77 research outputs found

    Sustainable valorization of Biomass into Syngas/H2 via Biocarbon catalyst

    No full text
    Environmental issues stemming from the rapid growth in global energy demand and carbon dioxide emissions require urgent resolutions. Biomass represents a viable alternative for displacing fossil fuels, as its energy can be converted into electricity, heat, fuels, and chemical precursors, thus substituting petrochemicals. It is also the only carbon-containing renewable resource with substantial potential to mitigate environmental degradation, attain carbon-negative emissions, and drive sustainable development. Syngas production from biomass pyrolysis and in-line catalytic upgrading has attracted an increased attention, since it is a promising approach for further generating renewable bio-fuels, bio-chemicals, and bio-materials. Hydrogen isolated from bio-syngas is a clean and promising secondary energy source and carrier, capable of advancing a carbon-free energy system across technological, economic, and societal dimensions.  This dissertation aims to realize a full valorization of biomass into renewable and affordable hydrogen-rich syngas and carbon-based battery anodes (hard carbons) through pyrolysis and in-line catalytic upgrading using biochar as the core of the catalyst strategy. Biochar, a carbon-enriched solid material with a carbon-neutral nature, emerges as a promising catalyst for promoting volatile upgrading owing to its extensively functionalized surface, porous structure, and resistance to coke deactivation. Optimization of the catalyst strategy using biochar-based catalysts in the catalytic upgrading process to enhance syngas quality is critical for scaling up the proposed process. This dissertation first investigated the effect of Ni-based, biochar, cascaded biochar+Ni-based, and engineered biochar catalysts on the catalytic performance in terms of the syngas yield, hydrogen yield, and gas energy conversion efficiency (GECE). Among them, the cascaded biochar+Ni-based catalyst and the Ni-doped biochar (NiBC) catalyst showed the most excellent catalytic performance. Using NiBC as a reforming catalyst introduced 78.2 wt. % of syngas consisting of an H2+CO proportion of 94.6 vol. % while applying cascaded biochar + NiAlO catalyst strategy resulted in 71 wt. % of syngas with a total H2+CO proportion of 89.5 vol. %. However, after a three-time test repetition, the Ni-doped biochar catalyst showed a slightly decreasing catalytic performance. In contrast, the cascaded biochar+NiAlO catalyst showed a stable promoting performance in terms of syngas and H2 yields after 15 feeding cycles. In addition, plastic waste, being a carbonaceous resource, was also applied in the pyrolysis and in-line catalytic upgrading process for hydrogen and high-value-added carbon production by using biochar as a cracking catalyst.  