281. 题目: Landscape determinants of pelagic and benthic primary production in northern lakes
282. 题目: Inhibition of humic acid on copper pollution caused by chalcopyrite biooxidation
Humic acid has the advantages of wide source, easy availability and environmental friendliness, which may be a good choice for inhibiting chalcopyrite biooxidation and alleviating copper pollution. However, there are few researches on the inhibitory effect and mechanism of humic acid on the biooxidation of chalcopyrite. In order to fill this knowledge gap, this study proposed and validated a novel method for inhibiting chalcopyrite biooxidation by means of humic acid. The results showed that the biooxidation of chalcopyrite could be effectively inhibited by humic acid, which consequently decreased the release of copper ions. Humic acid with a concentration of 120 ppm had the best inhibitory effect, which reduced the biooxidation efficiency of chalcopyrite from 40.7 ± 0.5 % to 29.3 ± 0.8 %. This in turn suggested that humic acid could effectively suppress the pollution of copper under these conditions. The analysis results of solution parameters, mineral surface morphology, mineral phases and element composition showed that humic acid inhibited the growth of Acidithiobacillus ferrooxidans, promoted the formation of jarosite and intensified the passivation of chalcopyrite, which effectively hindered the biooxidation of chalcopyrite, and would help to alleviate the pollution of copper.
283. 题目: Soil macroaggregation drives sequestration of organic carbon and nitrogen with three-year grass-clover leys in arable rotations
Conventional arable cropping with annual crops established by ploughing and harrowing degrades larger soil aggregates that contribute to storing soil organic carbon (SOC). The urgent need to increase SOC content of arable soils to improve their functioning and sequester atmospheric CO2 has motivated studies into the effects of reintroducing leys into long-term conventional arable fields. However, effects of short-term leys on total SOC accumulation have been equivocal. As soil aggregation may be important for carbon storage, we investigated the effects of arable-to-ley conversion on cambisol soil after three years of ley, on concentrations and stocks of SOC, nitrogen and their distributions in different sized water-stable aggregates. These values were benchmarked against soil from beneath hedgerow margins. SOC stocks (0–7 cm depth) rose from 20.3 to 22.6 Mg ha−1 in the arable-to-ley conversion, compared to 30 Mg ha−1 in hedgerows, but this 2.3 Mg ha−1 difference (or 0.77 Mg C ha−1 yr−1) was not significant). However, the proportion of large macroaggregates (> 2000 μm) increased 5.4-fold in the arable-to-ley conversion, recovering to similar abundance as hedgerow soils, driving near parallel increases in SOC and nitrogen within large macroaggregates (5.1 and 5.7-fold respectively). The total SOC (0–7 cm depth) stored in large macroaggregates increased from 2.0 to 9.6 Mg ha−1 in the arable-to-ley conversion, which no longer differed significantly from the 12.1 Mg ha−1 under hedgerows. The carbon therefore accumulated three times faster, at 2.53 Mg C ha−1 yr−1, in the large macroaggregates compared to the bulk soil. These findings highlight the value of monitoring large macroaggregate-bound SOC as a key early indicator of shifts in soil quality in response to change in field management, and the benefits of leys in soil aggregation, carbon accumulation, and soil functioning, providing justification for fiscal incentives that encourage wider use of leys in arable rotations.
284. 题目: Sustainable conversion of textile industry cotton waste into P-dopped biochar for removal of dyes from textile effluent and valorisation of spent biochar into soil conditioner towards circular economy
Effective immobilization of industrial waste into biochar development could be one of the most promising technologies for solid waste management to achieve circular economy. In this study, post-industrial cotton textile waste (PICTW), a cellulose rich industrial waste, was subjected to slow pyrolysis to develop a surface engineered biochar through phosphoric acid impregnation. Biochar produced at 500 °C designated as PICTWB500 showed a maximum methylene blue number (240 mg g−1) with remarkable specific surface area of 1498 m2 g−1. FESEM, FTIR, XRD and Raman spectra analysis were performed to investigate the surface texture and functionalities developed in the biochar. Adsorption efficiency of the biochar was assessed using drimarene red, blue, violet, and black dyes as model dye pollutants in batch mode at different biochar dose, pH and contact time. The maximum monolayer adsorption capacity was obtained in the range 285–325 mg g−1 for different dyes, determined from Langmuir adsorption model. The kinetic behaviour was more favourable with the pseudo second-order model. The recycling ability of PICTWB500 was proven to be effective up to 6th cycle without compromising its adsorption efficiency significantly. This study demonstrated an excellent adsorption capability of the biochar in dye laden real textile effluent and recycling of spent biochar as a precursor of bio compost. Hence, this study established a dual win strategy for waste utilization in textile industry using a closed loop approach with substantial techno-economic feasibility that may have potential applications.
