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141. 题目: Enhanced Cr(VI) Bioreduction by Biochar: Insight Into the Persistent Free Radicals Mediated Extracellular Electron Transfer
文章编号: N22091017
期刊: Journal of Hazardous Materials
作者: Cheng Yu, Xiaoxi Zhu, Abdelkader Mohamed, Ke Dai, Peng Cai, Shilin Liu, Qiaoyun Huang, Baoshan Xing
更新时间: 2022-09-10
摘要:

Biochar can act as a shuttle to accelerate the extracellular electron transfer (EET) by exoelectrogens. However, it is poorly understood how the persistent free radicals (PFRs) in biochar affected EET and the redox reaction. Herein, the effects of the biochar and chitosan modified biochar (CBC) on the Cr(VI) bioreduction by Shewanella oneidensis MR-1 (MR-1) was investigated. Kinetic study indicated that the Cr(VI) bioreduction rate constant by MR-1 was increased by 1.8-33.7 folds in the presence of biochar, and by 2.7-60.2 folds in the presence of CBC, respectively. Moreover, Cr(VI) bioreduction rates increased with the decreasing pH. Results suggested that the electrostatic attraction between Cr(VI) and redox-active particles could accelerate the EET by c-cytochrome due to the promotion of the the Cr(VI) migration from aqueous phase to biochar or CBC. Electron paramagnetic resonance analysis suggested that the PFRs affected the electron transfer from the ·O2- generated by MR-1 to Cr(VI) and accelerate the Cr(VI) bioreduction. Remarkably, in the presence of PFRs, this electron shuttling process was dependent on the non-metal-reducing respiratory pathway. Our results offer new insights that free radicals may be widely involved in the EET and strongly impact on the redox reaction in the environment.

142. 题目: A long-term overview of nitrogen in tropical rainwater and wet deposition fluxes in southern Brazil
文章编号: N22091016
期刊: Atmospheric Environment
作者: Jacques Florêncio, Dayane C O Reis, Cristina P Crispim, M Lucia A M Campos
更新时间: 2022-09-10
摘要:

This work reports inorganic and organic nitrogen concentrations in rainwater and estimates wet deposition fluxes in an agro-industrial region of São Paulo State (Brazil) impacted by biomass burning and vehicular public policies, spanning the period from 2005 to 2020. The overall volume weighted mean (VWM) concentration of nitrate in rainwater was 13.1 ± 0.5 μmol L−1 (n = 696). Despite decreasing vehicular emissions of NOx over the study period, there was no clear trend of nitrate concentrations in rainwater, possibly due to biomass burning emission sources. The overall ammonium VWM concentration was 24.3 ± 1.1 (n = 696). In contrast to nitrate, there was a 94% increase of ammonium in 16 years, attributed to increased emissions from vehicles and fertilizer use, together with variable biomass burning emissions. Dissolved organic nitrogen (DON) concentrations in individual samples ranged from 0.2 to 153 μmol N L−1, corresponding to between 1 and 73% of the total dissolved nitrogen, with VWM of 18.9 ± 0.9 μmol N L−1 (n = 377). Amino acids corresponded, on average, to 15% of the DON. For the majority of the years, the VWM concentrations of nitrate, ammonium, and DON were higher for the pool of samples collected during the dry season, compared to the wet season. These results highlighted the importance of biomass burning sources of reactive nitrogen in drier months, when wildfires are common. The wet deposition flux of total dissolved nitrogen was ∼12 kg N ha−1 yr−1, with ammonium corresponding to 43%, followed by DON (33%) and nitrate (23%). These results demonstrated the importance of including DON when modeling the biogeochemical cycle of nitrogen, especially in a world where wildfires may become more frequent and intense.

143. 题目: Vertical profiles of black carbon and nanoparticles pollutants measured by a tethered balloon in longyerbyen (Svalbard islands)
文章编号: N22091015
期刊: Atmospheric Environment
作者: David Cappelletti, Chiara Petroselli, David Mateos, Marcos Herreras, Luca Ferrero, Niccolò Losi, Asta Gregorič, Claudia Frangipani, Gianandrea La Porta, Michael Lonardi, D G Chernov, Alena Dekhtyareva
更新时间: 2022-09-10
摘要:

