of biopile. Incubated-microbes initially changed the microbial community composition, but had few effects on petroleum degradation due to the continuous mesophilic-range (298e323 K) and excessive soil drying. In greenhouses, temperature could affect not only microbial degradation but also volatilization of petroleum. COMSOL Multiphysics was adopted to estimate the volatilization of petroleum during greenhouse-enhanced biopile (GEB) process. The heat transfer between the biopile and the air in GEB process can be divided into three stages: forward heat transfer, two-way heat transfer and reverse heat transfer. The heat transfer drove the volatilization of petroleum in GEB process, and the optimum radius of biopile was 0.15 m. The half-life of petroleum in a surface of 5 cm biopile was 3 days. In GEB process, the removal of volatile organic compounds in surface soils reached 80% within 30 days, while that of semi-volatile compounds and non-volatile compounds were only 50% and 30%, respectively. Only volatile organic compounds were removed from the inner soil without turning over. The removal efficiency of petroleum doubled in GEB than that in normal temperature (298 K), and it correlated significantly with the ambient temperature during the GEB process. (c) 2021 Elsevier Ltd. All rights reserved.