共存物质对重金属絮凝剂 MCC 除镉性能的影响简

为进一步拓展天然高分子絮凝剂壳聚糖的应用范围，以壳聚糖、L-半胱氨酸为原料，通过酰胺化反应制备一种具有重金属捕集功能的高分子重金属絮凝剂-2-氨基-3-巯基丙酰壳聚糖（MCC），研究了水体中常见的阴阳离子、有机配位剂及浊度对MCC除镉性能的影响，探讨了絮体形貌与絮体分形维数及絮凝除镉效果间的关系。结果表明，Na⁺、Cl^-、NO₃^-、F^-、SO₄^2-的存在对MCC除Cd²⁺均有促进作用，Ca²⁺表现为明显的抑制作用；低浓度的EDTA对除镉有促进作用，随着EDTA浓度的增大，逐渐转为抑制作用；低浓度的腐殖酸对MCC去除Cd²⁺有显著的促进作用；在一定范围内，浊度可促进 MCC对Cd²⁺的去除；絮体间空隙越多，絮体分形维数越小，除镉效果越好。     

新型TCAS吸附树脂对水中Cd2+的吸附去除研究

通过静态吸附试验，研究一种由超分子受体化合物磺化硫杂杯芳烃（TCAS）与树脂结合的产物——新型TCAS吸附树脂对重金属Cd²⁺的吸附去除性能，并初步探讨了吸附机理。试验研究结果表明，TCAS吸附树脂对Cd²⁺的饱和吸附量为14.45 mg/g。当温度为20℃，0.5 g TCAS吸附树脂对10 mL浓度为5 mg/L的Cd²⁺溶液吸附60 min时， Cd²⁺的去除率可达到99%以上。pH值是影响TCAS吸附树脂吸附效果的重要因素，在pH=5～9时，Cd²⁺的去除率随着pH值的升高而增大。在试验范围内，TCAS吸附树脂对Cd²⁺吸附符合Freundlich方程。吸附在TCAS吸附树脂上的Cd²⁺可洗脱回收，TCAS吸附树脂也可再生利用。 TCAS吸附树脂对重金属Cd²⁺的吸附机理主要归因于TCAS对Cd²⁺的络合作用。     

pH值、离子强度和重金属离子对腐殖酸紫外谱图的影响

研究pH值、溶液离子强度和金属离子对腐殖酸紫外光谱的影响,分析腐殖酸的结构特征,探讨E3/E4与pH值和溶液离子强度的关系。结果表明,腐殖酸的紫外光谱吸收带,随pH值增大主要发生蓝移。但随溶液离子强度增大,pH值对腐殖酸紫外吸收带的影响逐渐降低直至不影响。随溶液离子强度增大,腐殖酸的紫外光谱吸收带都发生红移、吸收强度增大。且腐殖酸的E3/E4值与溶液离子强度具有显著的正相关性。腐殖酸的紫外光谱中的吸收带,随投加Cu2+或Cd2+浓度增大而发生红移。     

不同来源溶解态腐殖酸与Cu2+作用的荧光特性

利用三维荧光等高线图以及其所确定的荧光峰荧光强度随溶液化学条件的变化，研究不同来源溶解态腐殖酸与Cu²⁺作用的荧光特性。研究结果表明：溶解态天然腐殖酸中主要存在二类发射荧光的有机物官能团能与Cu²⁺发生络合作用。位于激发波长和发射波长分别为271～281 nm和335～351 nm的荧光峰1所代表的有机物官能团是与Cu²⁺发生络合配位的主要点位；pH值为4～6时，其络合受pH值影响较显著；而受溶液离子强度影响较小。位于激发波长和发射波长分别为223～246 nm和335～371 nm的荧光峰2所代表的有机物官能团与Cu²⁺的络合作用受溶液pH值影响较小，受溶液离子强度影响较显著。溶解态商品腐殖酸荧光峰1′所代表的有机物官能团与Cu²⁺的络合作用荧光特性，与天然腐殖酸荧光峰1所代表的有机物官能团和Cu²⁺络合作用荧光特性相似，在pH值为3～7时，其络合受pH值影响较显著。     