Airborne meteorological and aerosol measurements have been performed in Longyearbyen (Svalbard islands) in the Summer of 2018, coupling an instrumental aerosol payload with a meteorological radiosonde deployed on a tethered balloon. More than 70 vertical profiles of aerosol and meteorological properties have been recorded up to a maximum altitude of 1.2 km. As a main result, the present work provides a homogeneous gridded dataset of vertical profiles of equivalent black carbon (eBC) and nanoparticles (NP) concentrations and associated meteorological data (temperature, T, relative humidity, RH, pressure, P) to be employed for future modelling studies of Arctic pollution. Mean values (±SD) of eBC and NP below 500 m were 110 ± 10 ng m−3 and 1400 ± 400 particles cm−3, respectively. Mean values above 500 m were 150 ± 30 ng m−3 and 1000 ± 350 particles cm−3, respectively. Group medians of maximum eBC and NP concentrations in vertical profiles with temperature inversions were significantly higher than for those without inversion. The dataset has been complemented by continuous ground measurements of eBC with an average value of 208 ± 130 ng m−3 (median value 110 ± 70 ng m−3) for the entire campaign; the ground-based background (absence of local emission) eBC value was below 100 ng m−3 while maximum values were in the 1000–2000 ng m−3 range. Median eBC concentration measured at ground for two hours before the tethered balloon launch was higher when temperature inversion was observed. The ground-based measurements, coupled with aerosol optical depth measurements, allowed for a preliminary discussion of two case studies related to high pollutants concentration events.

144. 题目: Impact of environmental factors and tributary contributions on tidal dissolved organic matter dynamics
文章编号: N22091014
期刊: Chemosphere
作者: Gang Tang, Qianqian Wang
更新时间: 2022-09-10
摘要:

Riverine dissolved organic matter (DOM) transport was a key step in the carbon biogeochemical cycle while we had limited understanding of its contribution to the estuary DOM dynamics. This study focused on the river downstream (with three tributaries with differed urbanization degrees)-to-tidal estuary DOM variations and the control of environmental factors on this process. Though more aromatics were introduced to the urban tributary, the A250/A365 values and fluorescent index values indicated the DOM molecular size was uniformly reduced due to the enhanced microbial degradation during transport. The tidal DOM showed less varied spectroscopic indexes than the tributary DOM, but tidal cycles strongly impacted the fluorescent DOM quantified by the fluorescence regional integration (FRI). Salinity range can differentiate the fluorescent DOM variation patterns in river tributaries (e.g., <2.5, positive correlations; >2.5, negative correlations) and tidal cycles (>10, negative correlations). For tidal DOM, the high salinity decreased more humic-related components, resulting in increased proportions of protein-related components in high tides. The dissolved oxygen and nitrogen contents were negatively correlated with salinity, suggesting the microbial contributions and anthropogenic inputs in tributaries increased the tidal DOM quantity. The less urbanized tributaries contributed more to the low-tide DOM compositions/properties while the dynamic contribution of the urban tributary impacted more the tidal DOM dynamics. Our results highlighted the uneven declines of FRI values of different components by freshwater-saltwater mixing in estuaries and suggested the different functioning of urban, agro-urban, and suburban tributaries contributed to tidal DOM dynamics.

145. 题目: Rapid and efficient removal of organic matter from sewage sludge for extraction of microplastics
文章编号: N22091013
期刊: Science of the Total Environment
作者: Me Me Maw, Narin Boontanon, Shigeo Fujii, Suwanna Kitpati Boontanon
更新时间: 2022-09-10
摘要:

Microplastic pollution is recognized as an emerging global issue; however, no standardized method for the extraction of these pollutants from the environment currently exists and existing methods are ineffective for specific environmental matrices. An appropriate organic matter removal method is essential for the extraction of microplastics from organic-rich sludge to minimize interference during their identification and enhance compatibility of the identification steps. The present study aimed to establish an effective technique for the digestion of organic matter-rich sludge using hydrogen peroxide and Fenton's reagent at varying temperatures, times, and concentrations of an iron catalyst. The organic matter removal efficiency of the five protocols utilized varied from 81.5 % to 87.1 %. Polymers such as polyvinyl chloride (PVC), high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), and polystyrene (PS) retained most of their physical and chemical properties after the treatments, with minor changes in the surface area, weight, and FTIR spectra properties. Polyethylene terephthalate (PET), PET fiber, polyamide (PA) fiber, and polymethyl methacrylate (PMMA) fiber were significantly degraded via treating with H2O2 at 50 °C for 24 h. Protocol 4, treating with Fenton's reagent (H2O2 (30 %) + (0.05 M) FeSO4.7H2O) at 50 °C for 1 h is proposed as a rapid and effective method for the removal of organic matter from sludge. In addition to its rapidity, this method minimally impacts most polymers, and its high organic matter removal efficiency is associated with a significant reduction of suspended solids in sludge. The present study provides a validated approach that facilitates as an effective organic removal step during the extraction of MPs in sludge.

