Breakthrough of Carbon-Ash Recalcitrance in Hydrochar via Molten Carbonate:Engineering Mineral-Rich Biowaste Toward Sustainable Platform Carbon Materials

The function-led design of porous hydrochar from mineral-rich biowaste for environmental applications inevitably suffers from carbon-ash recalcitrance.However,a method to alter the original carbon skeleton with ash remains elusive and hinders the availability of hydrochar.Herein,we propose a facile strategy for breaking the rigid structure of carbon-ash coupled hydrochar using phase-tunable molten carbonates.A case system was designed in which livestock manure and NaHCO3 were used to prepare the activated hydrochar,and NH3 served as the target contaminant.Due to the redox effect,we found that organic fractions significantly advanced the melting temperature of Na2CO3 below 800℃.The Na species steadily broke the carbon-ash interaction as the thermal intensity increased and transformed inorganic constituents to facilitate ash dissolution,rebuilding the hydrochar skeleton with abundant hierarchical channels and active defect edges.The surface polarity and mesopore distribution collectively governed the five cycles NH3 adsorption attenuation process.Manure hydrochar delivered favorable potential for application with a maximum overall adsorption capacity of 100.49 mg·g^(-1).Integrated spectroscopic characterization and theoretical computations revealed that incorporating NH3 on the carbon surface could transfer electrons to chemisorbed oxygen,which promoted the oxidation of pyridine-N during adsorption.This work offers deep insight into the structure function correlation of hydrochar and inspires a more rational design of engineered hydrochar from high-ash biowaste.

The Role of Biochar to Enhance Anaerobic Digestion: A Review

Biochar,one of the products of thermochemical conversion of biomass,possesses specific physiochemical properties such as conductivity,pore adsorption,surface functional groups,and cation exchange capacity.Anaerobic digestion(AD)as a classical bio-wastes conversion technology,suffers from inhibitions,process instability,and methanogenic inefficiency which limit its efficiency.With the advantages of pH buffering,functional microbes enrichment,inhibitors alleviating,and direct interspecies electron transfer(DIET)accelerating,biochar suggests a promising application as additives for AD.Herein,this paper reviewed the noting physicochemical properties of biochar,and discussed its roles and related mechanisms in AD.Further,this paper highlighted the advantages and drawbacks,and pointed out the corresponding challenges and prospects for future research and application of biochar amending AD.

Discovery and development of tricyclic matrinic derivatives as anti-diabetic candidates by AMPKαactivation

We found compound 12N-p-trifluoromethylbenzenesulfonyl matrinane(1)was a potent anti-diabetic agent.Thirty-five tricyclic matrinic derivatives were synthesized and determined for their stimulatory effects on glucose consumption in L6 myotubes,taking 1 as the lead.In high-fat diet(HFD)and STZ induced diabetic mice,9a significantly lowers blood glucose,improves glucose tolerance,and especially alleviates diabetic nephropathy and islet damage.Mechanism study indicates that 9a simultaneously targets mitochondrial complex I to increase AMP/ATP ratio,as well as liver kinase B1(LKB1)and calcium/calmodulindependent protein kinase(Ca MKK),which synergistically activates AMPKαand then stimulates glucose transporter 4(GLUT4)membrane translocation and 2-deoxyglucose(2-DG)uptake to exert anti-diabetic efficacy.Therefore,compound 9a with a novel structure is a promising anti-diabetic candidate with the advantage of multiple-target mechanism,worthy of further investigation.

北冰洋海洋酸化和碳循环的研究进展

海洋响应大气CO_2升高,引起海水pH和碳酸钙饱和度下降,这一过程称为海洋酸化.海洋酸化可能会对海洋生物和生态系统造成严重危害.在过去的20年中,全球气候变化引起北冰洋发生一系列快速变化,包括:海表温度上升、海冰快速后退、太平洋入流水增多、北冰洋和大气环流异常、淡水储量增加、初级生产力变异等.全球气候变化所诱发的北极快速变化预计将放大北冰洋海洋酸化,通过CO_2吸收和碳输送,北冰洋在响应气候变化较其他大洋更快速和显著.本文以北冰洋近岸碳吸收和碳封存研究,海盆区域表层海水p CO_2变异机理研究,20年来西北冰洋的酸化水体扩张现象为主线,综述了北冰洋快速融冰背景下的区域碳循环研究进展,并分析了其酸化水体增长与过去20年的环境和气候变化之间的联系.