纳滤去除水中的内分泌干扰物

采用陶氏DOW FILMTEC NF270芳香聚酰胺类复合纳滤膜处理水中内分泌干扰物——17α-乙炔雌二醇（EE2），实验中分别考察了原液浓度、操作压力、pH值、Ca²⁺浓度及腐殖酸共存等不同条件下对EE2截留效果的影响。结果表明，NF270对于去除水中的EE2具有很好的效果，截留率可达到97.6%，而且，实验发现，原液浓度对EE2的截留效果影响较小；当操作压力为0.6 MPa时，膜对EE2的截留效果最好；而随着pH值和Ca²⁺浓度的增加，膜对EE2的截留率均呈上升趋势；而当腐殖酸存在时膜对EE2的截留率有明显提高，但同时也造成膜污染加剧和膜通量下降，特别是在EE2、腐殖酸和Ca²⁺共存时，膜污染更加严重。     

TiO2光催化降解水中土霉素的动力学研究

环境中抗生素的出现及其引起的危害正受到越来越多的关注。以高压汞灯为光源，选用较为广泛的抗生素土霉素（OTC）为处理对象。考察了初始质量浓度、反应过程中光照、催化剂投加量、溶液起始pH、溶液中DOM和NO^-₃对光催化降解的影响，研究了其光降解动力学。结果表明，TiO₂光催化氧化法能够有效去除水中半微量的OTC，OTC的光降解过程符合一级反应动力学模型；UV/TiO₂联用工艺对TOC也有很好的去除效果，反应90 min，TOC去除率可达74%；OTC的初始浓度从30 mg/L增大到90 mg/L，反应速率从0.0619 min^-1降低到0.0130 min^-1；随着光催化剂投加量的增大，光降解速率常数先增大后减小；增加溶液的pH值，速率常数逐渐减小；溶液中的DOM和NO^-₃也可以影响光降解效率。     

污泥基活性炭吸附Cu2+的应用研究

以城市污水处理厂剩余污泥为原料，以ZnCl₂为活化剂制取污泥基活性炭。以此污泥基活性炭为吸附剂，对含Cu²⁺的废水进行了吸附实验研究。考察了溶液pH值、Cu²⁺的起始浓度对Cu²⁺离子吸附量的影响；利用等温吸附实验作出吸附等温线，并考察了污泥基活性炭吸附剂吸附Cu²⁺的动力学方程。实验结果表明，污泥基活性炭对Cu²⁺具有良好的吸附性能。吸附的最佳pH值为5；吸附符合Langmuir和Freundlich吸附等温方程，吸附为优惠吸附，吸附量随着吸附质溶液浓度的增加而增大；吸附平衡时间为4 h，吸附动力学符合二级动力学方程。     

壳聚糖联合碱改性粉煤灰对重金属离子的吸附特性

采用浸渍法将壳聚糖负载在经NaOH改性的粉煤灰上，制备了联合改性的粉煤灰。随粉煤灰上壳聚糖负载量的增加，粉煤灰对Pb²⁺和Cd²⁺的吸附率均提高。当负载壳聚糖的质量分数为8%，吸附温度为30℃，吸附时间为120 min时，粉煤灰对Pb²⁺的吸附率最高（为98.9%），对Cd²⁺的吸附率也最高（为91.5%）。其吸附行为符合Freundlich等温吸附模型，但表现为2个线性区。粉煤灰负载壳聚糖的改性机理是粉煤灰与带正电荷的壳聚糖的化学键合作用。     

铈离子光催化降解茜素绿的性能和机理简

主要研究了简单铈离子（Ce³⁺）在紫外光（UV）的作用下对蒽醌染料茜素绿（AG）的光催化降解效果和反应机理。结果表明，UV/Ce³⁺体系能够有效降解AG，初始反应速率随AG浓度的倒数值和Ce³⁺浓度的增加而线性增加，随初始溶液pH的增加先降低后增加，在酸性条件下有很高的TOC去除率。荧光探针实验表明，反应过程中可以产生·OH自由基。UV/Ce³⁺体系对其他类型染料和对硝基苯酚都有较好的降解效果。     