146. 题目: Distribution characteristics of terrestrial and marine lipid biomarkers in surface sediment and their implication for the provenance and palaeoceanographic application in the northern South China Sea
文章编号: N22091012
期刊: Marine Geology
作者: Enobong Charles Udoh, Li Li, Meiyan Chen, Solomon Felix Dan, Lindi Chen, Jiangyong Zhang, Guodong Jia, Juan He
更新时间: 2022-09-10
摘要:

Multi biolipids, including plant wax, algal biomarkers, and glycerol dialkyl glycerol tetraethers (GDGTs), were studied in surface sediments of the northern South China Sea (SCS). Unusual elevated contents of odd n-alkanes (C27, C29, C31) and even n-alkanols (C22, C24, C26) derived from terrestrial plant wax in the outer shelf areas indicated the strong influence of deep-water counter current in redistributing and deposition of Taiwan Island sourced organic matter (OM) in the northern SCS. The spatial distribution of dinosterol and brassicasterol (corresponding to dinoflagellates and diatoms of high competitive advantage for nutrients), respectively, displayed a high abundance near the Pearl River Estuary (PRE), southwest off Taiwan Island, and southeast off Hainan Island, in contrast to the relatively high biomass of C37-alkenones, C30-diol/ketol and isoprenoid GDGTs (iGDGTs) in the outer shelf oligotrophic areas, indicating their feasibility in marine productivity reconstruction. The observed high contents of alkenones than brassicasterol in the sediment, albeit the overall dominance of diatoms in the SCS surface water, showed differences in the degradation and/or preservation efficiency of different organic lipids in sediments. The influences of season, source organisms, and different regression methods on the sea surface temperatures (SST) reconstruction were also evaluated in the region extending from shelf to deep water. The reconstructed SSTs based on U37K' mainly reflected spring SSTs, indicating the influence of growing seasons on the source organism. The reconstructed TEX86 SST corresponded more with the mean annual SST in the northern SCS, mainly in the deep-water regions. Changes in the total composition of the archaeal community and population is suggested to be the major factor causing the unusually low and wide range of TEX86 SSTs in the nearshore areas. The combination of the two organic paleothermometers offers complementary information on SST developments in the northern SCS. Multi-biomarkers study in the present work indicates the feasibility of lipids in paleoecology and paleoclimate reconstruction. However, care must be taken in palaeoceanographic reconstruction due to complex hydrological and biological influence, i.e., the deep lateral current on the continental matter transportation, the differential degradation of various organic lipids, and the different seasonal and/or source organism community bias on the organic thermometer in the study area.

147. 题目: Unravelling the fabrics preserved inside early diagenetic concretions: Insights for the distribution, accumulation and preservation of organic-rich mud in the interior of epicontinental basins
文章编号: N22091011
期刊: Sedimentary Geology
作者: Germán Otharán, Carlos Zavala, Juergen Schieber, Daniela Olivera, Marcelo Martínez, Pablo Díaz, Zalmai Yawar, Luis Agüero
更新时间: 2022-09-10
摘要:

Fine-grained sedimentary rocks generally undergo severe mechanical compaction during burial, which complicates the recognition of primary mudstone fabrics and associated sedimentary features. Early diagenetic concretions, however, provide a rare glimpse of primary fabrics because cement filling the pore space prevents the collapse of original grain arrangements. Hand specimens of concretions collected from the basal condensed section of the Late Jurassic-Early Cretaceous Vaca Muerta Formation (Neuquén Basin, Argentina), allow for analysis of sedimentary processes responsible for the dispersal, accumulation and burial of organic carbon-rich sediment in an epicontinental sea. Representative samples from central basin depositional localities were examined by optical, scanning electron microscopy and energy dispersive X-ray spectroscopy (EDS). Petrographic observations were complemented with palynological and organic geochemical analyses. Close examination of uncompacted fabrics reveals a significantly more complex and dynamic depositional scenario than previously assumed (suspension settling). Although many of the component grains in the studied samples were originally delivered to the sediment–water interface by suspension settling processes (i.e., marine snow, hypopycnal plumes, pumice rafts), there is substantial evidence of episodic sedimentation controlled by punctuated events of seafloor disturbance and erosion. The common presence of muddy intraclasts indicate that the seafloor was frequently reworked by bottom currents that caused the widespread distribution of organic carbon-rich sediment across distal basin depositional environments. Bottom current circulation supplied oxygen to the sediment–water interface and created suitable conditions for benthic life, contravening the assumption of bottom water anoxia as a prerequisite for organic carbon preservation. The excellent preservation state of freshwater algae (Pediastrum complex) suggests that organic matter contained inside composite mud particles can travel long distances before being deposited in distal depositional settings. Encapsulation protects organic components from mechanical/biogenic degradation and provides an anoxic microenvironment for preventing the oxidation of the organic matter contained inside of mud composite grains. The study shows that organic carbon encapsulation may be an important mechanism for organic carbon preservation in relatively energetic and non-anoxic settings, calling for a critical reappraisal of the processes responsible for the sequestration of organic carbon from the biosphere and its long-term storage in organic-rich mudstone successions.

