序批式生物膜反应器(SBBR)处理高氨氮渗滤液的脱氮机理研究

采用自主设计的SBBR反应器处理氨氮浓度含量较高的垃圾填埋场渗滤液并对其脱氮机理进行分析.在保持(32±0.4)℃的环境温度下,经过58 d的驯化和33 d的稳定,SBBR反应器的脱氮效率最高达到95%.实验结果表明,高频间歇式曝气方式在抑制了硝酸细菌的活性的同时也消除了亚硝酸盐浓度和pH大幅波动对亚硝酸细菌和厌氧氨氧化细菌活性的影响;在曝气阶段,溶解氧浓度被控制在1.2～1.4 mg·L-1,亚硝酸细菌成为主体细菌,亚硝酸盐积累;在缺氧阶段,随着溶解氧浓度迅速降低,厌氧氨氧化细菌成为优势菌种,曝气阶段积累的亚硝酸盐与氨氮同时被去除.     

电子与电器废弃物资源化处理技术

当今世界电子、电器工业快速发展,层出不穷的技术创新与持续膨胀的市场需求加速了电子与电器设备的更新换代,产生了大量的电子与电器废弃物(WEEE).鉴于WEEE所带来的严重的环境问题及其所含有的金属、贵金属、塑料及玻璃等高利用价值的材料,对WEEE进行资源化再循环处理已成为人们关注的热点.WEEE组成材料在密度、铁磁性、导电性等物理性质方面的较大差异使采用环境友好的机械物理方法对其进行资源化再循环处理成为可能.就WEEE拆解及其所含物质机械物理分离研究进展进行了综述.     

前置MAP-SBBR工艺处理早期及晚期垃圾渗滤液试验

针对垃圾填埋渗滤液水质随填埋时间的延长而日渐恶化的特点,设计前置MAPSBBR耦合工艺处理早、晚期垃圾渗滤液。试验结果表明,在最佳运行条件下,对早期垃圾渗滤液NH+4N的总去除率为99.6%,CODCr的总去除率为94.0%;对晚期垃圾渗滤液NH+4N的总去除率为99.3%,CODCr,的总去除率为87.1%。前置MAPSBBR耦合工艺适用于各期垃圾渗滤液的处理。     

河流水质系统灰色模型的识别、模拟和应用

借助于灰色系统理论的思想和方法可以构造河流水质灰色模型,根据实测水质资料可以识别出河流水质灰色模型中的最优灰参数,在此基础上,可以对河流水质系统进行灰色模拟。灰色模拟考虑了实际河流水质系统中客观存在的不确知因素和偶然因素影响。本文概述了河流水质灰色模型的构造、河流水质灰色模型的研究意义、河流水质灰色模型的灰参数识别、河流水质系统的灰色模拟及其在四川沱江水质系统模拟中的应用。     

复式钢管混凝土柱装配式连接锚固性能试验研究∗

预制混凝土构件通常采用先拼接后灌浆的连接方式,一旦灌浆不密实,将存在严重安全隐患。为了解决装配式复式钢管混凝土结构的连接问题,探索更方便可靠的连接方式,将先灌浆后插筋的连接方式运用到装配式复式钢管混凝土柱的连接中,系统研究了该连接方式下装配式复式钢管混凝土柱中的钢筋锚固性能和锚固长度。并通过设计制作 36 个复式钢管混凝土柱的灌浆插筋锚固试件,采用拉拔试验方法研究了钢筋直径、位置、锚固长度、预制孔形式及直径、灌浆料强度、混凝土强度 7 个影响因素对浆锚钢筋在复式钢管混凝土柱中的锚固性能影响。研究结果表明：（1）试件的典型破坏形式包括钢筋未屈服拔出、钢筋受拉屈服拔出、钢筋拉断三种形式,主要发生钢筋屈服后试件破坏,锚固性能良好;（2）浆锚钢筋在灌浆料中的受力过程主要分为四个阶段：弹性阶段、屈服阶段、强化阶段和破坏阶段;（3）预制孔直径、混凝土强度、灌浆料强度越大,锚固钢筋锚固性能越好;（4）角部浆锚钢筋的极限承载力和极限黏结应力均比中部浆锚钢筋大;（5）复合钢管混凝土柱装配式连接的锚固长度建议根据《混凝土结构设计规范》进行计算确定,且预制孔直径不小于 2 d,且不宜小于 32 mm。     