Application of zeolite adsorption and biological anaerobic digestion technology on hydrothermal liquefaction wastewater

The post-hydrothermal liquefaction wastewater(PHWW)was obtained from a conversion process of Spirulina sp.to bio-crude oil via hydrothermal liquefaction(HTL)technology that was rich in organic matter and toxicant.In this study,zeolite was applied to overcome the inhibitions and improve anaerobic digestion(AD)efficiency.Three zeolite adding ways were evaluated:PHWW pretreated with zeolite for 5 h with/without solid-liquid separation before AD process and zeolite added to PHWW AD process directly,in order to find the most ideal way to add zeolite.Results indicated that zeolite had a positive effect on the AD process of the PHWW.The gas potential of PHWW after adding zeolite,as well as the chemical oxygen demand(COD)removal rate,was much higher than those of its initial state.Especially when the PHWW was pretreated by zeolite for 5 h without separation,the biogas yield increased by 73.96%(6170μmol/g CODremoved)compared with the initial PHWW(3546.7μmol/g CODremoved).

Effects of organic strength on performance of microbial electrolysis cell fed with hydrothermal liquefied wastewater

Microbial electrochemical technology has drawn increasing attention for the treatment of recalcitrant wastewater as well as production of energy or value-added chemicals recently.However,the study on the treatment of hydrothermal liquefied wastewater(HTL-WW)using microbial electrolysis cell(MEC)is still in its infancy.This study focused on the effects of organic loading rates(OLRs)on the treatment efficiency of recalcitrant HTL-WW and hydrogen production via the MEC.In general,the chemical oxygen demand(COD)removal rate was more than 71.74%at different initial OLRs.Specially,up to 83.84%of COD removal rate was achieved and the volatile fatty acids were almost degraded at the initial OLR of 2 g COD/L·d in the anode of MEC.The maximum hydrogen production rate was 3.92 mL/L·d in MEC cathode,corresponding to a hydrogen content of 7.10%at the initial OLR of 2 g COD/L·d.And in the anode,the maximum methane production rate of 826.87 mL/L·d was reached with its content of 54.75%at the initial OLR of 10 g COD/L·d.Analysis of electrochemical properties showed that the highest open circuit voltage of 0.48 V was obtained at the initial OLR of 10 g COD/L·d,and the maximum power density(1546.22 mW/m3)as well as the maximum coulombic efficiency(6.01%)were obtained at the initial OLR of 8 g COD/L·d.GC-MS analysis revealed the existence of phenols and heterocyclic matters in the HTL-WW,such as 1-acetoxynonadecane and 2,4-bis(1-phenylethyl)-phenol.These recalcitrant compounds in HTL-WW were efficiently removed via MEC,which was probably due to the combination effect of microbial community and electrochemistry in MEC anode.

Progress in microalgae cultivation photobioreactors and applications in wastewater treatment:A review

Using microalgae to treat wastewater has received growing attention in the world because it is regarded as a novel means for wastewater treatment.It is commonly recognized that large-scale cultivation and commercial application of microalgae are limited by the development of photobioreactor(PBR).Although there are a lot of PBRs for microalgae pure cultivation which used culture medium,specialized PBRs designed for wastewater treatment are rare.The composition of wastewater is quite complicated;this might cause a very different photosynthetic effect of microalgae compared to those grown in a pure cultivation medium.Therefore,PBRs for wastewater treatment need to be redesigned and improved based on the existing PBRs that are used for microalgae pure cultivation.In this review,different PBRs for microalgae cultivation and wastewater treatment are summarized.PBR configurations,PBR design parameters and types of wastewater are presented.In addition,the wastewater treatment efficiency and biomass productivity were also compared among each type of PBRs.Moreover,some other promising PBRs are introduced in this review,and a two-stage cultivation mode which combines both closed and open system is discussed as well.Ultimately,this article focuses on current problems and gives an outlook for this field,aiming at providing a primary reference for microalgae cultivation by using wastewater.

Effects of strain,nutrients concentration and inoculum size on microalgae culture for bioenergy from post hydrothermal liquefaction wastewater

Cultivating microalgae in post hydrothermal liquefaction wastewater(PHWW)offers many benefits,including nutrients recovery and reuse,wastewater purification and biomass production.However,the high nutrients concentration and toxic substances in PHWW undermine the efficiency of biomass production and nutrient recovery.This study aimed to investigate the effects of the microalgae strains,initial nutrients concentrations and inoculum sizes on biomass production and nutrient recovery using PHWW as the cultivation medium.Results indicated that both biomass production and nutrients recovery were successfully improved by using the screened microalgae strain at the desirable initial nutrient concentration with the suggested algae inoculum size.Chlorella vulgaris 1067 probably demonstrated the strongest tolerance ability among the five microalgae strains screened,and performed well in the diluted PHWW,of which initial TN concentration was approximately 500 mg/L.The desirable inoculum size was determined to be 0.103-0.135 g/L.The biomass daily productivity was increased by 15.67-fold(reached 0.13 g/(L·d)).With the above optimal conditions,high biomass production and nutrient recovery from the PHWW to produce microalgae biomass for bioenergy production were achieved.