148. 题目: Implementation and initial calibration of carbon-13 soil organic matter decomposition in the Yasso model
文章编号: N22091010
期刊: Biogeosciences
作者: Jarmo Mäkelä, Laura Arppe, Hannu Fritze, Jussi Heinonsalo, Kristiina Karhu, Jari Liski, Markku Oinonen, Petra Straková, Toni Viskari
更新时间: 2022-09-10
摘要: Soils account for the largest share of carbon found in terrestrial ecosystems, and their status is of considerable interest for the global carbon cycle budget and atmospheric carbon concentration. The decomposition of soil organic matter depends on environmental conditions and human activities, which raises the question of how permanent are these carbon storages under changing climate. One way to get insight into carbon decomposition processes is to analyse different carbon isotope concentrations in soil organic matter. In this paper we introduce a carbon-13-isotope-specific soil organic matter decomposition add-on into the Yasso soil carbon model and assess its functionality. The new 13C-dedicated decomposition is straightforward to implement and depends linearly on the default Yasso model parameters and the relative carbon isotope (13C/12C) concentration. The model modifications are based on the assumption that the heavier 13C atoms are not as reactive as 12C. The new formulations were calibrated using fractionated C, 13C and δ13 measurements from litterbags containing pine needles and woody material, which were left to decompose in natural environment for 4 years. The introduced model modifications considerably improve the model behaviour in a 100-year-long simulation, where modelled δ13 is compared against fractionated peat column carbon content. The work presented here is a proof of concept and enables 13C to be used as a natural tracer to detect changes in the underlying soil organic matter decomposition.

149. 题目: Contrasting effects of different field-aged biochars on potential methane oxidation between acidic and saline paddy soils
文章编号: N22091009
期刊: Science of the Total Environment
作者: Zhen Wu, Liying Sun, Yubing Dong, Xintong Xu, Zhengqin Xiong
更新时间: 2022-09-10
摘要:

There is recognition that biochar addition is an appropriate measure to mitigate methane (CH4) emissions by promoting potential methane oxidation (PMO) in the field. However, the mechanism for different field-aged biochars and effective duration after field application are not well documented. Based on a long-term field experiment, biochar was field aged and separated from two contrasting acidic (Ba) and saline (Bs) paddy fields. Then, the effects of different aged biochars on PMO in acidic and saline paddy soils were explored by incubation experiment. There were five treatments for each soil group: soil without biochar (CK), biochar-enriched paddy soil (2 or 6 years) (NB), fresh biochar amendment (Bf), aged biochar separated from acidic paddy soil amendment (Ba), and aged biochar separated from saline paddy soil amendment (Bs). Results showed that saline paddy soils had a significantly higher PMO than acidic paddy soils under treatment without biochar, and that PMO in acidic paddy soil was enhanced by various biochar amendments, whereas those biochar amendments had no significant effects on PMO in saline paddy soil. PMO was positively correlated with pmoA abundance, N consumption rate and pH of soil-biochar mixture. Aged biochar separated from different fields had conflicting influences on soil pH, N consumption rate and PMO. Ba lost its initial effect on changing PMO as compared to Bf treatment when added back into acidic paddy soil. To the contrary, the acidic paddy soil NB treatment containing biochar added six years before possessed the highest value of PMO among all ten treatments. This study suggested that acidic paddy soil with biochar amendment could mitigate CH4 emissions by promoting PMO for a prolonged period, though aged biochar separated from the same field had a limited impact on reducing CH4 emissions.

150. 题目: Black carbon flux in terrestrial and aquatic environments of Kodaikanal in the Western Ghats, South India: Estimation, source identification, and implication
文章编号: N22091008
期刊: Science of the Total Environment
作者: V Karthik, B Vijay Bhaskar, S Ramachandran, Prashant Kumar
更新时间: 2022-09-10
摘要:

