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1.
The treatment of effluent from anaerobic digestion of organic wastes was carried out using chemical and electrochemical processes, namely, chemical coagulation (CC) with lime, electrocoagulation (EC) with iron consumable electrodes, and electrochemical oxidation (EO) with a boron-doped diamond anode, at different experimental conditions. In the CC assays, the highest chemical oxygen demand (COD) removal, 50%, was achieved for a lime concentration of 70 g L?1 after 2 h experiment. Under the experimental conditions studied, EC promoted COD removals of 80% after 5 h and EO led to COD removals of 43% after 6 h electrolysis, being this last removal increased to 60% when chloride was added to the effluent. A combined EC+EO treatment was also performed, utilizing the most favorable experimental conditions obtained in the individual processes, and global removals of 95% in COD and 44% in ammonia nitrogen were attained after 5 h of EC followed by 6 h of EO. These results proved that the combined process can be an efficient alternative in the treatment of effluents from anaerobic digestion of organic wastes with the characteristics of the studied effluent.  相似文献   

2.
The efficiency of nitrite removal in an electrochemical cell was investigated in this study using stainless steel electrodes. The experiments were designed to study the effects of current input, volume of the solution, initial pH, and number of electrodes on removal of nitrite at a concentration typical to aquaculture system effluents. Current variation causes opposite trends, while an increase in current would increase the oxidizing efficiency of the system, the voltage induced increase in pH due to hydrogen evolution would decrease the efficiency of the oxidizing agent formed. However, the highest nitrite removal was achieved at a current of 2 A and a complete removal was attained after a duration of ten minutes. A first order reaction model was developed to predict the effect of current on nitrite removal. The energy consumption was directly proportional to the initial pH and the solution volume, while it was inversely proportional to the number of electrodes.  相似文献   

3.
Economic and environmental stimuli for biodiesel production have also increased production of glycerol, a byproduct present in biodiesel industry wastewater (BIW). The objective of the present study was to analyze which factors influenced glycerol biodegradation in anaerobic sequencing batch reactors (AnSBR) in the attempt to optimize chemical oxygen demand (COD) removal efficiency. Six factors were analyzed: pH, temperature, mixing speed, influent COD, inoculum mass, and reaction time. The results indicated that mixing speed, temperature, mass of inoculum, and reaction time had direct influence on COD removal efficiency in BIW. The reactor used in the experiments operated with efficiencies and applied loads above those mentioned in the literature. The mathematical model generated in this study can be used for estimating efficiency, process control and scale up of AnSBR.  相似文献   

4.
土壤有机污染物电化学修复技术研究进展   总被引:2,自引:0,他引:2  
综述了有机污染土壤的电动力修复和微生物电化学修复的最新研究进展。分析了电动力修复中电极材料、运行条件等因素对污染物去除效果的影响,总结了添加表面活性剂、引入具有降解能力的基质、与化学或生物联合等方式对土壤修复效果的强化作用,阐述了微生物电化学修复的效果、影响因素和微生物群落演变的规律。电化学技术能够有效去除土壤中的有机污染物,且电动力较微生物电化学具有更好的去除效果。为了实现电化学技术在污染土壤修复中的应用,未来需要从土壤导电性、电极材料以及反应器构型等方面优化以提高修复效果;此外,电化学修复技术的机理、功能微生物的群落特征研究等也是下一步研究的重点。  相似文献   

5.
以两只750ml UASB反应器分别作为酸化相和甲烷相进行农业废弃物厌氧处理的研究,两相中,都培养出了颗粒污泥。酸化相有机负荷达240kgCOD/m~3[bed]·d,HRT=1.6h,酸化率66%,COD去除率4%~8%,甲烷相有机负荷达88kgCOD/m~3[bed]·d,HRT=3.7h,COD去除率大于85%。两相COD总去除率大于90%,总有机负荷60kgCOD/m~3[bed]·d。并结合扫描电镜照片,对两相颗粒污泥的形成,菌体分布规律等进行了探讨。  相似文献   