Biocrude oil production from Chlorella sp.cultivated in anaerobic digestate after UF membrane treatment

Algae cultivation in animal wastewater could recover nutrient resources,and harvest considerable amount of algae biomass for biofuel conversion.In this study,Chlorella sp.cultivated in ultrafiltration(UF)membrane treated anaerobic digestion effluent of chicken manure was converted into biocrude oil through hydrothermal liquefaction(HTL).The potential of biocrude production from grown Chlorella sp.was studied through changing the operational conditions of HTL,i.e.,holding temperature(HT,250℃-330℃),retention time(RT,0.5-1.5 h),and total solid(TS)(15 wt%-25 wt%)of the feedstock.The highest biocrude oil yield was 32.9%at 330℃,1.5 h and 20 wt%TS.The single factor experiments of HT also suggested that the biocrude oil yield decreased when the temperature was higher than 330℃.There were no significant differences of elemental contents in biocrude samples.The maximum higher heating values(HHV)of Chlorella sp.biocrude was 40.04 MJ/kg at HT of 330℃,RT of 1 h and TS of 15 wt%.This study suggests the great potential for energy recovery from Chlorella sp.cultivated in UF membrane treated anaerobic digestion effluent via HTL.

Nitrogen and phosphorous adsorption from post-hydrothermal liquefaction wastewater using three types of zeolites

Hydrothermal liquefaction(HTL)has been studied as a promising technology for converting wet biomass into bio-crude oil and the nutrient-rich post-hydrothermal liquefaction wastewater(PHWW)could be reused for algae and bacteria production.However,the PHWW from HTL contains various types of contaminants that need to be removed before reuse.Too high nutrients(nitrogen and phosphorous)contents,such as ammonium,are inhibitive to algal growth and bacteria species in anaerobic process.It is desirable to reduce nutrients concentration in PHWW to an acceptable level using zeolite adsorption.This study investigated nitrogen and phosphorous adsorption efficiencies from PHWW using three types of zeolites:activated clinoptilolite,natural clinoptilolite and Na-modified zeolite.Effects of ions and pH in the adsorption process were also investigated.Results showed that three zeolite variables affecting ammonium adsorption process could be ranked as follows:zeolite dosage>type>particle size,via an orthogonal experiment design.Activated clinoptilolite,with a particle size of 0.18-0.30 mm and a dosage of 0.4 g/mL demonstrated the highest ammonium adsorption efficiency of 54.92%.Zeolite could also adsorb organic nitrogen and had a high adsorption efficiency of phosphorous(97.85%).This study showed that zeolite is effective to adsorb nutrients in PHWW.The adsorption treated PHWW can then be used for culturing algae or anaerobic treatment,and the adsorbed nutrients can be reused later.

Fourth Environment-Enhancing Energy(E^(2)-Energy)Conference in Beijing,China,July 8-10,2016

The paradigm of Environment-Enhancing Energy(E2-Energy)is to produce renewable energy and chemicals from biowastes and biomass,and simultaneously improve the environment by reusing nutrients,capturing carbon and cleaning wastewater.The 1st E2-Energy Forum was initiated in 2010,Beijing,by Professor Yuanhui Zhang,University of Illinois at Urbana-Champaign(UIUC),China Agricultural University(CAU)and Zhejiang University(ZJU).The forum has grown to a biannual international conference in 2012 in Shanghai,and 2014 in Beijing.The 4th E2-Energy Conference was jointly organized by CAU,UIUC and Chongqing University,and convened at CAU International Conference Center,Beijing,China on July 6-8,2016.The conference was financially supported by the National Natural Science Foundation of China(5151101167,U1562107 and 51576206),the Bill&Melinda Gates Foundation(RTTC-C-R2-01-001)and Beijing Scienceand Technology Program(Z161100001316009).

Temporal changes in the characteristics of algae in Dianchi Lake,Yunnan Province,China

Algal blooms have become a worldwide environmental concern due to water eutrophication.Dianchi Lake in Yunnan Province,China is suffering from severe eutrophication and is listed in the Three Important Lakes Restoration Act of China.Hydrothermal liquefaction allows a promising and direct conversion of algal biomass into biocrude oil.In this study,algal samples were collected from Dianchi Lake after a separation procedure including dissolved air flotation with polyaluminum chloride and centrifugation during four months,April,June,August and October.The algal biochemical components varied over the period;lipids from 0.7%to 2.1%ash-free dry weight(afdw),protein from 20.9%to 33.4%afdw and ash from 36.6%to 45.2%dry weight.The algae in June had the highest lipid and protein concentrations,leading to a maximum biocrude oil yield of 24.3%afdw.Biodiversity analysis using pyrosequencing revealed different distributions of microbial communities,specifically Microcystis in April(89.0%),June(63.7%)and August(84.0%),and Synechococcus in April(2.2%),June(12.0%)and August(1.0%).This study demonstrated remarkable temporal changes in the biochemical composition and biodiversity of algae harvested from Dianchi Lake and changes in biocrude oil production potential.