High-solid Anaerobic Co-digestion of Food Waste and Rice Straw for Biogas Production

Anaerobic co-digestion of food waste（FW） and rice straw（RS） in continuously stirred tank reactor（CSTR） at high organic loading rate（OLR） was investigated. Co-digestion studies of FW and RS with six different mixing ratios were conducted at an initial volatile solid（VS） concentration of more than 3 g VS · L-1. The biogas production, methane contents, degradation efficiency of VS, chemical oxygen demand（COD） and volatile fatty acids（VFAs） were determined to evaluate the stability and performance of the system. The results showed that the co-digestion process had higher system stability and higher volumetric biogas production than mono-digestions. Increase in FW content in the feedstock could increase the methane yield and shorten retention time. The efficiency of co-digestion systems mainly relied on the mixing ratios of FW and RS to some extent. The highest methane yield was 60.55 m L· g V· S-1 · d-1 at a mass ratio（FW/RS） of 3 ： 1, which was 178% and 70% higher than that of mono-digestions of FW and RS, respectively. Consequently, the anaerobic co-digestion of FW and RS could have superior stability and better performance than monodigestions in higher organic loading system.

Nonionic Polymerizable Emulsifier in High-Solids-Content Acrylate Emulsion Polymerization

Stable high-solids-content acrylate emulsion were obtained with a nonionic polymerizable emulsifier allyloxy nonylphenoxy poly （ethyleneoxy） （10） ether （ANPEO10）, and a conventional emulsifier OP-10 as a reference sample. 1H NMR proves that the polymerizable emulsifier ANPEO10 has been incorporated into the resulted acrylate polymers. TEM demonstrates that there are some differences in the particle morphologies. AFM proves that the polymerizable emulsifier ANPEO10 migrating to the surface of the emulsion film was much less than the conventional emulsifier OP-10. The polymerizable emulsifier ANPEO10 can enhance the adhesion with glass plate compared to the conventional emulsifier. Furthermore, with increasing amount of emulsifier, the surface free energy of the films first decreased and then increased, and the adhesion with glass plate is initially enhanced and then attenuated. The water-resistance and solvent-resistance of the films prepared by the polymerizable emulsifier ANPEO10 are superior to those prepared by the conventional emulsifier OP-10.

SEED SEMICONTINUOUS EMULSION MULTI-COPOLYMERIZATION OF (METH) ACRYLATES WITH HIGH-SOLID CONTENT: EFFECT OF THE OPERATION CONDITIONS

The seeded semicontinuous emulsion multi-copolymerization of butyl acrylate (BA), 2-ethylhexyl acrylate (2EHA), methyl methacrylate (MMA), 2-hydroxyl propyl acrylate (HOPA) and acrylic acid (AA) was used to prepare the acrylic latexes with high-solid content. The effects of monomer emulsion feed rates (R(a)) and (R/E)(E) values, the ratio of emulsifier amount between the initial charge (R) and the addition monomer emulsion (E), on the polymerization reaction features, the viscosities, surface tensions,particle sizes and particle sizes distributions of latexes, T-g and the insoluble fractions of films, the 180 degrees peel strength, tack and holding power of pressure-sensitive adhesive (PSA) tapes, prepared from the latexes, were studied. Experimental study shows that the grafting and crosslinking fraction in the PSA tapes must be controlled within a suitable range to keep the balance of the 180 degrees peel strength, tack and holding power.

Integration of high-solid digestion and gasification to dispose horticultural waste and chicken manure

To realize full energy recovery from grass and chicken manure(CM), the integration of high-solid anaerobic digestion(HSAD) and gasification was investigated experimentally. The anaerobic biodegradability of grass can be enhanced through codigestion with CM. When the volatile solid(VS) ratio of CM to grass was 20:80, C/N ratio calculated to be 21.70, the cumulative biogas yield was the highest, 237 ml·(g VS)^(-1). The enhancement of biogas production was attributed to the buffering effects of ammonia and rich trace elements in CM. In semi-continuous systems, when the organic loading rate was 4.0 g VS·L^(-1)·d^(-1), the HSAD process was stable, with the average biogas yield 168 ml·(g VS)^(-1). More than 80% fractions of the digestates were volatile matters, which meant that the digestates can be used as feedstock for gasification to produce syngas. The VS ratio of grass to CM had significant overall energy generation through HSAD and gasification. Compared with gasification of digestate,cogasification with woodchips increased syngas yield and low heat value(LHV). Increasing of mass ratio of digestates to woodchips led to the decrease of LHV.