285. 题目: Hydrophilic spongy biochar crosslinked with starch and polyvinyl alcohol biocarrier for nitrate, phosphorus, and cadmium removal in low carbon wastewater: Enhanced performance mechanism and detoxification
This study aims to develop a functional biocarrier with hydrophilic spongy biochar crosslinked with starch and polyvinyl alcohol (WSB/starch-PVA) for simultaneous removal of NO3--N, total phosphorus (TP) and Cd2+ in low carbon wastewater. Results showed that the WSB/starch-PVA bioreactor achieved the maximum NO3--N removal efficiency in subphase 1.2 with 98.07% (3.64 mg L-1 h-1) versus control (75.30%, 2.81 mg L-1 h-1), and removed 54.84% and 73.97% of TP and Cd2+. Material characterization suggested that functional groups (related to C, N and O) on biocarrier and biofilm, and biogenic co-precipitation facilitated TP and Cd2+ removal. The WSB made the biocarrier pores larger and regular, and decreased fluorescent soluble microbial products. The predicted metagenome further suggested that central citrate cycle, oxidative phosphorylation of bio-community, and NO3--N removal were enhanced. Functions for microbial induced co-precipitation, Cd2+ transport/efflux, antioxidants, and enhanced biofilm formation favored the NO3--N/TP removal and Cd2+ detoxification.
286. 题目: Nickel-Catalyzed Mesoporous Biochar for Enhanced Adsorptive Oxidation of Aqueous Sulfide: An Investigation of Influencing Factors and Mechanisms
Biochar (BC) is a low-cost and electroactive adsorbent for removing sulfide in aqueous media, which toxifies aquatic organisms and corrodes water treatment facilities. However, it lacks a pore structure for sulfide ion (S2-) mass transfer to active sites. Herein, it is shown that nickel-modified biochar (BC-Ni) adsorbed S2- 2.72-fold faster than BC alone and attained a 1244 ± 252 mg-sulfide/g maximum adsorption capacity due to markedly increased mesopores, while BC attained 583 ± 250 mg-sulfide/g. Factors influencing S2-sorption and theoretical sorption kinetics and isotherms models were evaluated. Structural and surface compositions of BC and BC-Ni were examined using state-of-the-art characterizations. The results suggest that S2- was adsorbed via pore diffusion, pore filling, and cation bridging and oxidized to elemental sulfur and sulfate with quinone and hydrogen peroxide generated from dehydrogenation of hydroquinone on the BC-Ni by metallic nickel in the carbon matrix. This study would spur biomass valorization and desulfurization.
287. 题目: Of Sea and Smoke: Evidence of Marine Dissolved Organic Matter Deposition from 2020 Western United States Wildfires
288. 题目: Advances in Molecular and Microscale Characterization of Soil Organic Matter: Current Limitations and Future Prospects
289. 题目: Soil depth determine the ecological stoichiometry of soil aggregates after returning ancient rice terraces to forest
Soil carbon-nitrogen-phosphorus (CNP) ecological stoichiometry is an effective means of reflecting soil nutrient status, transformations, and limitations, but the effect of returning ancient rice terraces to forest on soil CNP stoichiometry is still unclear at the aggregate scale in the subtropical hilly areas of southern China. This study explored how the CNP content and stoichiometry of soil water-stable aggregates responded after returning ancient rice terraces to forest in the soil layer depth of 0–60 cm in subtropical hilly areas. The results showed that the stability, soil organic carbon (SOC), total nitrogen (TN), C/P, and N/P ratios of soil aggregates decreased significantly with soil depth in ancient rice terraces, Chinese fir (Cunninghamia lanceolata), and moso bamboo (Phyllostachys pubescens). The proportion of macroaggregates decreased gradually and the proportion of microaggregates increased significantly after the soil depth increased. Returning ancient rice terraces to Chinese fir was more conducive to increasing the SOC, TN, C/P, and N/P ratios of soil aggregates, which may be related to plant litter biomass. Eta squared analysis showed that soil depth had a greater impact on soil aggregate stability (34 %, 38 %, and 46 %), CNP content (34 %–45 %), and stoichiometry (34 %–57 %) than land use types and their interactions. These findings indicated that returning ancient rice terraces to Chinese fir and moso bamboo can significantly alter soil water-stable aggregate stability, CNP content, and stoichiometry, and soil depth plays an extremely important role in changing them. Future research should focus on the ecological impacts of soil depth on agroforestry ecosystems.