6.
Combinations of sequential anaerobic and aerobic process enhance the treatment of textile wastewater. The aim of this study was to investigate the treatment of diazo dye Reactive Black 5 (RB5)-containing wastewater using granular activated carbon (GAC)–biofilm sequencing batch reactor (SBR) as an integration of aerobic and anaerobic process in a single reactor. The GAC–biofilm SBR system demonstrated higher removal of COD, RB5 and aromatic amines. It was observed that the RB5 removal efficiency improved as the concentration of co-substrate in the influent increased. The alternative aeration introduced into the bioreactor enhanced mineralization of aromatic amines. Degradation of RB5 and co-substrate followed second-order kinetic and the constant (k 2) values for COD and RB5 decreased from 0.002 to 0.001 and 0.004 to 0.001 l/mg h, respectively, as the RB5 concentration increased from 100 to 200 mg/l in the GAC–biofilm SBR system.  相似文献   

7.
菌剂挂膜3D-RBC联合BCO工艺处理养猪沼液废水   总被引:2,自引:2,他引:0  
针对养猪沼液废水寡营养、高氨氮的水质特征,该研究采用耐高氨氮、适应贫营养生长的异养硝化-好氧反硝化(Heterotrophic Nitrification-Aerobic Denitrification,以下简称HN-AD)菌挂膜启动三维结构生物转盘+生物接触氧化反应器(3D-RBC+BCO)组合工艺对沼液进行处理。该文研究了3D-RBC+BCO组合工艺在真实沼液条件下的启动过程及污染物去除效果,重点考察了溶解氧(Dissolved Oxygen,DO)浓度和C/N比2个关键因素对组合工艺污染物去除效果的影响。同时,借助高通量测序技术对DO和C/N比优化过程中微生物群落结构的变化规律进行解析。结果表明:在真实沼液条件下,采用HN-AD菌剂挂膜启动方法,仅用12和18 d就分别完成3D-RBC和BCO反应器的挂膜启动,同时组合工艺对COD、NH4+-N和TN的去除率分别稳定在94.8%、95.7%和80.1%,出水优于城镇污水厂排放一级B标准。在对3D-RBC反应器DO和C/N比的优化过程中,增设底曝后COD、NH4+-N和TN等指标的去除率分别降低了25.4%、15.4%和15.5%。高通量测序结果显示,增加底曝后3D-RBC盘片生物膜中微生物菌属的数量小幅下降,但HN-AD优势菌属的种类与丰度显著降低,导致脱氮效率下降;贫营养型Acinetobacter、Pseudomonas菌属是3D-RBC可以对真实沼液高效脱氮的关键,提高C/N比会显著降低其丰度,进而影响脱氮效果。  相似文献   

8.
In the present investigation, treatment of metal cutting wastewater (MCW) using electrocoagulation (EC) process is designed and analyzed using response surface methodology (RSM). RSM is applied to optimize the operating variables viz. initial pH, current density, and operating time on the treatment of MCW in a batch mode by EC process using iron and aluminum electrodes. Quadratic models are developed for the responses such as chemical oxygen demand (COD), total organic carbon (TOC), and turbidity, and operating cost is calculated with respect to energy, electrode, and chemical consumptions. The actual COD, TOC, and turbidity removal efficiencies at optimized conditions are found to be 93.0%, 83.0%, and 99.8% for Fe electrode and 93.5%, 85.2%, and 99.9% for Al electrode, respectively, which agree well with the predicted response. The proposed model fits very well with the experimental data with R 2 adjusted correlation coefficients of 0.927 for COD, 0.924 for TOC, and 0.968 for turbidity removal for Al and 0.904 for COD, 0.976 for TOC, and 0.989 for turbidity removal for Fe electrodes, respectively. This study clearly shows that RSM is one of the suitable methods to optimize the operating conditions and maximize the COD, TOC, and turbidity removal efficiencies for both electrodes while keeping the operating costs to minimal (0.371 ?/m3 for Fe and 0.337 ?/m3 for Al electrodes).  相似文献   