A method for analyzing on-line video images of crystallization at high-solid concentrations

Recent research has demonstrated that on-line video imaging is a very promising technique for monitoring crystallization processes. The bottleneck in applying the technique for real-time closed-loop control is considered as image analysis that needs to be robust, fast and able to handle varied image qualities due to temporal variations of operating conditions such as mixing and solid concentrations. Image analysis at highsolid concentrations turns out to be extremely challenging because crystals tend to overlap or attach to each other and the boundaries between the crystals are usually ambiguous. This paper presents an image segmentation algorithm that can effectively deal with images taken at high-solid concentrations. The method segments crystals attached to each other along the mostly related concave points on the contours of crystal blocks. The detailed procedure is introduced with application to crystallization of L-glutamic acid in a hot-stage reactor.

High-solid anaerobic digestion of sewage sludge:achievements and perspectives

High-solid anaerobic digestion(HS-AD)has been applied extensively during the last few decades for treating various organic wastes,such as agricultural wastes,organic fractions of municipal solid wastes,and kitchen wastes.However,the application of HS-AD to the processing of sewage sludge(SS)remains limited,which is largely attributable to its poor process stability and performance.Extensive research has been conducted to attempt to surmount these limitations.In this review,the main factors affecting process stability and performance in the HS-AD of SS are comprehensively reviewed,and the improved methods in current use,such as HS sludge pre-treatment and anaerobic co-digestion with other organic wastes,are summarised.Besides,this paper also discusses the characteristics of substance transformation in the HS-AD of SS with and without thermal pre-treatment.Research has shown that the HS effect is due to the presence of high concentrations of substances that may inhibit the function of anaerobic microorganisms,and that it also results in poor mass transfer,a low diffusion coefficient,and high viscosity.Finally,knowledge gaps in the current research on HS-AD of SS are identified.Based on these,it proposes that future efforts should be devoted to standardising the definition of HS sludge,revealing the law of migration and transformation of pollutants,describing the metabolic pathways by which specific substances are degraded,and establishing accurate mathematical models.Moreover,developing green sludge dewatering agents,obtaining high value-added products,and revealing effects of the above two on HS-AD of SS can also be considered in future.

Modified ADM1 for modeling free ammonia inhibition in anaerobic acidogenic fermentation with high-solid sludge

Anaerobic acidogenic fermentation with high-solid sludge is a promising method for volatile fatty acid（VFA） production to realize resource recovery. In this study, to model inhibition by free ammonia in high-solid sludge fermentation, the anaerobic digestion model No. 1（ADM1） was modified to simulate the VFA generation in batch, semicontinuous and full scale sludge. The ADM1 was operated on the platform AQUASIM 2.0.Three kinds of inhibition forms, e.g., simple inhibition, Monod and non-inhibition forms,were integrated into the ADM1 and tested with the real experimental data for batch and semi-continuous fermentation, respectively. The improved particle swarm optimization technique was used for kinetic parameter estimation using the software MATLAB 7.0. In the modified ADM1, the Ksof acetate is 0.025, the km,acis 12.51, and the KI_NH3is 0.02,respectively. The results showed that the simple inhibition model could simulate the VFA generation accurately while the Monod model was the better inhibition kinetics form in semi-continuous fermentation at pH 10.0. Finally, the modified ADM1 could successfully describe the VFA generation and ammonia accumulation in a 30 m^3full-scale sludge fermentation reactor, indicating that the developed model can be applicable in high-solid sludge anaerobic fermentation.

