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17381. 题目: Biochar for urban agriculture: Impacts on soil chemical characteristics and on Brassica rapa growth, nutrient content and metabolism over multiple growth cycles With possible food crises looming in the near future, urban farming, including small-scale community and home gardens for home consumption, presents a promising option to improve food security in cities. These small-scale farms and gardens often use planter boxes and raised beds filled with lightweight soil or potting mixes. While previous studies on biochar focused on its application on large-scale contiguous farmlands, this study aimed to evaluate the suitability of biochar as a partial soil substitute to produce a durable and lightweight soil-biochar mix for small-scale urban farms. The effects of biochar on the chemical properties of the soil-biochar mix, crop yield and, particularly, crop nutrients and metabolic content were assessed. A germination test using pak choi seeds (Brassica rapa L. cultivar group Pak choi, Green-Petioled Form) showed that the biochar contained phytostimulants. Through a nursery pot experiment over four growth cycles, biochar treatments performed better than pure soil at retaining water-soluble NO3− and K+ ions, but were worse at retaining PO43− ions. Nonetheless, despite its positive effect on soil NO3− retention, biochar application did not improve crop yield significantly when the application rate varied from 0% to 60% (v/v). Untargeted metabolomic analyses showed that biochar application may increase the production of carbohydrates and certain flavonoids and glucosinolates. The results of this study showed that biochar can potentially be used to improve pak choi nutritional values and applied in large quantity to obtain a lightweight soil mix for urban farming. | |||||
17382. 题目: Acid-base properties of dissolved organic matter extracted from the marine environment Marine dissolved organic matter (DOM) plays a key role in the current and future global carbon cycle, which supports life on Earth. Trace metals such as iron, an essential micronutrient, compete with protons and major ions for the binding to DOM. These competitive effects and the DOM binding capacity are related to the DOM acid-base properties, which also influence DOM transport and reactivity in marine waters. Here we present the results of a complete set of acid-base titration experiments of a pre-concentrated marine DOM sample in the range 0.01 ≤ I ≤ 0.7 M and 3 ≤ pH ≤ 10. We characterize the obtained proton binding curves using a combination of the non-ideal competitive adsorption (NICA) isotherm and Donnan electrostatic model. Within the main chemical groups of marine DOM, the carboxylic distribution was accurately characterized from the obtained data (QmaxH, 1=2.52 mol·kg−1, = 3.26, m1 = 0.69 and b = 0.70). This carboxylic mode was found to be less acidic and more homogeneous than a generic fulvic acid, but the differences are consistent with the reported variability of fulvic acids of freshwater and terrestrial origin. We find that changes in temperature (down to 5.5 °C), and the presence of calcium or magnesium (at 0.01 M) resulted in no significant modification of the proton ion binding curves obtained at 25 °C and 0.7 or 0.1 M ionic strength, respectively. We demonstrate the relevance of proton binding parameters for the modelling of the system iron/marine DOM throughout a wide range of salinity and acidity conditions in the context of different future ocean scenarios. | |||||
17383. 题目: Construction waste as substrate in vertical subsuperficial constructed wetlands treating organic matter, ibuprophene, acetaminophen and ethinylestradiol from low-strength synthetic wastewater This study aimed to evaluate the removal of chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), total ammonia nitrogen (TAN), total phosphorus (TP), ibuprofen, acetaminophen and ethinylestradiol of synthetic effluent simulating low-strength sewage by sequencing-batch mode constructed wetlands (CWs). To verify the feasibility of using a floating macrophyte in CWs and compare different substrates, three CWs containing light expanded clay aggregates (CWL), expanded clay with porcelain tiles (CWLP) and bricks (CWB) were planted with Pistia stratiotes. The results showed that CWB achieved the highest removals of TKN (78%), TAN (70%) and TP (46%), and CWLP achieved the highest COD removal (75%). LECA favored the removal of ibuprofen (92%, p < 0.05) when compared to bricks (77%), probably by the combination of biodegradation and sorption