聚铁混凝-臭氧-BAF对晚期垃圾渗滤液深度处理的研究

联合运用聚铁混凝-臭氧-曝气生物滤池(BAF)对晚期垃圾场的渗滤液进行深度处理。在废水进水COD=601mg/L,色度=400倍时,提出最佳工艺条件:聚铁0.6 mL/L,臭氧用量144 mg/L,BAF停留时间7 h。研究表明,聚铁去除大部分悬浮性有机物,臭氧降解难生物降解有机物并提高废水的可生化性,BAF进一步降解有机物,最终出水COD为75 mg/L,深度处理成本仅为5.5元/t。     

基于易回收的磁性碳纳米管催化湿式氧化处理垃圾渗滤液中的DOM

采用液相化学沉淀法制备了易于回收的磁性碳纳米管催化剂,应用于催化湿式氧化实验处理垃圾转运站渗滤液。结果表明,在反应温度为200℃,n(COD)∶n(H_2O_2)=1∶1.8,时间为60 min,催化剂添加量为0.1 g·L~(-1)的最佳条件下,垃圾渗滤液的COD去除率达到86.38%。出水可溶解性有机物(DOM)的紫外和三维荧光分析表明,实验对芳香族化合物和腐殖质的去除效果良好,可生化性提高。磁性碳纳米管在外加强磁场作用下30 s内便可实现快速分离,重复5次使用回收率可达90%。     

混凝-Fenton-BAF深度处理垃圾渗滤液中试研究

针对经过SBR处理后,难以再进一步生化降解的垃圾渗滤液,提出混凝-Fenton-曝气生物滤池(BAF)工艺进行深度处理.首先利用混凝去除SBR出水的悬浮性有机物,降低Fenton试剂的处理成本;然后采用Fenton试剂进行氧化处理,既降低垃圾渗滤液的COD值,又提高其可生化性,最后通过BAF工艺去除有机物,实验结果表明,在SBR出水COD为600～800 mg/L的情况下,最终出水的COD低于80 mg/L,处理成本仅为2.6元/t.     

城市生活垃圾填埋场渗滤液生化处理过程中重金属离子问题

我国对城市生活填埋场渗滤液处理技术的研究主要集中在COD与NH4 -N的去除上,对渗滤液中重金属离子的专项研究几乎未见报道.本文首先总结了国内外城市生活垃圾渗滤液中重金属的种类及浓度,在渗滤液中的存在状态,渗滤液中重金属与其他成分(有机物、氨氮)的相互作用关系,辨证分析了重金属在渗滤液生化处理过程中的有益作用和毒性,归纳了重金属在渗滤液生化处理过程中的变化规律,同时总结分析了重金属的去除技术.     

填埋结构对渗滤液中氨氮脱除的影响

建立了模拟填埋试验中试装置,研究了准好氧填埋渗滤液NH3-N的变化特性和稳定期垃圾对渗滤液NH3-N的处理效果.结果表明,准好氧填埋结构下渗滤液NH3-N衰减很快,下降率可达99.6%,没有出现传统填埋场累积的现象,为渗滤液后续处理解决了氨氮浓度过高的难题;随着水力负荷的增大,NH3-N的去除率呈下降趋势,去除率由低水力负荷时的99.9%,下降到高水力负荷时的87.7%;准好氧填埋垃圾对低可生化性、高浓度氨氮的渗滤液有很好的处理能力,但反硝化能力不足;较高有机物浓度有利于反硝化作用,使氨氮彻底转化为氮气.     

垃圾焚烧发电厂渗滤液生化出水的催化臭氧氧化处理

垃圾焚烧发电厂渗滤液生化出水是一种高盐,且含腐殖酸类和水溶性小分子有机物的复杂废水.本研究提出了采用Ca(OH)2预处理,并催化臭氧氧化处理的新工艺路线,对工艺参数和催化过程机理进行了分析.结果表明,Ca(OH)2可以有效地预处理去除生化出水中的腐殖酸类大分子有机物,当其用量为12 g/L时,可使COD的去除率达到70％～75％.Ca(OH)2可强化催化臭氧氧化处理预处理废水中剩余的难降解小分子有机物,其机理可能是及时去除了反应体系中生成的碳酸根离子,其适宜用量为2 g/L废水.当搅拌转速小于600 r/min,进口气相中臭氧浓度小于66.24 mg/L时,增大反应体系搅拌强度和进口臭氧浓度可以强化废水COD的去除速率.该工艺在深度处理垃圾渗滤液生化出水中难降解有机物领域具有较大的应用前景.     

臭氧化对垃圾填埋场后期渗滤液的预处理研究

应用自制微孔扩散式接触反应器,考察了不同pH条件下垃圾填埋场后期渗滤液的臭氧化预处理效果.结果表明,渗滤液初始pH值升高,臭氧利用率增大,垃圾渗滤液中COD、腐殖酸的去除速率加快;当初始pH为10时,经臭氧化处理120 min后,模拟废水的BOD5/COD可从初始的0.17提高到0.36,改善了废水的可生化性,同时渗滤液的色度、浊度、腐殖酸和SS也有较高的去除率.     

填埋结构对渗滤液中氨氮脱除的影响

建立了模拟填埋试验中试装置,研究了准好氧填埋渗滤液NH3-N的变化特性和稳定期垃圾对渗滤液NH3-N的处理效果.结果表明,准好氧填埋结构下渗滤液NH3-N衰减很快,下降率可达99.6%,没有出现传统填埋场累积的现象,为渗滤液后续处理解决了氨氮浓度过高的难题;随着水力负荷的增大,NH3-N的去除率呈下降趋势,去除率由低水力负荷时的99.9%,下降到高水力负荷时的87.7%;准好氧填埋垃圾对低可生化性、高浓度氨氮的渗滤液有很好的处理能力,但反硝化能力不足;较高有机物浓度有利于反硝化作用,使氨氮彻底转化为氮气.     

晚期垃圾渗滤液综合物理化学法改性预处理技术可行性研究

介绍了化学酸性絮凝 催化氧化 中和沉淀综合物理化学技术，改性预处理晚期垃圾渗滤液(BOD／COD≤0.18)实验研究，给出了结果。最终，晚期垃圾渗滤液经综合物理化学技术改性预处理后，BOD／COD显著提高，由难生化(BOD／COD≤0．18)变为较易生化(BOD／COD达0．31)，为其进一步生化达标处理(一级标准)创造了条件。     

城市污水管网对水质的生化改善特性

研究建立了一套长1 200 m的城市污水模拟管网,分析研究了城市污水管网对水质的生化改善特性。研究表明,污水经过1 200 m管网输送后,水中TCOD、NO_3~--N和NH_3-N含量均发生了变化,其中TCOD、NO_3~--N含量分别由292~420 mg·L~(-1)、0.26~0.6 mg·L~(-1)降低至205~315 mg·L~(-1)、0.13~0.29 mg·L~(-1),NH3-N含量由31~50 mg·L~(-1)上升为35~66 mg·L~(-1)。采用三维荧光分析了水中有机物的变化情况,结果表明,蛋白质及腐殖质的含量均沿程减少,而蛋白质发生了蓝移,腐殖质则发生了红移,表明其物质的化学结构发生了改变。结合有机物的分子量分析可知污水中高分子量(蛋白质等)及部分中等分子量有机物(腐殖质)向小分子量有机物(乙酸等)转化。进一步的研究表明,管网中微生物改变了水中有机物的构成,将不饱和性有机物转变为易于生物利用的饱和性物质,从而提高了污水的生化性。     

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.     

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.     

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。     

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.     

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.     

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     

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.