污泥生物炭中氮硫行为及环境效应研究进展

污泥生物炭中氮硫元素含量高,其氮硫行为和环境效应对全球气候变化的影响不容忽视。以往的研究中,研究者往往以富碳生物炭作为主要研究对象,关注碳对全球气候变化的行为和功效,而对氮硫元素的作用关注不够。本文从原始污泥基本性质到其热解过程,再到生物炭的老化,逐步对污泥生物炭整个生命周期内氮硫的行为及其环境效应研究进行综述,并对未来应注重开展的研究方向进行展望,为生物炭中氮硫元素固定、释放及与之关联的环境效应和温室气体排放控制研究提供理论基础。分析表明,污泥中氮元素含量普遍高于硫元素,且热解过程中氮比硫更容易转移至气相产物。氮硫元素随热解温度的增加,在三相产物中的分配都是炭中持续减少,油中先增后减,气中一直增加。高温（＞800℃）条件下,气相中的氮含量高于固相,而硫元素则仍然主要存在于固相中。污泥生物炭老化及其环境效应研究表明,污泥生物炭氮硫元素与土壤的相互作用及其温室效应问题在今后的研究中应引起重视。     

生物炭作为土壤/填料改良剂的应用研究进展

归纳了生物炭的制备原料、方法;总结了部分生物炭的全碳和灰分含量与热解温度之间的对应关系以及随着热解温度的升高,不同来源的生物炭性质大致变化规律;综述了生物炭的土壤环境效应,对土壤中不同种类污染物质的净化机理以及作为改良剂在土壤修复、低影响开发(LID)中的应用进展。最后,探讨了目前该技术存在的不足,并对该技术未来的研究重点和方向进行展望。     

生物炭作为土壤/填料改良剂的应用研究进展

归纳了生物炭的制备原料、方法;总结了部分生物炭的全碳和灰分含量与热解温度之间的对应关系以及随着热解温度的升高,不同来源的生物炭性质大致变化规律;综述了生物炭的土壤环境效应,对土壤中不同种类污染物质的净化机理以及作为改良剂在土壤修复、低影响开发(LID)中的应用进展。最后,探讨了目前该技术存在的不足,并对该技术未来的研究重点和方向进行展望。     

鸡粪生物炭对铅镉复合污染黄土性质的影响研究

为探究生物炭对铅镉复合污染黄土性质的影响,将鸡粪生物炭以不同质量(0%、1%、3%、5%和10%)添加到镉-铅(Cd-Pb)复合污染的耕地黄土中进行培养,观测培养180 d后Cd-Pb污染黄土中pH、电导率(EC)、总有机碳(TOC)和CEC的变化。其中,添加生物炭可以增加黄土的TOC和CEC,TOC和CEC是土壤肥力的重要指标,因此,添加生物炭在一定程度上提高了土壤肥力;添加生物炭对黄土pH和EC也有增加效果,尤其是EC,其最大增幅达到224.2%。     

生物炭及改性生物炭的制备与应用研究进展

生物炭因具有制备原料来源广泛、比表面积大、孔隙发达、富含碳素、表面官能团丰富等特点而被广泛用于土壤改良、污染物去除、固碳减排等方面.近年来,研究发现将生物炭进行物理、化学或生物改性,会强化生物炭功能,有利于生物炭的高效利用.综述了生物炭及改性生物炭的制备,理化性质分析及其在土壤、水体、大气中的应用,并将改性前后生物炭进...     

生物炭对污染土壤修复的研究进展

土壤是生物圈的重要组成部分,是人类生存和发展的基础,同时也是保障国家粮食安全的最基本的生产材料。随着人类社会经济的发展和人类活动的高度密集,土壤污染程度越来越严重。土壤质量持续恶化,严重影响人类健康,因此开展针对污染土壤的修复工作刻不容缓。生物炭作为一种在土壤改良、生物能源生产、有机废物循环利用和温室气体减排等方面具有积极意义的物质,对于农业应用方面有重要意义,引起了国内外研究者的广泛关注,成为近年来的研究热点之一。     

生物炭的特性及其应用研究进展

介绍了生物炭的物理化学特性和应用现状,阐述了生物炭在环境保护、修复和改善土壤、缓解能源危机等方面的应用,指出了生物炭在能源危机、环境危机方面的重要意义及其发展方向。     