in the systems. The highest acetaminophen removal (71% to 96%) was observed in CWL, probably via biodegradation, but no significant differences were found between the CWs (p > 0.05). Ethinylestradiol was removed 76% in CWLP and 73% in CWB, both differing statistically from CWL (p < 0.05), demonstrating that brick and the combination of clay with porcelain were better than just clay in this hormone removal. After 188 days of operation, P. stratiotes was able to uptake nitrogen and phosphorus of approximately 0.28 g and 0.25 g in CWL, 0.33 g and 0.21 g CWLP, and 0.22 g and 0.09 g in CWB of, respectively. Adsorption of nitrogen and phosphorus onto the substrates was 0.48 g and 6.84 g in CWL, 0.53 g and 5.69 g in CWLP, and 0.36 g and 10.18 g in CWB, respectively. The findings on this study suggest that adsorption was possible the main process for TP removal onto the evaluated substrates whereas microbial activity was the most probable mechanism for TN removal in the evaluated CW systems. | |||||
17384. 题目: Effect of land use on organic matter composition in density fractions of contrasting soils: A comparative study using 13C NMR and DRIFT spectroscopy 13C CP-MAS nuclear magnetic resonance (NMR) and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopies were compared for evaluating their potential to characterise the influence of land use change on organic carbon (OC) chemistry of particulate organic matter (POM) and mineral associated OM (MOM) fractions of different soil types. Surface soil samples of Ferralsol, Luvisol, Vertisol and Solonetz were collected from native and crop lands and isolated into different density fractions. NMR and DRIFT showed distinct OC composition for all the soil fractions of two land uses. In NMR spectra, greater proportion of carbohydrate and aromatic C was observed in POM, while MOM fractions were rich in carbohydrate, amino groups and aliphatic C. DRIFT spectra showed greater carboxylic, aromatic C and amide N in MOM than corresponding POM. NMR spectroscopy detected charred aromatic C in both fractions, which was not feasible with DRIFT. The overall effect of land use in both techniques appeared similar on the composition of POM- OC, i.e., increased aromaticity and decreased alkyl C:O-alkyl C ratio. However, differences of land use impact were observed in MOM-OC, e.g., overall decreased aromaticity and increased alkyl C:O-alkyl C for all soils in NMR, and in DRIFT, it varied with soil type (aromaticity: Ferralsol, Vertisol > Luvisol, Solonetz). However, these trends were inconsistent and indistinct among fractions of four soils. Discrepancy in NMR and DRIFT results was ascribed to the sensitivity limitations of the two techniques in characterising soil OM in mineral rich fractions, and sample pre-treatment effect in NMR. We conclude that combination of NMR and DRIFT spectroscopy, preferably supplemented by other techniques e.g., mass spectroscopy and XPS, would improve the proficiency in elucidating small changes in soil OM composition with land use conversion. | |||||
17385. 题目: Digital photography as a tool for microscale mapping of soil organic carbon and iron oxides | |||||
17386. 题目: Variation of effluent organic matter (EfOM) during anaerobic/anoxic/oxic (A2O) wastewater treatment processes Here, we studied seasonal variation of effluent organic matter (EfOM), based on molecular weight distribution and fluorescent components, during the traditional anaerobic/anoxic/oxic (A2O) wastewater treatment processes. Microbial community structure and effect of temperature on some isolated pure strains were analyzed to explain the related mechanism. Results showed that the anaerobic process played a key role in EfOM removal by removing building blocks, low molecular weight (LMW) neutrals, biopolymers, and protein-related substances (C4 and C5), thus determining the fate of EfOM during the A2O processes. On the other hand, humic substances, LMW neutrals, large molecular-sized hydrophobic humic-like compounds (C3), and aromatic proteins (C4) were generated during the anoxic process in summer and winter. Proteobacteria (Gamma-, Beta-, and Alpha-proteobacteria) and Bacteroidetes constituted over 50% of the sludge community. Temperature was found to be positively correlated with the generation of soluble microbial products (SMP) based on the performance of the mixture of isolated Herbaspirillum sp. (Beta-proteobacteria) and Pseudomonas sp. (Gamma-proteobacteria). Through comprehensive analysis of the co-action of Proteobacteria and temperature, we proposed the Synergetic Effect of Temperature and Proteobacteria as a possible mechanism of the seasonal variation of EfOM. These findings are important for understanding the fate of EfOM during the wastewater treatment processes and therefore be helpful for better EfOM control. | |||||