290. 题目: FexN produced in pharmaceutical sludge biochar by endogenous Fe and exogenous N doping to enhance peroxymonosulfate activation for levofloxacin degradation
For preparing high performance biochar to be applicated in persulfate-based oxidation treatment of wastewater, the feasibility of deriving Fe-N biochar from pharmaceutical sludge by endogenous Fe and exogenous N doping was investigated. With exogenous urea doping, FexN contained biochar (PZBC800U) was successfully derived from endogenous Fe(OH)3 contained pharmaceutical sludge. PZBC800U effectively activated peroxymonosulfate (PMS) to remove 80 mg·L−1 levofloxacin (LEV) within 90 min. The main mechanism of PMS activation by PZBC800U for LEV degradation was revealed as non-radical pathways dominated by 1O2 generation and direct electron transfer. The formation of FexN combined with the increase of pyridinic-N in the biochar changed the electronic structure, improved the electron transfer ability, and thus achieved the excellent PMS activation capacity of the biochar. The vital function of endogenous Fe(OH)3 was verified by comparing PZBC800U to Fe leached and extra Fe added controls. A total of 18 intermediates in the degradation of LEV were identified, and degradation pathways were proposed. Combined with the average local ionization energy calculation, the priority of piperazine breakage during LEV degradation was experimentally proved and mechanistically elucidated. This study provides a new insight into FexN biochar preparation from pharmaceutical sludge and the mechanisms of its excellent PMS activation performance for LEV degradation.
291. 题目: Increased microbial and substrate complexity result in higher molecular diversity of the dissolved organic matter pool
292. 题目: Divergent responses of cropland soil organic carbon to warming across the Sichuan Basin of China
Cropland soils are considered to have the potential to sequester carbon (C). Warming can increase soil organic C (SOC) by enhancing primary production, but it can also cause carbon release from soils. However, the role of warming in governing cropland SOC dynamics over broad geographic scales remains poorly understood. Using over 4000 soil samples collected in the 1980s and 2010s across the Sichuan Basin of China, this study assessed the warming-induced cropland SOC change and the correlations with precipitation, cropland type and soil type. Results showed mean SOC content increased from 11.10 to 13.85 g C kg−1. Larger SOC increments were observed under drier conditions (precipitation < 1050 mm, dryland and paddy-dryland rotation cropland), which were 1.67–2.23 times higher than under wetter conditions (precipitation > 1050 mm and paddy fields). Despite the significant associations of SOC increment with crop productivity, precipitation, fertilization, cropland type and soil type, warming also acted as one of major contributors to cropland SOC change. The SOC increment changed parabolically with the rise in temperature increase rate under relatively drier conditions, while temperature increase had no impact on cropland SOC increment under wetter conditions. Meanwhile, the patterns of the parabolical relationship varied with soil types in drylands, where the threshold of temperature increase rate, the point at which the SOC increment switched from increasing to decreasing with warming, was lower for clayey soils (Ali-Perudic Argosols) than for sandy soils (Purpli-Udic Cambosols). These results illustrate divergent responses of cropland SOC to warming under different environments, which were contingent on water conditions and soil types. Our findings emphasize the importance of formulating appropriate field water management for sustainable C sequestration and the necessity of incorporating environment-specific mechanisms in Earth system models for better understanding of the soil C-climate feedback in complex environments.
293. 题目: Eggshell based biochar for highly efficient adsorption and recovery of phosphorus from aqueous solution: Kinetics, mechanism and potential as phosphorus fertilizer
Development of an efficient and green adsorbent is of great significance for phosphorus removal and recovery from eutrophic water. This work prepared an eggshell modified biochar (ESBC) by co-pyrolysis of eggshells and corn stalk. ESBC exhibited an excellent performance for phosphorus adsorption over a wide pH range (5–13), and achieved a maximum adsorption of 557.0 mg P/g. The adsorption process was well fitted by pseudo-second-order model (R2 > 0.962) and Sips model (R2 > 0.965), and it was endothermic (ΔH0 > 0) and spontaneous (ΔG0 < 0) according to thermodynamic analysis. The column experiment confirmed the feasibility of ESBC as a filter media for phosphorus removal in flow condition, and obtained a P removal of 460.0 mg/g. Soil burial tests indicated P-laden ESBC has a good P slow-release performance (maintained for up to 25 days). Overall, ESBC has a promising application potential as an efficient adsorbent for phosphorus recovery and subsequently as a slow-release fertilizer.