磁性生物炭的制备及其吸附性能的研究

利用微波辐照技术,以稻草秸秆为碳源,Fe Cl3为赋磁剂,在无需还原剂的条件下制备了磁性生物炭(MBC)吸附剂。对吸附剂进行了表征,并且分析了初始p H、温度、吸附时间等条件对MBC吸附孔雀石绿特性的影响。结果表明,MBC对孔雀石绿的吸附符合Langmuir等温模型和准二级动力学吸附方程;用微波再生法对MBC再生,重复5次后,MBC对孔雀石绿的吸附量为原始吸附量的70%,表现了良好的再生能力。     

牛粪生物炭的活化及其吸附铅的研究

以Na OH活化牛粪生物炭,分析了活化对牛粪生物炭理化性质的影响,并以生物炭吸附溶液中Pb2+(以0.01 mol/L为背景电解质)。结果表明活化处理能提高生物炭对Pb2+的吸附效果,吸附容量达到192.2 mg/g,相比未活化牛粪生物炭(50.4 mg/g)提高了约4倍。     

生物炭的基本特性及其应用领域的研究进展

生物炭作为一种新型环境功能材料,因其优良的环境效应成为国内外研究的前沿热点。文章介绍了生物炭的制备条件,基本特性以及具体的应用领域,对其在固碳减排,保障能源,改善环境等方面进行了综述,为推动生物炭的应用和推广提供了参考依据。     

Environmental Effects on the Properties of Biopolymer Service-ware Products

The current trend towards sustainability has promoted a new interest in biodegradable plastics. Although there have been many studies on the behavior of biodegradable plastics, the changes in properties that may occur during use have not been fully documented. The mechanical properties of seven commercial service-ware items produced with biodegradable plastics were analyzed in this investigation. The effects of UV exposure, humidity, and accelerated aging on the mechanical properties were studied. In general, samples from polylactic acid and wheat straw had properties comparable to traditional synthetic plastics used in this application. However, the strength of other polymers such as bagasse, fiber pulp and potato starch was less than that of comparable synthetic plastics. The mechanical properties of the biopolymers generally deteriorated significantly upon exposure to UV radiation and humidity, with polylactic acid, wheatstraw, potato starch, and the bamboo bulrush wheatstraw blend being affected the most. Accelerated aging data indicate that after 6 months under ambient conditions, the potato starch, wheatstraw, and bamboo bulrush wheatstraw blend have a significant reduction in strength and modulus. In general, the thermal analysis behavior of most of the plastics was similar indicating a major weight loss of about 69–97% over a temperature range of 250–400?C. Additional improvements may be necessary to increase the environmental resistance of these biopolymers so that they can be effective replacements for traditional plastics.     

花生壳生物炭吸附剂的制备及性能研究

以花生壳为原料,采用限氧升温法在300℃下处理一小时制备生物炭,研究了其对阳离子染料亚甲基蓝(MB)的吸附能力,并探究其吸附机理。实验结果表明,花生壳生物炭对亚甲基蓝有很强的吸附作用,当花生壳生物炭投加量为100 mg,亚甲基蓝溶液用量为50 mL,亚甲基蓝浓度小于60 mg/L情况下,对于亚甲基蓝的去除率可达90%以上,且吸附速率较快,达到吸附平衡所需时间约为30 min,吸附符合准二级动力学方程,吸附等温曲线符合Langmuir吸附等温模型,说明此花生壳生物炭对亚甲基蓝的吸附为化学吸附控速的单分子层吸附。实验为开发低成本高效新型吸附剂提供理论依据,也为农林废弃物与染料废水的联合处理提供新思路。     

生物炭复合材料的制备及对甲醛性能研究

甲醛在日常生活中普遍存在,且是最常见的有毒物质,由于其分布广泛且具有较强的隐蔽性,给人们的生活带来了很大的危害。该文针对甲醛的物质特性,采用生物炭复合材料进行电极两端催化,促进甲醛等有害物质的活化反应;选取光谱衍射仪、电子扫描显微镜等主要仪器设备进行生物炭石墨烯和复合材料的制备,通过傅里叶红外光谱图象特征分析,研究发现生物炭复合材料Cu(OH)_2/C更利于活化甲醛,有效提高了材料物质的导电性,为生物炭复合材料对甲醛的性能研究提供了参考价值。     

水葫芦生物炭的理化特性和养分特征

为水葫芦生物炭作为土壤改良剂提供依据,以水葫芦生物质为原料,在200~400℃之间进行炭化制备成水葫芦生物炭,探讨热解温度对水葫芦生物炭的理化特性和养分含量的影响。结果表明:产率随着热解温度的升高而降低,pH随热解温度的升高而升高,全氮随着热解温度的升高先升高后降,全磷、全钾和速效钾随着热解温度的升高而增加,水解性氮和有效磷随着热解温度的升高而降低。较高的热解温度在一定程度上富集了NPK养分,但降低了NP的有效性。水葫芦生物炭呈碱性且含有一定的营养元素,可作为一种较好的酸性土壤改良剂。     