17387. 题目: The branched chains and branching degree of exopolysaccharides affecting the stability of anammox granular sludge The effect of extracellular polysaccharides on the structural stability of granular sludge is widely recognized, and determining their mechanism of action on the stability of granules remains challenging. Herein, enzymatic experiments were used to systematically study the stability changes and internal mechanisms of anammox granular sludge following hydrolysis of extracellular proteins and polysaccharides (PS). The results revealed that the selective hydrolysis of the proteins hardly affected the stability of the granules, while the hydrolysis of the PS branched chains caused the granules to disintegrate. The hydrolysis of the PS chains in the EPS matrix decreased the degree of branching, width and height via nuclear magnetic resonance (NMR) spectroscopy and atomic force microscopy (AFM), and these parameters are closely related to granular stability. Moreover, scanning electron microscopy (SEM) showed a large number of pores and cracks on the granules, bacterial adhesion decreased, and the EPS adhered to the surface of the granules dissolved. The changes in the gel characteristics of the granules were studied by rheology, and the mechanical strength and viscosity of the granular sludge decreased. For the surface characteristics of granules, the zeta potential and hydrophobicity both decreased, revealing that changes in the branched-chain configuration of the PS and the degree of branching caused granular disintegration. Spectral analysis showed that the hydrolysis of the branch points and the branched glycosides of PS led to a higher proportion of hydrophilic and electronegative groups in the EPS matrix, which hindered bacterial aggregation and reduced anammox granule stability. This investigation clarifies the impact of the branched-chain configuration of the PS and their degree of branching on anammox granule stability, which will promote the further application of anammox granules. | |||||
17388. 题目: Offshore transport of organic carbon by upwelling filaments in the Canary Current System A coupled physical-biogeochemical model (ROMS-PISCES) forced by climatological fields is used to examine the role of upwelling filaments in the offshore exchange of particulate (POC) and dissolved (DOC) organic carbon in the Canary Current eastern boundary upwelling system (CanC EBUS). In this region, mesoscale filaments at Capes Ghir ( N) and Juby ( N) have been frequently described using both observational and numerical data. Due to their semi-permanent presence and unique dynamical characteristics, studies focusing on filaments often provide an incomplete picture of the physical and biological processes at work, and their effects on coast-to-ocean export. The present model experiment confirms the complex three-dimensional structure of the filaments that comprises both offshore and onshore flow components. The model shows strong seasonal variability in the offshore transport mediated by the filaments. Recirculation at the edges of the filaments returns water towards the shore, especially in autumn when they are diverted northwards by the large scale boundary circulation. By contrast, offshore transport peaks during late spring - early summer when onshore recirculation is limited. Overall, the estimated net annual offshore flux of excess total organic carbon (e-TOC, the non-refractory pools of DOC and POC) averages 2.0 kg C y-1, and may increase up to 4.3 kg C y-1 during the peak upwelling season, each filament contributing to export of up to 22.6% of the organic carbon within the first 100 km from shore along the CanC EBUS (between 9.5 to 32 N). These results strongly support the inclusion of offshore transport estimates by coastal filaments in regional carbon budgets. | |||||