Evolving Anthropocene epoch wields significant influence in altering atmospheric carbon, which affects the carbon cycle, leading to climate change. Understanding the carbon stock, fate, and transport across ecosystems is essential in determining India's carbon budget, hitherto, unavailable. In this study, we have analysed the stock, source, distribution, flux, and the relationship between terrestrial and aquatic black carbon over a high-altitude mountainous area in the Western Ghats region using the data collected from September 2019 to February 2021. Soil Organic Carbon (SOC) and Black Carbon (BC) are highest in the forest region (SOC:23 ± 3 g of C/kg (dry weight (dw)), BC:6 ± 3 g/kg) and are lowest in the urban region (SOC: 13 ± 2 g of C/kg (dw), BC:2 ± 1 g/kg). SOC is labile, whereas BC is non-labile. The BC/SOC ratio represents soil lability. Topsoil BC/SOC ratios vary by land use and land cover, with urban areas having greater labile carbon pools than the forests. Dissolved BC (DBC) concentrations were most strongly correlated with bulk dissolved Organic Carbon (DOC) concentrations in midstream (R = 0.6, p < 0.05), headwater streams (R = 0.3, p < 0.05) and to the soil bulk DBC (R = 0.3, p < 0.05), indicating the presence of transfer mechanism of soil to streams. The molecular associations revealed the presence of biolabile autochthonous compounds suggesting the crucial role land use and land cover play on watersheds. A positive relationship between DOC with seasonal hydrology and gradient significantly influences DBC flux across regional streams. Intercomparison of observed terrestrial and aquatic carbon stocks with globally modelled data indicates an overestimation of regional-scale stock. These new findings have repercussions to policy framework on regional climate change. Further, the results suggest that a consistent quantification of BC and integration of regional and global source-to-sink process are needed in order to understand and better quantify biogeochemical process cycles and associated climatic impacts.

151. 题目: An attempt to enhance the adsorption capacity of biochar for organic pollutants - Characteristics of CaCl2 biochar under multiple design conditions
文章编号: N22091007
期刊: Science of the Total Environment
作者: Fulin Shao, Jingtao Xu, Xingsheng Kang, Zhen Hu, Yuanyuan Shao, Chongxiao Lu, Congcong Zhao, Yangang Ren, Jian Zhang
更新时间: 2022-09-10
摘要:

Activators affect the physical and chemical properties of carbon products. However, the effects of different activation mechanisms and pyrolysis conditions on the properties of carbon products still need to be explored. In this study, we obtained a new biochar by impregnation of reed powder with an alkali metal salt (CaCl2) under a specific pyrolysis procedure and pyrolysis conditions. Impregnation by CaCl2 can reduce the activation energy of the biomass while capturing and immobilizing oxygenated organic matter during pyrolysis. The new biochar has a high adsorption capacity of organic matters, for example Bisphenol A (BPA). The adsorption results showed that the modified biochar demonstrated a 364.5 % improvement in the adsorption capacity compared to the original biochar. The final performance enhancement was correlated with the confinement conditions of the environment and the procedure of pyrolysis. These procedures ultimately changed the pore distribution, functional group type, aromaticity, and degree of defects of the modified biochar. This study is important to screen synthetic pathways for identifying compounds with excellent adsorption effects.

152. 题目: Multivariable modeling, optimization and experimental study of Cr(VI) removal from aqueous solution using peanut shell biochar
文章编号: N22091006
期刊: Environmental Research
作者: Ashwani Kumar, S N Upadhyay, P K Mishra, Monoj Kumar Mondal
更新时间: 2022-09-10
摘要:

Peanut shell biomass was selected and utilized to produce biochar through pyrolysis under N2 atmosphere at 923 K. After studying various effects of experimental parameters and by statistical modeling and optimization by RSM using Box-Benken design, optimized conditions of pH 2.0 ± 0.1, temperature 303 K, and adsorbent dose used of 2.5 g L−1 were obtained giving almost 99.99% removal for Cr(VI) from the solution. FESEM, FTIR, XRD, XPS, EDX, elemental mapping, and pHzpc were used for the evaluation of the surface characteristics of peanut shell biochar (PSB). Studies revealed C–O, C–H, CdoubleO, and O–H functional groups’ presence with the help of FTIR, majorly in control of adsorption mechanism and the EDX confirmed the presence of Cr(VI) onto peanut shell biochar (PSB). Further adsorption mechanism for Cr(VI) adsorption followed the pseudo-second-order rate with adsorption capacity of 29.38 mg g−1 given by the Langmuir isotherm. The thermodynamic study confirmed the exothermic and spontaneous nature of the process for Cr(VI) adsorption onto PSB. The adsorption mechanism showed electrostatic attraction, reduction, and complexation mainly responsible for Cr(VI) adsorption by PSB. Thus, PSB effectively removes Cr(VI) is confirmed by the present study.

153. 题目: Optical properties, molecular characterizations, and oxidative potentials of different polarity levels of water-soluble organic matters in winter PM2.5 in six China's megacities
文章编号: N22091005
期刊: Science of the Total Environment
作者: Tian Zhang, Zhenxing Shen, Shasha Huang, Yali Lei, Yaling Zeng, Jian Sun, Qian Zhang, Steven Sai Hang Ho, Hongmei Xu, Junji Cao
更新时间: 2022-09-10
摘要:

