微塑料的老化技术、特征及其毒性效应研究进展

环境中的微塑料通常会受到紫外辐照、热辐射、化学氧化、生物降解等环境因素的影响,进而经历光老化、热老化、化学老化、生物老化等过程,并且其物理化学性质均发生一定程度的改变.环境中微塑料的自然老化过程需要很长的时间,极大限制了对老化微塑料的研究.本文综述了微塑料的实验室加速老化技术,包括紫外老化、化学老化和生物降解等技术,阐述了老化后微塑料的表面形貌与官能团的变化及对吸附污染物的影响,并总结了老化微塑料对生物的发育毒性、生殖毒性、神经毒性和氧化应激等效应.本文旨在使人们更了解微塑料实验室加速老化技术及其对生物的潜在风险效应.     

生物炭的老化及其对温室气体排放影响的研究进展

生物炭是生物质在无氧或限氧条件下经高温热解后产生的多孔富碳物质,其被广泛施加到土壤中改良土壤性质,调节温室气体排放。生物炭施入土壤后,长期受外界物理、化学和生物等环境作用导致生物炭性质发生缓慢改变,这个过程称为生物炭的老化。文章综述了原位生物炭自然老化和实验室模拟老化的方法以及老化后生物炭理化性质的变化,从理化性质变化的角度论述了生物炭老化过程对二氧化碳(CO_2)、甲烷(CH_4)和氧化亚氮(N_2O)这3种温室气体排放的影响,并初步解释生物炭老化过程对增加或减少温室气体排放的可能机制。主要内容如下:生物炭老化方法可以分为自然老化和人工模拟老化,模拟老化方法包括生物、物理和化学老化。生物炭发生老化后,生物炭的比表面积(SSA)和孔容根据老化强度而有不同变化,自然或人工模拟的温和老化方法使生物炭表面上有新的纳米微孔生成,生物炭SSA增加,而使用强酸或强氧化剂的强烈老化方式可破坏生物炭孔隙结构,导致SSA和孔容下降。从化学性质方面来讲,生物炭C/N比随老化过程而降低,但是O/C比却随老化过程而升高;此外,当生物炭老化时,生物炭表面含氧官能团增加,例如羧基、羰基和酚基等,这些含氧基团可以和阳离子结合形成羧酸盐和酚盐,同时释放H~+,导致老化生物炭的pH值降低。基于有限的研究报道,老化生物炭仍然具有一定的CH4减排潜力,这得益于土壤通气状态的改善和甲烷氧化菌氧化CH_4潜力提升。相反,由于生物炭极性增强和pH值降低,生物炭老化过程有促进土壤有机质矿化增加CO_2和N_2O排放的趋势。然而为了辅正这一论断,准确评估生物炭老化的环境效应,长期原位生物炭老化并同时设置新鲜生物炭对照的研究需要进一步开展,以探明生物炭老化过程对温室气体排放的影响机制,为生物炭生产和合理施用提供科学应用指导。     

除镍化学镀镍废液制成复合肥的芥菜肥效试验研究

盆栽试验施用两种由磷、氮含量较高的化学镀镍废液沉淀除镍之浓缩液制成的复合肥。结果表明,芥菜施用浓缩液复合肥后,肥效与对照的“过磷酸钙”复合肥无显著差异;与不施肥相比,由于芥菜幼苗耐肥性较差,在一定程度上抑制芥菜的前期生长,芥菜地上部干质量显著降低,但对提高土壤Ｎ、Ｐ、Ｋ含量仍有显著帮助。     

聚氯乙烯微塑料的原位光解老化及其对土壤微生物群落的影响

近年来,微塑料污染越来越受到大众和科研人员的关注.微塑料被报道在水体、土壤和大气中广泛分布,它们在环境中可能受到物理、化学或生物作用而发生老化现象.目前大部分关于微塑料老化的研究都是在水环境中进行的,同时,有关微塑料的老化研究主要采用离线技术进行表征,只能测定微塑料老化前后的结构变化,不能准确认识微塑料界面反应过程,因此,亟待开发微塑料老化过程的在线监测技术及研究其在非水相环境中的老化过程.研究污染物性质的目的 之一是为研究其环境影响提供理论依据,因此,本研究选择了聚氯乙烯(PVC)农业地膜在空气中老化后进入土壤的环境过程,搭建了单颗粒微塑料的显微-傅里叶变换红外光谱原位监测装置,从分子水平揭示了PVC微塑料的光化学转化过程,同时也探究了老化后PVC微塑料对土壤微生物群落所产生的影响.     

