混凝-曝气法联合处理含油废水

报道了聚合氯化铝和聚丙烯酰胺混凝剂对去除含油废水中COD和含油量的实验结果。含油废水的曝气实验表明：废水中75％的油份可以通过曝气过程在20min内予以去除。在絮凝实验和曝气实验结果的基础上提出了联合利用气浮混凝－曝气技术处理含油废水的工艺流程。     

Water surface contacting cover system--the basic study for improving the oxygen transfer coefficient and the BOD removal capacity

In order to construct an environmental aeration basin in a sewage treatment plant, the suggested novel aeration basin was examined for the oxygen transfer coefficient by using tap water on a lab-scale and pilot-scale. We called it water surface contacting cover system (WSCCS) that was installed with a cover plate on the wafer surface and a slant plate in aeration basin, compared to a standard aeration basin (SRAS, spiral roll aeration system). Finally, the novel basin could be compared by adopting the slant and cover plates into the actual sewage treatment plant (W x L x D (m)=5.0 x 2.65 x 4.25, treatment capacity: 600 m3/d). As a result, only by adding a slant plate, the oxygen transfer coefficient (K(L)a) increased approximately by 15% more than that with a SRAS basin. And the slope of slant plate was optimized at 10 degrees . Additionally, in the WSCCS, the increasing efficiency of the oxygen transfer coefficient, affected only by the cover, was proved at about 25% on the lab-scale aeration basin and about 20% on the pilot plant. After all, the increasing effect of the oxygen transfer coefficient on WSCCS that was installed with the water contacting cover and the slant plate on standard aeration basin was proved to be above 35%. The distance between the air diffuser and the slant plate was 20-30 cm in the pilot-scale plant. As an effective factor for increasing the oxygen transfer rate, the width/depth ratio of aeration basin was proved to be 2. Through the short-term results of actual sewage treatment plant, it was known that BOD removal efficiency could be improved by about 3% by adopting tile WSCCS not but SRAS.     

Operating characteristics of the aerated submerged fixed-film (ASFF) bioreactor

A multi-stage fixed-film reactor was developed in which a stationary submerged biofilm is attached to ceramic tiles under diffused aeration. Tracer studies revealed that the reactor's hydraulic regime is described by a CSTR-in-series model. Reactor performance at 20 °C was examined using sucrose wastewaters with organic strength up to 900 mg l⁻¹ COD, at hydraulic loadings up to 0.1 m³ m⁻²d⁻¹ and organic loadings up to 90 g CODm⁻² d⁻¹. The reactor demonstrated the capability of achieving 97% soluble COD removals at low loadings and exhibited efficient and stable performance at high hydraulic and organic loadings. Even at application rates near the rate-limiting mass loadings, there was only a 9% loss in efficiency. Reactor operation at high loadings appears to be advantageous since organic substrate removal rates and attached biomass per unit surface area increased with the increase in organic loading. This can be attributed to the good oxygen transfer and the considerable quantity and type of attached biomass attained. Staging of the reactor proved to be effective in eliminating short circuiting and damping excessive loadings, although the majority of COD removal occurs in the first stage which retains the greatest quantity of attached biomass. A good quality effluent was produced.     

Mass transfer characteristics of a pilot pulsed baffled reactor

We report experimental measurements on the air-water mass transfer characteristics of a pilot pulsed baffled reactor. The experiments have identified, for the first time, the optimal baffle spacing and the optimal superficial gas velocity for mass transfer in the reactor. The mass transfer characteristics were also examined under various operational conditions and were corrected for the effect of temperature and oxygen probe response. The experimental results indicate that the mass transfer rate depends strongly on the combination of the baffle spacing, oscillation frequency and amplitude. The mass transfer data are also correlated in terms of power density and superficial gas velocity, and compared with those from a stirred tank reactor.     