Humic-like substances (HULIS) accounted for a great fraction of water-soluble organic matter (WSOM) in PM2.5, which efficiently absorb ultraviolet (UV) radiation and pose climate and health impacts. In this study, the molecular structure, optical properties, and oxidative potential (OP) of acid- and neutral-HULIS (denoted as HULIS-a, and HULIS-n, respectively), and high-polarity WSOM (HP-WSOM) were investigated in winter PM2.5 collected at six China's megacities. For both carbon levels and optical absorption coefficients (babs_365), HULIS-a/HULIS-n/HP-WSOM showed significant spatial differences. For each city, the carbon levels and babs_365 follow a similar order of HULIS-n > HULIS-a > HP-WSOM. Besides, the babs_365 of HULIS-n and HULIS-a showed the same order of Harbin > Beijing ≈ Wuhan > Xi'an > Guangzhou > Chengdu, while HP-WSOM exhibited an order of Wuhan > Chengdu > Xi'an > Harbin > Beijing > Guangzhou. Both HULIS-a and HULIS-n were abundant in aromatic and aliphatic compounds, whereas HP-WSOM was dominated by a carboxylic acid group. The OP (in unit of nmol H2O2 μg−1C) followed the order of HP-WSOM > HULIS-a > HULIS-n in all the cities. The OPs of HULIS-a, HULIS-n, and HP-WSOM in Harbin and Beijing were much higher than those of other cities, attributing to the high contribution from biomass burning. Highly positive correlations between reactive oxygen species (ROS) of HULIS-a and MAE365 were obtained in Chengdu, Wuhan, and Harbin, but ROS of HULIS-n had stronger correlation with MAE365 in Harbin, Chengdu, and Xi'an.

154. 题目: Treatment of distiller grain with wet-process phosphoric acid leads to biochar for the sustained release of nutrients and adsorption of Cr(VI)
文章编号: N22091004
期刊: Journal of Hazardous Materials
作者: Xiaohou Zhou, Dehua Xu, Jingxu Yang, Zhengjuan Yan, Zhiye Zhang, Benhe Zhong, Xinlong Wang
更新时间: 2022-09-10
摘要:

Soil amendment products, such as biochar, with both sustained nutrient release and heavy metal retention properties are of great need in agricultural and environmental industries. Herein, we successfully prepared a new biochar material with multinutrient sustained-release characteristics and chromium removal potential derived from distiller grain by wet-process phosphoric acid (WPPA) modification without washing. SEM, TEM TG-IR, in situ DRIFTS and XRD characterization indicated that biochar and polyphosphate formed simultaneously and were tightly intertwined by one-step pyrolysis. The optimal product (PKBC-400) had the most stable carbon structure and an adequate P-O-P structure with less P loss. Batch experiments illustrated that 92.83% P (ortho-P), 85.94% K, 41.49% Fe, 78.42% Al and 65.60% Mg were continuously released in water from PKBC-400 within 63 days, and the maximum Cr removal rate reached 83.57% (50 mg/L K2Cr2O7, pH=3.0) with an increased BET surface area (304.0557 m2/g) after nutrient release. SEM, IC and 31P NMR analyses revealed that the dissolution and hydrolysis of polyphosphates not only realized the sustained release of multiple nutrients but also significantly improved the sustained release performance. The proposed resource utilization strategy provided new ideas for Cr hazard control, biomass waste utilization and fertilizer development.

155. 题目: The migration and microbiological degradation of dissolved organic matter in riparian soils
文章编号: N22091003
期刊: Water Research
作者: Weihua Li, Muhammad Saboor Siddique, Mengjie Liu, Nigel Graham, Wenzheng Yu
更新时间: 2022-09-10
摘要:

Riparian zones are important natural means of water purification, by decreasing the aqueous concentration of terrestrial organic matter (OM) through adsorption and microbial degradation of the organic matter within the aquatic ecosystem. Limited studies have been reported so far concerning the migration of dissolved organic matter (DOM) in the horizontal and vertical planes of riparian zones. In this study, the migration of DOM in riparian zones, from forest soil to wetland soil, and with soil depth, were explored, based on a case study reservoir. Results showed that riparian wetlands can absorb the OM from the forest soils and adjacent reservoir, and act as a major OM sink through microbial action. Methylomirabilota and GAL15 bacteria increased with soil depth for the two soil systems, and the wetland soil system also contained microbial sulfates, nitrates and carbonates. These microorganisms successfully utilize the Fe3+, SO4, and CO3 as electron acceptors in the wetland system, resulting in enhanced OM removal. Although the variation of soil DOM in the vertical direction was the same for both forest and wetland soils, the Chemical structure of the DOM was found to be significantly different. Furthermore, the soil was found to be the main source of DOM in the forest ecosystem, with lignin as the main ingredient. The lignin structure was gradually oxidized and decomposed, with an increase in carboxyl groups, as the lignin diffused down into the soil and the adjacent reservoir. PLS-PM analysis showed that the soil physicochemical properties were the main factors affecting DOM transformation. However, microbial metabolism was still the goes deeper affecting factor. This study will contribute to the analysis that migration and transform of soil organic matter in riparian zone.

