高温污泥厌氧消化器的启动

污泥厌氧消化是最常用的污泥减量化和稳定化技术,高温消化污泥稳定快,但我国缺乏启动和运行经验,故进行了高温厌氧消化器处理剩余活性污泥的中试启动试验.所采用的消化器为内循环消化器,它属于升流式反应器.依赖回流沼气控制反应器的水力状况.启动采用了分步适应的策略,促进厌氧细菌适应温度、反应器构型和处理对象的变化.主要措施有:启...     

常温低氨氮SBR亚硝化启动策略研究

分析了不同接种污泥下,不同启动策略以及不同水质下SBR反应器亚硝化的启动.研究发现,控制低溶解氧(DO为0.30mg/L)条件,接种具有一定亚硝化效果的污泥,能在短时间内实现亚硝化的启动;而接种全程硝化污泥在29d(58个周期)的培养中都未出现亚硝酸盐的积累.而通过高、低溶解氧交替培养的模式,接种全程硝化污泥的反应器也能在27d(54个周期)内达到60%以上的亚硝化率.接种全程硝化污泥,控制低溶解氧(DO为0.30mg/L),用不同C/N的水质驯化污泥.其中使用C/N为0.40~0.93的A/O生物除磷工艺二级出水作为进水的反应器在32个周期的培养中出水未出现亚硝酸盐的积累;而使用C/N比在3.50~5.34范围内的小区化粪池水能实现亚硝化的快速启动.     

石墨炉原子吸收法测定食用菌中镉和铅

采用塞曼效应背景校正、最大功率升温和峰面积积分,以钯和抗坏血酸为基体改进剂,用恒温平台石墨炉原子吸收法测定食用菌中镉和铅,检出限镉为5.0×10-13g,铅为4.0×10-12g,相对标准偏差在2.8%~7.1%之间,加标回收率镉为92.0%~104%,铅为89.3%~95.0%。     

石墨炉原子吸收法最佳条件选择分析

主要对石墨炉原子吸收法测定铬元素的最佳实验条件的选择进行研究,最佳工作条件的选择包括石墨管的选择、石墨炉最佳升温程序的选择。     

Modelling of heating furnace fire scenarios using fault tree analysis,a bayesian network,and a thermal transfer method for system reliability analysis

Energy production for oil companies requires high-performance equipment. However, after a certain period of use, this equipment could be damaged, causing numerous problems and defects, impeding production, and leading to incidents that may cause material and human losses. Therefore, it is necessary to master the performance parameters of each equipment, which are key indicators of its functionality and can indicate the possibility of reusing it after inspection and diagnosis. However, it is worth noting that the studied system is a vertical cylindrical furnace in Algeria's refinery. This paper describes a new hybrid approach, a methodology that evaluates system reliability by combining two studies. The first is based on the surety of the system's functioning through an analysis with a fault tree to identify the risks, followed by a quantitative analysis using a Bayesian method. The second study follows the thermal calculation of the equipment's performance parameters, namely: the thermal efficiency (η), heat transfer coefficient (h), and heat absorbed quantity (Q), using heat balance equations to quantify the heat absorbed quantity and identify the fluid flow regime inside the tube. The calculation considers three cases: The design case, the failure case, and the after renovation case. The originality of this work appears when the collected findings from the second study are fed into the first study's Bayesian Network (BN) to analyse the system's reliability using the calculated parameters. Then, BN is used to calculate the Probabilistic Importance Factors (PIFs) in order to identify the most impactful system components. Finally, a prediction analysis was conducted. The latter reveals that one of the furnace's major faults is the fumes accumulation inside the combustion chamber. Corrosion, overheating, coke formation inside the tubes, dumper deformation, and burner tip clogging all contribute to this fault.     

基于不同接种污泥复合型厌氧氨氧化反应器的快速启动特征

为获得快速启动厌氧氨氧化的最佳污泥源及厌氧氨氧化颗粒污泥的快速形成工艺,采用本实验室自主研发复合型CAMBR反应器(厌氧折流板反应器(ABR)+膜生物反应器(MBR),分别接种厌氧颗粒污泥(R1)和絮状反硝化污泥(R2),考察不同接种污泥的厌氧氨氧化启动特征和颗粒化程度.结果表明,R1与R2反应器分别耗时45 d和60 d均成功快速启动厌氧氨氧化,其启动过程均可分为活性停滞期、活性提高期、活性稳定期3个阶段,但每个阶段氮素的去除规律略有不同,稳定运行期内,R1和R2反应器内NH_4~+-N和NO-2-N的平均去除率均高达95%以上;此外,R1反应器中形成了直径0.8~1.6mm为主的厌氧氨氧化红色颗粒污泥,R2反应器则以不规则块状和絮状为主,颗粒化程度较低,两个反应器内均可观察到红色颗粒污泥上浮现象;稳定运行期内NH_4~+-N、NO-2-N和NO_3~--N之间的定量关系分析表明:R1反应器内可能存在着硝酸盐型厌氧氨氧化,致使NH_4~+-N过量转化,R2反应器内则为典型亚硝酸盐型厌氧氨氧化.     