294. 题目: Treatment of cadmium and zinc-contaminated water systems using modified biochar: Contaminant uptake, adsorption ability, and mechanism
Cd and Zn contamination in water occurs frequently that threatens water supply, human health, and food production. MnFeB, a novel absorbent biochar modified using KMnO4 and hematite, was prepared and used for the treatment of Cd2+ and Zn2+solutions. MnFeB exhibits a rough surface structure, large specific surface area, higher total pore volume, massive functional groups, and abundant iron oxide, all of which contribute to higher Cd2+ and Zn2+ adsorption capacity. In single metal systems, maximum Cd2+ and Zn2+ adsorption capacities of MnFeB were 1.88 and 1.79 times higher than those of unmodified biochar (CSB). The maximum Cd2+ and Zn2+ adsorption capacities of MnFeB were 2.73 and 2.65 times higher than CSB in the binary metal system. Key adsorption mechanisms of Cd2+ and Zn2+ by MnFeB included electrostatic interaction, co-precipitation, π-π interaction, complexation, and ion exchange. Thus, MnFeB can be used as a novel absorbent to treat Cd and Zn-polluted water.
295. 题目: Micro-aerobic conditions based on membrane-covered improves the quality of compost products: Insights into fungal community evolution and dissolved organic matter characteristics
This study investigated the effects of micro-aerobic conditions on fungal community succession and dissolved organic matter transformation during dairy manure membrane-covered composting. The results showed that lignocellulose degradation in the micro-aerobic composting group (AC: oxygen concentration <5%) was slower than that in the static composting group (SC: oxygen concentration <1%), but the dissolved organic carbon in AC was greatly increased. The degree of aromatic polymerization was higher in AC than in SC. But the carboxyl carbon and alcohol/ether biodegradations were faster in SC than in AC, which promoted carbon dioxide and methane emissions, respectively. The relative abundances of pathogenic and dung saprotrophic fungi in AC were 44.6% and 10.59% lower than those in SC on day 30, respectively. Moreover, the relative abundance of soil saprotrophs increased by 5.18% after micro-aerobic composting. Therefore, micro-aerobic conditions improved the quality of compost products by influencing fungal community evolution and dissolved organic matter transformation.
296. 题目: Combined addition of biochar, lactic acid, and pond sediment improves green waste composting
Composting, as an eco-friendly method to recycle green waste (GW), converts the GW into humus-like compounds. However, conventional GW composting is inefficient and generates poor-quality compost. The objective of this research was to investigate the effects of the combined additions of biochar (BC; 0, 5, and 10 %), lactic acid (LA; 0, 0.5, and 1.0 %), and pond sediment (PS; 0, 20, and 30 %) on GW composting. A treatment without additives served as the control (treatment T1). The results showed that treatment R1 (with 5 % BC, 0.5 % LA, and 20 % PS) was better than the treatments with two additives or no additive and required only 32 days to generate a stable and mature product. Compared with T1, R1 improved water-holding capacity, electrical conductivity, available phosphorus, available potassium, nitrate nitrogen, OM decomposition, and germination index by 51 %, 48 %, 170 %, 93 %, 119 %, 157 %, and 119 %, respectively. R1 also increased the activities of cellulase, lignin peroxidase, and laccase. The results showed that the combined addition of BC, LA, and PS increased the gas exchange, water retention, and the microbial secretion of enzymes, thus accelerating the decomposition of GW. This study demonstrated the effects of BC, LA, and PS addition on GW composting and final compost properties, and analyzed the reasons of the effects. The study therefore increases the understanding of the sustainable disposal of an important solid waste.
297. 题目: Tailoring wood waste biochar as a reusable microwave absorbent for pollutant removal: Structure-property-performance relationship and iron-carbon interaction
This study innovated the concept in designing an efficient and reusable microwave (MW) absorbent through concurrent exploitation of carbon graphitization, oxygen functionalization, and carbothermal iron reduction underpinned by an endothermic co-pyrolysis of wood waste and low-dosage iron. A powerful MW assimilation was accomplished from nanoscale amorphous magnetic particles as well as graphitized microporous carbon-iron skeleton in the biochar composites. Relative to a weak magnetic loss derived from the iron phase, the graphitic carbon architecture with abundant surface functionalities (i.e., CO and CO) exhibited a strong dielectric loss, which was thus prioritized as major active sites during MW reuse. The MW-absorbing biochar demonstrated a fast, robust, and durable removal of a refractory herbicide (2,4-dichlorophenoxy acetic acid) under mild MW irradiation with zero chemical input, low electricity consumption, and negligible Fe dissolution. Overall, this study will foster carbon–neutral industrial wastewater treatment and wood waste valorization.
