超声波联合PAM对污泥脱水性能的影响

以污泥脱水性能与沉降性能为指标,研究了超声波调理联合PAM对污泥脱水性能的影响。实验结果表明,单独使用超声波调理的最佳调理时间为20 s,此时污泥比阻为0.68×109s2/g;采用PAM对污泥进行调理时,在浓度为0.1%,投加量为100 mg/L时污泥比阻最小,为0.32×109s2/g;采用超声波与PAM联合调理时,利用正交试验得到最适合的组合条件为:调理时间20s、PAM投加量100 mg/L、浓度0.15%。     

Improved models of failure time for atmospheric tanks under the coupling effect of multiple pool fires

Fire accidents of chemical installations may cause domino effects in atmospheric tank farms, where a large amount of hazardous substances are stored or processed. Pool fire is a major form of fire accidents, and the thermal radiation from pool fire is the primary hazard of domino accidents. The coupling of multiple pool fires is a realistic and important accident phenomenon that enhances the propagation of domino accidents. However, previous research has mostly focused on the escalation of domino accidents induced by a single pool fire. To overcome the drawback, in this study, the failure of a storage tank under the coupling effect of multiple pool fires was studied in view of spatial and temporal synergistic process. The historical accident statistics indicated that the accident scenario of two-pool fires accounted for 30.6% in pool fires. The domino accident scenario involving three tanks is analyzed, and the typical layout of tanks is isosceles right triangle based on Chinese standard “GB50341-2014”. The thermal response and damage of a target tank heated by pool fires were numerically investigated. The volume of 500 m³, 3000 m³, 5000 m³ and 10000 m³ were selected. Flame temperature was obtained by FDS, and then was input onto the finite element model. The temperature field and stress field of target tanks were simulated by ABAQUS. The results showed that the temperature rise rate of the target tanks under multiple pool fires was higher than that under a single pool fire. The failure time of the tank under the coupling effect of multiple fires was lower than that under the superposition of multiple fires without the first stage. The stress and yield strength were compared to judge the failure of the target tank. The model of failure time for the tank under the coupling effect of pool fires was established. Through the verification, the deviation of this model is 4.02%, which is better than the deviation of 15.76% with Cozzani's model.     

剩余污泥对柠檬黄-85的吸附行为

以城市污水厂中的剩余污泥为主要原料制备污泥吸附剂(SA),并用于柠檬黄-85(Tt-85)脱色的实验研究。静态实验主要考察了pH值、投加量、反应时间、反应温度和Tt-85初始浓度对吸附的影响。结果表明:在投加质量浓度为6 g/L,pH值=2.0,温度为25℃的条件下,反应90 min后,SS对水中初始质量浓度为65 mg/L和221 mg/L的Tt-85去除率分别达到了97%和75%。对动力学实验数据进行拟合,发现准二级动力学模型能较好地描述SA对Tt-85的吸附行为。动态吸附柱实验表明,污泥凝胶球对水中Tt-85的去除率为64%。Langmuir等温吸附模型符合SA对Tt-85的吸附过程,其最大吸附质量比为27.78 mg/g,由SEM,FTIR和XRD的分析可得,SA对柠檬黄-85的化学吸附主要发生在表面,其中SA表面羟基官能团起到关键性作用。     

浙江省污水污泥处理处置状况的调查

通过对丽水、宁波、衢州、诸暨等浙江省境内十几个地区的污水处理厂的调查发现:目前浙江省内的污水处理工艺中,A2/O、A/O、氧化沟三种工艺占了近50%的份额。而SBR因其方法特点正在受到越来越多的重视。在污泥处理工艺中,填埋占了最大的一部分,有近70%的污水处理厂将产生的污泥进行填埋处理。目前,污泥处理技术单一,需要继续探寻污泥的减量和资源化技术,为日益增多的污泥探寻出路。     

油品装卸过程静电特性研究

为了研究油品装卸过程中的静电危险性,在两个城市的油库和加油站对油品的装油、卸油过程,以及装油的油罐车从油库向加油站行驶的过程中,油罐车内油品的油面电位进行了静电检测。通过对大量油罐车内油面电位的检测数据分析可以看出,在正常装卸油过程中,油罐车内油品的油面电位远远小于标准所规定安全油面电位,有缩短稳油时间的可能性。     

