Research on Measurement and Calculation of Carbon Emission from the Production of Prefabricated Building Components

The measurement and calculation of the carbon emission from the production of prefabricated building components were studied.Based on the carbon emission factor method,a carbon emission calculation model of the components in the production phase was established.Besides,the actual measurement method and calculated at rated power method were proposed for the measurement and calculation of carbon emission,and several measurements were carried out in a component factory located in a coastal area of south China and a component factory located in Beijing,respectively.The results of the study show that the carbon emission factors of laminates and wallboards produced by factories located in coastal areas of southern China under natural curing conditions were 7.61 kg CO2/m3 and 5.84 kg CO2/m3 respectively.The carbon emissions conversion coefficients of concrete mixer,reinforcing bar production line and travelling crane between actual operation and with per the rated power were approximately 0.44,0.34 and 0.34 respectively.When the actual measurement cannot be performed,the conversion coefficient can be used to correct the data of the calculated at rated power to make it closer to the true value.The carbon emission factor of the laminated panels produced by the component factory in Beijing under steam curing concrete conditions was 132.15 kg CO2/m3,and the factory is used as a prototype,a complementary steam generation system model of solar energy and boiler was established,and it was calculated that the system can reduce CO2 emissions by about 300 tons throughout the year.

Nano-CaO_(2)Promotes the Release of Carbon Sources from Municipal Sludge and the Preparation of Double-Network Hydrogels with High Swelling Ratios

In this study,hydrogels were prepared from municipal sludge to recycle and realize the value-added utilization of the carbon components in this abundant waste material.The carbon sources were extracted from the municipal sludge using synthesised nano CaO_(2)as an oxidant,and the carbon sources were graft copolymerised with acrylic acid monomer using N,N′-methylenebisacrylamide as a crosslinking agent and ammonium persulfate as an initiator.The factors influencing the hydrogel preparation were investigated by single-factor experiments.Based on the results of the single-factor experiments,a hydrogel with a swelling ratio of up to 19768.4%at 12 h was prepared with an oxidant dosage of 0.20 g,a monomer dosage of 5.8 g,a neutralisation degree of the monomer of 70%,an initiator dosage of 0.15 g,and a crosslinking agent dosage of 0.15 g.The hydrogel preparation conditions were optimized using the response surface method,and the interactions between the different reaction conditions were analysed to obtain the best preparation conditions.X-ray diffraction results showed that hydrogels were amorphous in structure.Scanning electron microscopy images showed that the SiO_(2)particles from the sludge acted as crosslinking points between different layers of hydrogel chains.The crosslinking polymerisation and crosslinking agent worked together to form hydrogels with an inorganic-organic double network structure,and this structure was highly stretchable,resulting in hydrogels with good swelling properties.

Multiscale analysis of fine slag from pulverized coal gasification in entrained-flow bed

Fine slag(FS)is an unavoidable by-product of coal gasification.FS,which is a simple heap of solid waste left in the open air,easily causes environmental pollution and has a low resource utilization rate,thereby restricting the development of energy-saving coal gasification technologies.The multiscale analysis of FS performed in this study indicates typical grain size distribution,composition,crystalline structure,and chemical bonding characteristics.The FS primarily contained inorganic and carbon components(dry bases)and exhibited a"three-peak distribution"of the grain size and regular spheroidal as well as irregular shapes.The irregular particles were mainly adsorbed onto the structure and had a dense distribution and multiple pores and folds.The carbon constituents were primarily amorphous in structure,with a certain degree of order and active sites.C 1s XPS spectrum indicated the presence of C–C and C–H bonds and numerous aromatic structures.The inorganic components,constituting 90%of the total sample,were primarily silicon,aluminum,iron,and calcium.The inorganic components contained Si–O-Si,Si–O–Al,Si–O,SO_(4)^(2−),and Fe–O bonds.Fe 2p XPS spectrum could be deconvoluted into Fe 2p_(1/2) and Fe 2p_(3/2) peaks and satellite peaks,while Fe existed mainly in the form of Fe(III).The findings of this study will be beneficial in resource utilization and formation mechanism of fine slag in future.

