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23581. 题目: Light availability controls rhizosphere priming effect of temperate forest trees Plant can accelerate or slow down the soil organic carbon (SOC) decomposition by the rhizosphere priming effects (RPE). In forest ecosystems, the change of light availability due to canopy gap formation strongly influences growth of young trees and rhizosphere microbial activities in soil. However, the responses of RPE of forest young trees to light availability and its driving mechanisms remain elusive. We investigated the effects of about 60% shading on RPE of two dominant forest tree species (i.e., shade-tolerant species maple and photophilic species oak) over the four months of the growing season using the 13C natural tracer approach. Our results showed that the effects of shading on RPE were not dependent on the tree species. Under natural light, negative RPE on SOC decomposition prevailed during the experimental period (The loss of soil carbon via CO2 was 31.9% lower in planted soil than in unplanted soil). RPE under shading was 71.1% more positive than that under natural light. Under natural light mineral nitrogen (N) content and microbial biomass nitrogen (MBN) were lower in planted soil than in unplanted soil, suggesting that N competition between roots and microbes due to N uptake by plants may be responsible for the negative RPE. The results of two-way ANOVA showed that although shading only had the tendency of increasing MBC, it significantly increased MBN and C-acquiring enzyme activities. These changes contributed to more positive RPE under shading. The main reason for this result may be the alleviation of root-microbes competition, the higher demand of available substrates from SOC by microbes and the higher soil moisture conditions under shading. Our study also highlights the importance of soil microbial biomass and enzyme activity when studying the mechanisms of the responses of RPE to shading or other environmental changes. | |||||
23582. 题目: Evidence for involvement of keystone fungal taxa in organic phosphorus mineralization in subtropical soil and the impact of labile carbon Soil organic carbon (SOC) derived from manure increase phosphorus (P) availability by increasing the proportion of organic P (Po) in total P. However, what role SOC plays in the process of converting Po to available P (AP) and who modulates Po mineralization are still poorly understood. In this study, we collected three soil samples under long-term filed treatment with different organic (no carbon, straw, and manure) inputs. By comparing bacterial and fungal lecithin-enrichment liquid cultures, we observed that the lecithin-enriched fungal community showed higher capability for Po mineralization. Using high-throughput sequencing of the field and lecithin-enriched microbial communities, we identified Po-mineralizing taxa in the soil. Co-occurrence network analysis revealed that the keystone fungal taxa Geastrum sp. and Chaetomium sp. in the fungal network negatively associated with Po-mineralizing fungal taxa, whereas keystone bacterial taxon was not directly related to Po-mineralizing bacteria. We found labile C limits the growth of keystone fungal taxa and that the addition of lactose enhanced Po mineralization by increasing the abundance of Po-mineralizing fungal taxa. Our results emphasize the importance of soil fungi for Po mineralization in acidic soil from a community perspective and provide evidence that easily degradable C drives Po mineralization and influences P availability through limitation of keystone fungal taxa. Our study gives insight into the biological mechanisms underlying specific organic carbon-induced interactions between fungal taxa and provides crucial information for the facilitation of P cycling. | |||||
23583. 题目: Untangling the diagenetic history of uranium isotopes in marine carbonates: a case study tracing the δ238U composition of late Silurian oceans using calcitic brachiopod shells The U isotope composition of ancient marine carbonates has been used to determine the δ238U of past oceans based on the premise that the δ238U signatures of marine carbonates reflect the δ238U of seawater at the time of deposition. However, recent work from the Bahamas shows that diagenesis alters the δ238U signatures of bulk carbonates by effectively creating a positive and variable offset from seawater. Therefore, finding a sedimentary archive that reliably records and preserves the δ238U signal from seawater becomes fundamental. Calcitic brachiopod shells may provide such an archive, as their shell structure can endure the effects of diagenesis and, thus, their δ238U signatures can record the U isotope composition of the seawater in which they lived. To explore whether calcitic brachiopods can more robustly record seawater δ238U than bulk carbonates, we analyzed brachiopod shells and their host carbonate matrices from five different stratigraphic levels across the upper Silurian 'Lau' Carbon Isotope