树脂基固态胺吸附材料的选择性CO2吸附性能

基于简单的湿浸渍法将聚乙烯亚胺(PEI)有效负载到多孔树脂(HP20)中,制备获得树脂基固态胺吸附材料,并探究了PEI负载量(30%~60%)、吸附温度(30~90℃)和压力(2~100kPa)对材料CO₂吸附性能的影响.研究表明树脂基固态胺吸附材料的最佳PEI负载量为50%,过量的PEI会致使材料CO₂吸附容量和胺基利用效率的显著降低.所筛选的材料在较低或较高的CO₂分压范围内均能展现出优异的CO₂吸附性能,在30℃下的CO₂吸附容量达到3.06~3.78mmol/g,表明该材料在不同CO₂分压的多种碳捕集应用中均有着较好的适用性.此外,树脂基固态胺吸附材料的CO₂/CH₄和CO₂/N₂选择性在2~100kPa的压力范围内分别有262~5858和708~11551,在各类传统或新兴的固体吸附材料中处于较高水平.     

离子交换树脂在污泥处理中的应用及展望

离子交换树脂(IER)因其不溶性以及可循环利用性被广泛用于废水处理,但目前仍缺乏其对污泥应用研究的综述。本文汇总了污泥中常见IER类型(阳离子交换树脂、阴离子交换树脂以及螯合树脂),并介绍了树脂的基本特性以及适用的污泥方向,其中阳离子交换树脂,尤其是强酸性苯乙烯系阳离子交换树脂,适用范围最广。IER在污泥中的应用归为4类,分别为去除/回收重金属、回收磷、胞外聚合物提取以及调理污泥,并阐述了基本应用机理以及优缺点。针对IER在污泥中应用的不足,提出未来的研究方向,包括改性或开发新型IER去除/回收污泥中的重金属,优化IER直接回收污泥中磷的方法,改进IER调理污泥的方式以及开发新型分离IER与污泥的手段。本文有助于研究人员更好的了解IER在污水厂污泥中的应用现状,优化IER处理污泥的应用方式以及开发应用于污泥处理的新型IER。     

Non-targeted metabolomics reveals the stress response of a cellulase-containing penicillium to uranium

Human industrial activities have caused environmental uranium (U) pollution, resulting in uranium(VI) had radiotoxicity and chemical toxicity. Here, a cellulase-producing Penicillium fungus was screened and characterized by X-ray fluorescence (XRF), and Fourier transform infrared reflection (FT-IR), as well as by GC/MS metabolomics analysis, to study the response to uranium(VI) stress. The biomass of Penicillium decreased after exposure to 100 mg/L U. Uranium combined with carboxyl groups, amino groups, and phosphate groups to form uranium mineralized deposits on the surface of this fungal strain. The α-activity concentration of uranium in the strain was 2.57×10⁶ Bq/kg, and the β-activity concentration was 2.27×10⁵ Bq/kg. Metabolomics analysis identified 118 different metabolites, as well as metabolic disruption of organic acids and derivatives. Further analysis showed that uranium significantly affected the metabolism of 9 amino acids in Penicillium. These amino acids were related to the TCA cycle and ABC transporter. At the same time, uranium exhibited nucleotide metabolism toxicity to Penicillium. This study provides an in-depth understanding of the uranium tolerance mechanism of Penicillium and provides a theoretical basis for Penicillium to degrade hyper-enriched plants.     

螯合剂对小麦幼苗吸收金属以及土壤金属形态的效应

本文通过盆栽试验研究三种螯合剂（EDTA、[s,s】-EDDS、DTPA）对小麦幼苗吸收土壤中重金属及其它微量元素的效应,并且通过改进的BCR连续提取法分析了种植后土壤样品中金属元素的形态。结果表明：EDTA、DTPA的添加导致小麦幼苗地上部分生物量以及叶片叶绿素a含量显著下降。螯合剂的存在明显增加了Pb和Mn在幼苗根部和茎叶的富集,并增加其由根部向茎叶的传输．但对Fe和Ni的作用比较小。小麦幼苗收获时,除Zn之外,其它元素酸溶／可交换态金属含量与对照组相比均有非常显著的增加,而各元素的可还原态由于EDTA等螯合剂的添加而有明显下降。添加螯合剂的情况下,富集量与酸溶／可交换态含量之间的相关系数大大提高,且各处理组茎叶富集量与酸溶／可交换态之间呈显著（P〈0．05）或极显著相关（P〈0．01）。因此,三种螯合剂的添加主要影响的是生物可利用形态以及潜在的生物可利用形态,并且可能导致可还原态以及可氧化态向酸溶／可交换态转变,增加金属的生物可利用性,从而也增加潜在生态风险。     

Organic matter composition in sediments of the Oman Margin

The quantity and biochemical composition of organic matter (OM) in the sediments underlying and below oxygen minimum zone (OMZ) in the Arabian Sea were studied to provide information on the diagenetic processes of organic carbon under different environmental conditions. Concentrations of total organic carbon (TOC), total nitrogen (TN) and total hydrolysable amino acids (THAA) were significantly higher in sediments within rather than below OMZ, while those of total carbohydrates (TCHO) were slightly lower in the latter, suggesting the presence of a larger supply of labile compounds into the sea bottom at the shallower site (i.e. within OMZ). Hydrolysable amino acid and carbohydrate contribution to TOC were even lower (about 10% in surficial sediments) than the values obtained from the abyssal oligotrophic North Pacific, suggesting that OM food availability in the Oman Margin sediments within OMZ was lower than that observed at abyssal depths. The presence of the highest THAA and TCHO concentrations in the top 40?mm of the sediment core at both sites reflected the presence of bioturbation processes. In contrast with the general view of the deep sea as a stable and constant system, below OMZ in the Arabian Sea sediments, some differences were observed in the two investigated cores indicating the presence of a certain spatial variability in OM content and diagenesis.     