298. 题目: Silica modified biochar mitigates the adverse effects of salt and drought stress and improves safflower (Carthamus tinctorius L.) growth
Water scarcity and soil salinity are among the major factors responsible for lower plant growth and production. Many studies have reported beneficial effects of biochar application in mitigating salt and drought stress in soil. This study was conducted to investigate the efficiency of poultry manure-derived biochar (BC) and silica modified BC (SBC) to mitigate the waning effects of soil salinity and water scarcity on safflower (Carthamus tinctorius L.) plant growth.
Materials and methods
A pot experiment was conducted in greenhouse with soil collected from local agricultural farm. Amendments were added to soil at three rates: 0%, 1%, and 3% (w/w), and three levels of salinity (0, 50, and 100 mM) were applied, while in a separate pot experiment, plants were irrigated at 2-level water contents, i.e., 50% and 100% of field capacity (FC).
Results and discussion
Plants grown in soil with BC and SBC showed comparatively higher growth against control treatment with no added amendments. Soil receiving SBC displayed an increase in pH value by 0.07–0.47, lower electrical conductivity value (0.86–1.17 dS m−1), and higher uptake of P (878.57 to 1753.58 µg plant−1). Furthermore, higher K+ and lower Na+ availability and plant uptake were found in SBC-amended soil compared with control. Overall, 3% SBC application performed outclass in improving plant growth under 50% FC.
In nutshell, BC and SBC displayed substantial potential in reducing soil salinity and drought stress and improved nutrient availability and plant uptake.
299. 题目: Sediment phosphorus speciation changes by extracellular enzymatic activity (EEA) of three phosphatase pH-dependent isoforms
Salt marshes are key ecosystems for biogeochemical cycling of nutrients in coastal areas, providing essential sequestration of contaminants and elemental organic forms while recycling these last to more bioavailable forms. Extracellular phosphatase-mediated phosphorus biogeochemical cycling acquires this way a reinforced role. In terms of speciation, salt marsh sediments exhibited a large pool of P in a bioavailable form (> 60%), being this pool characterized by being readily accessible to plants by weak chemical reactions. Regarding phosphatase activity, the acid isoform was found to be the most abundant pH-isoform present in salt marsh rhizosediments. A positive correlation could be found between humic acid bound P and total and acid phosphatase activities, possibly driven by the action of acid phosphatase on the acidic molecules of humic acids, using organic P as substrate, and releasing inorganic P into the desorbable P-pool. This process is more evident during the cold seasons, where the largest necromass input is observed entering the sediments, due to seasonal plant senescence. It could also be observed a positive correlation between inorganic phosphorus forms and phosphatase activity, consistent with phosphatases-driven inorganic phosphorus production from the recycling of organic forms, and thus a possible direct effect of phosphatase, as it was described for other ecosystems. This biogeochemical cycling is key for the ecosystem nutrient recycling, while passive remediator of eutrophication, but also for maintaining the salt marsh areas high primary productivity and their role as habitat, shelter and feeding ground of many animal species.
300. 题目: Utilization of Algal Waste Biomass-Derived Biochar Prepared by a Microwave-Assisted Method for Aniline Green Adsorption
In this study, environmentally friendly activated biochar was produced from the wastes of the algal biodiesel industry (Gongolaria barbata (Stackhouse) Kuntze) using a microwave-assisted method. It was used as an adsorbent to remove hazardous aniline green dye from wastewater. The biochar, activated with phosphoric acid (BCH) was prepared in one step by a microwave-assisted method. Scanning electron microscopy (SEM), pHpzc (pH at point of zero charges), Fourier transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) techniques were used for the characterization of the adsorbent. The activated biochar presented a micropore volume of 0.181 cm3 g−1 and SBET of 1089 m2 g−1. The effects of contact time, pH, and adsorbent amount on the adsorption were investigated. The optimal condition for the maximum adsorption of aniline green (AG) was found as pH (7.0), adsorbent amount (1 g L−1), equilibrium time (40 min), and pollutant concentration (50 mg L−1). The maximum removal percentage was proved to be 99.9% of AG removal. Analyses of experimental data were discussed using nonlinear model equations. The isotherm model can be well described by the Freundlich model. The pseudo-second-order model was suitable for the adsorption kinetics. The reusability ability of BCH for AG dye uptake was found to be 88.3% and 71.6%, for the 50 and 100 mg L−1 pollutant concentrations, respectively, after the third cycle. Three cycles of adsorption and desorption showed that activated biochar is reusable. The economic analysis based on electricity consumption proved that the prepared adsorbent is suitable for large-scale use.