In order to evaluate the techno-economic viability of the proposed process, a novel biorefinery concept was simulated and assessed based on the above results, aiming to produce affordable hydrogen and high-quality hard carbons from biomass and to realize negative carbon emissions. The proposed biorefinery was estimated to produce 75 kg of H2, 169 kg of hard carbon, and 891 kg of captured CO2 (95% purity) per metric ton of biomass while realizing a payback period (PBP) within two years at reference prices of 13.7 €/kg and 5 €/kg for HCs and H2. At the same time, a negative emission of the proposed biorefinery could be achieved with -0.89 kg CO2-eq/kg-biomass based on Sweden’s wind electricity, considering the captured CO2. A pilot-scale system using a continuous pyrolysis reactor was deployed to scale up the capacity of the proposed process. The catalytic performance of biochar was examined in terms of products’ distribution, gas composition and gas properties. Critical parameters, such as the weight hourly space velocity (WHSV), particle size and the morphology of the catalysts, and pressure drop of the catalyst bed, were evaluated. The results showed that a lower WHSV favours a higher syngas yield, a higher H2+CO proportion, and a higher hydrogen yield due to a longer residence time for volatiles-char contacts. Smaller catalyst particle sizes correspond to higher bed pressure drop, which resulted in a higher syngas and hydrogen yield. In addition, biochar particles with larger bulk density and more spherical and rounded shape introduced higher syngas yield, H2 +CO proportion, and H2 yield compared to the particles with elongated and angular shape. The stability of using biochar as a catalyst in a continuous feeding system was also examined and verified in this dissertation, which indicated its great anti-coking performance.Miljöproblem som uppkommer frĂ„n den snabba tillvĂ€xten av den global energiefterfrĂ„gan och koldioxidutslĂ€pp krĂ€ver brĂ„dskande lösningar. Biomassa representerar ett hĂ„llbart alternativ för att ersĂ€tta fossila brĂ€nslen, eftersom dess energi kan omvandlas till elektricitet, vĂ€rme, brĂ€nslen och kemiska prekursorer och dĂ€rigenom ersĂ€tta petrokemikalier. Det Ă€r ocksĂ„ den enda existernade kolbaserade förnybara resursen och som har en betydande potential att mildra miljöförstöring, uppnĂ„ koldioxidnegativa utslĂ€pp och driva hĂ„llbar utveckling. En syngasproduktion frĂ„n en kombinerad pyrolys av biomassa och en katalytisk uppgradering har attraherat ökad uppmĂ€rksamhet, eftersom det Ă€r ett övertygande tillvĂ€gagĂ„ngssĂ€tt för att generera förnybara biodrivmedel, biokemikalier och biomaterial. VĂ€tgas som isolerats frĂ„n bio-syngas utgör en ren och lovande sekundĂ€r energikĂ€lla och bĂ€rare som kan frĂ€mja ett kolfritt energisystem med avseende pĂ„ teknologiska, ekonomiska och samhĂ€lleliga dimensioner. Denna avhandling syftar till att förverkliga en fullstĂ€ndig vĂ€rdering av biomassa till förnybart och prisvĂ€rt vĂ€te-rik syngas och kolbaserade batterianoder (hĂ„rdkol) genom att anvĂ€nda pyrolys i kombnination med en katalytisk uppgradering  dĂ€r biokol anvĂ€nds som kĂ€rnan i katalysstrategin. Biokol, som Ă€r ett kolberikat fast material med en koldioxidneutral natur, framstĂ„r som en lovande katalysator för att frĂ€mja en uppgradering av flyktiga komponenter pĂ„ grund av dess omfattande funktionaliserade yta, porösa struktur och motstĂ„ndskraft mot kokning. En optimering av katalysatorstrategin med biokolbaserade katalysatorer i den katalytiska uppgraderingsprocessen för att förbĂ€ttra syngaskvaliteten Ă€r avgörande och grundlĂ€ggande för att skala upp den föreslagna processen. Denna avhandling