生活污水处理厂污泥处置技术研究

针对生活污水处理厂污泥处置技术,介绍了国内外污泥的处理现状,提出了传统的污泥处置技术,主要是海洋倾倒,污泥消化技术法,污泥堆肥技术法,污泥的土地利用和污泥的有效利用法,给出林地利用与绿化利用随着污泥量的增长,污泥的处置越来越来受到人们的关注。介绍了国内外污泥处理现状和传统污泥处理处置方法,分析了污泥稳定和资源化处置技术及应用进展,提出了污泥堆肥和堆肥后污泥的土地利用是符合中国国情的污泥处置与资源化利用途径。     

渭河流域关中段城镇污水处理厂污泥处理技术调查与分析研究

根据渭河流域关中段的污染状况及《(渭河流域水污染防治三年行动方案(2012-2014年)》对科技攻关的实际需求,采用资料搜集、实地调查、问卷发放、数理统计等方式对渭河流域关中段55座城镇污水处理厂的污泥处理情况进行了调查与分析。根据调查分析结果,提出了渭河流域关中段城镇污水处理厂污泥处理技术在应用过程中存在的一些问题,并结合该流域实际情况提出了相应建议,期望能够对该流域污泥处理技术的良性发展提供"第一手"的参考资料。     

城镇污水处理厂脱氮除磷好氧污泥颗粒化研究

采用序批式生物反应器(SBR)培养好氧颗粒污泥处理模拟废水,优化好氧颗粒污泥内部好氧-兼氧-厌氧微环境,在反应器的快速启动、稳定运行阶段分别考察不同优化条件下系统的脱氮除磷性能。提出了优化污泥沉降时间、调控曝气方式等好氧污泥快速颗粒化途径,并研究排泥方式对颗粒污泥反应器稳定性的影响,通过强化脱氮除磷功能菌富集,实现氮磷同步高效去除。     

Experimental study on agitated drying characteristics of sewage sludge under the effects of different additive age

Drying experiments of dewatered sewage sludge (DSS) were conducted on a agitated paddle dryer, and the effects of additive agents, i.e., CaO, pulverized coal (PC), heavy oil (HO), and dried sludge ("DS" through back mixing) on the agitated drying characteristics of DSS were investigated. The results indicated that CaO can significantly increase the drying rate of DSS. The drying rate at CaO/DSS (mass ratio) = 1/100 was 135% higher than that of CaO/DSS = 0. Pulverized coal has no obvious effect on drying rate, but the increase of PC/DSS can promote breaking up of sludge lump. Heavy oil was found to be slightly effective in improving the drying rate of DSS in the examined experimental range of HO/DSS = 0-1/20. It is also found thatHOcan reduce the torque of the dryer shaft, due to its lubrication effect. Back mixing of DS was found to be effective in alleviating the unfavorable effect of the lumpy phase by improving the mixing effect of the paddle dryer. There was a marked increase of drying rate with an increase of the DS/DSS in the experimental range of DS/DSS = 0-1/3.     

Aerobic granules cultivated and operated in continuous-flow bioreactor under particle-size selective pressure

A novel method based on the selective pressure of particle size （particle-size cultivation method, PSCM） was developed for the cultivation and operation of aerobic granular sludge in a continuous-flow reactor, and compared with the conventional method based on the selective pressure of settling velocity （settling-velocity cultivation method, SVCM）. Results indicated that aerobic granules could be cultivated in continuous operation mode by this developed method within 14 days. Although in the granulation process, under particle-size selective pressure, mixed liquor suspended solids （MLSS） in the reactor fluctuated greatly and filamentous bacteria dominated the sludge system during the initial operation days, no obvious difference in profile was found between the aerobic granules cultivated by PSCM and SVCM. Moreover, aerobic granules cultivated by PSCM presented larger diameter, lower water content and higher specific rates of nitrification, denitrifieation and phosphorus removal, but lower settling velocity. Under long term operation of more than 30 days, aerobic granules in the continuous-flow reactor could remain stable and obtain good chemical oxygen demand （COD）, NH4^＋-N, total nitrogen （TN） and total phosphorus （TP） removal. The results indicate that PSCM was dependent on the cultivation and maintenance of the stability of aerobic granules in continuous-flow bioreactors.