新型组合工艺对微污染原水中有机污染物和消毒副产物前体物的去除

本采用中试试验装置研究了生物陶粒过滤一微絮凝砂滤一活性炭吸附组合工艺，对微污染原水中有机污染物和消毒副产物前体物的去除效果。在原水UV254为0．047～0．065cm^-1，DOC为2．70～4．10mg／L，TOC为3．50～5．00mg／L的条件下，组合工艺对UV254，DOC、TOC平均去除率分别为98．4％、74．1％、69．2％。色-质联机分析结果表明，经组合工艺处理水中有机物由54种降至25种。组合工艺出水中三卤甲烷总含量不及常规工艺出水中该物质含量的五分之一。组合工艺能有效控制和消除水中有机物的污染，提供安全的优质饮用水。     

阳光下TiO2/GAC光催化处理洗涤剂废水的研究

利用太阳光作光源，采用固定在颗粒活性炭中的TiO2(TiO2／GAC)作光催化剂，利用其将活性炭极好的吸附性与TiO2优良的光催化性能结合于一体的特性，设计了对以洗衣粉配置的洗涤剂模拟废水的两种处理方案：同时光照-吸附法和吸附饱和-光照水洗再生法，并在实验基础上对两种方案的一些性能进行了讨论。     

Effect of backwashing on activated carbon adsorption using plug flow pore surface diffusion model

A fixed bed is gradually exhausted from top to bottom without backwashing; however, backwashing can rearrange the concentration gradient in the bed. After backwashing, saturated particles which are located at the top of the bed are homogeneously distributed in the bed. The used model to predict adsorption and backwashing effect of organic component is the plug flow pore surface diffusion model (PFPSDM). A sensitivity analysis was performed to determine which parameters have the greatest impact on the model results for components which can represent various organics. In addition, the effects of backwashing were examined by rearranging concentration gradient. For single component sensitivity analysis, the molecular weight was an important parameter. The breakthrough of the smaller molecular weight component was impacted more by backwashing. The SPDFR showed a significant impact on the breakthrough pattern. When surface diffusion was the dominant mechanism, high SPDFR, the breakthrough profile was sharper than when pore diffusion was dominant, low SPDFR. The adsorbability was an important parameter in determining the breakthrough pattern. As expected, the strongly adsorbable component showed the later breakthrough. Backwashing yielded earlier breakthrough for all single components and multi-components examined.     

Behavior Of Glyoxal During Granular Activated Carbon Treatment

Glyoxal, which was the strong mutagen formed by ozonation of humic substances, was treated with granular activated carbon (GAC) and the behavior of glyoxal was investigated. Glyoxal itself was adsorbed well on GAC at pH 5–7. But, glyoxal increased by GAC treatment of ozonated humic substances when the ozone dose was insufficient to decolorize the humic substances. The precursors of glyoxal may be among other ozonated products which may be changed to glyoxal on GAC.     

活性炭对原水中有机污染物去除效果的研究

文中针对原水水质特点,利用常规+活性炭吸附工艺对原水进行处理,着重分析了活性炭对有机物的去除效果。     

Hamming重量为k的布尔函数的全局特征和非线性度

该文给出了布尔函数的自相关系数和互相关系数的一些性质,得到n元布尔函数f (x)满足t 阶扩散准则时,n,t 和Hamming重量wt(f)的制约关系,给出了任意Hamming重量为k的布尔函数的平方和指标下界表达式,推出了仅由布尔函数Hamming重量所确定的非线性度的上界表达式。这些结论推广了已有结果。     

Removing low ppb level perchlorate, RDX, and HMX from groundwater with cetyltrimethylammonium chloride (CTAC) pre-loaded activated carbon

