H2O2处理酸性大红GR染料废水的研究

通过对废水pH值、H2O2用量、催化剂用量、反应时间、反应温度等工艺条件的考察,确定了H2O2催化氧化处理酸性大红染料废水的最佳工艺条件pH 4、H2O2用量6 mL/L、催化剂用量3 g/L、反应时间100 min、反应温度70℃.在该条件下,COD和色度的去除率分别为76.7%和99.4%;通过反应前后的紫外-可见光光谱分析表明,H2O2催化氧化处理酸性大红GR染料废水有比较好的效果,为该工艺处理酸性大红GR染料废水提供了科学依据.     

H2O2处理酸性大红GR染料废水的研究

通过对废水pH值、H2O2用量、催化剂用量、反应时间、反应温度等工艺条件的考察，确定了H2O2催化氧化处理酸性大红染料废水的最佳工艺条件：pH4、H2O2用量6mL／L、催化剂用量3g／L、反应时间100min、反应温度70℃。在该条件下，c0D和色度的去除率分别为76．7％和99．4％；通过反应前后的紫外一可见光光谱分析表明，H2O2催化氧化处理酸性大红GR染料废水有比较好的效果，为该工艺处理酸性大红GR染料废水提供了科学依据。     

粉煤灰负载铁离子催化氧化活性黄染料废水

以粉煤灰为载体,制备铁/粉煤灰负载型催化剂,并利用该催化剂催化H2O2氧化降解活性黄染料废水,探讨了H2O2投加量、催化剂投加量、染料初始浓度和初始pH值等因素对染料废水COD去除率和脱色率的影响。结果表明,当染料废水COD初始浓度为200 mg/L,初始pH值为1.7,投加0.5 g/100 mL催化剂及加入1.0 mL浓度为1.13 mol/L的H2O2溶液时,处理效果最好,此时染料废水的COD去除率和脱色率分别达到63%和99%,并且废水的可生化性得到很大的提高。利用该负载催化剂能够有效地减少活性黄染料废水中Fe3+的残留量。     

负载型纳米复合半导体WO_3-TiO_2/AC光催化降解刚果红废水

采用溶胶-凝胶-浸渍-焙烧法制备了负载型纳米复合半导体WO3-TiO2/AC光催化剂,以偶氮染料刚果红为目标降解物,通过正交实验优化了刚果红废水的降解条件,并对其光催化动力学进行了探讨.结果表明,刚果红废水的最佳降解条件为:催化剂投加量10 g/L,pH=7,H2O2用量为3.5 mL/L.在最佳条件下,当刚果红废水起始浓度为40 mg/L时,反应120 min后,刚果红溶液的去除率可达95.21%,较相同条件下TiO2/AC对刚果红染料的降解率提高了19.57%.光催化剂对刚果红的光催化降解符合Langmuir-Hinshelwood(L-H)模型.     

催化臭氧氧化降解糖蜜酒精废水的研究

以SnO2为催化剂,研究糖蜜酒精废水在臭氧条件下的氧化降解反应,为糖蜜酒精废水的治理提供一种新的处理方法.研究表明,SnO2加速了臭氧氧化反应,使糖蜜酒精废水的氧化降解加快.影响糖蜜酒精废水氧化降解的主要因素有臭氧流量、废水的初始pH和催化剂用量等.加大臭氧流量及增加催化剂用量,均有利于糖蜜酒精废水的降解.适宜的反应条件是:糖蜜酒精废水的稀释倍数为10倍,臭氧流量为130 mg/h,催化剂用量为2.500 g/L,废水的初始pH为4.25,温度为30 ℃.在该条件下反应60 min,废水的脱色率为60.2%,COD去除率为44.5%.动力学分析表明,单独臭氧氧化降解糖蜜酒精废水和SnO2催化臭氧氧化降解糖蜜酒精废水均为拟一级反应.     