煤泥对水溶液中Ca2+的吸附性能研究

在静态条件下，研究了Ca²⁺在煤泥表面的吸附动力学。考察了不同Ca²⁺初始浓度的吸附实验，并对实验结果进行了动力学方程的拟合，结果表明，煤泥对Ca²⁺的吸附过程较好地符合准二级动力学方程。研究了初始Ca²⁺浓度、溶液pH值、振荡速度和煤泥质量对Ca²⁺吸附量的影响，实验结果表明：（1）煤泥对Ca²⁺吸附量随着Ca²⁺溶液浓度的增加而增大，Ca²⁺浓度大于3.828 mmol/L时，吸附量基本保持不变；（2）溶液pH<9时煤泥颗粒对Ca²⁺的吸附主要是静电吸附，pH>9时Ca²⁺在煤泥表面主要是沉淀吸附和一羟基吸附；(3) Ca²⁺在煤泥表面吸附的最佳振荡强度为150 r/min。     

次氯酸钠发生器的研制

介绍了电解法生产次氯酸钠的原理 ,并在原有生产工艺的基础上进行了重新设计和对设备的重新选择、改造 ,得出了各个工艺参数的最佳值 ,生产出高品质的次氯酸钠     

Estimation of uncertainty of sampling for analysis of pesticide residues

Abstract

A computer model was used to take random samples from primary sample populations obtained from field trials to simulate the uncertainty of sampling for residue analysis of plant commodities and soil. The results indicate about 40%, 30% and 20% relative uncertainty when random samples of size 5, 10 and 25 are taken respectively, from a single lot. Therefore the sample size should be the same for establishing and enforcing legal limits.     

不同泥源对厌氧氨氧化反应器启动的影响

采用2套上流式生物膜反应器,分别接种少量厌氧氨氧化污泥和大量硝化污泥,考察其对厌氧氨氧化反应器启动的影响。污泥接种入反应器后,测得接种厌氧氨氧化污泥的反应器(R1)内MLSS为0.22 g/L,另一个反应器(R2)MLSS为2.7 g/L。与直接接种厌氧氨氧化污泥相比,R1经过72 d的运行才显现出厌氧氨氧化特性。经过114 d的培养,前者氮去除速率由0.23 kg/(m3.d)提升到5.29 kg/(m3.d),总氮去除率大于89%;R2的氮去除速率由0.01 kg/(m3.d)提升到1.1 kg/(m3.d),总氮去除率大于84.6%。说明普通污泥启动需要一个较长的筛选过程,直接接种少量的厌氧氨氧化污泥比接种普通的污泥能够更快启动厌氧氨氧化反应器。     

Evaluation of the presence of drugs of abuse in tap waters

A total of seventy samples of drinking water were tested for non-controlled and illicit drugs. Of these, 43 were from Spanish cities, 15 from seven other European countries, three from Japan and nine from seven different Latin American countries. The most frequently detected compounds were caffeine, nicotine, cotinine, cocaine and its metabolite benzoylecgonine, methadone and its metabolite EDDP. The mean concentrations of non-controlled drugs were: for caffeine 50 and 19 ng L⁻¹, in Spanish and worldwide drinking water respectively and for nicotine 13 and 19 ng L⁻¹. Illicit drugs were sparsely present and usually at ultratrace level (<1 ng L⁻¹). For example, cocaine has mean values of 0.4 (Spain) and 0.3 ng L⁻¹ (worldwide), whereas for benzoylecgonine, these mean values were 0.4 and 1.8 ng L⁻¹, respectively. Higher concentrations of benzoylecgonine were found in Latin American samples (up to 15 ng L⁻¹). No opiates were identified in any sample but the presence of methadone and EDDP was frequently detected. Total mean values for EDDP were 0.4 ng L⁻¹ (Spain) and 0.3 ng L⁻¹ (worldwide). Very few samples tested positive for amphetamines, in line with the reactivity of chlorine with these compounds. No cannabinoids, LSD, ketamine, fentanyl and PCP were detected.     