Perchlorate contaminates vast amounts of groundwater throughout the United States which could potentially be used as potable water. Activated carbon pre-loaded with cetyltrimethylammonium chloride has been shown in this research to be an effective adsorbent for removing perchlorate from three low conductivity (50-66 microS/cm) groundwaters containing perchlorate (ClO(4)(-)) concentrations of 0.85, 1.0, and 5.6 parts per billion (ppb), respectively. In rapid small-scale column tests (RSSCTs), the virgin granular activated carbon (GAC) (used as a control) treated between 20,000 and 40,000 bed volumes (BV) of water. In contrast, the activated carbon that was pre-loaded with CTAC processed 170,000-270,000 BV before perchlorate was detected above 0.25 ppb in the effluent. Though this pre-loading significantly increased the capacity for perchlorate, it also diminished the GAC's capacity to remove organics. The groundwater containing 1 ppb ClO(4)(-) also contained the nitro-organics HMX (0.6 ppb) and RDX (5.5-6.6 ppb). RDX was detected in the effluent from the CTAC-pre-loaded bed after only 8000 BV had been processed whereas 308,000 BV could be processed through the virgin bed before RDX was detected. Likewise, HMX breakthrough was observed after 116,000 BV in the CTAC-pre-loaded bed while the virgin RSSCT exhibited no breakthrough of HMX during a test that was operated for 309,000 BV. However, by combining a CTAC-pre-loaded bed followed by a virgin GAC bed in series, both perchlorate and RDX could be removed for the same length of time.     

Rayleigh衰落信道中分组码最大似然译码的性能

摆脱了传统代数译码方法,对分组码进行基于广义阵列码（ＧＡＣ）结构的网格译码（Ｔｒｅｌｌｉｓ ｄｅｃｏｄｉｎｇ）,研究了Ｒａｙｌｅｉｇｈ衰落信道中分组码与这种软判决最大似然译码方法相结合的性能。模拟结果显示。分组码采用网格译码,可为移动衰落信道带来显著的性能改善。     

Application of Taguchi method for the optimization of Fe2+ removal from contaminated synthetic groundwater using a rotating packed bed contactor

Malaysia contains elevated levels of iron in shallow groundwater in the range of 3–7 mg Fe/L compared to the USEPA safe limit of 0.3 mg Fe/L. Air Kelantan Sdn Bhd in Malaysia uses the ‘River Bank Filtration’ (RBF) technology to harvest hyporheic water. The RBF treatment removes the turbidity of the river water through the river bed acting as a filter, but is unable to remove the Fe from the harvested water. This work proposes a technology to reduce Fe concentration in the extracted water using granular activated carbon in a laboratory‐scale rotating packed bed contactor (RPBC). The Taguchi method was used for optimizing the operating conditions for the adsorption of Fe onto activated carbon in the RPBC system. Taguchi optimization results showed that a removal efficiency of 87% Fe from a 50 mg Fe/L concentration could be achieved by a RPBC at an initial pH of 6.5, a feed rate of 40 L/h, a rotating speed of 1600 rpm and a packing density of 357 kg/m³.     

Rapid and direct estimation of active biomass on granular activated carbon through adenosine tri-phosphate (ATP) determination

Granular activated carbon (GAC) filtration is used during drinking water treatment for the removal of micropollutants such as taste and odour compounds, halogenated hydrocarbons, pesticides and pharmaceuticals. In addition, the active microbial biomass established on GAC is responsible for the removal of biodegradable dissolved organic carbon compounds present in water or formed during oxidation (e.g., ozonation and chlorination) processes. In order to conduct correct kinetic evaluations of DOC removal during drinking water treatment, and to assess the state and performance of full-scale GAC filter installations, an accurate and sensitive method for active biomass determination on GAC is required. We have developed a straight-forward method based on direct measurement of the total adenosine tri-phosphate (ATP) content of a GAC sample and other support media. In this method, we have combined flow-cytometric absolute cell counting and ATP analysis to derive case-specific ATP/cell conversion values. In this study, we present the detailed standardisation of the ATP method. An uncertainty assessment has shown that heterogeneous colonisation of the GAC particles makes the largest contribution to the combined standard uncertainty of the method. The method was applied for the investigation of biofilm formation during the start-up period of a GAC pilot-scale plant treating Lake Zurich water. A rapid increase in the biomass of up to 1.1 x 10(10)cells/g GAC dry weight (DW) within the first 33 days was observed, followed by a slight decrease to an average steady-state concentration of 7.9 x 10(9)cells/g GAC DW. It was shown that the method can be used to determine the biomass attached to the GAC for both stable and developing biofilms.