姜黄素修饰CNC传感器与水凝胶制备及其检测和去除Pb2+的研究

本研究利用EDC/NHS耦合法将姜黄素（Cur）接枝于羧基化纤维素纳米晶体（CCNC）,制备纳米纤维素接枝姜黄素（CCNC-Cur）传感器和CCNC-Cur复合海藻酸钠（CCNC-Cur-SA）水凝胶吸附剂,用于检测和去除Pb²⁺。结果表明,CCNC-Cur传感器可特异性吸附Pb²⁺,利用Image J软件对传感器的颜色深度进行数字化处理后,得到Pb²⁺的检出限为6.25 mg/L;在静态吸附实验的优化条件下（吸附时间105 min、pH值=5、吸附剂用量0.08 g）,CCNC-Cur-SA水凝胶对Pb²⁺的吸附量达98.3 mg/g。     

改性木质素胺吸附剂对废水中Pb2+的吸附

以木质素、二乙烯三胺和甲醛为原料,通过Mannich反应合成改性木质素胺吸附剂,考察了不同吸附条件对Pb2+吸附效果的影响。实验结果表明：n(木质素)∶n(二乙烯三胺)∶n(甲醛)=1∶1.5∶4.5条件下,改性木质素胺吸附剂对Pb2+吸附效果最好;在吸附温度为45℃、吸附剂用量为1.2g/L、溶液pH值为5.0、吸附时间为24h的最佳吸附条件下,合成的吸附剂对Pb2+的去除率为59.82％,吸附量为49.85 mg/g。该吸附过程为慢性吸附,动力学模型符合McKay二级吸附动力学。改性木质素胺对Pb2+吸附过程是受颗粒内扩散和液膜扩散的共同影响,其中颗粒内扩散是主要的控制步骤。     

综合法制备二氧化氯过程中的分解控制措施

简要介绍了使用综合法(R6法)制备ClO_2的原理及工艺流程,对常见的ClO_2产生分解的原因进行分析,并针对各项原因提出相应措施。     

木素脱氢聚合物-葡萄糖复合体形成机理的研究

为阐明植物纤维细胞壁中木素与聚葡萄糖化学键的连接,本研究探讨了在(6-13C)葡萄糖和纤维二糖的存在下,松柏醇葡萄糖苷的过氧化物酶催化脱氢聚合过程中与碳水化合物之间化学键的形成。研究发现,木素脱氢聚合物(DHP)能与(6-13C)葡萄糖形成DHP-(6-13C)葡萄糖的聚合物,核磁共振碳谱(13C NMR)分析结果表明,葡萄糖C6位上的碳与木素结构单元以苯甲醚键连接。此外,研究还发现,木素前驱物与纤维二糖之间发生了共聚,得到了DHP-纤维二糖的复合体,13C NMR分析结果表明,纤维二糖与DHP之间可能存在苯甲醚键、苯甲酯键和α-缩醛键等化学键的连接。     

交联胺化改性剂TETS改性棉纤维染色性能的研究

用多官能团的交联胺化改性剂TETS对纤维素纤维进行改性，在赋予织物抗皱功能的同时，纤维的染色性能也发生了很大的变化，活性染料染色的上染率和固色率大大提高．TETS改性为纤维素纤维的交联胺化改性以及实现活性染料的酸性（或中性）无盐染色提供了一条新的途径．     

球形木素树脂的胺化改性研究

用3-氯-2-羟丙级-三甲基氯化铵(CHPTA)对球形木素磺酸盐树脂(RLS)进行了胺化改性,在树脂结构中引入季铵基团,得到的产品同时具有阴阳离子交换与吸附作用,是一种含有磺酸基、羟基、羰基和季铵基等多功能基团的球形木素基吸附剂(ARLS)。通过正交实验确定了实验室研究的优化条件,在优化条件下制得的胺化改性产品的阴离子交换容量为0.67mmol/g,阳离子交换容量为2.22mmol/g。     