undersökte först effekten av anvĂ€ndandet av Ni-baserade, biokol, kaskad biokol+Ni-baserad och ingenjörskonstruerade biokolkatalysatorer pĂ„ den katalytiska prestandan med avseende pĂ„ syngasutbyte, vĂ€teutbyte och effektivitet för gasenergikonvertering (GECE). Bland dessa sĂ„ var prestandan med anvĂ€ndande av kaskad biokol+Ni-baserad och Ni-tillsatt biokolkatalysatorer de bĂ€sta. AnvĂ€ndning av NiBC som en reformeringskatalysator introducerade 78,2 viktprocent av syngas bestĂ„ende av en H2+CO-andel pĂ„ 94,6 volymprocent, medan tillĂ€mpning av kaskadbiokol + NiAlO katalysatorstrategi resulterade i 71 viktprocent av syngas med en total H2+CO-andel pĂ„ 89,5 volymprocent. Dock visade försöken med en Ni-tillsatt biokolkatalysator en nĂ„got minskad katalytisk prestanda efter tre upprepningar, medan försöken med en kaskad biokol+NiAlO-katalysatorn visade en stabil prestanda med avseende pĂ„ syngas- och H2-utbyten efter anvĂ€nding under 15 cykler. Försök med plastavfall, som Ă€r en kolbaserad resurs, gjordes ocksĂ„ med den kombinerade pyrolysen följt av en katalytisk uppgraderingsprocess för produktion av vĂ€te och vĂ€rdefulla kolprodukter med hjĂ€lp av biokol som kracknings katalysator. Dessutom sĂ„ utvĂ€rderades genomförbarheten av den föreslagna processen genom framtagande och simuleringar av ett ny bioraffinaderikoncept baserad pĂ„ ovanstĂ„ende resultat, med mĂ„let att producera vĂ€te och högkvalitativa hĂ„rda kol till pĂ„ ett ekonomiskt gĂ„ngbart sĂ€tt frĂ„n biomassaavfall under en samtida generering av negativa koldioxidutslĂ€pp. Den föreslagna bioraffinaderikonceptet berĂ€knades producera 75 kg H2, 169 kg HCs och 891 kg CO2 (95% renhet) per metrisk ton biomassaavfall. Dessutom sĂ„ berĂ€knades Ă„terbetalningstiden (PBP) till upp till tvĂ„ Ă„r vid referenspriser pĂ„ 13,7 €/kg och 5 €/kg för HCs och H2. Samtidigt uppnĂ„ddes en negativ emission för den föreslagna bioraffinaderikonceptet motsvarande -0,89 CO2-ekv/kg biomassa baserat pĂ„ svensk vindkraftsel, med hĂ€nsyn till koldioxidinfĂ„ngning. Slutligen implementerades ett pilotskaligt system med en kontinuerlig pyrolys reaktor för att skala upp kapaciteten hos den föreslagna processen. Den katalytiska prestandan undersöktes i termer av produktfördelning, gassammansĂ€ttning och gasegenskaper. Följande kritiska parametrar utvĂ€rderades: viktig per timme rymdhastighet (WHSV), partikelstorlek och katalysatorernas morfologi, tryckfall i katalysatorbĂ€dden. Resultaten visade att ett lĂ€gre WHSV vĂ€rde gynnar ett högre syngasutbyte, en högre H2+CO-andel och ett högre vĂ€tgasutbyte pĂ„ grund av en lĂ€ngre uppehĂ„llstid för kontakter mellan flyktiga Ă€mnen och kol. Mindre katalysatorpartikelstorlekar innebĂ€r högre tryckfall i bĂ€dden, vilket resulterade i högre syngas- och vĂ€teutbyten. Dessutom introducerade biokolpartiklar med högre bulkdensitet och mer sfĂ€risk och rundad form ett högre syngasutbyte, H2+CO-andel och vĂ€tgasutbyte, jĂ€mfört med partiklar med en osfĂ€rsik formjĂ€mfört med partiklarna med lĂ„ngstrĂ€ckt och kantig form. Stabiliteten vid anvĂ€ndning av biokol som katalysator i ett kontinuerligt matningssystem undersöktes ocksĂ„ och verifierades i denna avhandling, dess utmĂ€rkta anti-koksningsprestanda. Nyckelord:  Pyrolys, Katalytisk uppgradering, Biomassa, Biokol, Syngas, VĂ€tgas