Five-year warming does not change soil organic carbon stock but alters its chemical composition in an alpine peatland

Climate warming may promote soil organic carbon(SOC)decomposition and alter SOC stocks in terrestrial ecosystems,which would in turn affect climate warming.We manipulated a warming experiment using open-top chambers to investigate the effect of warming on SOC stock and chemical composition in an alpine peatland in Zoigêon the eastern Tibetan Plateau,China.Results showed that 5 years of warming soil temperatures enhanced ecosystem respiration during the growing season,promoted above-and belowground plant biomass,but did not alter the SOC stock.However,labile O-alkyl C and relatively recalcitrant aromatic C contents decreased,and alkyl C content increased.Warming also increased the amount of SOC stored in the silt-clay fraction(<0.053 mm),but this was offset by warming-induced decreases in the SOC stored within micro-and macroaggregates(0.053–0.25 and>0.25 mm,respectively).These changes in labile and recalcitrant C were largely associated with warming-induced increases in soil microbial biomass C,fungal diversity,enzyme activity,and functional gene abundance related to the decomposition of labile and recalcitrant C compounds.The warming-induced accumulation of SOC stored in the silt-clay fraction could increase SOC persistence in alpine peatland ecosystems.Our findings suggest that mechanisms mediated by soil microbes account for the changes in SOC chemical composition and SOC in different aggregate size fractions,which is of great significance when evaluating SOC stability under climate warming conditions.

Geochronological and geochemical constraints on the petrogenesis and geodynamic process of Hemler,Vlinder,and Il'ichev seamount lavas in NW Pacific

Oceanic intraplate volcanoes with linear age progressions are usually accepted to be derived from melting of an upwelling mantle plume.Several seamount groups in NW Pacific,however,show complex age-distance relationships that are difficult to explain using the classic“mantle plume hypothesis”,and thus their origins are controversial.In this study,we present ^(40)Ar-^(39)Ar age,geochemical,and Sr-Nd-Pb-Hf isotopic data of lavas from Hemler,Vlinder,and Il’ichev seamounts in NW Pacific,to elucidate their petrogenesis and geodynamic process.The lavas from Hemler,Vlinder,and Il’ichev seamounts are classified as alkali basalt,basanite/nephelinite,and trachyte.Lavas with Mg O>8 wt.%exhibit high contents of CaO,FeO^(T),and TiO_(2),similar to the composition of melts formed from reaction between carbonated eclogite-derived melts and fertile peridotite.These lavas have elevated Zr/Hf ratios(40.6-45.2)and negative Zr and Hf anomalies,indicating the presence of a carbonate component in the mantle source.They are enriched in incompatible trace elements and have enriched mantle 1(EM1)-like SrNd-Pb-Hf isotopic compositions.The isotopic compositions of Vlinder,Il’ichev basanite,and Hemler lavas in this study are similar to the Rarotonga hotspot.Although occurring at the same seamount,the Il’ichev alkali basalts display more depleted SrNd-Hf isotopic compositions compared to Il’ichev basanite.According to plate tectonic reconstruction results,the ages of Hemler(100.1 Ma),Vlinder pre-(100.2 Ma)and post-shield(87.5 Ma),and Il’ichev(56.4 Ma)lavas clearly deviate from the Macdonald,Arago,Rarotonga,and Samoa hotspot tracks,indicating that they cannot directly originate from mantle plumes.We propose that in the mid-Cretaceous,when the Pacific plate passed over Rarotonga hotspot,melting of Rarotonga plume formed the Vlinder(main-shield stage),Pako,and Ioah seamounts.The Rarotonga(and possibly Samoa)plume materials would have been dispersed into the surrounding asthenosphere by mantle convection.These diffuse plume materials would undergo decompression melting beneath lithosphere fractures that are widely distributed in the Magellan area,generating non-hotspot related Hemler and pre-and post-shield Vlinder lavas.The Il’ichev alkali basalts and basanite probably result from lithospheric fracture-induced melting of heterogeneous enriched components randomly distributed in the asthenosphere.