低浓度氨氮废水单级自养脱氮EGSB反应器的快速启动

将单级自养脱氮生物膜污泥作为种泥接种于膨胀颗粒污泥床反应器中,并对该反应器进行启动.在温度为(30±2)℃,p H值为7.8~8.2,DO为0.2~1.1 mg·L~(-1),上升流速为2.0~4.0 m·h~(-1)的条件下,进行了低浓度氨氮(60~100 mg·L~(-1))废水的单级自养脱氮工艺快速启动研究.结果表明,经过83 d的运行,反应器历经适应期、提高期和稳定期后,稳定运行阶段NH_4~+-N、TN去除率分别达到99.4%和80.7%.通过控制回流比和提高进水氨氮负荷维持了稳定的低DO状态,有效抑制了硝化细菌的生长,而部分亚硝化反应和厌氧氨氧化反应为主导反应并能保持高效、稳定的脱氮效果,成功实现了在膨胀颗粒污泥床反应器中单级自养脱氮过程的启动.颗粒污泥平均粒径从174μm增大到296μm.扫描电镜显示颗粒污泥表面光滑,微生物以球菌、短杆菌为主.FISH结果显示亚硝化细菌分布在颗粒污泥表面,厌氧氨氧化菌分布在颗粒污泥内部.反应器中构建了稳定的自养脱氮颗粒污泥系统.     

事故树法在煤气发生炉环境风险评价中的应用

针对煤气发生炉事故特点,采用事故树分析法对其进行环境风险评价,从最小割集、最小径集以及结构重要性3个方面解释煤气发生炉事故的主要原因,根据基本事件的重要性,比较分析事故的预防重点,并提出相应防控措施和应急预案。事故树法能够全面描述事故发生的原因及其逻辑关系。     

四区一体反应器冬季启动脱氮特性及硝化菌群结构分析

我国分散型污水处理问题亟待解决,研究开发了四区一体式生物膜-活性污泥生物脱氮反应器,采用梯度缩短HRT方法,考察了冬季8~15℃水温环境下的反应器COD、NH+4-N、TN去除效果,同时,采用荧光原位杂交技术(FISH)对种泥及其启动过程中的生物膜硝化菌群(AOB、NOB)结构进行分析,并对反应器运行效果与功能微生物的相关关系进行了探讨.结果表明,在HRT为9.2 h下COD、NH+4-N、TN去除率分别为92.11%、99.21%、61.63%;启动末期生物膜内AOB、NOB数量是种泥的5.82倍、6.14倍,硝化细菌占总菌量由6.12%上升至16.38%,成为生物膜的优势菌群;末期硝化效率由初期78.49%上升至97.52%,NOB数量增长5.61倍,AOB/NOB值优化为1.47,反应器内富集生长的AOB、NOB及合适的AOB/NOB比值是确保硝化出水水质的重要保障.     

Rapid start-up of mesophilic dry anaerobic digestion of kitchen waste in a continuous stirred tank reactor (CSTR)

Under mesophilic conditions (37 °C), a bench-scale experiment of dry fermentation start-up using kitchen waste was conducted in a fed-batch single phase reactor over a period of 40 days. The results showed that (1) comparing biogas production, efficiencies, and methane concentrations, three apparent different stages emerged: adaption, growth, and stability; (2) in adaption and growth stages, daily biogas production was 0–0.2 L/day and 0.2–0.4 L/day, respectively, and the concentration of methane in the biogas was 22.91% and 48.79%, respectively, with a biodegradation rate of approximately 34.72% in the adaption phase and 27.60% during the growth phase; (3) in the stability stage, the biogas production efficiency attained the maximal level and stabilized at approximately 0.6–0.4 L/day and the concentration of methane was 54.32%. Furthermore, the pH fell to 4.15, and the concentration of chemical oxygen demand increased from 51.139 to 119.295 mg/ml.