分子印迹膜-固相萃取-高效液相色谱法同时检测橙子中噻苯隆和氯吡脲

以聚多巴胺(polydopamine,PDA)修饰的聚偏氟乙烯(polyvinylidene fluoride,PVDF)膜为基膜,噻苯隆(thidiazuron,TDZ)为模板,甲基丙烯酸(methacrylic acid,MAA)为功能单体,乙二醇二甲基丙烯酸酯(ethylene glycol dimethacrylate,EGDMA)为交联剂,合成TDZ分子印迹膜(molecularly imprinted membrane,MIM),并将其应用于橙子中TDZ及其结构类似物氯吡脲(forchlorfenuron,CPPU)的高选择性同时提取。扫描电子显微镜表征结果表明,致密分子印迹聚合物通过PDA涂层固定在PDA@PVDF膜的三维网络结构表面;性能测试结果表明,MIM对TDZ和CPPU的吸附容量分别是相应非印迹膜的1.80、1.89倍,分别在20、30 min达到吸附平衡;MIM对干扰物质香豆素和3-叔丁基苯酚的特异性因子分别达到23.2和19.3。以MIM为固相萃取膜片,成功从橙子样品中高选择性同时提取TDZ和CPPU,在加标浓度为2.0、3.0、5.0μmol/L时,高效液相色谱法检测的加标回收率分别为90.3%~99.4%和88.2%~98.1%,相对标准偏差分别为0.9%~2.5%和1.2%~3.0%(n=3)。该方法能同时快速检测TDZ和CPPU,操作简单,具有较好的灵敏度、精密度及回收率,检测成本低,适用于果蔬中TDZ和CPPU残留的检测。

High-solids anaerobic mono-digestion of riverbank grass under thermophilic conditions

The purpose of this study was to investigate the potential of high-solids anaerobic mono-digestion of riverbank grass under thermophilic conditions, focusing on the effects of the strength and the amount of inoculum. Ensiled grass was inoculated with three different inocula; inoculum from liquid anaerobic digester（LI）, inoculum from dry anaerobic digester（DI）, and mixture of LI and DI（MI）, at feedstock-to-inoculum ratio（FIR） of 1, 2 and 4. The ensiling process of riverbank grass reduced moisture content（p 〉 0.05）, while the hemicellulose content was significantly increased from 30.88% to 35.15%（p 〈 0.05）, on dry matter basis. The highest methane production was at an FIR of 2 with MI（167 L/kg VSadded）,which was significantly higher（p 〈 0.05） than with DI, but not significant compared to LI（p 〉 0.05）. At an FIR of 4, digesters inoculated with LI and DI failed to produce methane,whereas 135 LCH4/kg VSaddedwas obtained with MI. The kinetic studies showed that at an FIR of 1 with LI and MI, the inoculum had less of effects on the hydrolysis rate constant（0.269 day-1and 0.245 day-1） and methane production（135 versus 149 L/kg VSadded）; rather,it affected the lag phase. In a thermophilic HS-AD of riverbank grass, the mixture of inoculum with low and high total solids content（TS） helps increase the TS of inoculum and digestion process. An FIR of 2 was deducted to be the limit for a better startup time and higher volumetric productivity of methane.

煤基固废与高盐废水“固液协同”充填处置关键技术

【目的和背景】受地域、经济和技术水平等限制,大部分煤基固废仍以露天堆填的形式积存而未进行处置,不仅占用大量土地资源,还会对环境造成二次污染。高盐废水(如矿井高盐水、煤化工高盐水)的妥善处置及减量化是实现废水“零排放”的关键环节,然而现有高盐废水处理技术普遍存在工程初期投资大、运行费用较高等问题。【方法】提出煤基固废和高盐废水“固液”两废协同处理技术,即使用高盐废水代替普通用水和早强剂等添加剂,采用固废胶凝材料代替水泥材料,将煤基固废和高盐废水搅拌混合后得到充填膏体,泵送至煤矿井下空间。为了分析该技术的可行性,以宁夏宁东煤炭基地某煤矿为研究区,研究煤基固废充填膏体的力学性能及其对环境的潜在影响。采用单轴抗压强度测试试验(UCS)、扫描电镜(SEM)和电感耦合等离子体质谱仪(ICP-MS)分析固化充填膏体的力学性能、微观结构及重金属浸出特征。【结果和结论】结果表明:随着时间的延长,固化充填膏体的强度不断增加,而随着矿粉添加量的增多,胶凝材料比例下降,固化充填膏体的强度逐渐减小。值得注意的是,随着时间延长,所有使用高盐废水作为拌合水的充填膏体3 d强度都高于0.5 MPa,基本满足NB/T 11432−2023《煤矿矸石基固废充填技术规范》中的最低要求,14 d强度达到3.38~5.99 MPa,能够满足绝大部分煤矿充填的各种场景要求。内梅罗污染指数法评价结果显示,固化充填膏体浸出液中重金属的综合污染指数为0.25,评价分级标准为安全;从固化充填膏体的浸出试验结果可以看出,浸出液中主要污染物的浓度均低于GB 5085.3−2007《危险废物鉴别标准浸出毒性鉴别》及GB/T 14848−2017《地下水质量标准》中所列的Ⅲ类水标准要求。因此,煤基固废和矿井高盐水协同处理技术,在力学性能和环境稳定性评估方面均满足相关标准,可实现煤基固废及高盐废水的可循环、低成本和全量化利用,具有显著的经济效益和环境生态效益,在无废矿山、无废化工建设方面有较好的应用前景。