17389. 题目: Quantification of sulphide oxidation rates in marine sediment The marine sulphur cycle is driven by the reduction of sulphate to sulphide coupled to microbial decomposition of organic matter. The sulphide produced by sulphate reduction may either react with Fe or organic matter to be buried as pyrite or organic sulphur, respectively; or may be oxidised through different pathways and intermediates. The amount of sulphide that is oxidised in marine sediments is not well constrained, yet oxidative sulphur cycling has critical implications for hypoxic coastal waters and oxygen minimum zones, carbon mineralisation, microbial metabolism and the interpretation of ancient and modern stable isotope signatures. Here, we present an experimental method to directly determine sulphide oxidation rates in undiluted marine sediment incubations. We find that sulphide oxidation rates in the top two centimetres of organic-rich coastal sediments were greater than rates of sulphide production through sulphate reduction and calculate that in the top 6 centimetres, up to 92 % of sulphide produced during sulphate reduction was reoxidised. The rates decreased steeply with depth, however, and sulphide oxidation to sulphate could no longer be quantified 10 cm below the seafloor. Fe oxides were the primary oxidant for sulphide and the sulphide oxidation rate was related to the amount and reactivity of the Fe minerals. These results provide important insights into the magnitude and processes of the sulphur cycle in marine sediments. | |||||
17390. 题目: Impact of sample pretreatment on the results of texture analysis in different soils Soil texture, derived from the particle size distribution, is an essential soil parameter as it influences numerous soil properties. Most determination methods include a pretreatment that removes bonding agents like organic matter, chalk and/or iron oxides in order to guarantee full dispersion of the soil particles. Particle size analysis with no pretreatment of the samples causes shifts in the particle size distribution that lead to a coarser soil texture. Particle size analysis (sieve and sedimentation method) with pretreatment and with no pretreatment was performed on 93 top- and subsoil samples, subdivided into four sample groups from Germany (glacial and marine sediments) and one sample group from the Ukraine (loess). Particle size analysis with no pretreatment significantly reduced the clay content (by 54–89 % of the content after particle size analysis with pretreatment) and increased the silt content (by 13–36 % of the content after particle size analysis with pretreatment) and sand content (by 3–483 % of the content after particle size analysis with pretreatment) in all sample groups. The shifts in the particle size distribution were attributed to the preservation of water stable aggregates and correlated with soil organic carbon content, pH, and exchangeable cation composition. The specific surface area of the soil samples decreased significantly (by 38–65%) after particle size analysis with no pretreatment in all sample groups. The derivation of soil parameters from no pretreatment texture reduced the estimates of effective cation exchange capacity by 29–62 % and the estimates of not plant available water capacity by 18–54 % compared to the estimates from pretreatment texture. For soils with a high aggregation potential at the microscale, new pedotransfer functions for the derivation of soil parameters based on no pretreatment texture data should be developed. | |||||
17391. 题目: Complementary irrigation with saline water and soil organic amendments modified soil salinity, leaf Na+, productivity and oil phenols of olive trees (cv. Chemlali) grown under semiarid conditions Compost, olive mill wastewater and legume cover crops combined with complementary irrigation by saline water were tested under field conditions during 2016 and 2017 cropping seasons ('Off' and 'On' years respectively), in an organic mature olive grove cv Chemlali, grown at a density of 100 trees. ha-1. The experiment was conducted with four agronomic practices (TC-no amendment; TP-olive trees amended with compost, TM-olive trees amended with olive mill wastewater and TL-olive trees intercropped with legumes) factorially combined with two irrigation treatments (NI: non-irrigated olive trees and IR: olive trees irrigated with saline water of 4 g.l-1). The complementary irrigation by a limited quantity of saline water (4 m3.tree-1 per season) applied during the fruit growth (May-September) increased significantly the soil water content (SWC) mainly in the plot amended with compost. In both irrigated and rain-fed plots, the soil electrical conductivity (SEC) increased significantly during the dry season mainly in the control and the plot amended with olive mill wastewater (OMWW). Under rain-fed conditions, leaf sodium contents decreased by about 30 and 50%, respectively in olive trees amended by compost and those intercropped with legumes. Complementary irrigation with saline water increased leaf sodium levels in all plots, mainly in trees amended with OMWW, by about 40% compared to those of OMWW plot grown under rain-fed conditions. The level of leaf nitrogen increased by the application of both soil organic amendments and irrigation, while leaf phosphorus level was only affected by irrigation salinity, except for trees intercropped with legumes. Shoot growth, oil yield and fruit pomological characteristics were significantly improved either by the soil organic amendments or by the complementary irrigation. Nevertheless, phenol contents in fruits and in olive oil were significantly affected by compost and irrigation with saline water. Intercropping olive trees with legumes enhanced phenol contents in fruits and olive oil. | |||||
