ASM1中化学计量系数与动力学参数的测定

为了应用活性污泥1号模型模拟印染废水为主的污水集中处理厂,针对该厂实际废水,选取关键的化学计量系数YH和动力学参数bH及H进行测定.详细叙述了YH、bH和H的测定原理及具体操作过程.YH、bH和H的实测结果分别为0.65、0.50、3.23,这些值不同于ASM1中20 ℃下城市污水的推荐值0.67、0.62、6.0.     

活性污泥数学模型中异养菌产率系数测定方法的研究

采用间歇活性污泥法和呼吸计量法测定活性污泥数学模型中异养菌产率系数.研究结果表明,间歇活性污泥法测定结果受试验控制条件特别是污泥有机负荷的影响非常大,且试验周期比较长;人工配水条件下,呼吸计量法测定异氧菌产率系数(YH)在0.71以上,比活性污泥数学模型推荐值高,其结果与底物性质有关,该方法准确性高,重现性良好.     

奥贝尔氧化沟工艺中异养菌动力学参数测定与分析

以西安市某污水处理厂奥贝尔氧化沟工艺为研究对象,运用呼吸计量法测试了该污水厂氧化沟内异养菌的产率系数、衰减系数和最大比增长速率参数值,并与ASM1推荐值比较分析认为,本实验测试结果可靠,更符合该污水处理厂的实际情况,并能为后续精确模拟和优化该厂工艺运营奠定基础。     

ECOSUNIDE工艺活性污泥中自养菌浓度的测定与分析

设计并利用在差压仪中密闭投加基质的实验方法,根据ASM模型中自养菌和硝化过程耗氧速率的关系,对比研究了ECOSUNIDE工艺和其他4个污水处理厂曝气池混合液中自养菌的浓度。研究表明,在不考虑自养菌增长和衰减情况下,ECOSUNIDE工艺混合液自养菌生物浓度为48.15 mg COD/L,该结果显著高于其他受试污水处理厂的混合液自养菌生物浓度(17.2～37.5 mg COD/L),表明ECOSUNIDE工艺在提高活性污泥中自养菌生物浓度上有较强的优势。设计的实验方法可以简便、有效地测定用于ASM模型中的自养菌浓度。     

采用序半连续反应器进行硝化和反硝化工艺的数学模拟

研究了生物废水处理应用于序半连续式反应器(SFBR)工艺中的微生物生长、硝化和反硝化动力学。基于活性污泥1号模型(ASM No．1)中的原理和结论，导出了在有氧阶段和缺氧阶段微生物生长速率、铵、硝酸盐、易生物降解基质等的反应速率及它们的物料平衡方程。在实验的基础上，对模型中的各参数采用了合适的方法进行参数估值，即：龙格-库塔法解常微分方程组和黄金分割法搜索最小误差，该模型的最小误差ε≈4．799；得出了应用于本工艺中数学模型中的各动力学参数和化学计量系数，如Ks39．997，KNO0．397，KNH1．997，KOA0．404，KOH0．297，μA0．0026，μH0．207，YA0．24，YH0．6。     

高负荷活性污泥法中污水有机组分表征

污水有机组分表征是高负荷活性污泥法(HRAS)模型建立的基础。针对经典活性污泥1号模型不适用于HRAS这一问题,提出了相应的双水解模型,即将污水有机组分中水解型有机物分为快速水解型与慢速水解型2种,发现两者水解动力学参数具有明显差异。对原水氧利用速率进行参数拟合,通过灵敏度和共线性分析,估计了快速生物降解型有机物、快速水解型有机物、慢速水解型有机物以及异养菌等4种污水有机组分,探讨了污水有机组分与增加HRAS碳源捕获率的关系。结果表明:以上4种有机组分均可被准确识别,共线性指数γK低于经验限值,各组分比例分别为13.9%、11.6%、12.6%和12.8%;从污水组分角度来说,提高HRAS碳源捕获率的3个方向分别为:反应器中的异养菌尽可能将快速生物降解型有机物和快速水解型有机物同化生成细胞物质;避免絮体污泥中的慢速水解型有机物过量水解;抑制异养菌衰减,减少内源呼吸产物的产生。双水解模型对污水有机组分成功表征有助于HRAS的设计、运行及优化。     

应用GPS-X软件模拟CAST污水处理厂及优化化学除磷

利用GPS-X软件模拟某污水处理厂循环式活性污泥法(CAST)工艺的处理效果,同时对其化学除磷过程提出改进措施。结合实测进水COD组分(SS,XSandSA),对ASM2模型参数(μh、Ks、kh、Kx)进行了校核,参数优化结果为:μh=4.36 d-1,Ks=1.6 g COD/m3,kh=2.01 d-1,Kx=0.01 g COD/m3。经模型组分和参数校正后出水COD、NH4+-N以及TN的模拟结果与实测值的误差小于10%。根据进水TP浓度和流量变化,实时灵活地调整化学药品投加量,模拟结果显示可以节约50%左右的消耗量。     

