Compounded chelating agent derived from fruit residue extracts effectively enhances Cd phytoextraction by Sedum alfredii

Chelating agent is known as the enhancer for metal phytoextraction;however,there is still a lack of efficient and environmentally sustainable chelators.Here,lemon residue extraction(LRE),prepared from 11 kinds of fruit wastes,was combined with N,N-bis(carboxymethyl)glutamic acid(GLDA),and tea saponin(T.S.)for the compounded plant-derived chelator(CPC),and their influences on Cd phytoextraction by the hyperaccumulator Sedum alfredii was evaluated.Among these fruits,the lemon residue extracted the most significant amount of Cd from the soil.The most effective CPC was at the volume ratio of three agents being 15:4:1(LRE:GLDA:T.S.).Compared with the deionized water,the solubility of three Cd minerals was increased by 85–256 times,and Cd speciation was substantially altered after CPC application.In the pot experiment,CPC addition caused evident increases in plant shoot biomass,Cd phytoextraction efficiency,and organic matter content compared with EDTA and nitrilotriacetic acid(NTA)application.CPC induced fewer changes in bacterial community composition compared with EDTA and had no pronounced influence on microbial biomass carbon and bacterialα-diversity,suggesting CPC had a subtle impact on the microbiological environments.Our study provides a theoretical base for the reutilization of fruit wastes and the development of environmental-friendly chelator that assists Cd phytoextraction.

Thermodynamic insights into n-alkanes phase change materials for thermal energy storage

n-Alkanes have been widely used as phase change materials(PCMs) for thermal energy storage applications because of their exceptional phase transition performance, high chemical stability, long term cyclic stability and non-toxicity. However, the thermodynamic properties, especially heat capacity, of n-alkanes have rarely been comprehensively investigated in a wide temperature range, which would be insufficient for design and utilization of n-alkanes-based thermal energy storage techniques. In this study, the thermal properties of n-alkanes(C;H;-C;H;), such as thermal stability, thermal conductivity, phase transition temperature and enthalpy were systematically studied by different thermal analysis and calorimetry methods, and compared with previous results. Thermodynamic property of these n-alkanes was studied in a wide temperature range from 1.9 K to 370 K using a combined relaxation(Physical Property Measurement System, PPMS), differential scanning and adiabatic calorimetry method, and the corresponding thermodynamic functions, such as entropy and enthalpy, were calculated based on the heat capacity curve fitting. Most importantly, the heat capacities and related thermodynamic functions of n-heneicosane and n-docosane were reported for the first time in this work, as far as we know. This research work would provide accurate and reliable thermodynamic properties for further study of n-alkanes-based PCMs for thermal energy storage applications.

Elevated carbon dioxide stimulates nitrous oxide emission in agricultural soils: A global meta-analysis

Elevated carbon dioxide (CO_(2))(e CO_(2)) has been shown to affect the nitrous oxide (N_(2)O) emission from terrestrial ecosystems by altering the interaction of plants,soils,and microorganisms.However,the impact of e CO_(2) on the N_(2)O emission from agricultural soils remains poorly understood.This meta-analysis summarizes the effect of e CO_(2) on N_(2)O emission in agricultural ecosystems and soil physiochemical and biological characteristics using 50 publications selected.The e CO_(2) effect values,which equal to the percentage changes of N_(2)O emission under e CO_(2),were calculated based on the natural logarithm of the response ratio to e CO_(2).We found that e CO_(2) significantly increased N_(2)O emission (by 44%),which varied depending on experimental conditions,agricultural practices,and soil properties.In addition,e CO_(2) significantly increased soil water-filled pore space (by 6%),dissolved organic carbon content (by11%),and nitrate nitrogen content (by 13%),but significantly reduced soil p H (by 1%).Moreover,e CO_(2) significantly increased soil microbial biomass carbon(by 28%) and soil microbial biomass nitrogen (by 7%) contents.Additionally,e CO_(2) significantly increased the abundances of ammonia-oxidizing bacteria(AOB) amo A (by 21%),nir K (by 15%),and nir S (by 15%),but did not affect the abundances of ammonia-oxidizing archaea (AOA) amo A and nos Z.Our findings indicate that e CO_(2) substantially stimulates N_(2)O emission in agroecosystems and highlight that optimization of nitrogen management and agronomic options might suppress this stimulation and aid in reducing greenhouse effect.

Applications of low temperature calorimetry in material research

Low temperature calorimetry is an experimental method of heat capacity measurements, and heatcapacity is one of the most important and fundamental thermodynamic properties of substances. Theheat capacity can provide an average evaluation of the thermal property of a sample since it is a bull（property of substances. In the other hand, the condensed states of substances could be mainly controlledby the molecular motions, intermolecular interactions, and interplay among molecular structures. Thephysical property reflected in a material may be closely related to the energy changes in these threefactors, which can be directly observed in a heat capacity curve. Therefore, low temperature calorimetryhas been used not only to obtain heat capacity, entropy, enthalpy and Gibbs free energy, but also toinvestigate and understand lattice vibrations, metals, superconductivity, electronic and nuclearmagnetism, dilute magnetic systems and structural transitions. In this review, we have presented theconcept of low temperature calorimetry and its applications in the related field of material researches,such as nano-materials, magnetic materials, ferroelectric materials, phase change materials and othermaterials.