石化企业填埋场污染现状及治理进展

石油化工企业在日常生产过程中会产生废催化剂、碱渣、炉渣、油泥等固体废物,当前通常采用填埋的方式处理固体废物。固废填埋场由于管控措施不到位,导致填埋场渗滤液超标排放、渗漏问题严重,产生的固废渗滤液和有害气体会严重影响生态环境和人体健康。石化企业填埋场常用的固废处理技术包括就地封存的源控制技术、可渗透性反应墙、原位好氧稳定化处理等原位处置技术和整体搬迁、高效分离资源化等异位处置技术,适用于不同的固废情况。填埋场固废渗滤液的主要处理技术有膜生物反应器(MBR)、升流式厌氧污泥床工艺(UASB)、碟管式反渗透工艺(DTRO)、缺氧/好氧(A/O)工艺、序列式活性污泥(SBR)和组合工艺等。针对填埋场一般固废,某石化企业采用异位筛分、资源化利用和渗滤液异位处置的方案进行处理;另一石化企业则采用分区清挖、分离减量化方案分别处理填埋场的危废和一般固废。建议未来进一步改进固废筛分技术和设备,提高渗滤液生物处理技术的节能水平。     

膜生物反应器处理及回用高浓度含氨氮废水

采用缺氧好氧预处理工艺的膜生物反应器（MBR）＋RO处理回用高浓度含氯氮废水。工艺切实可行，运行费用低，对化学需氧量（COD）的去除率达到90％以上，对氯氮的去除率达到80％以上，出水采用RO进行深度处理，成本更经济合理。     

A/O生物滤池处理生活污水的挂膜启动试验研究

本试验中,A/O生物滤池挂膜启动分为两个阶段进行:第一阶段,好氧柱利用活性污泥接种后循环曝气培养生物膜;第二阶段,缺氧柱通入待处理的水及从挂膜完成后好氧柱回流的水,并逐步提高滤速启动,进行缺氧微生物的培养和驯化。本试验二级好氧滤柱采用沈阳北部污水处理厂回流污泥接种,以待处理的原水启动挂膜。试验结果表明,当滤速8.8L/h(2m/h)小流量进水,回流比1:1,二级好氧柱曝气量25L/h时,在25天内,能在填料表面形成较稳定的生物膜,出水COD、NH3-N及浊度能分别稳定到12mg/L、5.22mg/L及10NTU以下。     

微生物燃料电池电能产生及污废水处理的研究进展

微生物燃料电池（microbial fuel cell, MFC）是采用微生物催化的电化学系统,可用于污废水处理领域。目前关于MFC的研究多集中在提高产电能力和去污效能方面。通过综述近期MFC的研究进展,建议该技术在污废水处理领域的研究重点放在产电微生物筛选培养、低成本电极材料修饰研发、调控MFC运行条件等方面,并应加强MFC与序批式反应器（sequencing batch reactor, SBR）、厌氧好氧（anoxic oxic, A/O）、膜生物反应器（membrane bio-reactor, MBR）等常见污废水处理工艺耦合联用的研究。     

两级A/O-MBR+NF/RO处理垃圾渗滤液

垃圾填埋场渗滤液为难降解高浓度有机废水,处理难度较大。以某生活垃圾填埋场升级改造工程设计为依托,从垃圾渗滤液的来源、水质、水量、处理工艺、单体构筑物、运行效果及投资等多方面详细介绍渗滤液处理工艺设计,确定该工程采用两级A/O (缺氧/好氧)-MBR (膜生物反应器)-NF (纳滤)/RO (反渗透)的组合工艺。实际运行结果表明,该工艺处理效果好,出水COD_(Cr)≤100 mg/L,NH_3-N质量浓度≤25 mg/L,可满足GB 16889—2008 《生活垃圾填埋场污染控制标准》的要求。     