化学老化后稻壳生物炭理化性质的改变及微观结构表征

为研究化学老化对生物炭理化性质与微观结构的影响,本研究采用H_2O_2、HNO_3老化不同温度(350℃和550℃)下制备的稻壳生物炭,并利用元素分析、扫描电镜、漫反射红外光谱、X射线光电子能谱等测定比较生物炭老化前后表面理化性质及微观结构的变化.结果表明,经两种氧化剂老化后两种生物炭中O元素含量及O/C原子比均增加.与老化前生物炭相比,老化后两种生物炭中羟基、羧基、酮羰基、脂肪醚、酯基等含氧官能团的含量均发生不同程度的变化.通过漫反射红外与X射线光电子能谱分析相结合,发现两种稻壳生物炭经H_2O_2、HNO_3老化后均生成了羟基、羧基等含氧官能团,从而使得生物炭极性增加.此外,经HNO_3老化后稻壳炭表面生成硝基、硝酸盐等含氮基团,N元素含量亦显著增加.但氧化剂对两种温度下制备的生物炭中炭元素含量影响存在差异:经H_2O_2、HNO_3氧化后550℃制备的生物炭(R550)中C元素含量与芳香性降低;而经H_2O_2氧化后,350℃制备的生物炭(R350)中C元素含量与芳香性均上升.     

过氧化氢氧化对生物炭表面性质的改变及其对双酚A吸附的影响

本研究以H_2O_2作为氧化剂模拟生物炭在土壤中的化学老化过程,并通过其被氧化前后表面性质和对双酚A吸附能力的差异,来评估生物炭在土壤中的稳定性及其老化后与双酚A的相互作用。结果表明,经过为期7 d的氧化,H_2O_2的氧化使200℃下制备的生物炭结构片段流失,其吸附性能降低以及生物炭总量减少;而500℃下制备的生物炭虽然碳损失率较低,但由于其极性增强和芳香性减弱导致其吸附性能减弱。2种生物炭在土壤中长期暴露后都可能导致其吸附双酚A能力下降,相对于200℃下制备的生物炭,500℃下制备的生物炭老化后吸附双酚A的能力下降程度更大。     

液质联用方法用于灭鼠剂的分析检测

杀鼠剂经常用来消灭老鼠 ,大多数的杀鼠剂同时也对人和家禽有毒害作用 ,其毒性作用是由于干扰血液凝结机制而导致的抗凝血剂中毒 .本文介绍了利用液质联用方法分析复杂基体中几种常见的杀鼠剂 .1　实验条件所有实验都是在Ａｇｉｌｅｎｔ1 1 0 0液质联用系统上进行的 ,整个系统由二元泵、真空在线脱气机、自动进样器、柱温箱 (带柱切换阀 )、二极管阵列检测器和质谱仪组成 .液质联用仪可用电喷雾离子源或大气压化学电离离子源 .由安捷伦化学工作站进行数据采集和分析 .分析纯的化学药品和色谱纯的液相溶剂用于流动相和标准溶液制备 .用于本研…     

老化作用对水稻秸秆生物炭吸附Cd(Ⅱ)能力的影响

环境变化使生物炭材料发生老化作用,老化后的生物炭是否仍具有较强的吸附能力是评价生物炭对Cd修复的长期稳定性的重要指标.本文采用自然老化(Spontaneous aging,SPON),冻融循环老化(Freeze-thaw cycles aging,FTC)和高温老化(High temperature aging,HT)的方法对水稻秸秆生物炭进行2个月的人工加速老化,运用扫描电镜(SEM-EDS)、元素分析仪、傅里叶红外光谱分析仪(FTIR)研究老化作用对秸秆生物炭材料的影响,再通过等温吸附实验研究生物炭老化前后对Cd吸附性能特征的变化.结果表明,老化作用使生物炭材料局部发生破碎,增加了生物炭表面O/C比.老化作用显著影响秸秆生物炭表面的官能团,降低了生物炭表面—OH的数量,增加了CO、—COOH和Si—O—Si的数量,出现了C≡C键,可为Cd提供更多的吸附位点.等温吸附试验进一步证明了老化后的生物炭提高了对Cd(Ⅱ)的吸附性能.与生物炭原样相比,冻融循环老化、高温老化、自然老化使生物炭的Cd最大吸附量分别达到了26.49、33.30、23.40 mg·g~(-1),增加了27.8%,60.7%,12.9%.本研究表明老化作用改变了生物炭材料的表观结构和官能团,增强了对Cd(Ⅱ)的吸附能力,因此生物炭对Cd的修复具有一定的长期稳定性.     