9.
固定床厌氧反应器处理高浓度糖蜜废水   总被引:9,自引:4,他引:5  
为开发高效处理高浓度有机废水的厌氧沼气发酵技术,以活性炭纤维作为生物膜载体,在实验室规模上对固定床厌氧反应器处理高浓度糖蜜废水的运行性能进行了研究。初始进水COD为5 000 mg/L,水力停留时间(HRT)保持在2 d左右。在进水COD为47 000 mg/L以内时,相应的有机容积负荷(OLR,COD含量)达到21.38 kg/(m3×d),COD去除率保持在86%以上,沼气容积产气率为9.51 L /(L×d),甲烷容积产气率为6.46 L /(L×d);当OLR进一步从21.38 kg/(m3×d) 逐步升高到35.13、39.06、44.88 kg/(m3×d) 时,COD去除率从86.48%分别降低到74.40%,67.02% 和63.50%,相应的沼气容积产气率为13.71,13.98和11.44 L/(L×d),甲烷容积产气率为8.84,8.67和5.89 L/(L×d)。进水的pH值通常在3.5~5.6之间,OLR低于35.13 kg/(m3×d) 时,无需对pH值进行中和调节,出水的pH值自然维持在6.8~7.6的良好状态,超出此范围,则需加碱对进水的pH值作适当调节。最终进水COD高达78 600 mg/L,相应的OLR为44.88 kg/(m3×d)。在165 d的运行过程中污泥形成量小,没有发生堵塞现象,固定床厌氧反应器表现出高效的处理酸性高浓度有机废水和较强的抗负荷冲击的能力。  相似文献   

10.
采用以天然植物中空纤维作为填料的生物质一生物膜反应器(BBFR)串联复合垂直流人工湿地(IVCW)的组合工艺处理系统,研究了5种不同的运行工况,即不同的停留时间、水力及污染负荷条件下对城镇生活污水的处理效果。结果表明,5种工况下组合系统的出水均能达到一级排放标准,COD、TN和TP的平均去除率分别达到89.86%、93.5%和74.78%。各工况条件下因为装置控制参数和稳定程度的不同,各运行阶段下的净化效果也有一定的差异。通过探讨BBFR和IVCW的最佳耦合模式,即系统处理效果达到最佳时的运行参数,实现了BBFR和IVCW二者间的优势互补。  相似文献   

11.
Static granular bed reactor (SGBR) and upflow anaerobic sludge blanket (UASB) reactor were demonstrated at mesophilic condition for the treatment of pulp and paper mill wastewater. The hydraulic retention times (HRTs) were varied from 4 to 24 h following 29-day start-up period. The overall chemical oxygen demand (COD) removal efficiency of the SGBR was higher than the UASB during this study. At 4 h HRT, the COD removal was greater than 70 % for the SGBR and 60 % for the UASB. Biomass yield and volatile fatty acids concentration of SGBR were slightly less than UASB at organic loading rates ranging from 1.2 to 5.1 kg/m3/day. The results indicated that the SGBR system can be considered a viable alternative system for anaerobic treatment for pulp and paper wastewater.  相似文献   

12.
A kinetic analysis of the anaerobic digestion process of wastewater derived from the production of protein isolates from extracted sunflower flour was carried out. The digestion was conducted in a laboratory-scale fluidized bed reactor with saponite (magnesium silicate) as support for the mediating bacteria at psychrophilic temperature (15-19 degrees C). Soluble chemical oxygen demand (COD(s)) removal efficiencies in the range of 95.9-69.0% were achieved in the reactor at organic loading rates (OLR) of between 0.57 and 2.49 g total COD (COD(t))/L d, hydraulic retention times (HRT) of between 20.0 and 4.5 days, and average feed total COD concentration of 11.3 g/L. The yield coefficient of methane production was 0.32 L of methane (at STP) per gram of COD(t) removed. The total volatile fatty acid (TVFA) levels and the TVFA/alkalinity ratio were lower than the suggested limits for digester failure for OLR and HRT up to 2.26 g COD(t)/L d and 5.0 days, respectively. The specific rate of substrate uptake, r (g COD(s)/g VSS d), correlated with the concentration of biodegradable substrate, S (g COD(s)/L), through an equation of the Michaelis-Menten type. The maximum substrate utilization rate, k, and the Michaelis constant, K(s)(), were found to be 0.125 g COD(s)/g VSS d and 124 mg COD(s)/L, respectively. This proposed model predicted the behavior of the reactor very accurately showing deviations lower than 10% between the experimental and theoretical values of substrate uptake rates. A mass (COD(t)) balance around the reactor allowed the COD equivalent of methane volume (W(CH)4) to be obtained, which gave a value of 2.89 g COD(t)/L CH(4), which was virtually coincident with the theoretical value of 2.86 g COD(t)/L CH(4).  相似文献   