改性蔗渣纤维素吸附剂的制备研究进展

蔗渣来源广泛,价格便宜,改性蔗渣纤维素吸附剂是一种天然高分子水处理剂,成本低,使用量小,制备简单,大力发展其在水处理当中的应用,符合绿色化学的发展的方向。本文简单介绍了蔗渣纤维结构及形态特点,并对近年来改性蔗渣在水处理中的应用作了具体的综述。     

改性木素的絮凝脱色作用

以造纸黑液中提取的木素为合成原料,通过Mannich反应使木素胺化改性;以氮元素含量来确定木素的改性率;采用正交实验来确定温度、甲醛和己二胺的用量对木素改性率的影响,从而确定最佳工艺条件。比较了超声活化对木素的胺化改性效果的影响。通过红外、电镜对木素和改性木素的结构进行了分析,并用改性木素进行了品红溶液的絮凝脱色实验,研究了脱色时间和改性木素用量对品红溶液脱色效果的影响。结果表明,影响木素改性率的主要因素是甲醛用量和温度,改性木素对品红溶液具有很强的絮凝脱色效果,当脱色时间为100 min、样品用量为10 mg（即0.5 g/L）时脱色率高达93%。     

超声作用对木质素胺化改性的影响

以制浆黑液中提取的木质素为原料,通过Mannieh反应使木质素胺化改性合成阳离子木质素胺,以含氮量来确定木质素的改性程度.探讨了超声作用对木质素胺化改性的影响,采用红外、差热等分析测试方法对木质素和术质素胺的结构进行研究,通过黏度和表面张力的测定对木质素胺的物理性能进行了分析.结果表明,超声处理有助于提高木质素的反应活性,使木质素的改性率增加,木质素经碱活化后再超声处理的改性效果更好,改性样品表面活性明显增强.     

苎麻纤维胺化改性对其染色性能的影响

利用三乙醇胺、二甲胺和乙二胺3种胺类化合物对苎麻纤维进行改性,改善苎麻纤维的染色性能。通过考察活性染料对改性苎麻纤维的上染率和固色率,确定了3种胺类化合物对苎麻改性的工艺条件。三乙醇胺最佳改性工艺：温度80℃,浓度1．2mol／L,时间120min,介质50％乙醇;二甲胺最佳改性工艺：温度60℃,浓度1．2mol／L,时间120min,介质50％乙醇;乙二胺的最佳改性工艺：温度40℃,浓度0．6mol／L,时间90min,介质50％乙醇。结果表明,胺化改性可以显著提高苎麻纤维的染色性能。     

造纸污泥基纳米复合材料的制备及其对废水中重金属的吸附

利用造纸污泥与壳聚糖制备造纸污泥-壳聚糖(SL-CSA)纳米复合吸附材料,研究了SL-CSA纳米复合材料对废水中铬离子(Cd²⁺)和铅离子(Pb2+)的吸附性能。通过傅里叶变换红外光谱仪(FT-IR)和扫描电子显微镜(SEM)表征证明了复合材料的成功制备。吸附实验表明,SL-CSA纳米复合材料对Cd²⁺和Pb²⁺的吸附均遵循准二级动力学方程,属于化学吸附。根据Langmuir模型,SL-CSA纳米复合材料对Cd²⁺和Pb2+的最大吸附量分别为314.05 mg/g和320.06 mg/g。     

两株乳酸菌对铅的吸附作用

以双歧杆菌和鼠李糖乳杆菌为研究对象,研究其对不同浓度铅的耐受性和吸附性,对pH值、初始湿菌量以及初始铅离子浓度进行单因素试验,利用热力学及动力学模型对两株乳酸菌结合铅离子的过程进行模拟。分析结果表明:两株菌对铅的耐受性较好,初始铅离子浓度为50 mg/L,吸附最佳条件是pH值6,初始湿菌添加量1g/L,该条件下双歧杆菌和鼠李糖乳杆菌对铅的吸附率分别为97.44%,96.87%;Langmuir-Freundlich模型比Langmuir模型和Freundlich模型更适合其结合铅离子的过程,准二级动力学模型比准一级动力学模型更适合,说明两株菌与铅的作用机制为化学吸附和物理吸附。     