金属有机骨架基固相萃取-高效液相色谱法检测水产品中5种氟喹诺酮类药物残留

采用溶剂热法合成新型金属有机骨架材料UiO-66-NH_(2),建立基于UiO-66-NH_(2)的固相萃取-高效液相色谱同时检测水产品中5种氟喹诺酮类药物残留的方法。样品经体积分数1.0%甲酸-乙腈溶液提取,正己烷脱脂,提取液旋蒸浓缩后,采用pH 8.0的氨水溶液复溶,经装有30 mg UiO-66-NH_(2)的固相萃取柱富集净化,6 mL 20%乙酸-甲醇溶液洗脱,氮吹近干复溶后,利用高效液相色谱-荧光检测器检测。在建立的实验条件下,5种FQs在0.005~0.50 mg/L范围内线性关系良好,决定系数(R^(2))为0.999 9~1.0,回收率为81.4%~104.8%,相对标准偏差为1.29%~4.93%,检出限为0.21~2.05μg/kg。制备的固相萃取柱可重复使用达5次,绿色环保、经济成本低,所建立的方法具有良好的准确度、精密度、重现性及选择性,适用于水产品中多种痕量氟喹诺酮类药残的同时检测。

工业固废制备复合助熔剂用于调控高灰熔点煤灰的熔融特性研究

煤灰的熔融特性是气化用煤的重要指标,添加助熔剂是降低高灰熔点煤灰熔融温度的主要方法。复合助熔剂可利用不同组分间的协同作用,显著降低助熔剂添加量,提高煤气化整体效率。选取钢渣(GZ)和赤泥(CN)两种工业固废制备复合助熔剂,考察气化条件下复合助熔剂对高灰熔点潞安煤(LA)灰熔融特性的影响,并分析了高温下煤灰中矿物质的变化。结果表明:添加量为2%~8%的钢渣、赤泥和钢渣与赤泥制备的复合助熔剂,均能降低潞安煤灰的熔融温度,且随钢渣与赤泥混合质量比的增加,潞安煤灰的熔融特征温度呈“V”型变化;钢渣与赤泥对降低潞安煤灰的熔融特征温度存在显著的协同作用,且协同作用与添加量、钢渣与赤泥的混合质量比密切相关;添加量为2%与混合质量比为9∶1、添加量为4%与混合质量比大于5∶5、添加量为6%和8%与所有混合质量比条件下,添加复合助熔剂后潞安煤灰的熔融特征温度均低于单独添加钢渣、赤泥后潞安煤灰的熔融特征温度。高温下潞安煤灰矿物质组成表明,添加量为2%与混合质量比为9∶1,添加复合助熔剂显著降低了潞安煤灰中莫来石和硅线石的含量;添加量为4%~8%,高温下潞安煤灰中钠长石与钙长石、方钙石、钙铝黄长石等含钙矿物质发生低温共熔,这是复合助熔剂对降低潞安煤灰熔融特征温度存在协同作用的根本原因。