呼吸测量法测定废水中活性异养菌COD组分

废水中的活性异养菌(XH)会影响废水生物处理过程动力学,过程模拟需要对其定量表征.通过2种方法对城市污水中XH进行呼吸测量,分别结合XH最大比呼吸速率参数(P方法)和细胞生长过程模型拟合(F方法)测定其中的XH-COD组分.结果表明,F方法的测量结果是P方法的0.6～0.9倍,两者存在一定的丰廿关性;对于含高XH、低易生物降解基质(RBCOD)的废水,呼吸测量得不到明显的呼吸速率指数上升段,影响F方法的测定结果,水样稀释和外加RBCOD是可行的改进办法.使用P方法得到某城市污水厂进水的XH-COD占总COD的23%～46%(平均31%),高于多数文献报道结果.     

异养型生物过滤床硝化净化一氧化氮

采用生物滤床处理NO模拟废气,研究了停留时间(EBRT)、有机物浓度等在生物硝化去除NO技术中的作用过程.实验结果表明,EBRT和有机物含量是影响NO硝化去除效率的主要因素,NO去除效果随着有机物含量和EBRT的增大而提高;当进口浓度50 mg/m3,营养液中葡萄糖40 mg/L,EBRT＞3 min时,NO去除率达95%以上.比较自养菌和异养菌对NO硝化去除的效果,异养菌的去除效率提高20%～30%,具有广泛应用前景.     

利用数学模拟方法分析硝化MBR系统中SMP转换过程

为深入了解膜生物反应器(MBR)中微生物代谢产物(SMP)的生成降解以及利用情况,研究了以NH4Cl为惟一能源物质的硝化MBR反应器中SMP浓度以及分子量(MW)变化情况,并运用活性污泥模型3(ASM3)准确地计算出微生物利用底物相关的溶解性产物(UAP)和微生物死亡相关的溶解性产物(BAP)的量分别是多少,最终证明硝化系统中产生的SMP可作为能源物质被异养菌进一步利用,而且相较于BAP而言UAP更易于被生物降解,得出结论 BAP是SMP中的主要污染成分。     

Genetic polymorphisms in CYP1A1 and GSTM1 predispose humans to PCBs/PCDFs-induced skin lesions

INTRODUCTION: Polychlorinated biphenyls (PCBs) and dibenzofurans (PCDFs) are ubiquitous persistent pollutants in humans. Whether people with different genotypes are with different susceptibility to these chemicals are unknown. In a group of people highly exposed to PCBs/PCDFs, we tested the hypothesis that genotypic polymorphisms affected susceptibility for development of skin manifestations. METHODS: In 1979, approximately 2000 people in central Taiwan ingested cooking oil contaminated with PCBs/PCDFs. Skin disorder such as chloracne, abnormal nail, hyperkeratosis and skin allergy were found in PCBs/PCDFs exposed group. We recruited exposed and community background exposure subjects for blood testing and telephone-interview. Single nucleotide polymorphisms, AhR Arg554Lys, CYP1A1 Ile462Val, CYP1A1 T6235C, and GSTM1/T1 deletion, were determined. Occurrence of skin manifestations was compared among people with different genotypes while stratified by PCB exposure levels by logistic regression. RESULTS: Data on exposure, medical history, and genotypes were obtained from 393 exposed and 181 background exposure groups. Skin manifestations including chloracne, allergy, abnormal nail, and hyperkeratosis were more prevalent in exposed people in a dose-related manner. Among highly exposed individuals, combined CYP1A1-MspI mutant genotype and GSTM1-null genotype were associated with increased risk of chloracne (odds ratio 2.8, 95% confidence interval 1.1-7.6). Among intermediately exposed individuals, GSTM1 null genotype was associated with skin allergy. AhR Arg554Lys genotype and GSTT1 null genotype were not related to susceptibility to skin manifestations in PCB/PCDF-exposed population. CONCLUSION: CYP1A1 and GSTM1 genotypic polymorphisms might be related to the susceptibility to PCB/PCDF-induced skin manifestations.     

简化河流水质1号模型(RWQM1)实验研究

为了建立标准、一致的河流水质模型,并使它们可与标准活性污泥模型直接相连,国际水协会(IWA)专门成立了河流水质建模任务组,并发布河流水质1号模型(RWQM1)。根据河流水质1号模型(RWQM1)子模型选择原则,通过试验研究,得出以下两点结论:(1)简化河流水质1号模型能充分考虑废水生物处理自身的特点,较为深入地反映活性污泥生物反应过程的主要行为;(2)通过参数灵敏度分析,发现对模拟COD值影响较大的动力学参数是kgro,H,aer,To和khyd,To,对模拟TP值影响较大的动力学参数是kgro,H,aer,To、kgro,N1,To和βN1,对模拟NH3-N值影响较大的动力学参数是kgro,N1,To和βN1。     