Simultaneous determination of calcium,magnesium and zinc in different foodstuffs and pharmaceutical samples with continuous wavelet transforms

This work presents novel and very simple spectrophotometric methods by ratio spectra–continuous wavelet transformation for the simultaneous determination of ternary mixtures of calcium, magnesium and zinc without prior separation steps. The methods are based on the complexation reaction of these elements with bromopyrogallo red (BPR) at pH 9.4. The results showed that calcium, magnesium and zinc could be determined simultaneously in the range of 0.1–3.5 mg L⁻¹, 0.2–3.2 mg L⁻¹ and 0.5–3.8 mg L⁻¹, respectively. Mexican hat and Morlet from the family of continuous wavelet transforms were selected and applied under the optimal conditions for multi-component determinations. In this study for improving the sensitivity the normalized spectra of divisors were used instead of standard spectrum of divisor. The method was tested by analyzing various synthetic ternary mixtures of Ca²⁺, Mg²⁺ and Zn²⁺. Under the working conditions, the proposed methods were successfully applied to simultaneous determination of elements in cows’ milk, powder milk, pharmaceutical product and tea samples.     

Influence of Ni and Co on methanogenic activity and the amounts of coenzymes involved in methanogenesis

The requirement of Ni²⁺ and Co²⁺ addition on methanogenic activity and the coenzymes involved in methanogenesis were investigated in anaerobic continuous cultivation with synthetic wastewater using acetate as the sole carbon source. Addition of Ni²⁺ and Co²⁺ to the synthetic wastewater drastically increased the maximum dilution rate of the cultivation. The concentrations of coenzymes F₄₃₀ and corrinoids in the biomass increased to 0.62 μmol-Ni/g-VSS and 0.67 μmol-Co/g-VSS, respectively with the increase of the dilution rate. Methanogenic activity of the culture broth also increased with an increase of dilution rate. However, without addition of Ni²⁺ and Co²⁺, F₄₃₀ and corrinoids were not detected in the biomass and methanogenic activity was only a trace level at a dilution rate of 0.025 d⁻¹. When the amounts of Ni²⁺ and Co²⁺ added at a dilution rate of 0.6 d⁻¹ were lowered in steps, the concentrations of F₄₃₀ and corrinoids in the biomass and methanogenic activity decreased with decreasing amounts of Ni²⁺ and Co²⁺ added. These results suggest that Ni²⁺ and Co²⁺ were required for the methane-producing reactions via increases of coenzymes F₄₃₀ and corrinoids.     

Molecular structure of La3+-induced methanol dehydrogenase-like protein in Methylobacterium radiotolerans

La(3+) and not Ca(2+) increases methanol dehydrogenase (MDH) activity in Methylobacterium radiotolerans NBRC15690. La(3+)- and Ca(2+)-MDH-like proteins were found to be homodimeric (α(2)) and heterotetrameric (α(2)β(2)), respectively. N-terminal amino acid sequences of these proteins revealed that La(3+)- and Ca(2+)-MDH-like proteins were encoded by xoxF and mxaFI, respectively.     

Synthesis of Fe3+-doped Aminated Lignin as A Peroxidase Mimic for Colorimetric Detection of H2O2 and Glucose

Peroxidase plays an important role in living systems; however, its storage difficulty and easy inactivation have limited its applications in complex environments. To address these problems, herein, we proposed a method to synthesize peroxidase mimics by amination, carbonization, and Fe³⁺-doping of industrial alkali lignin. The Fe³⁺-doped lignin-based peroxidase mimic (Fe-LPM), with active centers of coordination between Fe³⁺ and N atoms, showed higher tolerance to pH value and temperature than natural peroxidase. Using Fe-LPM, 10-100 mmol/L of H₂O₂ and glucose could be colorimetrically detected with the lowest detection limits of 80 μmol/L and 1.5 mmol/L and visual detection limits of 1.0 mmol/L and 10 mmol/L, respectively. The Fe-LPM maintained peroxidase-like activity after 10 cycles and could even be used for H₂O₂ detection in practical samples. This work not only provides a new approach to synthesize peroxidase mimics using biomass materials but also promotes the high-value utilization of lignin.