13.
This paper presents a comparative study of the performance of ferrate(VI), FeO 4 2? , and ferric, Fe(III), towards wastewater treatment. The ferrate(VI) was produced by electrochemical synthesis, using steel electrodes in a 16 M NaOH solution. Domestic wastewater collected from Hailsham North Wastewater Treatment Works was treated with ferrate(VI) and ferric sulphate (Fe(III)). Samples were analysed for suspended solids, chemical oxygen demand (COD), biochemical oxygen demand (BOD) and P removal. Results for low doses of Fe(VI) were validated via a reproducibility study. Removal of phosphorous reached 40% with a Fe(VI) dose as low as 0.01 mg/L compared to 25% removal with 10 mg/L of Fe(III). For lower doses (<1 mg/L as Fe), Fe(VI) can achieve between 60% and 80% removals of SS and COD, but Fe(III) performed even not as well as the control sample where no iron chemical was dosed. The ferrate solution was found to be stable for a maximum of 50 min, beyond which Fe(VI) is reduced to less oxidant species. This provided the maximum allowed storage time of the electrochemically produced ferrate(VI) solution. Results demonstrated that low addition of ferrate(VI) leads to good removal of P, BOD, COD and suspended solids from wastewater compared to ferric addition and further studies could bring an optimisation of the dosage and treatment.  相似文献   

14.
污水回用是解决城市缺水问题的一条有效途径。该文提出了一种新方法,尝试利用多孔介质毛细管作用过滤生活污水。制造了4个毛管逆滤渗污水净化器,采用普通河砂作为过滤介质进行了室内试验。试验采用两个因素:水势差、滤池内外径比。水势差选取4个水平:0.11、0.26、0.41、0.56 m,外层与内层水池直径比选取3个水平:14/6、12/6、10/6,以研究利用毛细管作用净化污水的可行性,并定量确定水势差及内外层水池的相对大小对该系统运行效果的影响。用反应器去除污水COD的多少来评价过滤效果。结果表明,过滤速度及净化效果与水势差之间呈极显著的对数相关关系,两者都随着水势差的增大而提高。当水势差为0.56 m时,COD的去除率可高达80%左右,过滤速度可以高达0.15 m/h。外层与内层水池的直径比(D/d)越大滤速越小,但该比值对COD的去除率无明显影响。该装置在运行过程中,污水被过滤介质所覆盖,有效地避免了污水的刺激性气味和蚊蝇孳生对周边环境的影响。  相似文献   

15.
A novel biofilm reactor named as `rotating perforated tubes biofilm reactor' was used for treatment of synthetic wastewaterwith and without liquid phase aeration. Effects of major processvariables such as feed wastewater flow rate, COD concentration and loading rate, liquid phase aeration on the rate and extent ofCOD removal were investigated. Liquid phase aeration was provento be advantageous especially for high strength wastewaters at highCOD loading rates. Kinetics of COD removal was investigated andkinetic constants were determined by using the experimental data.An empirical design equation was developed to quantify the system's performance as a function of major process variables.  相似文献   