17392. 题目: Effect of pyrolysis temperature on the composition of DOM in manure-derived biochar Dissolved organic matter (DOM) plays an important role in the migration and transformation of nutrients and pollutants. Recently, DOM derived from biochar has the potential to determine the application of biochar and has attracted much researcher's attention. However, the effects of pyrolysis temperature on the composition evolution of DOM in manure-derived biochar are still unclear. In this study, DOM solutions extracted from a series of biochars derived from three kinds of manure (chicken, swine and dairy) at six pyrolysis temperature (200–700 °C) were analyzed using UV–Visible, Fourier transform infrared and fluorescence spectroscopy, aiming to investigate the effects of pyrolysis temperature on the composition evolution of DOM. The results showed that, with the increased of pyrolysis temperature, the dissolved organic matter (DOC) content sharply declined to reach stable. High DOC content was obtained at low pyrolysis temperature. Moreover, the DOM mainly contained humic acid-like and protein-like substances. With the pyrolysis temperature increased, the protein-like substances firstly decreased and then increased, while there was an opposite trend for the humic acid-like substances. Moreover, functional groups evolution of DOM depended on the pyrolysis temperature and manure type, evidenced by the Fourier transform infrared spectroscopy with two-dimensional correlation analysis. This study highlights the importance of optical analysis and may provide valuable information regarding the characteristics evolution of biochar-derived DOM. | |||||
17393. 题目: Study of the binding regularity and corresponding mechanism of drinking water odorous compound 2-MIB with coexisting dissolved organic matter 2-Methylisoborneol (2-MIB), a major cause of taste and odor (T&O) in drinking water, tends to combine with the coexisting dissolved organic matter (DOM), resulting in the altering of the physico-chemical properties of 2-MIB, and its corresponding migration and removal behaviors during water treatment. In this study, dialysis and ultrafiltration were set up to differentiate bound and free 2-MIB, and the binding of different types of DOMs to 2-MIB was investigated. At 298 K, the Freundlich constants, KF ((ng/mg)(L/ng)1/n), representing the combination ability between 2-MIB and the model pollutants, followed the order hen egg-white lysozyme (HEL 22.52) > bovine serum albumin (BSA 19.23) > sodium carboxymethyl cellulose (CMC 9.69) > sodium alginate (SA 7.78), and humic substances exhibited a weak association with 2-MIB, indicating that aromatic structures provide few binding sites. The KF of natural organic matter (NOM 196.15) in real raw water was much larger than that of model pollutants owing to the complex composition and the wide molecular weight distribution. The major interactions between DOM and 2-MIB were van der Waals forces and hydrogen bonding, except that HEL were hydrophobic interactions. Common metal ions affected these associations and generally decreased KF. The findings in this study are of particular significance for the selection of proper strategy to maintain the water quality during the outbreak of T&O in the source. | |||||