利用Waters Alliance LC/MS ZMD系统分析除草剂混合物

利用Waters液质联用系统可方便而灵敏地检测复杂样品基质中的目标化合物.本例使用 Waters液质联用系统,大气压化学电离源(APCI)，选择离子监测方式分析了从大麦中提取的12种除草剂混合物.     

化学浸提法研究土壤中活性铝的溶出及形态分布

本文提出用KC1、NH_4AC、HC1、NaOH四种化学浸提液将土壤中活性铝溶出,根据不同的溶出机理,得到铝的各种化学形态,然后编制电脑程序,计算出土壤中活性铝溶出的形态分布百分率,并对影响铝溶出的若干因子进行了探讨。     

High performance of multi-layered alternating Ni–Fe–P and Co–P films for hydrogen evolution

Judiciously engineering the electrocatalysts is attractive and challenging to exploit materials with high electrocatalytic performance for hydrogen evolution reaction. Herein, we successfully perform the interface engineering by alternately depositing Co–P and Ni–Fe–P films on nickel foam, via facile electroless plating and de-alloying process. This work shows that there is a significant effect of de-alloying process on alloy growth. The electronic structure of layered alloys is improved by interface engineering. The multilayer strategy significantly promotes the charge transfer. Importantly, the Co–P/Ni–Fe–P/NF electrode fabricated by interface engineering exhibits excellent electrocatalytic hydrogen evolution activity with an overpotential of 43.4 mV at 10 mA cm-2 and long-term durability for 72 h in alkaline medium (1 mol L-1 KOH). The innovative strategy of this work may aid further development of commercial electrocatalysts.     

无氰碱性镀锌新工艺中试试验

将无氰碱性电镀锌新工艺的实验室小规模的最佳配方和工艺组合放大200倍进行中试,与原有的有氰电镀工艺产品一起经中性盐雾试验(NSS)检测比较,得出该无氰碱性电镀锌新工艺可取代原有的有氰电镀工艺的结论。     

Adsorption of rhodium(III) from plating solutions by calcined gibbsite

Gibbsite calcined at 400°C (GB400) was prepared, and its ability to adsorb rhodium(III) was investigated. Optimal pH, effect of contact time, temperature, adsorption isotherms, and recovery percentage were evaluated. The optimal pH was 6.3. The adsorption equilibrium was achieved within 24 h. The adsorption rate was found to be of pseudo-first order. The experimental data were fitted to both the Freundlich (r = 0.90–0.93) and Langmuir (r = 0.94–0.96) equations. The amount of rhodium(III) adsorbed decreased with increasing temperature. Rhodium(III) being adsorbed from phosphate or sulfate plating solution was recovered using hydrochloric acid and sodium hydroxide solutions at 1, 10, and 100 mmol L^?1.     

Efficient removal of heavy metals from electroplating wastewater using polymer ligands

Poly(hydroxamic acid)-poly(amidoxime) chelating ligands were synthesized from poly(methyl acrylate-co-acrylonitrile) grafted acacia cellulose for removing toxic metal ions from industrial wastewaters. These ligands showed higher adsorption capacity to copper (2.80 mmol?g⁻¹) at pH 6. In addition, sorption capacities to other metal ions such as iron, zinc, chromium, and nickel were also found high at pH 6. The metal ions sorption rate (t_1/2) was very fast. The rate of adsorption of copper, iron, zinc, chromium, nickel, cobalt, cadmium and lead were 4, 5, 7, 5, 5, 8, 9 and 11 min, respectively. Therefore, these ligands have an advantage to the metal ions removal using the column technique. We have successfully investigated the known concentration of metal ions using various parameters, which is essential for designing a fixed bed column with ligands. The wastewater from electroplating plants used in this study, having chromium, zinc, nickel, copper and iron, etc. For chromium wastewater, ICP analysis showed that the Cr removal was 99.8% and other metal ions such as Cu, Ni, Fe, Zn, Cd, Pb, Co and Mn removal were 94.7%, 99.2%, 99.9%, 99.9%, 99.5%, 99.9%, 95.6% and 97.6%, respectively. In case of cyanide wastewater, the metal removal, especially Ni and Zn removal were 96.5 and 95.2% at higher initial concentration. For acid/alkali wastewater, metal ions removing for Cd, Cr and Fe were 99.2%, 99.5% and 99.9%, respectively. Overall, these ligands are useful for metal removal by column method from industrial wastewater especially plating wastewater.     