Ⅲ型纤维素高固酶解及纤维素酶动态吸附过程研究

高效高固含量酶解过程是木质纤维素生物炼制大规模工业化的前提。然而,木质纤维素酶解转化率随着固含量增加而下降,导致高固含量酶解成为生物炼制的一大难题。本研究对比了Ⅲ型纤维素及Ⅰ型纤维素高固酶解时的酶解效率及纤维素酶动态吸附过程,探究了不同抑制物对酶解的影响,并考察了外切葡聚糖酶分子结构对纤维素酶解效率的影响。结果表明,与Ⅰ型纤维素相比,Ⅲ型纤维素在高固酶解及特定抑制物存在情况下均具有优势性,其中外切葡聚糖酶的碳水化合物结合模块对Ⅲ型纤维素酶解优势有显著影响。该研究结果为解决木质纤维素高固酶解转化率低的难题提供了新思路。

固体高次谐波产生:半导体布洛赫方程的进展

高次谐波(High-Order Harmonic Generation,HHG)是强激光与物质相互作用过程中产生的一种重要的非微扰、非线性光学现象.它不仅开辟了产生极紫外光源的新途径,还被用于合成阿秒脉冲,从而开启了阿秒物理学的大门.与气体相比,固体具有更高的原子密度,高次谐波的产生机制也更为复杂.半导体布洛赫方程(Semiconductor Bloch Equations,SBEs)作为研究固体HHG的一种重要理论方法,在揭示固体HHG的物理机制、解释和预测实验现象等方面扮演着重要角色.本文综述了SBEs的理论框架和最新进展.首先总结了布洛赫基组和绝热休斯顿基组下的SBEs,并分析了它们在数值计算中的优势与局限性.针对波函数随机相位问题,探讨了平滑波函数相位的平行输运规范和扭曲的平行输运规范.最后重点介绍了规范不变形式和瓦尼尔规范SBEs.它们不仅完美地解决了随机相位问题,还为分析固体高次谐波的产生提供了新的视角.

CaLa_(2)(WO_(4))4:Eu^(3+),Sm^(3+)新型白光LED用红色荧光粉的发光性能研究

本文采用高温固相法制备了CaLa_(2)(WO_(4))_(4)∶Eu^(3+)和CaLa_(2)(WO_(4))_(4)∶Eu^(3+),Sm^(3+)系列红色荧光粉。通过X射线衍射仪、扫描电子显微镜等对样品的晶体结构、光谱、热稳定性、荧光寿命及色度坐标进行表征与分析。结果表明,Eu^(3+)和Sm^(3+)的掺入没有改变CaLa_(2)(WO_(4))_(4)晶体结构,为单一纯相。在394 nm激发下,CaLa_(2)(WO_(4))_(4)∶Eu^(3+)荧光粉在615 nm处红光发射最强,源自Eu^(3+)的^(5)D0→7F_(2)电偶极跃迁,最佳掺杂量为0.09。Sm^(3+)掺入后,发射峰增强,荧光粉的寿命明显增加,Sm^(3+)对Eu^(3+)起到敏化作用,共掺杂体系中Sm^(3+)向Eu^(3+)进行能量传递。CaLa_(2)(WO_(4))_(4)∶Eu^(3+),Sm^(3+)随着温度的升高,Eu^(3+)的^(5)D0→^(7)F_(2)跃迁发射的积分面积逐渐减小,当温度升高到100℃时,发光强度变为初始温度的53%,出现温度猝灭。在共掺杂体系中,色度坐标随着Sm^(3+)掺杂量的增加,向红光区域移动,当Sm^(3+)的掺杂量为0.02时,对应的色度坐标为(0.6458,0.3538)。基于CaLa_(2)(WO_(4))_(4)∶Eu^(3+),Sm^(3+)荧光粉的特性,可以将其作为潜在的白光LED用红色荧光粉。

掺入固体废弃物的蒸压加气混凝土板制备及性能研究

我国磷石膏、脱硫灰、废土等工业固体废物堆存量巨大,利用率不足,含有污染物,对环境安全具有潜在风险。通过配合比设计、原料预处理、气泡调节和多温段养护等工艺,成功制备出具有优异功能的高掺合固废功能性蒸压加气混凝土板,原料最佳配比为磷石膏:废土:脱硫灰:水泥:石灰=8:50:20:10:12,干燥质量比75%,板的抗压强度5.2MPa,标准干密度606kg/m3,干燥收缩值0.36mm/m。