    Sustainable valorization of Biomass into Syngas/H2 via Biocarbon catalyst

    No full text
    Environmental issues stemming from the rapid growth in global energy demand and carbon dioxide emissions require urgent resolutions. Biomass represents a viable alternative for displacing fossil fuels, as its energy can be converted into electricity, heat, fuels, and chemical precursors, thus substituting petrochemicals. It is also the only carbon-containing renewable resource with substantial potential to mitigate environmental degradation, attain carbon-negative emissions, and drive sustainable development. Syngas production from biomass pyrolysis and in-line catalytic upgrading has attracted an increased attention, since it is a promising approach for further generating renewable bio-fuels, bio-chemicals, and bio-materials. Hydrogen isolated from bio-syngas is a clean and promising secondary energy source and carrier, capable of advancing a carbon-free energy system across technological, economic, and societal dimensions.  This dissertation aims to realize a full valorization of biomass into renewable and affordable hydrogen-rich syngas and carbon-based battery anodes (hard carbons) through pyrolysis and in-line catalytic upgrading using biochar as the core of the catalyst strategy. Biochar, a carbon-enriched solid material with a carbon-neutral nature, emerges as a promising catalyst for promoting volatile upgrading owing to its extensively functionalized surface, porous structure, and resistance to coke deactivation. Optimization of the catalyst strategy using biochar-based catalysts in the catalytic upgrading process to enhance syngas quality is critical for scaling up the proposed process. This dissertation first investigated the effect of Ni-based, biochar, cascaded biochar+Ni-based, and engineered biochar catalysts on the catalytic performance in terms of the syngas yield, hydrogen yield, and gas energy conversion efficiency (GECE). Among them, the cascaded biochar+Ni-based catalyst and the Ni-doped biochar (NiBC) catalyst showed the most excellent catalytic performance. Using NiBC as a reforming catalyst introduced 78.2 wt. % of syngas consisting of an H2+CO proportion of 94.6 vol. % while applying cascaded biochar + NiAlO catalyst strategy resulted in 71 wt. % of syngas with a total H2+CO proportion of 89.5 vol. %. However, after a three-time test repetition, the Ni-doped biochar catalyst showed a slightly decreasing catalytic performance. In contrast, the cascaded biochar+NiAlO catalyst showed a stable promoting performance in terms of syngas and H2 yields after 15 feeding cycles. In addition, plastic waste, being a carbonaceous resource, was also applied in the pyrolysis and in-line catalytic upgrading process for hydrogen and high-value-added carbon production by using biochar as a cracking catalyst.  In order to evaluate the techno-economic viability of the proposed process, a novel biorefinery concept was simulated and assessed based on the above results, aiming to produce affordable hydrogen and high-quality hard carbons from biomass and to realize negative carbon emissions. The proposed biorefinery was estimated to produce 75 kg of H2, 169 kg of hard carbon, and 891 kg of captured CO2 (95% purity) per metric ton of biomass while realizing a payback period (PBP) within two years at reference prices of 13.7 €/kg and 5 €/kg for HCs and H2. At the same time, a negative emission of the proposed biorefinery could be achieved with -0.89 kg CO2-eq/kg-biomass based on Sweden’s wind electricity, considering the captured CO2. A pilot-scale system using a continuous pyrolysis reactor was deployed to scale up the capacity of the proposed process. The catalytic performance of biochar was examined in terms of products’ distribution, gas composition and gas properties. Critical parameters, such as the weight hourly space velocity (WHSV), particle size and the morphology of the catalysts, and pressure drop of the catalyst bed, were evaluated. The results showed that a lower WHSV favours a higher syngas yield, a higher H2+CO proportion, and a higher hydrogen yield due to a longer residence time for volatiles-char contacts. Smaller catalyst particle sizes correspond to higher bed pressure drop, which resulted in a higher syngas and hydrogen yield. In addition, biochar particles with larger bulk density and more spherical and rounded shape introduced higher syngas yield, H2 +CO proportion, and H2 yield compared to the particles with elongated and angular shape. The stability of using biochar as a catalyst in a continuous feeding system was also examined and verified in this dissertation, which indicated its great anti-coking performance.Miljöproblem som uppkommer frĂ„n den snabba tillvĂ€xten av den global energiefterfrĂ„gan och koldioxidutslĂ€pp krĂ€ver brĂ„dskande lösningar. Biomassa representerar ett hĂ„llbart alternativ för att ersĂ€tta