Excursion (CIE). Using the data from brachiopod shells, our results suggest that seawater δ238U values were relatively stable and lower than present day (δ238U = –0.58±0.11‰, 2sd, n=17), indicative of a more anoxic ocean state across the positive CIE. We also find that carbonate matrices display a distinctive positive δ238U offset from contemporaneous seawater that varies between beds. Some beds show a ca. +0.30‰ offset, similar to what is described in the Bahamas; whereas others display no offset from the inferred seawater U-isotope composition. We propose the variability of the observed δ238U offset to be a function of the degree of U(VI) exchange between anoxic porewaters and seawater. A diminished U(VI) exchange would define a closed-system style of diagenesis and mute the net isotope offset expressed between sediments and contemporaneous seawater. Some of the factors affecting the degree of U(VI) exchange include organic matter fluxes into the sediments and diagenetic fluid flow rates, which could vary due to relative sea-level changes. As a result, the observed δ238U variability of the analyzed carbonate matrix samples could be the result of the environmental changes caused by the sea-level fluctuations described for the studied stratigraphic interval. We conclude that calcitic brachiopod shells provide an important archive for evaluating the δ238U of ancient oceans and the style of diagenesis of U in marine carbonates. | |||||
23584. 题目: Excitation–Emission Matrix Spectroscopy for Analysis of Chemical Composition of Combustion Generated Particulate Matter | |||||
23585. 题目: Variability in the composition of extracellular polymeric substances from a full-scale aerobic granular sludge reactor treating urban wastewater Within the framework of the circular economy, there is a need for waste management alternatives that promote the reuse of materials produced in wastewater treatment plants (WWTP). An interesting option is the recovery of extracellular substances from sludge. The variability of characteristics of potential recovered bioproducts has to be assessed in full scale operational settings. In this study, aerobic granular sludge (AGS) from a full-scale WWTP treating urban wastewater was regularly collected for 4 months to assess variability in extracellular polymeric substances (EPS) composition and in granular morphology. Variations in the EPS composition occurred with time. Proteins and humic substances were the main EPS components (329–494 and 259−316 mg/g VSS of AGS, respectively), with polysaccharides and DNA representing minor components. The application of an extra purification step after extraction to obtain a purer EPS led to a decrease in the yield of each EPS component, particularly pronounced for the polysaccharides. The final product had a rather constant composition for the monthly samples. The granules showed morphological stability throughout the sampling period and the yield of EPS was correlated to the size of the granules, higher when there was a higher content of small granules (Deq<150 μm) comparing to intermediate (150 ≤ Deq<1500 μm) or large granules (Deq≥1500 μm). This is the first time that a potential valorization strategy for surplus AGS biomass is studied in a full-scale environment. Knowledge on yield and product homogeneity is important as these features are essential for downstream application of the recovered EPS. | |||||
23586. 题目: What is a good level of soil organic matter? An index based on organic carbon to clay ratio Simple measures of appropriate levels of soil organic matter are needed for soil evaluation, management and monitoring, based on readily‐measurable soil properties. We test an index of soil organic matter based on the soil organic carbon (SOC) to clay ratio, defined by thresholds of SOC/clay ratio for specified levels of soil structural quality. The thresholds were originally delineated for a small number of Swiss soils. We assess the index using data from the initial sampling (1978–83) of the National Soil Inventory of England and Wales, covering 3809 sites under arable land, grassland and woodland. Land use, soil type, annual precipitation and soil pH together explained 21% of the variance in SOC/clay ratio in the dataset, with land use the most important variable. Thresholds of SOC/clay ratio of 1/8, 1/10 and 1/13 indicated the boundaries between 'very good', 'good', 'moderate' and 'degraded' levels of structural condition. On this scale, 38.2, 6.6, and 5.6% of arable, grassland and woodland sites, respectively, were degraded. The index gives a method to assess and monitor soil organic matter at national, regional or sub‐regional scales based on two routinely measured soil properties. Given the wide range of soils and land uses across England and Wales in the dataset used to test the index, we suggest it should apply to other European soils in similar climate zones. | |||||