污泥基生物炭的制备技术及环境应用与研究热点

污泥炭化技术是污泥资源化处置的研究热点之一.通过中国期刊全文数据库和Web of Science核心合集数据库,对2000年—2020年发表的关于污泥基生物炭的文献进行检索与综述分析.详细分析了污泥基生物炭研究的年度发文量和研究热点,讨论了现有制备技术的优缺点及未来发展趋势,同时,结合污泥基生物炭的理化性质特征,探讨其...     

A Comprehensive Review on Effects of Seawater on Engineering Properties of Concrete

Silicon - The concrete and natural seawater have a complex relationship between them, which requires special attention. Therefore, various studies have been conducted to consider the effects of...     

Discussion of the Physicochemical Effects of Modifiers on the Extraction Properties of Hydroxyoximes. A Review

Abstract

The physicochemical aspects of hydroxyoxime modification with various modifiers containing oxygen atoms are discussed. This kind of modification is unique to hydroxyoxime reagents, which form weak intramolecular and intermolecular hydrogen bonds. These bonds can easily be destroyed not only by modifier molecules (alcohols, alkylphenols, and esters) but also by solvating diluents. Alcohols are stronger modifiers than alkylphenols. The drawback of these modifiers is their strong self‐association, which is eliminated in esters and sterically hindered alcohols. The extraction properties of strong hydroxyoxime extractants can also be modified by adding weak reagents (hydroxyoximes or β‐diketones), which form co‐associates with strong extractants. The use of sterically hindered esters seem rational for two reasons: they inhibit hydroxyoxime adsorption at the hydrocarbon/water interface with oximino group penetrating the aqueous layers; and they show negligible adsorption. Due to these phenomena, hydroxyoxime extractants are more stable, and a retardation of the extraction is not observed in the presence of hindered esters. There is currently no general explanation of the chemistry of modification. Many published works focus only on the interactions of modifiers with extractants, neglecting the interactions with metal complexes. In order to achieve a substantial progress in our understanding of the phenomenon of modification, interactions between complexes and modifiers must be studied and explained.     

Reinforcing Effects of Modified Nanodiamonds on the Physical Properties of Polymer-Based Nanocomposites: A Review

Exceptional mechanical and other physical properties of nanodiamond (ND) have recently attracted much attention. For thermosetting polymers, the reinforcing effects of as-received and amine-functionalized nanodiamonds on the mechanical and tribological properties have been examined and demonstrated the advantages of covalent incorporation of ND into epoxy structure resulting in strong nanofiller-matrix interface. In epoxy matrix composites, the ultimate mechanical reinforcement was achieved using high loadings level of ND powder along with improved thermal conductivity and reduced friction coefficients. In this regard, several complementary mechanical characterization techniques including pin-on-disk, nanoindentation, vickers, tensile, and compression were used to study the reinforcing mechanisms.     

养护制度对超高性能混凝土微观结构和力学性能影响的研究综述

超高性能混凝土(UHPC)是指兼具超高抗渗性能和力学性能的纤维增强水泥基复合材料.在制备UHPC过程中,高温、加压的养护制度是UHPC获得高性能的重要手段.本文综述了不同的养护制度对UHPC基本力学性能和微观结构的影响,并分析其作用机理.研究表明,热养护加速了UHPC的水化过程,提高了材料的密实度,使其具有超高强度.在...     

锰铁氧体/生物炭复合材料的制备及吸附Cd2+性能

以核桃壳生物炭为原料,利用一步水热法合成锰铁氧体/生物炭复合材料(BMFC),采用SEM、XRD和FTIR对BMFC进行了表征,并研究了pH、吸附时间、起始浓度等对BMFC吸附Cd~(2+)性能的影响,通过XPS对BMFC吸附Cd~(2+)机理进行了研究。结果表明:在25℃下,BMFC对Cd~(2+)的最佳吸附pH为7.0,吸附平衡时间为80min,最大饱和吸附量为32.74mg/g;吸附过程符合准二级动力学方程和Langmuir等温吸附方程,对Cd~(2+)的吸附过程属于单分子层化学吸附;根据XPS分析表明,Cd~(2+)的去除是因其与BMFC表面的官能团发生作用。解吸-吸附实验发现,BMFC进行5次循环吸附后,仍对Cd~(2+)表现出较好的再生吸附性能。