17394. 题目: Transforming goat manure into surface-loaded cobalt/biochar as PMS activator for highly efficient ciprofloxacin degradation The excessive discharge of goat manure has placed a serious burden on the environment and accordingly how to transform this type of waste into functional materials is of practical significance yet remains challenging. Herein, surface-loaded cobalt/biochar (Co-GMC-900) was successfully prepared for the first time by carbonizing Co-impregnated goat manure waste. The Co-GMC-900 exhibited excellent performance in activating peroxymonosulfate (PMS) to degrade ciprofloxacin (CIP), which could remove 96.5% of CIP within 30 min. Additionally, in the cycle experiments, the Co-GMC-900 presented robust stability due to the synergy of excellent magnetism, inherent ellipsoid of goat manure and strengthened interactions between cobalt nanoparticles and graphitized biochar network. In the light of a series of characterization analyses, carbonization temperature played a crucial role in tailoring the physicochemical properties (crystal structure, graphitized degree, the ratio of C=O groups and specific surface area) of composites. Based on detected active species, radical process (SO4•−, •OH and O2•−) in conjunction with the non-radical process (1O2 and charge transfer) resulted in the CIP degradation, in which the radical process mainly contributed to the degradation process, and Co0 played a leading role in the radical process. Favorably, this work might provide great promise for utilizing goat manure waste in a valuable manner and simultaneously achieving environmental remediation. | |||||
17395. 题目: A comparative study of UV/H 2 O 2 and UV/PDS for the degradation of micro-pollutants: kinetics and effect of water matrix | |||||
17396. 题目: Algal Biodiesel Production with Engineered Biochar as a Heterogeneous Solid Acid Catalyst This study evaluates the use of engineered biochar as a heterogeneous solid acid catalyst for transesterification of algal oil derived from a native microalgal consortium. Biochar derived from sugarcane bagasse, coconut shell, corncob and peanut shell were evaluated for catalytic activity following surface modification. Peanut shell pyrolyzed at 400 °C with the sulfonic acid density of 0.837 mmol/g having 6.616 m2/g surface area was selected for efficient catalysis. The efficiency of transesterification was evaluated with 1-7 wt.% catalyst loading, methanol: oil ratio of 6:1 to 30:1 at 55-85 °C over 2-8 h. Biodiesel yield of 94.91% was obtained with 5 wt.% catalyst loading, MeOH: oil ratio of 20:1 at 65 °C after 4 h. Spectral analysis of algal biodiesel showed the presence of functional groups corresponding to esters. GC-MS analysis revealed the prominent presence of palmitic and oleic acids, further advocating the suitability of the technology for commercial application. | |||||
17397. 题目: Interactions between activated sludge extracellular polymeric substances and model carrier surfaces in WWTPs: A combination of QCM-D, AFM and XDLVO prediction To understand the biofilm formation of biofilm-based processes in wastewater treatment plants (WWTPs), the interaction mechanisms between extracted extracellular polymeric substances (EPS) and three model carrier surfaces (i.e., negatively charged hydrophilic silica, positively charged hydrophilic alumina, and neutral charged hydrophobic polystyrene) were investigated employing a laboratory quartz crystal microbalance with dissipation monitoring equipment (QCM-D) and an atomic force microscope (AFM). The data suggested that surface charge and hydrophobicity of both EPS and carriers played significant roles in the interaction behaviors. Moreover, increases in ionic strength could lead to the increasing zeta potential and hydrophobicity of EPS. It is worth noting that long-range DLVO forces dominated the EPS deposition on carriers in lower ionic strength while short-range Lewis acid-base (AB) interaction controlled the adhesion behaviors in higher ionic strength. Besides, the presence of calcium ions contributed to the adhesion behaviors because of strong charge neutralization and hydrophobic effect. Bound EPS (BEPS) showed higher affinity to model carriers than dissolved EPS (DEPS), which conformed to XDLVO prediction rather than classical DLVO model. Overall, these results provide insights into the influence mechanisms of carrier characteristics, ionic strength, calcium ion and EPS components on the interaction between EPS and representative carriers, contributing to predict and regulate biofilm formation in biofilm-based processes. | |||||