接触氧化-MBR在小区中水回用中的应用

膜生物反应器（MBR）目前已在水处理领域得以广泛应用,为了进一步扩大该技术在小区废水处理中的应用及有效控制膜运行及污染问题,接触氧化-MBR组合工艺将成为小区中水回用项目首选工艺。在介绍接触氧化-MBR组合工艺原理的基础上,论述了接触氧化减轻对膜污染影响及延长膜运行时间,及该工艺在小区中水回用项目中的应用前景。     

A/A/O生物脱氮处理焦化污水工艺介绍

萍钢焦化厂新建酚、氰废水处理站采用了先进的A/A/O法生物脱氮工艺,此工艺将污水二级处理中的缺氧、好氧两大类方法有机结合在一起,对焦化废水中的酚、氰、COD、氨氮等多种污染物均有较高的去除率,尤其是出水氨氮含量远远低于钢铁行业一级排放标准(15mg/l).文章详细介绍了A/A/O生物脱氮的原理、运行控制和工艺流程.     

膜生物反应器在造纸废水中的应用

膜生物反应器(MBR)是近年来发展起来的一种新型的废水处理工艺.介绍废水处理领域中的膜生物反应器的基本特点及国内外近年来利用膜生物反应器处理造纸等工业废水的研究成果,并对它用于制浆造纸废水处理的前景及存在的问题进行评述.     

某工业园区污水处理厂低负荷运行方案优化研究

某工业园区污水处理厂建成后,短期内进水量少,针对进水水质、水量不稳定、碳氮比不合理,造成总氮、总磷出水不稳定,有超标风险等问题提出了相应的解决办法;优化了运行方案,即采用一组生化池作为匀质池,优化原厌氧-缺氧-好氧(A2/O)工艺为倒置A2/O工艺,并定时开启污水处理系统控制曝气量以及其他节能措施,优化后节能降耗效果明...     

A/O膜生物反应器处理炼油污水试验研究

通过A/O膜生物反应器处理炼油污水模型试验,研究A/O膜生物反应器去除炼油污水氨氮的可行性。结果表明,A/O膜生物反应器能有效去除炼油污水中氨氮。氨氮(NH3-N)和CODcr容积负荷分别在0.04～0.08kg/m3.d范围内和0.30～0.84kg/m3.d范围内时,出水中NH3-N浓度小于5mg/L;NH3-N及CODcr达标排放。     

炼油厂含油污水处理装置的优化措施

大庆石化炼油厂第一净化水车间含油污水处理装置存在隔油单元隔油效率低、一级A/O生化单元中A池缺氧反硝化作用低,以及二级A/O污泥有机负荷低引起的出水悬浮物高等问题。利用两次大检修机会,对这些问题进行整改治理：将隔油罐出水虹吸管由原来距罐底0.8m抬高至1.5m,延长油泥沉降时间,同时加装油泥监测管,随时监测罐内油泥高度,及时排泥,避免油泥夹带;将一级A/O生化单元鼓风搅拌改为液下搅拌器搅拌,降低溶解氧含量,提高缺氧反硝化作用;采用跨线的方式,将一级A/O生化单元进水部分（约15m3/h）分配给二级A/O生化单元,提高二级A/O生化单元进水有机物含量,改善二级A/O生化单元的污泥生化效果;加大二沉池剩余污泥的排放量,避免沉淀污泥在二沉池中发生反硝化反应产生氮气,引起污泥上浮。实施以上优化措施后,装置外排污水COD逐渐降低,综合合格率逐年提高,由2010年开工初期的90.9%提高到2012年的99.4%。     

粉末活性炭控制一体式膜生物反应器膜污染的作用

投加粉末活性炭以减缓膜生物反应器膜污染,延长反应器工作周期,降低膜反应器电耗。试验结果表明:投加80~100目活性炭,可减缓膜污染速度,平均膜比通量比对照反应器提高3.82×10-6m3/(m2.m.s);投加200~300目活性炭,由于粒径过小,会造成严重膜污染,反应器膜比通量下降速度较对照反应器更快;投加40~60目活性炭,由于粒径过大,活性炭会在反应器内沉淀,很难有效控制膜污染。投加粉末活性炭时,膜生物反应器具有比普通膜生物反应器更稳定的出水水质,COD、BOD5分别提高3.1%、2.4%。     