fossila brĂ€nslen, eftersom dess energi kan omvandlas till elektricitet, vĂ€rme, brĂ€nslen och kemiska prekursorer och dĂ€rigenom ersĂ€tta petrokemikalier. Det Ă€r ocksĂ„ den enda existernade kolbaserade förnybara resursen och som har en betydande potential att mildra miljöförstöring, uppnĂ„ koldioxidnegativa utslĂ€pp och driva hĂ„llbar utveckling. En syngasproduktion frĂ„n en kombinerad pyrolys av biomassa och en katalytisk uppgradering har attraherat ökad uppmĂ€rksamhet, eftersom det Ă€r ett övertygande tillvĂ€gagĂ„ngssĂ€tt för att generera förnybara biodrivmedel, biokemikalier och biomaterial. VĂ€tgas som isolerats frĂ„n bio-syngas utgör en ren och lovande sekundĂ€r energikĂ€lla och bĂ€rare som kan frĂ€mja ett kolfritt energisystem med avseende pĂ„ teknologiska, ekonomiska och samhĂ€lleliga dimensioner. Denna avhandling syftar till att förverkliga en fullstĂ€ndig vĂ€rdering av biomassa till förnybart och prisvĂ€rt vĂ€te-rik syngas och kolbaserade batterianoder (hĂ„rdkol) genom att anvĂ€nda pyrolys i kombnination med en katalytisk uppgradering  dĂ€r biokol anvĂ€nds som kĂ€rnan i katalysstrategin. Biokol, som Ă€r ett kolberikat fast material med en koldioxidneutral natur, framstĂ„r som en lovande katalysator för att frĂ€mja en uppgradering av flyktiga komponenter pĂ„ grund av dess omfattande funktionaliserade yta, porösa struktur och motstĂ„ndskraft mot kokning. En optimering av katalysatorstrategin med biokolbaserade katalysatorer i den katalytiska uppgraderingsprocessen för att förbĂ€ttra syngaskvaliteten Ă€r avgörande och grundlĂ€ggande för att skala upp den föreslagna processen. Denna avhandling undersökte först effekten av anvĂ€ndandet av Ni-baserade, biokol, kaskad biokol+Ni-baserad och ingenjörskonstruerade biokolkatalysatorer pĂ„ den katalytiska prestandan med avseende pĂ„ syngasutbyte, vĂ€teutbyte och effektivitet för gasenergikonvertering (GECE). Bland dessa sĂ„ var prestandan med anvĂ€ndande av kaskad biokol+Ni-baserad och Ni-tillsatt biokolkatalysatorer de bĂ€sta. AnvĂ€ndning av NiBC som en reformeringskatalysator introducerade 78,2 viktprocent av syngas bestĂ„ende av en H2+CO-andel pĂ„ 94,6 volymprocent, medan tillĂ€mpning av kaskadbiokol + NiAlO katalysatorstrategi resulterade i 71 viktprocent av syngas med en total H2+CO-andel pĂ„ 89,5 volymprocent. Dock visade försöken med en Ni-tillsatt biokolkatalysator en nĂ„got minskad katalytisk prestanda efter tre upprepningar, medan försöken med en kaskad biokol+NiAlO-katalysatorn visade en stabil prestanda med avseende pĂ„ syngas- och H2-utbyten efter anvĂ€nding under 15 cykler. Försök med plastavfall, som Ă€r en kolbaserad resurs, gjordes ocksĂ„ med den kombinerade pyrolysen följt av en katalytisk uppgraderingsprocess för produktion av vĂ€te och vĂ€rdefulla kolprodukter med hjĂ€lp av biokol som kracknings katalysator. Dessutom sĂ„ utvĂ€rderades genomförbarheten av den föreslagna processen genom framtagande och simuleringar av ett ny bioraffinaderikoncept baserad pĂ„ ovanstĂ„ende resultat, med mĂ„let att producera vĂ€te och högkvalitativa hĂ„rda kol till pĂ„ ett ekonomiskt gĂ„ngbart sĂ€tt frĂ„n biomassaavfall under en samtida generering av negativa koldioxidutslĂ€pp. Den föreslagna bioraffinaderikonceptet berĂ€knades producera 75 kg H2, 169 kg HCs och 891 kg CO2 (95% renhet) per metrisk ton biomassaavfall. Dessutom sĂ„ berĂ€knades Ă„terbetalningstiden (PBP) till upp till tvĂ„ Ă„r vid referenspriser pĂ„ 13,7 €/kg och 5 €/kg för HCs och H2. Samtidigt uppnĂ„ddes en negativ emission för den föreslagna bioraffinaderikonceptet motsvarande -0,89 CO2-ekv/kg biomassa baserat pĂ„ svensk vindkraftsel, med hĂ€nsyn till koldioxidinfĂ„ngning. Slutligen implementerades ett pilotskaligt system med en kontinuerlig pyrolys reaktor för att skala upp kapaciteten hos den föreslagna processen. Den katalytiska prestandan undersöktes i termer av produktfördelning, gassammansĂ€ttning och gasegenskaper. Följande kritiska parametrar utvĂ€rderades: viktig per timme rymdhastighet (WHSV), partikelstorlek och katalysatorernas morfologi, tryckfall i katalysatorbĂ€dden. Resultaten visade att ett lĂ€gre WHSV vĂ€rde gynnar ett högre syngasutbyte, en högre H2+CO-andel och ett högre vĂ€tgasutbyte pĂ„ grund av en lĂ€ngre uppehĂ„llstid för kontakter mellan flyktiga Ă€mnen och kol. Mindre katalysatorpartikelstorlekar innebĂ€r högre tryckfall i bĂ€dden, vilket resulterade i högre syngas- och vĂ€teutbyten. Dessutom introducerade biokolpartiklar med högre bulkdensitet och mer sfĂ€risk och rundad form ett högre syngasutbyte, H2+CO-andel och vĂ€tgasutbyte, jĂ€mfört med partiklar med en osfĂ€rsik formjĂ€mfört med partiklarna med lĂ„ngstrĂ€ckt och kantig form. Stabiliteten vid anvĂ€ndning av biokol som katalysator i ett kontinuerligt matningssystem undersöktes ocksĂ„ och verifierades i denna avhandling, dess utmĂ€rkta anti-koksningsprestanda. Nyckelord:  Pyrolys, Katalytisk uppgradering, Biomassa, Biokol, Syngas, VĂ€tgas