23587. 题目: Introducing a mechanistic model in digital soil mapping to predict soil organic matter stocks in the Cantabrian region (Spain) Digital soil mapping (DSM) is an effective mapping technique that supports the increased need for quantitative soil data. In DSM, soil properties are correlated to environmental characteristics using statistical models like regression. However, many of these relationships are explicitly described in mechanistic simulation models. Therefore, the mechanistic relationships can, in theory, replace the statistical relationships in DSM. This study aims to develop a mechanistic model to predict soil organic matter (SOM) stocks in Natura2000 areas of the Cantabria region (Spain). The mechanistic model is established in four steps: i) identify major processes that influence SOM stocks, ii) review existing models describing the major processes and the respective environmental data that they require, iii) establish a database with the required input data, and iv) calibrate the model with field observations. The SOM stocks map resulting from the mechanistic model had a mean error (ME) of ‐2 t SOM/ha and a root mean square error (RMSE) of 66 t SOM/ha. The Lin's concordance correlation coefficient was 0.47 and the amount of variance explained (AVE) was 0.21. The results of the mechanistic model were compared to the results of a statistical model. It turned out that the correlation coefficient between the two SOM stocks maps was 0.8. This study illustrated that mechanistic soil models can be used for DSM, which brings new opportunities. Mechanistic models for DSM should be considered for mapping soil characteristics that are difficult to predict by statistical models, and for extrapolation purposes. | |||||
23588. 题目: Dissolved and colloidal phosphorus affect P cycling in calcareous forest soils Dissolved and colloidal phosphorus (P) represent the mobile P fractions in soils, but their role in P cycling in forests is still largely unclear. In this study of four calcareous forest soil profiles, the elemental compositions of different size fractions of water dispersible colloids (WDC) were investigated by asymmetric field flow fractionation. Nuclear magnetic resonance spectroscopy (NMR) was applied to identify the organic P compounds in soils, WDC, and soil solutions. Carbon was the dominant element in WDC of all soil horizons, including mineral soils that were rich in Ca or Si. Although chemical composition of P varied dramatically with increasing depth, the colloidal P composition remained unchanged. This contrasting difference between mineral soil and its WDC fraction indicated that the colloids were not locally generated but originated from the overlying organic soil horizons. Carbonate minerals were unlikely involved in colloid formation under acidic condition. Instead, Ca2+ probably drove colloid formation by bridging organic matter, including P-containing compounds released from litter degradation. Colloid formation was influenced by climate, vegetation, and soil characteristics. No dissolved P was detected in deeper mineral soil horizons due to efficient retention by Ca minerals. Colloidal P was still present in deeper soil layers and thus of significance for potential P vertical transfer. | |||||
23589. 题目: Effects of water, organic matter, and iron forms in mid-IR spectra of soils: Assessments from laboratory to satellite-simulated data The soil mineralogical constitution directly influences its chemical, physical and hydraulic characteristics. Although very important, it is still rarely used for decision-making in agriculture, mainly due to the complexity and cost of standard analyzes. In this sense, the middle infrared spectroscopy (mid-IR, 4000 to 400 cm−1) has great potential to obtain soil mineralogical information quickly and accurately. Nevertheless, some soil constituents can severely influence the spectra and produce misinterpretations. In this research, we aim to detect changes in the mid-IR spectra caused by water, iron forms and organic matter (OM), and to relate soil attributes to laboratory spectra and remote sensing simulated spectral bands. The research area is located in São Paulo State, Brazil, where seventeen soil samples were collected. The reflectance intensities, shapes and absorption features of the mid-IR spectra before and after the removal of OM and iron forms and the addition of water were described. Soil attributes, such as kaolinite, gibbsite, 2:1 minerals among others were correlated with the mid-IR spectra and simulated ASTER spectral bands by Pearson's analysis, to verify its potential on mineralogical evaluation. The description of mid-IR revealed that the removal of the OM from the soil samples decreased the reflectance intensities between 4000 and 2000 cm−1. Iron forms mainly influence the 3250 – 1200 cm−1 spectral range and mask the spectral features of other minerals as well. The addition of water masked several absorption features and decreased the reflectance intensities from 3700 to 2700 cm−1. High correlation coefficients were obtained between soil attributes and ASTER simulated spectral bands, which allowed the selection of potential spectral regions for future satellite sensors: 2760 – 2500 cm−1 (3600 – 4000 nm), 2150 – 1875 cm−1 (4600 – 5300 nm), and 840 – 740 cm−1 (11900 – 3500 nm). | |||||