负载型纳米复合半导体WO3-TiO2/AC光催化降解刚果红废水

采用溶胶-凝胶-浸渍-焙烧法制备了负载型纳米复合半导体WO₃-TiO₂/AC光催化剂，以偶氮染料刚果红为目标降解物，通过正交实验优化了刚果红废水的降解条件，并对其光催化动力学进行了探讨。结果表明，刚果红废水的最佳降解条件为：催化剂投加量10 g/L，pH=7，H₂O₂用量为3.5 mL/L。在最佳条件下，当刚果红废水起始浓度为40 mg/L时，反应120 min后，刚果红溶液的去除率可达95.21%，较相同条件下TiO₂/AC对刚果红染料的降解率提高了19.57％。光催化剂对刚果红的光催化降解符合Langmuir-Hinshelwood（L-H）模型。     

活性炭负载Fe~(3+)催化H_2O_2氧化邻苯二甲酸二甲酯

将Fe3+负载在活性炭上制得载铁催化剂Fe/AC,并研究了该催化剂对邻苯二甲酸二甲酯(DMP)的催化降解性能。通过正交实验和单因素实验,探讨了催化剂投加量、H2O2投加量、溶液pH值和反应温度对水中DMP降解率的影响,同时对DMP矿化度进行了分析。实验结果表明,制得的载铁催化剂具有较高的催化活性;降解效果的影响顺序是反应温度催化剂投加量H2O2投加量溶液pH值;在反应温度为80℃、催化剂投加量为4 g/L、H2O2投加量为20 mL/L和溶液pH值为3的条件下反应120 min后,质量浓度为10 mg/L的DMP降解率最高可达97.73%;在优化的实验条件下反应150 min,DMP矿化度可达62.73%;催化剂反复使用5次仍具有较好的催化活性,DMP降解率仍可达到77%以上;反应过程中溶液Fe3+浓度的变化维持在1.07 mg/L左右,且可推测催化降解DMP主要是由非均相和均相催化氧化反应共同作用的。     

非均相UV/Fenton氧化法降解水中六氯苯的研究

采用超声辐照促进浸渍法制备了非均相UV/Fenton催化剂Fe/Al2O3,并对其进行了表征.以制备的催化剂对水中六氯苯进行非均相UV/Fenton法氧化降解.考察了铁的负载量、初始pH、H2O2投加量、催化剂投加量和反应时间对六氯苯降解效果的影响,并探讨了六氯苯的降解动力学规律.结果表明,制备的催化剂表面活性组分分散均匀,对六氯苯具有较高的催化活性和重复利用性.非均相UV/Fenton法降解六氯苯的最佳实验条件为:铁的负载量为2%,废水初始pH为3,H2O2和Fe/Al2O3催化剂的投加量分别为34 mg/L和150 mg/L,反应时间为20 min.在此条件下,浓度为500μg/L的六氯苯降解效率达94.5%.HCB的降解反应动力学规律可用Langmuir-Hinshwood方程很好地描述.六氯苯在催化剂表面的吸附常数为1.962 L/mg,表面反应速率常数为0.08 mg/(L·min).     

活性炭负载Fe^3＋催化H2O2氧化邻苯二甲酸二甲酯

将Fe3＋负载在活性炭上制得载铁催化剂Fe/AC,并研究了该催化剂对邻苯二甲酸二甲酯（DMP）的催化降解性能。通过正交实验和单因素实验,探讨了催化剂投加量、H2O2投加量、溶液pH值和反应温度对水中DMP降解率的影响,同时对DMP矿化度进行了分析。实验结果表明,制得的载铁催化剂具有较高的催化活性;降解效果的影响顺序是反应温度〉催化剂投加量〉H2O2投加量〉溶液pH值;在反应温度为80℃、催化剂投加量为4 g/L、H2O2投加量为20 mL/L和溶液pH值为3的条件下反应120 min后,质量浓度为10 mg/L的DMP降解率最高可达97.73%;在优化的实验条件下反应150 min,DMP矿化度可达62.73%;催化剂反复使用5次仍具有较好的催化活性,DMP降解率仍可达到77%以上;反应过程中溶液Fe3＋浓度的变化维持在1.07 mg/L左右,且可推测催化降解DMP主要是由非均相和均相催化氧化反应共同作用的。     

喷射环流三相光催化反应器可见光下降解酸性湖兰A的研究

设计了一种喷射环流三相光催化反应器。用该反应器在可见光下,对染料酸性湖兰A在不同初始浓度、催化剂浓度、pH、光照时间下光催化降解脱色率的影响进行了研究。实验结果表明,反应最佳pH为6,反应最佳时间为20min,催化剂最佳投加量为8g／L。在最优条件下,染料脱色率达90％以上。     

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.     

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.     

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。     

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