    Characteristics of intestinal microbiota in preterm infants and the effects of probiotic supplementation on the microbiota

    No full text
    ObjectiveIn this study, we investigated the characteristics of the intestinal microbiota of preterm infants, and then analyzed the effects of probiotics supplementation on intestinal microbiota in preterm infants.MethodsThis study enrolled 64 infants born between 26 and 32 weeks gestational age (GA) and 22 full-term infants. 34 premature infants received oral probiotic supplementation for 28 days. Stool samples were obtained on the first day (D1) and the 28th day (D28) after birth for each infant. Total bacterial DNA was extracted and sequenced using the Illumina MiSeq Sequencing System, specifically targeting the V3-V4 hyper-variable regions of the 16S rDNA gene. The sequencing results were then used to compare and analyze the composition and diversity index of the intestinal microbiota.ResultsThere was no significant difference in meconium bacterial colonization rate between premature and full-term infants after birth (p > 0.05). At D1, the relative abundance of Bifidobacterium, Bacteroides, and Lactobacillus in the stool of preterm infants was lower than that of full-term infants, and the relative abundance of Acinetobacter was higher than that of full-term infants. The Shannon index and Chao1 index of intestinal microbiota in preterm infants are lower than those in full-term infants (p < 0.05). Supplementation of probiotics can increase the relative abundance of Enterococcus and Enterobacter, and reduce the relative abundance of Escherichia and Clostridium in premature infants. The Chao1 index of intestinal microbiota decreased in preterm infants after probiotic supplementation (p < 0.05).ConclusionThe characteristics of intestinal microbiota in preterm infants differ from those in full-term infants. Probiotic supplementation can reduce the relative abundance of potential pathogenic bacteria and increase the abundance of beneficial microbiota in premature infants

    Characteristics of micro scale nonlinear filtration

    No full text
    Take the flow characteristics of fluid in micro tube as the object, the characteristics of nonlinear filtration in low permeability reservoirs were studied using micro scale method by simulating the micro pore throat of reservoir with the micro tube which has the similar scale pore throat of low permeability reservoirs. The flow characteristics of de-ionized water flowing through fused silica capillary tubes with radius of 10.0 ÎŒm, 7.5 ÎŒm, 5.0 ÎŒm and 2.5 ÎŒm were investigated in experiments. Relationship between average flow rate and pressure gradient, effect of pressure gradient on fluid boundary layer, and relationships between flow resistance coefficient and Reynolds number were analyzed respectively in these experiments with different micro tubes. The flow of fluid through micro tubes with low velocity has nonlinearity, and the extent of nonlinearity increases with the tube radius decreasing. Nonlinear flow experimental points can be matched by quadratic curve. In micro flow, the percentage of effective fluid boundary layer thickness to micro tube radius decreases with the pressure gradient increasing. Research results indicated that Reynolds number can be used as the criteria of nonlinear flow. Flows with Reynolds number less than 10−3 have nonlinear features. Key words: low permeability reservoir, micro scale, nonlinear flow, boundary fluid laye

    Optimal cultivation of simultaneous ammonium and phosphorus removal aerobic granular sludge in A/O/A sequencing batch reactor and the assessment of functional organisms

    No full text
    <div><p>In this study, sequencing batch reactor (SBR) with an anaerobic/aerobic/anoxic operating mode was used to culture granular sludge. Optimal adjustment of cycle duration was achieved by the direction of pH, oxidation reduction potential and dissolved oxygen parameters. The results showed that the treating efficiency was significantly improved as the cycle was shortened from 450 to 360 min and further to 200 min. Nitrogen and phosphorus removal were nearly quantitative after 50 days operation and maintained stable to the end of the study period. The typical cycle tests revealed that simultaneous denitrification and phosphorus removal occurred when aerobic granules were gradually formed. The nitrite effect tests showed that less than 4.8 mg N/L of the nitrite could enhance superficial specific aerobic phosphate uptake rate (SAPUR) under aerobic condition, indicating that the traditional method to evaluate the capability of total phosphate-accumulating organisms (PAOs) was inaccurate. Additionally, a high level of nitrite was detrimental to PAOs. A novel method was developed to determine the activity of each kind of PAOs and other denitrifying organisms. The results showed that (1) nitrate, besides nitrite, could also enhance SAPUR and (2) aerobic granular sludge could perform denitrification even when phosphate was not supplied under anoxic condition, suggesting that other denitrifying organisms besides denitrifying phosphate-accumulating organisms also contributed to denitrification.</p></div