固体阿秒探测技术

随着超快飞秒激光技术的不断进步,泵浦-探测技术已成为研究凝聚态材料中电子态动态变化的重要手段.然而,当探索尺度缩小至原子级别,对探测技术的时间分辨率提出了更高要求.2023年诺贝尔物理学奖的颁发,表彰了在产生阿秒光脉冲以研究电子动力学方面的杰出贡献,标志着阿秒科学的重大突破.固体阿秒探测技术的出现,为实时观测和记录固体中电子的超快运动提供了前所未有的精度,揭示了这些过程背后的物理机制.本文重点介绍了阿秒光电子能谱、固体高次谐波和阿秒瞬态吸收谱这三种主要实验技术,阐述了它们的基本原理、相关应用,并展望了未来的发展趋势和方向.这些研究不仅对于全面揭示光与物质相互作用的深层次信息至关重要,也为开发新一代达到光频的超快光电子器件奠定了坚实基础.

安装方式对高速列车车顶电缆终端形变特性影响分析

高速列车车顶电缆终端伞裙根部的应力集中可能会诱发终端界面间产生缺陷,界面缺陷的存在会畸变电场分布,严重时会造成终端炸裂。建立流固耦合计算模型,仿真分析风向、安装方式和安装夹角对电缆终端伞裙形变特性的影响,并提出改善应力与形变的优化措施。仿真结果表明:安装方式和风速影响电缆终端伞裙边缘的形变量和伞裙根部应力,同一风速下,纵向安装时电缆终端伞裙形变量最大;横向安装方式下,安装夹角对于伞裙的形变和应力影响不明显;纵向安装方式下,安装夹角在15°~25°范围内,伞裙根部最大应力变化较为明显;适当增加伞裙材料硬度和在车顶加装导流罩均可减小伞裙形变量。文中结果可为车顶电缆终端安装方式和结构优化提供参考。

分子印迹磁固相萃取-高效液相色谱法检测牛奶中己烯雌酚残留量

以磁性活性炭为载体,己烯雌酚为模板分子,甲基丙烯酸为功能单体,三羟甲基丙烷三甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,乙腈为致孔剂,通过表面分子印迹技术制备己烯雌酚磁性分子印迹聚合物(magnetic mo-lecularly imprinted polymers,MMIPs),并对该聚合物进行表征与吸附性能研究,建立磁固相萃取与高效液相色谱联用检测牛奶中己烯雌酚残留量的方法。结果表明:己烯雌酚浓度在0.15~150.00 mg/L范围内,与对应峰面积呈良好线性关系,MMIPs对己烯雌酚的最大吸附容量为127.85 mg/g,检出限为2.00×10^(-6) mg/mL,对牛奶进行加标回收试验,加标回收率为87.56%~98.58%,相对标准偏差(relative standard deviation,RSD)为3.26%~6.28%。

高速铁路桥梁巨震响应分析

为保障高速列车的运行安全,高铁桥梁应具有足够的刚度,这势必会增大结构的地震反应。同时铁路组网,如川藏铁路,已经延伸到西部大震风险区。在高铁桥梁中建立第四级设防的分析方法。在振动台上测试了3个1/5和6个1/8缩尺的圆端矩形截面钢筋混凝土实体桥墩,并进行数值分析。试验结果表明,桥墩在峰值加速度为0.96g(原型0.32g,七度罕遇)以内的地震作用下,墩身仍保持较好的完整性和稳定性,桥墩的地震损伤程度不明显,混凝土桥墩试件没有出现明显的开裂和剥落现象,这表明按规范设计的桥梁具备较好抗震安全性。当地震强度增加到1.71g(原型0.57g,八度罕遇)时,桥墩顺桥向出现中等到严重损伤,而横桥向大多还处于中等损伤。但所有桥墩试件在强度为1.86g的巨震作用下不会发生倒塌破坏。研究表明,在相同地震动作用下,随着纵筋率提高,结构耗能总体呈增加趋势;随着地震设防水平增加,耗能随纵筋率的变化更加显著,试验桥墩可以承担更大的地震荷载。纵筋率对桥墩滞回曲线形状影响较大,增加纵筋率,耗能能力随之增大。需要强调的是,由于高铁桥墩不是按照延性设计,桥墩的体积配箍率均较低,研究表明其对桥墩的滞回性能的影响不明显。