An application of the theory of kinematics of mixing to the study of tropospheric dispersion

The most common technique used for numerical simulations of tracer mixing is that of the numerical solution of the advection–diffusion equation with the unresolved fluxes parameterized using the similarity theory. Despite correct predictions of the overall directions of transport, models based on a numerical solution of the advection–diffusion equation lack sufficient accuracy to correctly reproduce the coupling of mixing with small scale processes which are sensitive to the microstructure of the tracer distribution. The objective of this paper is to revisit the basic formalism employed in numerical models used to investigate atmospheric tracers. The main mathematical method proposed here is the theory of kinematics of mixing which could be applied effectively for simulations of atmospheric transport processes. At the beginning of the paper, we introduce simple mathematical transformations in order to demonstrate how complex topological structures are created by mixing processes. These idealistic flow systems are essential to explain transport properties of much more complex three-dimensional geophysical flows. An example of the application of the kinematics of mixing to the analysis of tracer transport on a planetary scale is presented in the following sections. The complex filamentary structures simulated in the numerical experiment are evaluated using some commonly applied statistical measures in order to compare the results with the data published in the literature. The results of the experiment are also analysed with the help of simple conceptual models of fluid filaments. The microstructure of the tracer distribution introduced in the paper is essential to increase our understanding of atmospheric transport and to develop more realistic parameterizations of small-scale mixing. The presented results could also be used to improve calculations of the coupling between microphysical processes and tracer mixing.     

Mechanisms of biodegradation of dibenzoate plasticizers

Biodegradation mechanisms were elucidated for three dibenzoate plasticizers: diethylene glycol dibenzoate (D(EG)DB), dipropylene glycol dibenzoate (D(PG)DB), both of which are commercially available, and 1,6-hexanediol dibenzoate, a potential green plasticizer. Degradation studies were done using Rhodococcus rhodochrous in the presence of pure alkanes as a co-substrate. As expected, the first degradation step for all of these systems was the hydrolysis of one ester bond with the release of benzoic acid and a monoester. Subsequent biodegradation of the monobenzoates of diethylene glycol (D(EG)MB) and dipropylene glycol (D(PG)MB) was very slow, leading to significant accumulation of these monoesters. In contrast, 1,6-hexanediol monobenzoate was quickly degraded and characterization of the metabolites indicated that the biodegradation proceeded by way of the oxidation of the alcohol group to generate 6-(benzoyloxy) hexanoic acid followed by β-oxidation steps. This pathway was blocked for D(EG)MB and D(PG)MB by the presence of an ether function.The use of a pure hydrocarbon as a co-substrate resulted in the formation of another class of metabolites; namely the esters of the alcohols formed by the oxidation of the alkanes and the benzoic acid released by hydrolysis of the original diesters. These metabolites were biodegraded without the accumulation of any intermediates.     

混凝试验搅拌器的研制

影响混凝效果的因素众多,混凝沉淀烧杯试验是进行水的混合、絮凝、沉淀工艺研究、设计和生产指导的最有效方法之一,阐述了智能型混凝试验搅拌器的设计原理和技术性能.     

产油微藻培养与回收的关键技术研究进展

寻找廉价而高效的替代原料是实现生物柴油产业化的关键所在.微藻以含油量高、生长周期短、环境适应能力强、生物产量高等优点,有望成为一种极具潜力的生物柴油生产原料.然而,目前尚存在微藻培养低效成本高和微藻回收效率低两大难题.综述了微藻培养与回收过程中的关键技术,并对存在的两大难题及其改进技术进行了详细的探讨.最后,总结并展望了微藻培养、回收技术未来的发展趋势.     

生物质快速热裂解主要参数对生物油产率的影响

以松木木屑为原料,在自制的小型流化床上,开展了生物质热裂解温度、生物质粒径和进料速率对生物油产率的影响实验研究.结果表明,在热裂解温度分别为450、475、500、525和550℃条件下,当热裂解温度为500℃时,生物油产率最高,平均产率达到53.33%（质量百分比）.反应温度越高,炭产量越低,不可冷凝气体产量越高,气体发热值越高;粒径＜1 mm的生物质其粒径对生物油产率影响不大;生物质进料速率增加时,生物油产率增加.本研究为生物能的利用提供了新的途径.     

造纸废水混凝处理中SFT助凝替代性研究

中小造纸厂废水处理常用PAC作混凝剂 ,PAM作助凝剂。由于PAM成本很高 ,影响了处理设备的投运率。用超细滑石粉 (SFT)替代PAM助凝 ,与混凝剂PAC配合 ,其混凝处理效果基本相当 ,但是处理成本降低 0 .10元 /m3 。由于SFT属环境无害材料 ,不会给排泥带来二次污染