Biochar application significantly increases soil organic carbon under conservation tillage:an 11-year field experiment

Biochar application and conservation tillage are significant for long-term organic carbon(OC)sequestration in soil and enhancing crop yields,however,their effects on native soil organic carbon(native SOC)without biochar carbon sequestration in situ remain largely unknown.Here,an 11-year field experiment was carried out to examine different biochar application rates(0,30,60,and 90 Mg ha^(−1))on native SOC pools(native labile SOC pool I and II,and native recalcitrant SOC)and microbial activities in calcareous soil across an entire winter wheat-maize rotation.The proportions of C_(3) and C_(4)-derived native SOC mineralization were quantified using soil basal respiration(SBR)combined with 13C natural isotope abundance measurements.The results showed that 39-51%of the biochar remained in the top 30 cm after 11 years.Biochar application rates significantly increased native SOC and native recalcitrant SOC contents but decreased the proportion of native labile SOC[native labile SOC pool I and II,dissolved organic carbon(DOC),and microbial biomass carbon(MBC)].Biochar application tended to increase the indicators of microbial activities associated with SOC degradation,such as SBR,fluorescein diacetate hydrolysis activity,and metabolic quotient(qCO_(2)).Meanwhile,higher biochar application rates(B60 and B90)significantly increased the C_(4)-derived CO_(2) proportion of the SBR and enhanced C_(4)-derived native SOC mineralization.The effect of the biochar application rate on the content and proportion of native SOC fractions occurred in the 0-15 cm layer,however,there were no significant differences at 15-30 cm.Soil depth also significantly increased native labile SOC pool Ⅰ and Ⅱ contents and decreased qCO_(2).In conclusion,the biochar application rate significantly increased native SOC accumulation in calcareous soil by enhancing the proportion of native recalcitrant SOC,and biochar application and soil depth collectively influenced the seasonal turnover of native SOC fractions,which has important implications for long-term agricultural soil organic carbon sequestration.

Effects of organic fertilizers on organic carbon accumulation in alkalized saline soil and silage maize yield

To understand the combined effect of organic and chemical fertilizers on soil carbon emissions and carbon balance of a farmland ecosystem,this study investigated the organic fertilizer nitrogen replacing different proportions of chemical fertilizer nitrogen.The results showed that,compared to F_(100),the O_(15)F_(85) treatment increased the yield and net ecosystem productivity carbon sequestration of silage maize under mild,moderate,and severe salinization levels,as well as the contents of soil organic carbon,microbial carbon,and humin carbon,while reducing plant carbon emissions.The O_(15)F_(85) treatment did not significantly increase soil carbon emissions(CEC),but O_(30)F_(70),O_(45)F_(55) and O_(100) treatments significantly increased CEC.The soil carbon balance analysis showed that the farmland ecosystem was a“sink”for atmospheric CO_(2) under each treatment.The O_(15)F_(85) treatment produced an“excitation effect”to enhance the carbon sink effect of silage maize farmland under mild,moderate and severe salinization levels while maintaining stable production and emissions.Although the O_(100) treatment increased the carbon sink of farmland under different salinization levels,the yield was significantly reduced and did not represent practical production levels.Correlation analysis showed that soil organic carbon components and ecosystem carbon balance were closely related to soil total salt,pH and bulk density,while soil dissolved organic carbon,humus carbon components and carbon emissions were closely related to soil moisture and temperature.Therefore,the purpose of improving the carbon sink of saline-alkali land can be achieved through soil salt inhibition,soil structure remodeling and water supplement and warming regulation,which provides technical and theoretical support for reducing carbon emissions,achieving carbon neutrality and alleviating global warming.