污泥膨胀对膜生物反应器脱氮效果的影响

通过采用A/O膜生物反应器工艺处理生活污水的动态模拟方法,研究污泥膨胀对该系统脱氮效果的影响。结果表明,污泥膨胀对总氮的去除率基本无影响,丝状菌比表面积大,在低底物浓度的条件下对基质的亲和能力比菌胶团强,使得CODcr的平均去除率提高3.8%,NH3-N的平均去除率提高3%。丝状菌的捆绑、覆盖所引起的膜污染极其严重,膜通量无法保持稳定。     

污泥膨胀对膜生物反应器脱氮效果的影响

通过采用A/O膜生物反应器工艺处理生活污水的动态模拟方法,研究污泥膨胀对该系统脱氮效果的影响。结果表明:污泥膨胀对总氮的去除率基本无影响,丝状菌比表面积大,在低底物浓度的条件下对基质的亲和能力比菌胶团强,使得CODCr的平均去除率提高了3.8%,NH3-N的平均去除率提高了3%。丝状菌的捆绑、覆盖所引起的膜污染极其严重,膜通量无法保持稳定。     

污水处理场MBR膜通量下降原因及缓解措施

中国石化海南炼油化工有限公司的污水处理场采用了MBR工艺处理其炼油污水,设计处理能力为450m3/h.进入2008年以后,MBR膜在运行中出现膜通量下降较快的问题,造成实际生产能力不到设计值的1/2.通过分析,造成膜通量下降的原因为:系统中污泥龄较长,污泥颗粒细小,沉降性能差,容易形成生物黏泥；进水油含量超标以及吹扫风带油,造成油类污染；反洗频次较高,而且反洗水质得不到保证;系统膜组件的抖动风设计不合理,风量供应不均,风孔有堵塞现象；现场操作不当,导致膜丝间积存大量活性污泥,缠裹膜丝.采取了有针对性的措施:缩短污泥龄,降低活性污泥对膜的粘附性;调整清洗方案及药剂,采用1％氢氧化钠和0.3％次氯酸钠对膜件进行离线化学清洗；提高膜区风量,改进膜件底部的布气设施;优化工艺操作,控制进水油含量和吹扫风带油；加强溶气浮选的运行控制以及现场操作.措施实施后,MBR系统处理量由2006～2009年的180～220m3/h提高到2012年的140～160m3/h,跨膜压差控制在35～55kPa,膜通量的下降幅度远远低于前措施实施前,出水水质保持稳定.     

Responses of the methanogenic reactor to different effluent fractions of fermentative hydrogen production in a phase-separated anaerobic digestion system

Phase-separated anaerobic digestion (AD) system was suggested to recover energy in the form of CH₄ from different effluent fractions of fermentative hydrogen production. In the present study, a two-phase AD system consisting of an H₂-producing fixed-bed reactor (RH) and a CH₄-producing upflow anaerobic sludge bed reactor (RM) was employed to investigate the responses of RM to three types of pretreated RH effluents: membrane-filtered, centrifuged, and poorly settled. The results showed that RM easily converted soluble byproducts in the membrane-filtered effluent, but it had difficulties in degradation of the mixture of soluble and colloidal organic matters in the centrifuged effluent under high organic loadings. The colloidal matters originated from extracellular and intracellular macro-polymers were believed to have been adsorbed onto the surface of granular sludge and formed a film of increasing thickness which retarded the soluble substrate supply to the inner acetogens and methanogens. Due to the fact that the degradation of H₂ biomass residue in the slightly settled RH effluent was inefficient under a tested hydraulic retention time (HRT) of 20 h, they were either trapped in RM causing the expansion of sludge bed or washed out with the effluent. This study recommended the suspended solids in the RH effluent be removed from the feed to RM; be treated elsewhere or recycled. Extra care should be taken to fine tune RM to accommodate the degradation of colloidal solids.     