23590. 题目: Addition of oyster shell to enhance organic matter degradation and nitrogen conservation during anaerobic digestate composting | |||||
23591. 题目: Application of biochar, compost and ZVI nanoparticles for the remediation of As, Cu, Pb and Zn polluted soil | |||||
23592. 题目: Amorphous Co3O4 Nanoparticles-Decorated Biochar as an Efficient Activator of Peroxymonosulfate for the Removal of Sulfamethazine in Aqueous Solution In this study, amorphous Co3O4 nanoparticles-decorated biochar was synthesized and employed to activate peroxymonosulfate (PMS) for sulfamethazine (SMT) degradation in aqueous solution. Hydrochar of corn straw obtained from hydrothermal carbonization was impregnated in CoCl2 solution for anchoring cobalt nanoparticles onto biochar surface before pyrolysis. Application conditions of as-prepared cobalt-loaded biochar (Co-BC) involving dosage, pyrolysis temperature, cobalt loading, solution pH and groundwater components were examined; and the stability of the catalyst was investigated by examining its performance in recycling experiments (3 rounds) and the variation of catalytic mechanism in recycling experiment was investigated. 100% SMT was removed under the optimum condition within 60 min: 1.0 mmol/L CoCl2 aqueous solution, 800°C of pyrolysis temperature, 400 mg/L Co-BC, 0.06 mM PMS, solution pH 8. The results turned out that the amorphous Co3O4 nanoparticles were favorable for the activation of PMS. BC not only played as a support for dispersion of Co3O4 nanoparticles but also acted as an electron shuttle between Co3O4 and PMS/SMT molecules. During the recycling use, the key free radicals changed from ▪OH and SO4▪- to SO4▪- and only low degree of cobalt ions leaching was monitored. Additionally, the mixed groundwater components exerted trivial influence on the reaction system. | |||||
23593. 题目: Sources of black carbon during severe haze events in the Beijing–Tianjin–Hebei region using the adjoint method The Beijing-Tianjin-Hebei (BTH) region in China has been frequently suffering from severe haze events (observed daily mean surface fine particulate matter PM2.5 concentrations larger than 150 μg m−3) partially caused by certain types of large-scale synoptic patterns. Black carbon (BC), as an important PM2.5 component and a primarily emitted species, is a good tracer for investigating sources and formation mechanisms leading to severe haze pollutions. We apply GEOS-Chem model and its adjoint to quantify the source contributions to BC concentrations at the surface and at the top of the planetary boundary layer (PBL) during typical types of severe haze events for April 2013–2017 in BTH. Four types of severe haze events, mainly occurred in December–January-February (DJF, 62.3%) and in September–October-November (SON, 26.3%), are classified based on the associated synoptic weather patterns using principal component analysis. Model results reasonably capture the daily variations of BC measurements at three ground sites in BTH. The adjoint method attributes BC concentrations to emissions from different source sectors and from local versus regional transport at the model spatial and temporal resolutions. By source sectors, the adjoint method attributes the daily BC concentrations during typical severe haze events (in winter heating season) in Beijing largely to residential emissions (48.1–62.0%), followed by transportation (16.8–25.9%) and industry (19.1–29.5%) sectors. In terms of regionally aggregated source influences, local emissions in Beijing (59.6–79.5%) predominate the daily surface BC concentrations, while contributions of emissions from Beijing, Hebei, and outside BTH regions are comparable to the daily BC concentrations at the top of PBL (~200–400 m). Our adjoint analyses would provide a scientific support for joint regional and targeted control policies on effectively mitigating the particulate pollutions when the dominant synoptic weather patterns are predicted. | |||||
23594. 题目: Morphology, structure, and composition of sulfidized silver nanoparticles and their aggregation dynamics in river water The sulfidized form represents an environmentally relevant transformation state of silver nanoparticles (Ag-NPs) released into natural systems via wastewater route. However, the detailed characterization of sulfidized silver nanoparticles (S-Ag-NPs) is missing and their colloidal stability in aquatic systems is only insufficiently studied. The aim of this study was to systematically evaluate the surface properties, morphology, structure, composition, as well as aggregation dynamics of S-Ag-NPs in synthetic and natural river water. The S-Ag-NPs were prepared by sulfidation of citrate-coated silver nanoparticles (Cit-Ag-NPs). The sulfidation of Ag-NPs was accompanied by the formation of fiber-like Ag2S