半纤维素水解液发酵木糖醇的关键因子

为了提高Candida sp.ZU-04发酵玉米芯半纤维素水解液生产木糖醇的得率，采用石灰中和、石灰过中和、活性炭脱色、离子交换树脂吸附等措施对水解液进行脱毒处理，并在3.7 L发酵罐中（30 ℃、转速300 r/min、pH 5.5）考察了不同通气条件对发酵工艺的影响.结果表明，弱碱性离子交换树脂D301对半纤维素水解液具有良好的脱毒效果，能明显改善半纤维素水解液的发酵性能；分阶段改变通气速率比恒定通气速率发酵生产木糖醇得率更高，前期（0～24 h）通气速率为3.75 L/min，后期（24～96 h）通气速率为0.75 L/min，木糖醇得率为76.0％，体积生产速率为0.76 g/(L·h)，该工艺为工业上利用半纤维素水解液大规模发酵生产木糖醇奠定了基础.     

有侧吹风环流料封阀水平孔口流动阻力特性

引　言循环流化床锅炉由于具有诸多优点 ,使其在国内外得以迅速发展 .然而在已投运的循环流化床锅炉中也暴露出一些亟待完善解决的问题 .环流料封阀是目前在循环流化床锅炉上应用最多的一种固体颗粒回送控制装置 .实际运行表明 ,这种返料装置结构简单、运行可靠 ,能够很好地满足稳定返料和密封的要求 ,是一种很有发展前途的返料器 .但它缺乏对循环物料的调节和控制能力 ,返料室有时会出现局部流化不良从而导致结焦 .试验研究表明[1～ 3],只要环流料封阀在结构上设计合理 ,它就能像Ｌ阀一样 ,对固体颗粒循环量具有调节和控制作用 ,且可在较宽…     

油田采出水的高温水解-好氧处理工艺研究

根据油田采出水的水质特征，采用厌氧(水解)-好氧(接触氧化)处理工艺。实验表明，虽然油田采出水的BOD5／CODCr，较低，属于难生物降解废水，但是当温度为50～60℃时，选择厌氧停留时间为6h，好氧停留时间为3．5h，气水比为10～20，可使其出水的CODCr稳定在120mg／L左右。如果排除Cl^-产生的影响，CODCr，约为60～70mg／L，达到GB8978-1996一级排放标准。     

在线水质仪在城市污水处理厂精确曝气中的应用

介绍了在污水处理厂应用在线水质分析仪器实施精确曝气的作用,即能够实现水质的连续检测,为精确曝气等各种优化控制提供有效可靠的测量数据,从而提高处理效率,节能降耗。说明了精确曝气的开环控制、闭环控制和复合控制系统的特点及其应用。     

水解/跌水曝气/快渗工艺处理山地城镇生活污水

为了探讨适用于三峡库区山地小城镇污水处理的工艺,结合山地小城镇具有较大自然地形高差和较多荒地荒沟的特点,采用"厌氧水解/自然跌水曝气/改良人工土快渗系统"组合工艺建设生活污水处理示范工程。分析了该示范工程对主要污染物的去除效果,考察了温度和进水负荷对去除污染物的影响,并进行了经济分析。结果表明,该组合工艺具有较强的抗冲击负荷能力和较好的污染物去除效果;系统对COD和NH4+-N的去除效果与温度显著相关,而对TP的去除效果受温度的影响较小;各污染物的单位面积去除负荷与进水负荷近似服从对数关系;该组合工艺的基建费用较之常用污水处理工艺减少20%～50%,运行成本仅为0.29元/m3。     

接触氧化+人工湿地处理小区污水的试验研究

介绍了采用"接触氧化 人工湿地"组合工艺处理小区污水的试验研究。组合工艺的试验运行分两个阶段:前阶段生物接触氧化池连续运行,后阶段生物接触氧化池间歇运行。试验结果表明,间歇运行的生物接触氧化池与人工湿地组合,其运行效果优与连续运行的工艺组合。组合工艺的最佳运行工况为曝气强度为4.0 m3/(m2.h),进水0.25 h,曝气2 h,沉淀1 h,排水0.25 h,此时出水水质可达到《城镇污水处理厂污染物排放标准》(GB18918-2002)的一级A标准,经过消毒后可以回用。同时针对不同浓度的小区污水,还可以通过调整组合工艺的运行方式以满足排放标准要求。