17398. 题目: Mechanisms for the removal of Cd(II) and Cu(II) from aqueous solution and mine water by biochars derived from agricultural wastes The capacity of biochars derived from agricultural wastes to remove Cd(II) and Cu(II) from aqueous solution and contaminated mine water was evaluated using laboratory-based batch sorption experiments. To examine immobilization of heavy metals, biochars produced in a commercial-scale mobile pyrolizer from feedstocks: poultry litter; lucerne shoot; vetch shoot; canola shoot; wheat straws; and sugar-gum wood, were tested in a liquid-based system. Biochars were characterized by FTIR, XPS and XRD before and after the mine water treatment. Lucerne biochar had the highest Langmuir sorption capacity of Cd(II) (6.28 mg g−1) and vetch-derived biochar had the highest Cu(II) sorption capacity (18.0 mg g−1) at pH 5.5. All the biochars exhibited higher sorption capacity for Cu(II) than for Cd(II). The smaller ionic radius and higher electronegativity of Cu(II), and the PO43−, CO32− and N-containing functional groups of biochars enhanced their binding affinity. The results demonstrated that poultry litter-derived biochar was effective at removal of the Cd(II) and Cu(II) from mine water up to the levels recommended by the World Health Organisation. The results revealed that precipitation with CO32− and PO43−, complexation with –OH and –COOH groups and electrostatic interaction with O-containing surface functional groups were the main mechanisms involved in the removal of multi-metals by biochars, and that selection of feedstock materials for biochar production is important to maximise remediation of multi-metals in contaminated water. | |||||
17399. 题目: Effects of biochar on the chemical changes and phase separation of bio-asphalt under different aging conditions Bio-asphalt replaced petroleum-asphalt for paving asphalt pavements, which is a technology with a wide range of application prospect. This work is aimed at improving the performance of aged bio-oil modified asphalt (bio-asphalt) for use in road pavement construction. Biochar and bio-oil are renewable resources and use in this research that are pyrolyzed from waste wood. The effects of different aging conditions on biochar-modified bio-asphalt and ordinary bio-asphalt were investigated in terms of their chemical functional groups, molecular formulas, radius distribution functions, rheological parameters, and phase separation. The aging conditions considered in this research are short-term aging, ultraviolet (UV) aging, pressure aging vessel (PAV), and low-temperature hardening. Biochar plays a significant role in the UV aging process. This study found that, with an increase in biochar modification, the alkyl group numbers increased and the sulfoxide and carbonyl numbers decreased during the aging process of bio-asphalt. It also shows that the inclusion of biochar improved the aging resistance of the bio-asphalt, but that biochar modification did not affect the bio-asphalt's low-temperature hardening performance. Four asphalt components were studied: saturates, asphaltenes, resins, and aromatics (SARA). The effects of biochar on saturates and aromatics were significant, and the biochar was able to adsorb these components. This study also found that, with an increase in UV aging and PAV, the phase separation grows. | |||||
17400. 题目: Research on the redox behavior changes of humic-like substances wastewater during electrochemical oxidation process and using the treated effluent to improve the heavily contaminated soil: Taking petroleum hydrocarbon contaminated soil as example Humic-like substance-containing wastewater is the main type of wastewater. This study investigated the redox behavior of organic matter during the treatment process of humic-like substances by electrochemical oxidation as well as the feasibility of improving heavily polluted soil (using petroleum hydrocarbon contaminated soil as an example) with the effluent from different treatment levels. Molecular spectrum analysis and electrochemical analysis showed that the quinone and aromatic groups of the humic-like substances were degraded by electrochemical oxidation, directly leading to a decreased electron donating capability. Meanwhile, this process promoted the formation of protein-like substances and fulvic-like substances, and was accompanied by an improved electron accepting capability. Since the increasing amount of electron accepting capability was greater than the decreasing amount of electron donating capability throughout the whole process, the electrochemical oxidation process increased the total electron transfer capacity of the organic matter. In addition, bioinformatic analysis shows that the organic matter in the treated effluent enhanced the activity and abundance of dominant indigenous microorganisms in petroleum hydrocarbon contaminated soil, which is advantageous to the natural remediation of heavily polluted soils based on degradation by indigenous bacteria. This study provides a detailed basis for understanding the electrochemical degradation process of humic-like substances as well as the resource utilization of residual organic matter after electrochemical treatment of humic-like substance-containing wastewater. | |||||
