Removal of viruses, parasitic protozoa and microbial indicators in conventional and membrane processes in a wastewater pilot plant

The aim of this study was to investigate variations in the occurrence and removal of enterovirus and norovirus genomes, Giardia cysts, Cryptosporidium oocysts and the most commonly used faecal indicators in a Swedish wastewater pilot plant. Paired samples were taken from the inlet and outlet of each treatment line: tertiary filtration, membrane bioreactor (MBR) and upflow anaerobic sludge blankets (UASB). (Oo)cysts and indicators were enumerated using standard methods and viruses using RT-PCR. Giardia cysts and enteroviruses were constantly detected, mean numbers 10(3.11) cysts and 10(4.0) PCR units L(-1), respectively. Oocysts were found in 5/19 samples, mean number 5 L(-1). Noroviruses were found in 6/7 influent samples, with an average titre of 10(3.28)L(-1), during winter, but only in 2/15 in the rest of the year (mean 200 L(-1)). MBR treatment removed indicators more efficiently than did the other two lines, with 5log removal of E. coli. Human virus genome removal did not differ between the MBR and tertiary treatment line. Microorganism removal in UASB was significantly lower for all the organisms studied. E. coli, enterococci and Cl. perfringens removal was correlated (p<0.05) with enterovirus genome removal, with R-values around 0.4. However, values for removal of indicators were more strongly correlated to each other. Removal of viruses based on enumeration using RT-PCR probably underestimates infectious virion removal.     

Rheological and fractal characteristics of granular sludge in an upflow anaerobic reactor

The rheological and fractal characteristics of the granular sludge in an upflow anaerobic sludge blanket (UASB) reactor were investigated in this study. The influences of sludge concentration and temperature on the rheological properties of the granular sludge were evaluated, and the Bingham model was adopted to describe its rheology. In addition, image analysis was used to determine the sludge fractal dimension. The results indicate that the UASB granular sludge showed a shear-thinning behavior. The relationships between the limiting viscosity and the sludge concentration, as well as the limiting viscosity and temperature could be respectively modeled using an exponential equation and Arrhenius equation well. The Bingham model was able to adequately describe the rheology of the granular sludge. The fractal dimension of the granular sludge, 2.79+/-0.03, was larger than that of some other aggregates, suggesting that the granular sludge were more compact and denser. Furthermore, the relationship between rheological and fractal properties of the granular sludge could be properly described with the model proposed by Shih et al. [1990. Scaling behavior of the elastic properties of colloidal. Phys. Rev. A 42, 4772-4779].     

改良UASB反应器处理海藻酸钠废水的试验研究

本试验采用改良UASB反应器在常温条件下现场处理海藻酸钠废水,试验历时94 d,在絮状污泥为主条件下,容积负荷6.0 kgCOD/(m3.d)时,COD去除率达到85%,出水pH 6.8左右,VFA稳定在400 mg/L左右,设备运行稳定.试验结果表明,常温下利用改良UASB处理海带渣废水是可行的.     

豆制品废水一级厌氧处理工程

豆制品是我国的传统食品,在豆制品生产过程中产生的高浓度有机废水,采用总容积为4000m^3一级厌氧（UASB）法处理杭州某豆制品厂1500m^3／d的豆制品废水。原水COD浓度为4000～6000mg／L,出水COD浓度降至300～400mg／L,COD去除率达到95％以上,满足三级排放标准的要求。沼气产量2700～3000m^3／d,用于燃烧加热原水。     

UASB+接触氧化+SBR工艺在酒精废水处理中的应用

采用UASB＋接触氧化＋SBR新工艺处理某酒厂高浓度酒精废水,酒精糟液废水水质为COD42000mg／L,BOD521000mg／L,SS9000mg／L,水温60-70℃;出水水质为COD≤300mg／LIBOD5≤100mg／L,SS≤150mg／L,出水达到国家污水综合排放二级标准（GB8978-96）。运行结果表明,该工艺运行稳定,处理效果好。对废水处理过程中产生的沼气进行回收利用,经济效益显著。     

UASB启动的试验研究

研究了上流式厌氧污泥床(UASB)的启动过程。结果显示:在中温条件下(35±1)℃,接种普通厌氧污泥,通过逐步增加反应器负荷,经过61天的运行,完成污泥颗粒化。此时进水CODCr为5736 mg/L,有机负荷10.13 kg CODCr/(m3.d-1),产气率达到0.33 m3/kg CODCr,CODCr去除率92.8%。形成的颗粒污泥内部为黑色,外部包裹一层白色胶状物质,粒径大部分在1~2 mm。     

厌氧生物处理的动力学综述

综述了有机物厌氧生物处理的动力学模型,对厌氧生物的降解机理、生物处理技术的特点做了概括性论述,并对典型的UASB厌氧生物处理反应器的流场数值和动力学进行了模拟.     

UASB反应器处理石灰法草浆黑液过程辨识与参数估计

ＵＡＳＢ反应器处理石灰法草浆黑液过程中，出水基质浓度Ｃｅ，沼气产生速率Ｑ９和进水基质浓度Ｃｉ的关系。运用Ｂｏｘ－Ｊｅｎｋｉｎｓ方法和ＡＩＣ准则，建立了Ｃｉ，Ｑｇ序列对Ｃｉ序列的传递函数及噪声模型，传递函数较好地拟合了ＵＡＳＢ反应器过程，且比噪声部分显得重要，运用建立的模型，对Ｃｅ，Ｑｇ序列进行预测，其平均预测误差分别为４．６７％和８．００％。     

UASB+SBR工艺处理糖果废水

针对糖果废水的特点,采用UASB SBR工艺处理箭牌糖果(中国)有限公司番禺工厂的糖果废水,通过介绍处理工艺流程和工艺调试运行过程,提出了影响工艺调试的因素及相应的控制措施。工程实践证明,UASB SBR工艺是糖果废水有效的处理工艺,出水水质达到《水污染物排放限值》(DB44/26-2001)中第二时段的三级标准。     

Separation of the propionate degradation to improve the efficiency of thermophilic anaerobic treatment of acidified wastewaters

The degradation of propionate generally is limiting in the thermophilic methane digestion of acidified wastewaters. In this paper the propionate degradation in thermophilic systems is studied. A two-stage process is developed, in which the propionate degradation is spatially separated from other conversions in which hydrogen is involved. Significantly better results were obtained with the two-stage system as compared with a one-stage system with an equal total volume: loading rates of 20–50 kg COD m⁻³ day⁻¹ showed a 10–13% better treatment efficiency in the two-stage system. It is concluded that the removal of the biogas evolved in the first degradation processes is the cause of the superior performance of the two-stage system.