Performances comparison between three technologies for continuous ethanol production from molasses

Molasses are a potential feedstock for ethanol production. The successful application of anaerobic fermentation for ethanol production from molasses is critically dependent to the development and the use of high rate bioreactors. In this study the fermentation of sugar cane molasses by Saccharomyces cerevisiae for the ethanol production in a continuously stirred tank reactor (CSTR), an immobilised cell reactor (ICR) and a membrane reactor (MBR) was investigated. Ethanol production and reactor productivities were compared under different dilution rates (D). When using the CSTR, a decent ethanol productivity (Qp) of 6.8 g L⁻¹ h⁻¹ was obtained at a dilution rate of 0.5 h⁻¹. The Qp was improved by 48% and the residual sugar concentration was reduced by using the ICR. Intensifying the production of ethanol was investigated in the MBR to achieve a maximum ethanol concentration and a Qp of 46.5 g L⁻¹ and 19.2 g L⁻¹ h⁻¹, respectively. The achieved results in the MBR worked with high substrate concentration are promising for the scale up operation.     

Integration of microbial fuel cell with independent membrane cathode bioreactor for power generation,membrane fouling mitigation and wastewater treatment

A microbial fuel cell (MFC) was integrated with flat sheet membrane bioreactor (MBR) and studied for electricity generation, membrane fouling mitigation and artificial wastewater treatment. The cell potential was ∼0.2 V with 100 Ω external load during closed circuit operation. Batch tests identified that the sludge properties and aeration in cathodic chamber were the main affecting factors on electricity generation. Integration of microbial fuel cell can significantly alleviate membrane fouling, under closed circuit condition, membrane filtration lasted 21 days – 27 days and under the open circuit condition it lasted only 13 days - 15 days, before the transmembrane pressure (TMP) reached 0.03 MPa. The calculated electrostatic repulsion force between membrane surface and membrane foulant was about 2.5 × 10⁻¹⁴ N in this integrated reactor. The chemical oxygen demand (COD), ammonia nitrogen, phosphorus and offensive smell could be effectively removed by the sequential anaerobic-aerobic treatment system. The effluent pH was neutral and turbidity was very low.     

A pilot study of biohythane production from cornstalk via two-stage anaerobic fermentation

This study aimed to study the feasibility and stability of biohythane production from cornstalk via two-stage anaerobic fermentation without hydrolysis step in a semi-continuous pilot scale system. The present study applied a 1 m³ continuous stirred tank reactor for biohydrogen production and a 0.5 m³ up-flow anaerobic sludge bed for biomethane production. During the entire operation, a hydrogen production yield of 25.02 L/kg TS and hydrogen production rate of 0.46 L/L/d was achieved in first-stage. In addition, a methane yield of 95.38 L/kg TS and methane production rate of 4.06 L/L/d was achieved in second-stage by using the liquid effluent after first-stage. The percentage of hydrogen in the biohythane gas was 18.47% which suitable for vehicle fuel. Moreover, it was feasible to use the solid residue as a growth medium in seedlings to improve energy and carbon recovery. The results suggest that biohythane production from cornstalk could be a promising biofuel avenue.     

Dynamic behavior of metal–hydrogen reactor during hydriding process

The present study involves numerical simulation of transient transport of hydrogen and heat within a metal–hydrogen reactor connected to a hydrogen tank during the hydriding process. This problem is of particular interest in the design of many installations in the field of energy technology (compressor, heat pumps, thermal or hydrogen storage systems). The reactor presents an expansion volume for hydrogen. The hydrogen flow is described by general momentum conservation equations instead of Darcy's law. The evolutions of the temperature, of the hydrogen concentration and of the hydrogen flow velocity are presented. The effects of the reactor dimensions, the inlet diameter, the volume of the expansion part, the tank volume, the initial pressure and the amount of hydrogen in the tank, on the heat and hydrogen transfer are determined.