Spatial health risk assessment and hierarchical risk management for mercury in soils from a typical contaminated site,China

Due to rapid urbanization and the implementation of ecological civilization construction in China, many industrial factories have been closed or relocated. Therefore, numbers of contaminated sites were generated with contaminated soils which may pose a risk to receptors living nearby. This study presented a spatial health risk assessment and hierarchical risk management policy making for mercury (Hg) in soils from a typical contaminated site in the Hunan Province, central China. Compared with the second class value (0.3 mg/kg) of the Chinese Environmental Quality Standard for Soils, the mean concentrations of Hg in the three soil depths exceeded the second class value. The non-carcinogenic risk of Hg probably posed adverse health effects in 41, 30 and 36 % of the surface soil, the moderate soil and subsoil, respectively, under a sensitive land scenario. The non-carcinogenic risk temporarily posed no adverse health effects in most areas under an insensitive land scenario except for the area around sampling site S29. Spatially, the central, southwest and northeast parts of the contaminated land under a sensitive land scenario should be regarded as the priority regions. For non-carcinogenic effects, the exposure pathways that resulted in the higher levels of exposure risk were ingestion and inhalation of vapors, followed by dermal contact and inhalation of particles. A risk-based integrated risk management policy including the hierarchical risk control values for different soil depths and the calculated remediation earthwork was proposed with consideration of the cost-benefit effect for the related decision-makers.     

厌氧反应器的发展及ABSBR的工艺特点

新型高效厌氧反应器的发展使生活污水的厌氧处理成为可能.介绍了ABSBR(恒水位操作厌氧生物膜序批式反应器,Anaerobic Biofilm Sequencing Batch Reactor)的工艺特点,并对其处理生活污水进行了初步研究.试验结果表明,ABSBR工艺是活性污泥法与生物膜法的结合,具有强的生物固体截留能力...     

Enhancement of ultrasonic disintegration of sewage sludge by aeration

Sonication is an effective way for sludge disintegration,which can significantly improve the efficiency of anaerobic digestion to reduce and recycle use of sludge.But high energy consumption limits the wide application of sonication.In order to improve ultrasonic sludge disintegration efficiency and reduce energy consumption,aeration was introduced.Results showed that sludge disintegration efficiency was improved significantly by combining aeration with ultrasound.The aeration flow rate,gas bubble size,ultrasonic density and aeration timing had impacts on sludge disintegration efficiency.Aeration that used in later stage of ultrasonic irradiation with low aeration flow rate,small gas bubbles significantly improved ultrasonic disintegration sludge efficiency.At the optimal conditions of 0.4 W/m L ultrasonic irradiation density,30 m L/min of aeration flow rate,5 min of aeration in later stage and small gas bubbles,ultrasonic sludge disintegration efficiency was increased by 45% and one third of ultrasonic energy was saved.This approach will greatly benefit the application of ultrasonic sludge disintegration and strongly promote the treatment and recycle of wastewater sludge.     

Spectroscopic studies of dye-surfactant interactions with the co-existence of heavy metal ions for foam fractionation

The interaction between a cationic dye Methylene Blue (MB) and an anionic surfactant sodium dodecyl sulfate (SDS) with the presence of Cd²⁺ was investigated spectrophotometrically in a certain concentration range. The spectrophotometric measurements of dye-metal ion-surfactant system were carried out. The results indicated that the SDS concentration had a significant influence on the dye spectrum, while the addition of Cd²⁺ hardly caused change of the maximum value of absorbance. According to this observation, we concluded that electrostatic and hydrophobic interaction between dye and surfactant occurred up to a certain level, and the homo-ions Cd²⁺ almost exerted no effect on the dye-surfactant complexation, establishing a theoretical foundation for simultaneous removal of organic dye and heavy metal using foam fractionation. Meanwhile, the effects of their interaction on foam performance were investigated. The results showed that the addition of Cd²⁺ favored the tendency to ameliorate foam properties just contrary to MB. The feasibility of foam separation for dye and heavy metal removal from simulated wastewater was also confirmed using a continuous foam fractionator. In the simultaneous removal process, with the initial SDS concentration ranging from 0.5 to 5.0 mmol/L, the maximum removal efficiencies of MB and Cd²⁺ were obtained as 99.69% and 99.61%, respectively. The enrichment ratios were reduced from 24.34 to 7.65 for MB and from 22.01 to 3.35 for Cd²⁺.