nano-bridges, Ag0-Ag2S core-shell structures, and hollow regions. In contrast to the published literature, the nano-bridges were thinner (2–9 nm) and longer (up to 60 nm), they formed at higher S2−/Ag molar ratio (2.041), and the formation of the core-shell structures was observed even in the absence of natural organic matter (NOM). Furthermore, we observed selective sulfidation of nanoparticles which can induce the hot spots for the release of toxic Ag+ ions. The critical coagulation concentration (CCC) of Ca2+ determined for S-Ag-NPs in reconstituted river water was 2.47 ± 0.23 mmol/L and thus higher than the CCC obtained for Cit-Ag-NPs in our earlier study revealing higher colloidal stability of S-Ag-NPs. In natural river water, S-Ag-NPs were also colloidally more stable compared to the Cit-Ag-NPs. Furthermore, the stabilizing effect of NOM was much higher for S-Ag-NPs than for Cit-Ag-NPs. For S-Ag-NPs stabilized by a low amount of citrate, we expect longer residence times in the water phase of rivers and thus higher risk for aquatic organisms. In contrast to this, the pristine Cit-Ag-NPs are expected to be accumulated faster in the sediments representing higher risk for benthic organisms. This study contributes to better understanding of environmental fate and effects of Ag-NPs released via wastewater route. | |||||
23595. 题目: Massive loss of aboveground biomass and its effect on sediment organic carbon concentration: Less mangrove, more carbon? Mangroves play an important role in the nutrient cycle of coastal areas, contributing to the health of adjacent ecosystems by retaining carbon, nitrogen and phosphorous. Different studies have shown that sediment organic carbon (SOC) stock decrease with the loss of above-ground forest biomass. Our objective was to assess the effect of deforestation on the ability of mangroves to store carbon and retain nutrients in the sediment. We hypothesized that conserved forests contain the highest values of SOC compared to sites where the vegetal cover was completely lost. The sampling was carried out in a highly altered ecosystem in the South Caribbean, where a freshwater diversion project had been implemented between 1993 and 1998 to rehabilitate 290 km2 of a deforested mangrove area after hypersalination of the sediment. Based on our results, we reject our initial hypothesis; SOC stores in areas where massive mangrove mortality occurred were between 258 ± 2 and 339 ± 19 Mg C ha−1, i.e., two times higher than those in conserved mangrove forest areas (156 ± 16 Mg C ha−1). Nitrogen (N) followed a trend similar to that of SOC, in which sites with degraded mangroves had greater N stores (between 15.5 ± 0.4 and 19.1 ± 1.0 Mg N ha−1) than conserved site (11.7 ± 0.8 Mg N ha−1). In contrast, phosphorus (P) presented higher values at the conserved site (3.2 ± 0.3 Mg P ha−1) than at degraded sites (between 0.8 ± 0.2 and 2.0 ± 0.2 Mg P ha−1). The higher concentration of SOC in highly degraded sites may be driven by the balance between the large accumulation of dead plant material due to hypersalination and the low decay rates due to anoxia sediment conditions. | |||||
23596. 题目: Carbon and nitrogen dynamics in soil organic matter fractions following eucalypt afforestation in southern Brazilian grasslands (Pampas) The southern Brazilian grasslands (Pampas) are a new frontier of eucalypt plantation expansion, but the impacts of this land use change (LUC) on soil organic matter (SOM) are not well documented. In this study, we evaluated changes in the particulate organic matter (POM) and mineral-associated organic matter (MAOM) fractions following the afforestation of a grassland in southern Brazil over an entire eucalypt rotation. Additionally, SOM dynamics was assessed in two soil zones [row (R) and inter-row (IR)] created by soil preparation, which consists on scraping the soil surface from the IR to the R along with subsoiling to build ridges for eucalypt plating (i.e., ridge tillage). The soil was sampled to a depth of 60 cm in the R and IR positions, and the carbon (C) and nitrogen (N) in the SOM fractions were determined. We used natural 13C abundance differences to compare the contributions of the 'new' C input (C3, eucalypt stands) to the 'native' SOM (C4, grasslands). The conversion of the grassland to eucalypt stands resulted in losses in C and N stocks in both the R and IR after 68 months. Soil management controlled the magnitude and directions of C and N changes. The C loss in the R was ∼1.3-fold higher than that in the IR (20.6 Mg ha−1; p < 0.001). The POM-C loss was restricted to the R, while losses in the MAOM-C were observed in both soil zones. The largest changes in soil N levels occurred in the IR, where MAOM-N stocks declined by 4.3 Mg ha−1 (p < 0.001), and POM-N stocks (0−60 cm) increased by 0.17 Mg ha−1 (p = 0.025) at the end of the eucalypt stand rotation. We observed a higher C substitution (C3-new; 0−60 cm) in the R compared to the IR in both SOM fractions (POM: p < 0.001; MAOM: p < 0.001). After 68 months, about 36% of the C stock in the R was eucalypt-derived. Our results provide quantitative information on C and N changes following grassland afforestation and demonstrate distinct SOM dynamics in the R and IR imposed by soil management. These findings highlight the importance of adequate soil management and eucalypt fertilization programs, particularly for N, to prevent a progressive impoverishment of the SOM. | |||||