156. 题目: Insights into olation reaction-driven coagulation and adsorption: A pathway for exploiting the surface properties of biochar
文章编号: N22091002
期刊: Science of the Total Environment
作者: Fulin Shao, Jingtao Xu, Feiyong Chen, Daoxing Liu, Congcong Zhao, Xiaoxiang Cheng, Jian Zhang
更新时间: 2022-09-10
摘要:

In this study, characterization of biochar for the efficient removal of cadmium was investigated. Biochar has a specific distribution of functional groups on its surface and has a natural electronegativity. Using carbonate as an olation reagent, the biochar coagulates with the olation reaction products. The maximum removal capacity reached 430.4 mg/g at pH = 4 (Langmuir Fit). Carbonate hydrolyzed on the surface of biochar, Cd2+ in solution undergoes olation with OH and forms specially structured nanochains that are positively charged on the surface. The biochar with electronegativity on the surface coagulates with the cadmium hydroxide nanochains, and the cadmium-containing colloid formed by electrostatic attraction settles rapidly and removed. The biochar's re-flocculation performance was consistent, and the loadings could be changed to effectively remove cadmium while keeping the pH neutral at equilibrium.

157. 题目: Investigation of the maturation effects on biomarker distributions in bituminous coals
文章编号: N22091001
期刊: Organic Geochemistry
作者: Feixuan Cai, Ruwei Wang, Jiawei Cai, Qing Huang, Zhuliang Huang, Yuchan Xu, Qiling Yang
更新时间: 2022-09-10
摘要:

Biomarkers in coal can evolve dramatically in terms of their concentration and distribution during coalification, limiting their use in source allocation of coal-derived pollution. Here we analyzed a broad range of aliphatics (i.e., 26 n-alkanes, 6 isoprenoids, 32 terpanes, 19 steranes) and 77 polycyclic aromatic compounds (PACs) in the Permo-Carboniferous and Late Triassic coals from the Chinese Huainan and Da Baoding coalfields, respectively. These coals, classifying as high volatile bituminous B to low volatile bituminous with vitrinite reflectance (Rr) values ranging from 0.71 to 1.74%, show variable organic geochemical features owing to the combined effects of thermal maturity and organofacies. Changes in the n-alkanes and isoprenoids indicate the loss of aliphatic fractions associated with maturation owing to cracking of the long-chain alkanes. The stratigraphic changes in the pristane to phytane ratios (Pr/Ph), Pr/n-C17, and Ph/n-C18 reflect a control exerted by the depositional environment in the Huainan coals. In addition, principal component analysis (PCA) recognizes the Pr/n-C17, Ph/n-C18, carbon preference index (CPI), and odd-to-even predominance 2 (OEP 2) as organofacies sensitive indices. Intercomparison of the PAC distributions suggest different maturation pathways for the coals from the Huainan and Da Baoding coalfields. The demethylation processes related to coalification preferentially occur on the polymethyl substitutes that occur to a greater degree in the Da Baoding coals than in the Huainan coals. Nine PAC indices display distinctive patterns when plotting against Rr. The DMP-2 vs. DBT:DBF cross-plot explicitly separates the Huainan and Da Baoding coals into three distinctive zones representing different depositional environments and sources of organic matter. Moreover, PCA explicitly discriminate the maturation sensitive indices (i.e., MNR, DNR-1, TrMN-1, TrMN, TeMN, MPR, and MPI-1) from organofacies sensitive indices (i.e., DMP-2 and DBT:DBF).

158. 题目: Specific chemical adsorption of selected divalent heavy metal ions onto hydrous γ-Fe2O3-biochar from dilute aqueous solutions with pH as a master variable
文章编号: N22090914
期刊: Chemical Engineering Journal
作者: Cuijuan Feng, Michael Huang, Chin-pao Huang
更新时间: 2022-09-09
摘要:

A γ-Fe2O3-biochar was synthesized using ferrate as precursor. Results showed that ferrate treatment of biochar increased surface acidity and magnetism strength, which enhanced metal ion adsorption and enabled easy magnetic separation of spent biochar after use. The adsorption characteristics of selected metal ions including Cu(II), Pb(II), Zn(II), Ni(II), Cd(II) and Co(II) onto hydrous γ-Fe2O3-biochar were studied. The adsorption isotherms were well fitted by the Langmuir adsorption model. The γ-Fe2O3-biochar exhibited significantly high monolayer metal coverage capacity. For example, the maximum Cu(II) adsorption density was 55.45 × 10-5 mol/g, which was 4.0 times that of plain biochar (13.75 × 10-5 mol/g) at pH 6. Metal ion adsorption reactions could be described by surface complex formation, involving all M(II) hydroxy species and surface hydroxy species, i.e., FeOH and COH. Both experimental and calculation results suggested the formation of inner- and outer-sphere complexes. Coulombic and specific chemical forces contributed to the total adsorption energy, with specific chemical energy being the dominating component for the adsorption of hydrolyzable metal ions onto γ-Fe2O3-biochar surface. Under the context of surface complex formation, it is visualized that metal ion hydrolysis reactions occurred on γ-Fe2O3-biochar surface, in parallel to that in the bulk phase.