废裂化催化剂中镍去除的研究

本文采用浸取法,硫化氧化法,硫化氯化法工艺进行去除废裂化催化剂中镍的研究。并对各工艺的运行条件,去除效率及可行性进行了分析比较,为工业化再生利用废裂化催化剂提供了一科学依据。     

Recovery of Ni(II) from real electroplating wastewater using fixed-bed resin adsorption and subsequent electrodeposition

Resin adsorption and subsequent electrodeposition were used for nickel recovery. Treated wastewater can meet the Electroplating Pollutant Discharge Standard. The spent resin is completely regenerated by 3 BV of 4% HCl solution. 95.6% of nickel in concentrated eluent was recovered by electrodeposition. Effective recovery of high-value heavy metals from electroplating wastewater is of great significance, but recovering nickel ions from real electroplating wastewater as nickel sheet has not been reported. In this study, the pilot-scale fixed-bed resin adsorption was conducted to recover Ni(II) ions from real nickel plating wastewater, and then the concentrated Ni(II) ions in the regenerated solution were reduced to nickel sheet via electrodeposition. A commercial cation-exchange resin was selected and the optimal resin adsorption and regeneration conditions were investigated. The resin exhibited an adsorption capacity of 63 mg/g for Ni(II) ions, and the average amount of treated water was 84.6 bed volumes (BV) in the pilot-scale experiments. After the adsorption by two ion-exchange resin columns in series and one chelating resin column, the concentrations of Ni(II) in the treated wastewater were below 0.1 mg/L. After the regeneration of the spent resin using 3 BV of 4% (w/w) HCl solution, 1.5 BV of concentrated neutral nickel solution (>30 g/L) was obtained and used in the subsequent electrodeposition process. Using the aeration method, alkali and water required in resin activation process were greatly reduced to 2 BV and 3 BV, respectively. Under the optimal electrodeposition conditions, 95.6% of Ni(II) in desorption eluent could be recovered as the elemental nickel on the cathode. The total treatment cost for the resin adsorption and regeneration as well as the electrodeposition was calculated.     

失活甲醇催化剂用于脱除硫化氢的研究

本文研究了失活甲醇催化剂用于脱除硫化氢的试验。结果表明,失活甲醇催化剂具有较好的脱硫性能,其重量硫容在室温和６２３Ｋ时稍低于工业氧化锌脱硫剂,在４２３Ｋ－５２３Ｋ的温度范围内则大于工业氧化锌脱硫剂,其体积硫容在室温下大于工业氧化锌脱硫剂,失活甲醇催化剂的工作硫容随着的升高而增长,而且在低反应空速时或者经过还原后具有更大的硫容。     

酸阻滞法处理含酸及其相应盐的废液

本文主要介绍在含酸及其相应盐的废液中分离酸和盐的一种方法。将含酸及其相应盐的废液，通过装有强碱性阴离子交换树脂柱，其中的酸受到阻滞，而相应的盐能顺利通过，然后用水洗脱，则流出的是含酸的溶液，使酸和相应的盐得到了分离。经ＦｅＳＯ４－Ｈ２ＳＯ４和ＺｎＳＯ４－Ｈ２ＳＯ４两组废液的试验，均能使酸和金属得到回收。分离后的废水，可达标排放，废液得到了处理。酸阻滞法简单易行，易于投产使用，不受规模大小的限制。     

Spent rechargeable lithium batteries in e-waste: composition and its implications

The amount of spent rechargeable lithium batteries （RLBs） is growing rapidly owing to wide application of these batteries in portable electronic devices and electric vehicles, which obliges that spent RLBs should be handled properly. Identification of spent RLBs can supply fundamental information for spent RLBs recycling. This study aimed to determine the differences of physical components and chemical compositions among various spent RLBs. All the samplings of RLBs were rigorously dismantled and measured by an inductive coupled plasma atomic emission spectrometer. The results indicate that the average of total weight of the separator, the anode and the cathode accounted for over 60% of all the RLBs. The weight ratio of valuable metals ranged from 26% to 76%, and approximately 20% of total weight was Cu and Al. Moreover, no significant differences were found among different manufacturers, applications, and electrolyte types. And regarding portable electronic devices, there is also no significant difference in the Co-Li concentration ratios in the leaching liquid of RLBs.