23597. 题目: Aqua regia digestion cannot completely extract Hg from biochar: A synchrotron-based study Mercury (Hg) is commonly extracted from solid phase samples using aqua regia for total Hg (tHg) analysis. However, uncertainties exist regarding the complete extraction of Hg by aqua regia, especially from carbonaceous materials. To investigate whether aqua regia can completely extract Hg from biochars, batch-style experiments were carried out to evaluate extraction efficiency of aqua regia with respect to Hg-loaded biochar and to characterize the residual Hg speciation and spatial distribution. Different types of biochars (raw, FeCl3-modified, and FeSO4-modified, prepared at different temperatures) were reacted with Hg-spiked solution before the digestion experiments. Adsorption analyses indicate the biochars were successfully loaded with Hg and that the Hg content was higher in biochars pyrolyzed at higher temperature (900 versus 300 or 600 °C). The results of digestion experiments indicate Hg could not be completely extracted from the biochars tested, with a greater percentage of residual Hg in biochars pyrolyzed at 600 (60 ± 15%) and 900 (75 ± 22%) than 300 °C (7 ± 2%). Furthermore, the fraction of residual Hg in FeSO4-modified biochars after aqua regia digestion was significantly lower than in FeCl3-modified and unmodified biochars. Confocal micro-X-ray fluorescence imaging (CMXRFI) showed residual Hg in biochars is concentrated on surfaces prior to digestion, but more homogeneously distributed after digestion, which indicates Hg on biochar surface is more easily digested. Hg extended X-ray absorption fine structure (EXAFS) spectra modelling showed residual Hg in biochars mainly exists as Hg(II)–Cl. These results indicate extra caution should be paid for tHg determinations using aqua regia digestion method in soil (especially in forest), sediment, and peat samples containing black carbon, activated carbon, or biochar. | |||||
23598. 题目: Three-dimensional porous graphene-like biochar derived from Enteromorpha as a persulfate activator for sulfamethoxazole degradation: Role of graphitic N and radicals transformation Three-dimensional graphene-like biochar derived from Enteromorpha (EGB) was prepared as a persulfate (PS) activator for sulfamethoxazole (SMX) degradation. The graphitic N in the EGB samples not only endowed the superior binding energy towards SMX adsorption, but also promote the PS binding with the EGB, which was crucial to the catalytic degradation of SMX in EGB/PS system. Different from the radical-based oxidation in biochar prepared at 400 °C via the persistent free radicals (PFRs), both 1O2 and surface electron transfer served as non-radical pathways in the EGB samples prepared above 500 °C, acting together with free radicals (O2∙−) on SMX degradation. Oxidation of SMX and its substructural analogues indicated that the selective oxidizing reaction occurred in the EGB/PS system and the isoxazole ring in SMX molecule was insensitive to be attacked 1O2. In addition, toxicity predication indicated that the overall biotoxicity of the intermediates during SMX degradation was decreased. | |||||
23599. 题目: Change in characteristics of water-soluble and water-insoluble brown carbon aerosols during a large-scale biomass burning | |||||
23600. 题目: Cation-exchange resin regeneration waste liquid as alternative NaCl source for enhancing anaerobic fermentation of waste activated sludge: Compositions of dissolved organic matters and chemical conditioning performance This study reported the NaCl-enhanced anaerobic fermentation with cation-exchange resin regeneration waste liquid (CRWL) as alternative NaCl source for waste activated sludge (WAS) disposal and carbon recovery. Through 4-day CRWL-enhanced anaerobic fermentation at Na+ concentration of 0.34 mol/L, the Na+-caused sludge disintegration triggered numerous release of dissolved organic matters (DOMs), i.e. 371.6 mg/g VSS, with composition distribution: acetic acid (28.2%) > butyric acid (16.1%) ≈ valeric acid (17.8%) ≈ proteins (16.4%) > propionic acid (14.4%) > unknown (3.2%) > carbohydrates (3.9%). Satisfying chemical conditioning performance for the fermented sludge was observed at the FeCl3 dosage of 0.3 g/g DS, attributing to the roles of double-layer compression and electric neutralization. The capillary suction time (CST) and sludge cake moisture content were decreased to 60.3 s and 75.1%, against those of 607 s and 93.5% before conditioning, respectively. Such treating waste by waste strategy could provide numerous environmental and economic benefits. | |||||