Chelating resin immobilized sawdust packed chromatographic column: Application to separation and preconcentration of lead ion

Naturally abundant rubber sawdust has been utilized as a stationary support, which after immobilization with a chelating polyelectrolyte (xylenol orange as counterion) gets converted into a suitable column packing material for isolation and enrichment of trace level target analyte, accurately detectable by the technique of differential pulse anodic stripping voltammetry. The sorbent is robust and re-usable in column-chromatography without showing any leaching and interference complications. Its unique lead ion selectivity from multielemental complex matrices (synthetic water sample, blood serum) at optimized column conditions (pH 2.5 and flow rate 0.5?mL?min^?1) mitigates the usual problems of intermetallic and readsorption effects. Effects of flow rate, pH, equilibration time, and other variables are reported. The system has advantageous feature to be used in a single-column ion chromatography with satisfactory performance. A modest attempt has been made to determine lead fractions in human blood serum samples on the bases of selective retention of ionic and labile fractions on complexing resin.     

锰氧化物-阳离子交换树脂复合材料的制备及其对水中重金属的吸附性能

采用原位沉淀-空气氧化法将锰氧化物负载于大孔强酸性阳离子交换树脂D001上,制备出一种新型锰氧化物-阳离子交换树脂复合材料Mn-D001,并对该材料吸附水中Pb2+、Cd2+、Cu2+的性能进行了深入研究.TEM、XRD以及XPS的分析结果表明,负载的锰氧化物以MnO2的形态存在.基于单一金属离子静态吸附的一元体系实验表明,Mn-D001比D001对Pb2+、Cd2+、Cu2+具有更高的吸附选择性,在高浓度竞争离子Ca2+、Mg2+、Na+共存的情况下,仍能保持较高的重金属去除率;Mn-D001对Pb2+、Cd2+、Cu2+的吸附行为符合准一级动力学模型(R2>0.99)和Langmuir吸附等温线模型(R2>0.99).在温度为303 K时,Mn-D001对3种重金属的饱和吸附容量可分别达到476.19 mg.g-1、243.90 mg.g-1及196.08 mg.g-1,优于原有树脂D001.基于复合重金属离子竞争吸附的二元、三元体系的实验表明,Mn-D001对3种重金属的吸附能力顺序为Pb2+>Cu2+>Cd2+,吸附能力由原有树脂D001以及负载的锰氧化物的性质共同决定.     

树脂D001负载纳米Pd/Fe双金属脱溴2,2’,4,4’-四溴联苯醚(BDE-47)的研究

采用大孔树脂D001交换吸附Pd2+、Fe2+并在厌氧条件下以硼氢化钠溶液还原吸附的钯铁离子制备成负载纳米Pd/Fe双金属树脂。利用该树脂对2,2’,4,4’-四溴联苯醚(BDE-47)进行脱溴反应,探讨了该法的可行性和特性。结果表明:当大孔树脂D001、氯化钯、硫酸亚铁用量分别为0.75 g、2μg和0.2 g时所制备的双金属树脂脱溴水-乙醇溶液中的BDE-47效果最佳,反应遵循准一级动力学,速率常数k约为0.161 d-1,半减期为1.21 d。负载Pd/Fe的D001连续3次脱溴反应都有较好的效果,水-乙醇溶液中超过90%以上的BDE-47在反应6 d后被降解。负载Pd/Fe双金属的树脂可以重复活化再生,但再生2次后其脱溴效率变差,反应6 d只有47.3%的BDE-47被降解。用气相色谱-质谱联用仪和离子色谱仪跟踪Pd/Fe双金属树脂脱溴BDE-47反应,可知产物包括溴离子、三溴联苯醚、二溴联苯醚、一溴联苯醚和联苯醚。     

生物活性炭法处理ABS树脂生产废水

采用负载经驯化后微生物的活性炭与未负载微生物的空白活性炭处理ABS凝聚干燥工段废水,研究生物活性炭系统中存在的生物再生作用.结果表明,生物活性炭能够高效分解转化ABS废水中的有机腈类及芳香类污染物,其处理出水的COD、TOC及Org-N的去除率均达到80%以上,并且废水中的有机氮主要分解转化为NH3-N,其NH3-N转化率高达65%.生物活性炭表面繁殖了大量的长杆菌、钟形虫及少量的球菌,活性炭能够为微生物生长提供适宜的环境,并保护微生物避免受有毒难降解污染物的抑制作用,同时活性炭表面生长的微生物能够对活性炭进行生物再生,使其长期保持高效的吸附能力.