废旧锂电池正极材料LiNi1/3Co1/3Mn1/3O2中钴的回收

随着新能源汽车工业的快速发展,废旧三元动力锂电池的量在不断地增加。三元动力锂电池中含有丰富的Co、Mn、Li和Ni资源,回收三元动力锂电池是防止环境污染和回收贵重金属的理想选择。利用抗坏血酸(C6H8O6)的酸性和还原性对废旧三元锂电池正极材料进行浸出,KMnO_4的强氧化性回收浸出液中的Co制备β-CoC_2O_4·2H_2O,采用浓度为1.3 mol·L~(-1)的C_6H_8O_6,在60℃的条件下对正极材料浸出20 min,向浸出夜中加入1 mol·L-1的H_2SO_4反应20 min后加入KMnO_4继续反应1 h,制得β-CoC_2O_4·2H_2O。实验结果表明,Co的回收率达91%,Li的浸出率可达96.4%,Mn和Ni完全浸出,可实现简单环保地浸出有价金属并回收Co。     

Heterogeneous reactions of ozone with pyrene, 1-hydroxypyrene and 1-nitropyrene adsorbed on particles

This work deals with the kinetic study of the reactions of ozone with pyrene, 1-hydroxypyrene and 1-nitropyrene, adsorbed on model particles. Experiments were performed at room temperature and atmospheric pressure, using a quasi-static flow reactor in the absence of light. Compounds were extracted from particles using pressurized fluid extraction (PFE) and concentration measurements were performed using gas chromatography/mass spectrometry (GC/MS). The pseudo-first order rate constants were obtained from the fit of the experimental decay of particulate polycyclic compound concentrations versus reaction time. Experiments were performed at three different O₃ concentrations from which second order rate constants were calculated. The following rate constant values were obtained at 293 K: k(O₃ + Pyrene) = (3.2 ± 0.7) × 10^?16 cm³ molecule^?1 s^?1; k(O₃ + 1OHP) = (7.7 ± 1.4) ×10 ^?16 cm³ molecule^?1 s^?1; and k(O₃ + 1NP) = (2.2 ± 0.5) × 10^?17 cm³ molecule^?1 s^?1, for pyrene, 1-hydroxypyrene and 1-nitropyrene adsorbed on silica particles. The variation in the rate constants demonstrates the strong influence of the substituent (OH or NO₂) on the heterogeneous reactivity of pyrene. The pyrene particulate concentration was also varied in order to check how this parameter may influence the experiments. Finally, oxidation products were investigated for all reactions and some were detected and identified for the first time for ozone heterogeneous reaction with pyrene adsorbed on particles.     

Recommended Standard Method for Continuing Dust Fall Survey (APM-1, Revision 1)

The suggested standard method of dust fall collection, as set forth in the following sections, is presented in an effort to promote a uniform approach to measurement of rate of dust fall     

Biosynthesis of (S)-1-(1-naphthyl) ethanol by microbial ketoreductase

Environmental Science and Pollution Research - (S)-1-(1-naphthyl) ethanol (SNE) is a chiral drug intermediate for the production of mevinic acid analog, a potent cholesterol agent. It acts as an...     

Effects of dietary habits and CYP1A1 polymorphisms on blood dioxin concentrations in Japanese men

The major source of dioxin impurities in Japan in the past was agrochemical formulations; more recently, it has been exhaust from waste incinerators. To examine the environmental and genetic factors that influence blood dioxin concentration, we investigated the relationship among dioxin concentrations, dietary habits and cytochorome P450 1A1 (CYP1A1) polymorphisms (MspI type and Ile-Val type) in Japanese fishermen and farmers, including also a group of office workers as controls. The mean dioxin concentrations in the fishermen, the farmers and the controls were 161369, 79079 and 100500 pg/g fat, respectively. The elevated dioxin concentration with polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and coplanar-PCBs found in the fishermen may be due to the frequent consumption of fish; no such relationship was found both in the farmers and the controls. We found that the concentrations of congeners found as impurities in certain chemicals such as those previously used in agriculture showed no significant differences among the three groups; we consider it unlikely that the farmers would be directly exposed to dioxins from such chemicals. Thus, it is probable that the primary route of dioxin exposure in the Japanese population is through the food chain via fish consumption, regardless of occupation. No meaningful relationship between blood dioxin concentration and CYP1A1 polymorphisms was found in this study, although there was a significant difference between the concentration of total non-ortho-PCBs in genotypes A and B. Further studies on more subjects, including those of genotype C, are needed to confirm the relationship between blood dioxin concentrations and MspI polymorphisms.     

微生物絮凝剂EBU-1的化学性质分析

对一株产碱假单胞菌(Pseudomonas alcaligenes)产生的微生物絮凝剂EBU1的化学性质进行初步研究,结果显示，EBU-1具有良好的热稳定性；呈色反应为多糖的颜色反应，没有蛋白质的颜色反应；紫外和红外扫描确定EBU-1含多糖及少量核酸，含量分别为82.3%和8.6%；电负性实验表明，EBU-1是阴离子型微生物絮凝剂。