159. 题目: A global synthesis of patterns in soil organic matter and temperature sensitivity along the altitudinal gradient
文章编号: N22090913
期刊: Frontiers in Environmental Science
作者: Chao Li, Chunwang Xiao, Mingxu Li, Li Xu, Nianpeng He
更新时间: 2022-09-09
摘要:

Although it is important to determine how the global carbon (C) cycle is responding to climate change in our three-dimensional Earth, variation in the soil organic matter (SOM) and temperature sensitivity (Q10) of soil respiration along the altitudinal gradient remains unclear globally. This study explored spatial variability in SOM and Q10 and its regulatory mechanisms from a three-dimensional perspective. We collected SOM and Q10 datasets from published studies for 0–10 cm soil depth along elevational gradients of mountain ranges globally. We found that the SOM content in most mountains changed significantly with increasing altitude; unexpectedly, these changes with altitude significantly differed across different climate zones. Specifically, the SOM content increased with increasing altitude in tropical and subtropical regions, while it decreased with increasing altitude in temperate and plateau regions. Climate factors (mean annual temperature and mean annual precipitation) and soil properties (total N content, C/N ratio, and pH) together accounted for 83% of spatial variation in SOM with altitude. Q10 values, under both laboratory incubation and in situ studies, did not significantly correlate with altitude, and no apparent global patterns were detected (mean: 2.07); however, Q10 was regulated by variation in soil substrate quality along altitudinal gradients, to some extent. In the context of global climate change, this new information on SOM and Q10 in relation to the altitude at a global scale might enhance our understanding of soil C−climate feedbacks.

160. 题目: Synthesis and applications of bismuth-impregnated biochar originated from spent coffee grounds for efficient adsorption of radioactive iodine: A mechanism study
文章编号: N22090912
期刊: Environmental Pollution
作者: Jinwoo Kwak, Sang-Ho Lee, Jaegwan Shin, Yong-Gu Lee, Sangwon Kim, Changgil Son, Xianghao Ren, Jae-Ki Shin, Yongeun Park, Kangmin Chon
更新时间: 2022-09-09
摘要:

The adsorption of radioactive iodine, which is capable of presenting high mobility in aquatic ecosystems and generating undesirable health effects in humans (e.g., thyroid gland dysfunction), was comprehensively examined using pristine spent coffee ground biochar (SCGB) and bismuth-impregnated spent coffee ground biochar (Bi@SCGB) to provide valuable insights into the variations in the adsorption capacity and mechanisms after pretreatment with Bi(NO3)3. The greater adsorption of radioactive iodine toward Bi@SCGB (adsorption capacity (Qe) = 253.71 μg/g) compared to that for SCGB (Qe = 23.32 μg/g) and its reduced adsorption capability at higher pH values provide evidence that the adsorption of radioactive iodine with SCGB and Bi@SCGB is strongly influenced by the presence of bismuth materials and the electrostatic repulsion between their negatively charged surfaces and negatively charged radioactive iodine (IO3). The calculated R2 values for the adsorption kinetics and isotherms support that chemisorption plays a crucial role in the adsorption of radioactive iodine by SCGB and Bi@SCGB in aqueous phases. The adsorption of radioactive iodine onto SCGB was linearly correlated with the contact time (h1/2), and the diffusion of intra-particle predominantly determined the adsorption rate of radioactive iodine onto Bi@SCGB (Cstage II (129.20) > Cstage I (42.33)). Thermodynamic studies revealed that the adsorption of radioactive iodine toward SCGB (ΔGº = −8.47 to −7.83 kJ/mol; ΔHº = −13.93 kJ/mol) occurred exothermically and that for Bi@SCGB (ΔGº = −15.90 to −13.89 kJ/mol; ΔHº = 5.88 kJ/mol) proceeded endothermically and spontaneously. The X-ray photoelectron spectroscopy (XPS) analysis of SCGB and Bi@SCGB before and after the adsorption of radioactive iodine suggest the conclusion that the change in the primary adsorption mechanism from electrostatic attraction to surface precipitation upon the impregnation of bismuth materials on the surfaces of spent coffee ground biochars is beneficial for the adsorption of radioactive iodine in aqueous phases.

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