16.
选择宁波地区的A/O一体化、生物滤池、生物转盘和人工湿地等4种典型农村生活污水处理工艺为研究对象,于2013年1月—2015年12月期间开展各工艺终端处理设施的进出水水质跟踪监测,进行各处理工艺的污染物去除率和稳定性比较分析。结果表明,4种处理工艺的COD、BOD_5、SS多年平均去除率大小顺序均为A/O一体化生物滤池生物转盘人工湿地,TN多年平均去除率大小顺序为生物滤池生物转盘A/O一体化人工湿地,其中A/O一体化、生物滤池和生物转盘工艺的COD、BOD_5、TN平均去除率均显著高于人工湿地工艺;A/O一体化、生物滤池和生物转盘工艺随着终端处理设施运行年限的延长,COD、BOD_5、SS、TN去除率均保持稳定,而人工湿地工艺的COD、BOD5、TN去除率均呈现明显的下降趋势;各处理工艺在低温期(11月—次年4月)和高温期(5月—10月)的SS去除率差异不明显,但各处理工艺的COD、BOD_5、TN去除率在低温期明显低于高温期,其中A/O一体化工艺差异相对较小,生物滤池工艺差异最大。  相似文献   

17.
生物反应器填埋场系统中有机垃圾降解特性研究   总被引:1,自引:0,他引:1       下载免费PDF全文
针对渗滤液回灌型生物反应器填埋场中存在着有机酸积累的问题,试验将产甲烷反应器作为渗滤液回灌前的预处理设施引入生物反应器填埋场,研究了其系统中有机垃圾的降解和产气规律。结果表明,在本模拟试验条件下,有机垃圾在填埋场、产甲烷反应器和生物反应器填埋场系统的总产气量分别为62.1、456和518.1 L,其中产甲烷反应器产气量占生物反应器填埋场系统产气量的88%以上。在产甲烷反应器中产气速率与有机物去除率成正比,回归系数为0.4614 L/g COD。基于生物反应器填埋场系统中有机物降解的特征,建立了其产气动力学模型。该模型可用来初步估算相关生物反应器填埋场系统中填埋垃圾稳定化所需时间及产气量,为系统填埋气的能源化利用提供理论依据。  相似文献   

18.
分段组合式厌氧反应器的运行性能   总被引:1,自引:0,他引:1  
为研发高效厌氧生物反应器,采用模拟有机废水,对分段组合式厌氧反应器的运行性能进行了研究。试验结果表明:该反应器具有很高容积效能,容积负荷可达110.97?g/(L·d),容积负荷去除率可达84.35?g/(L·d),容积产气率可达57.00?L/(L·d)。该反应器内的基质浓度及中间产物浓度较高,平均化学需氧量和挥发性有机酸浓度分别是常效反应器相应值的18.49倍与37.52倍,可提供较大的反应推动力。该反应器具有良好的运行性能,但趋近满负荷时性能参数波动较大,易导致反应器工况失稳。  相似文献   

19.
Pesticides presently being discharged into the aquatic environment are not only toxic but also only partially biodegradable, they are not easily removed by conventional water treatment plants. Air ionization devices using an atmospheric pressure corona discharge process show great promise in improving degradation of chemical and biological contaminants in water purification plants. In order to assess the effectiveness of this air ionization apparatus, laboratory scale degradation experiments were carried out systematically in a bubble column reactor containing a variety of pesticides such as triazines, carbamates, phenyl urea derivates and chlorophenols relative to the addition of humic acid and inorganic chemicals as well as to pH variation. Chemical oxygen demand (COD) decreased with air ionization treatment and the rate of the biological oxygen demand related to this (BOD/COD) showed improved pesticide biodegradability. Changes in water toxicity were monitored by Daphnia- and Luminescence Bacteria tests. This novel water treatment process is shown to be a potent oxidation technique for persistent organic pollutants such as pesticides.  相似文献   

20.
选择一种新型高效反应器系统对奶牛养殖场废水进行处理试验研究,这种反应器系统主要包括两级组合生物巢厌氧反应器和砂式沼液处理池。试验结果表明,该系统处理奶牛养殖废水速度快,两级组合生物巢厌氧反应器水力停留时间(HRT)仅为15h,处理效率高,砂式沼液处理池结构简单,对生物巢厌氧反应器出水处理效果好。该新型高效反应器组合系统对化学需氧量(COD)、生化需氧量(BOD)、氨氮(NH3-N)和总固体悬浮物(TSS)的平均去除率分别为97.6%、98.2%、81.3%和98.1%,出水体积质量平均值分别为89.0、27.1、15.7mg·L^-1和64.9mg·L^-1,满足国家二级排放标准。  相似文献   

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