日本污水脱氮除磷深度处理工艺分析

为提高进入琵琶湖水体水质和有效恢复并保持琵琶湖流域水生态环境,日本滋贺县10家下水道污水处理厂全部采用脱氮除磷深度处理工艺。湖南中部净化中心目前规模为26.85万t/d,采用缺氧-好氧循环硝化/反硝化(AO)、厌氧-缺氧-好氧(AAO)和多段进水多级缺氧-好氧硝化/反硝化(SMAO)3种深度处理工艺。AAO工艺是国内城镇污水处理厂广泛采用的二级生化工艺,AO、SMAO工艺在国内还没有应用实例。AO、AAO工艺采用内循环硝化/反硝化反应脱氮,SMAO工艺采用无内循环的多段进水多级硝化/反硝化反应脱氮。AO、SMAO工艺采用化学方式除磷,PAC添加浓度约50mg/L。AAO工艺采用化学和生物组合方式除磷,PAC添加浓度降低到约30 mg/L。AO、AAO工艺出水BOD、CODMn、SS、TN和TP均值分别约为0.9 mg/L、5.2 mg/L、1 mg/L、6.5 mg/L和0.06 mg/L,相应的去除率约为99.5%、94.2%、99.5%、78.0%和98.1%。SMAO工艺出水TN约为2.5 mg/L,TN去除率提高到91.6%,其他指标和AO、AAO工艺基本相同。     

高浓度柠檬酸生产废水处理

采用厌氧 兼氧 好氧工艺处理柠檬酸生产排放的高浓度有机废水 ,处理后废水的BOD5和CODCr去除率达95 %以上 ,出水BOD5平均值为 5 8.5mg/L ,CODCr平均值为 30 4mg/L ,pH =6～ 9,达到排放标准 ,并生产沼气供生产生活使用。     

厌氧-两级SBR法处理高浓度洋蓟废水的研究

采用厌氧两级SBR工艺处理洋蓟罐头生产排放的高浓度有机废水,确定了厌氧、SBR工艺的最佳运行参数。结果表明,通过该工艺处理后,COD的总去除率达到98%以上,出水COD为78mg/L,达到国家排放标准。     

基于HPLC的厌氧 好氧生物降解工艺处理模拟苯胺废水的研究

采用改进的好氧-厌氧方法处理苯胺废水,研究了各个操作变量梯度包括苯胺浓度、硝基苯浓度等对苯胺废水处理的影响,并加入硝基苯作为影响参数。实验结果表明,各个变量均在不同程度上影响苯胺废水的处理。经过厌氧-好氧处理后,COD降到200 mg/L以下;提高苯胺浓度时,COD值增大;进水TOC浓度为167.80 mg/L,去除率为79.6%;加入硝基苯与苯胺的降解具有协同作用。在厌氧温度35～40℃,好氧温度28～32℃条件下,进水COD在4 000～6 000 mg/L,苯胺浓度180～250 mg/L左右,处理后出水COD值达到200～500 mg/L,苯胺4.5～6.5 mg/L左右,去除率约85%以上。出水水质可达到《污水综合排放标准（》GB 8978-1996）的排放标准。     

MBBR-SA工艺处理模拟大豆深加工废水厌氧出水及污泥减量化

针对大豆深加工高浓度有机废水厌氧出水的特点,采用移动床生物膜反应器-沉淀池-厌氧池(MBBR-SA)工艺进行处理,重点考察了其COD去除、脱氮以及污泥减量化的性能。处理前厌氧出水水质参数为COD 1 350～1 851 mg/L、TN 45～73 mg/L和TP 35～55 mg/L。结果表明,经过70 d的运行,在最佳水力停留时间(HRT)1.68 d与最佳回流比0.75条件下,出水平均COD、TN和NH4+-N浓度分别为91.5、12.4和11.4 mg/L,分别达到了《城镇污水处理厂污染物排放标准》二级标准、二级标准和一级B标准,其平均去除率分别为96.0%、87.4%和88.3%;该工艺未排放剩余污泥,其表观污泥产率为0.13,比MBBR降低了43.5%,具有明显的污泥减量化特性。     

厌氧折流板反应器-接触氧化工艺处理果汁废水

某果业有限公司果汁废水水量为1 500 m3/d,COD为4 500 mg/L,BOD为2 500 mg/L,,ss为2 500 mg/L,pH为6～7.采用厌氧折流板反应器(ABR)一接触氧化工艺处理该废水,出水COD为70 mg/L,BOD为10 mg/L,SS为55 mg/L,pH为8,达到<污水综合排放标准>(GB 8978-1996)一级排放标准.     

混凝沉淀-厌氧折流板反应池-两级好氧生化工艺处理毛毯废水

采用混凝沉淀 厌氧折流板反应池 两级好氧生化工艺处理毛毯废水。在废水 pH为 4 .6 3— 6 .95、CODCr为96 6— 1990mg/L、BOD5为 2 4 3— 4 97mg/L、SS为 344— 4 36mg/L、色度 4 0 0倍时 ,处理出水达到一级排放标准。该处理技术先进、可靠。     

MBBR处理猪场废水厌氧消化液的研究

采用移动床生物膜反应器(MBBR)处理猪场废水厌氧消化液,考察了水力停留时间(HRT),进水COD和NH3-N浓度对反应器处理效果的影响.结果表明,在温度为20～30℃,填料填充比为50%,进水COD和NH3-N浓度分别为1016 mg/L和496 mg/L条件下,当HRT为12.5 h时,COD和NH3-N去除率可分别达到62%和77%,猪场废水厌氧消化液中可生物降解性有机物基本得到去除,当HRT增至23.8 h时,COD和NH3-N去除率分别为64%和86%,出水COD和NH3-N浓度分别为368 mg/L和70 ms/L,均达到了<畜禽养殖业污染物排放标准>(GB18596-2001)的要求.     

高浓度柠檬酸生产废水处理

采用厌氧-兼氧-好氧工艺处理柠檬酸生产排放的高浓度有机废水，处理后废水的BOD5和CODCr去除率达95％以上，出水BOD5平均值为58．5mg／L，CODCr平均值为304mg／L，pH=6～9，达到排放标准，并生产沼气供生产生活使用。     

混凝-IBAC深度处理焦化废水的试验研究

以哈尔滨某气化厂焦化废水为目标,探讨混凝-固定化生物活性炭(IBAC)工艺对哈尔滨气化厂焦化废水进行深度处理的净化效能及其可行性.采用筛选、驯化的脱酚菌,对活性炭(GAC)进行固定,使之形成固定化生物活性炭.当该工艺进水COD＜800 mg/L时,出水COD在100 mg/L以下,平均去除率在80%左右;当进水总酚在200 mg/L以下时,出水的总酚含量基本在20 mg/L以下;当进水氨氮浓度在75 mg/L以下时,出水氨氮浓度在25 mg/L以下.焦化废水中各污染物指标经混凝-IBAC工艺深度处理后可达污水综合排放标准(GB 8978-1996)的二级标准.     

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