    Ni-Catalyzed Dimerization and Arylation of Diarylacetylenes with Arylboronic Acids

    No full text
    A new, facile, and efficient protocol for the synthesis of polysubstituted conjugated 1,3-dienes through Ni-catalyzed tandem dimerization/cross-coupling reaction of diarylacetylenes and arylboronic acids in the presence of a catalytic amount of B<sub>2</sub>pin<sub>2</sub> has been developed. A series of arynes and arylboronic acids with different substituents participated well in this catalytic system, affording a variety of useful conjugated 1,3-dienes

    Hydrophilic and Compressible Aerogel: A Novel Draw Agent in Forward Osmosis

    No full text
    Forward osmosis (FO) technology is an efficient route to obtain purity water for drinking from wastewater or seawater. However, there are some challenges in draw solution to limit its application. We first introduce a novel sodium alginate–graphene oxide (SA-GO) aerogel as draw agent for highly efficient FO process. The GO nanosheets covalently cross-linked to SA matrix to form a three-dimensional and highly porous aerogel to provide excellent water flux and operation stability, together with the property of compressibility served by SA-GO aerogel resulting in easy water production and regeneration process. When deionized water was used as the feed solution, the SA-GO aerogel exhibited a higher water flux (15.25 ± 0.65 L m<sup>–2</sup> h<sup>–1</sup>, abbreviated as LMH) than that of 1 mol L<sup>–1</sup> NaCl (1 M), and there was no nonreverse osmosis phenomenon. The water fluxes were stabilized in the range of 5–6.5 LMH during recycle process of absorbing and releasing water as high as 100 times. It also had a great desalination capacity (water flux was 7.49 ± 0.61 LMH) with the seawater (Huanghai coast) as the feed solution. Moreover, the water production and regeneration process of the SA-GO aerogel can be rapidly and cost-effectively accomplished with low-strength mechanical compression (merely 1 kPa). The results present that the SA-GO aerogels as a promising, innovative draw agent can make the FO process simpler, more efficient, and lower energy consumption. It can be a potential material for hydration bags to fast and repeatable product fresh water from saline water or wastewater

    Hydrophilic and Compressible Aerogel: A Novel Draw Agent in Forward Osmosis

    No full text
    Forward osmosis (FO) technology is an efficient route to obtain purity water for drinking from wastewater or seawater. However, there are some challenges in draw solution to limit its application. We first introduce a novel sodium alginate–graphene oxide (SA-GO) aerogel as draw agent for highly efficient FO process. The GO nanosheets covalently cross-linked to SA matrix to form a three-dimensional and highly porous aerogel to provide excellent water flux and operation stability, together with the property of compressibility served by SA-GO aerogel resulting in easy water production and regeneration process. When deionized water was used as the feed solution, the SA-GO aerogel exhibited a higher water flux (15.25 ± 0.65 L m<sup>–2</sup> h<sup>–1</sup>, abbreviated as LMH) than that of 1 mol L<sup>–1</sup> NaCl (1 M), and there was no nonreverse osmosis phenomenon. The water fluxes were stabilized in the range of 5–6.5 LMH during recycle process of absorbing and releasing water as high as 100 times. It also had a great desalination capacity (water flux was 7.49 ± 0.61 LMH) with the seawater (Huanghai coast) as the feed solution. Moreover, the water production and regeneration process of the SA-GO aerogel can be rapidly and cost-effectively accomplished with low-strength mechanical compression (merely 1 kPa). The results present that the SA-GO aerogels as a promising, innovative draw agent can make the FO process simpler, more efficient, and lower energy consumption. It can be a potential material for hydration bags to fast and repeatable product fresh water from saline water or wastewater
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