A2/O+MBBR系统的快速启动及反硝化除磷特性

本研究针对A2/O +移动床生物膜反应器 (A2/O + MBBR) 双污泥系统,考察启动过程的污泥特性和反硝化除磷特性,建立系统的快速启动策略。研究结果表明：启动过程21 d完成,污泥结构稳定且具有较好的污泥沉降性和生物活性;SVI值在95 mL/gMLSS以下,反硝化聚磷菌(DNPAOs)占聚磷菌(PAOs)的百分比从接种污泥时的10.87%增加到25.46%。在平均进水C/N为3.44的运行条件下,A2/O + MBBR系统可实现有机物、氮、磷等污染物的同步高效去除,稳定运行阶段出水COD、NH4+-N、TN和PO43--P浓度分别为38.5,1.15,14.2,0.15 mg/L,COD、TN和PO43--P去除率分别为82.23%,74.72%和96.80%。DO、pH和ORP等实时控制参数的联合调控有利于促进系统的快速启动和稳定运行。     

Kinetic modeling microbial storage process in activated sludge under anoxic conditions

A new kinetic model is developed to describe the microbial storage process under anoxic conditions in activated sludge. The accumulation of nitrite in denitrification is taken into account in this model. The formation of storage polymers under anoxic conditions is coupled with energy generation and anoxic respiration, and their formation rate is found to be proportional to the substrate utilization rate. The sensitivity of the nitrogen uptake rate toward the stoichiometric and kinetic coefficients of the established model is analyzed by using an “absolute-relative” sensitivity function implemented in software AQUASIM. Batch denitrifying experiments were conducted to calibrate and validate the established model. The model is compared with ASM1 and ASM3, the two commonly used activated sludge models. Results show that the kinetic model established in this work is able to better describe the microbial storage processes under anoxic conditions.     

A／O工艺处理吉化混合化工废水试验研究

提出了一种化工生产中废水处理的新工艺──Anoxic／Oxic（A／O）工艺。实验室研究结果表明，该工艺能通过硝化-反硝化作用使吉化混合化工废水中COD、NH3－N和TN同时得到有效降解，为废水达标排放提供了一条有效途径。     

Heterotroph anoxic yield in anoxic aerobic activated sludge systems treating municipal wastewater

As input to the steady state design and kinetic simulation models for the activated sludge system, the correct value for the heterotroph anoxic yield is essential to provide reliable estimates for the system denitrification potential. This paper examines activated sludge anoxic yield values in the literature, and presents experimental data quantifying the value. In the literature, in terms of the structure of ASM1 and similar models, theoretically it has been shown that the anoxic yield should be reduced to approximately 0.79 the value of the aerobic yield. This theoretical value is validated with data from corresponding aerobic OUR and anoxic nitrate time profiles in a batch fed laboratory scale long sludge age activated sludge system treating municipal wastewater. The value also is in close agreement with values in the literature measured with both artificial substrates and municipal wastewater. Thus, it is concluded that, in ASM1 and similar models, for an aerobic yield of 0.67mg COD/mg COD, the anoxic yield should be about 0.53 mg COD/mg COD. Including such a lower anoxic yield in ASM1 and similar models will result in a significant increase in denitrification potential, due to increased denitrification with wastewater RBCOD as substrate. In terms of the structure of ASM3, for the proposed substrate storage yields and the aerobic yield of 0.63 mg COD/mg COD, experimental data indicate that the corresponding anoxic yield should be about 0.42 mg COD/mg COD. This is significantly lower than the proposed value of 0.54 mg COD/mg COD, and requires further investigation.     

EARLY TOARCIAN SOURCE‐ROCK POTENTIAL IN THE CENTRAL HIGH ATLAS BASIN (CENTRAL MOROCCO): REGIONAL DISTRIBUTION AND DEPOSITIONAL MODEL

The early Toarcian is characterized by the occurrence of widespread black shale deposits, recorded extensively across Europe and interpreted to be related to an Oceanic Anoxic Event. In order to investigate the source‐rock potential of lower Toarcian deposits in Morocco, detailed sedimentary logging accompanied by outcrop spectral gamma‐ray measurements were carried out on four sections representative of different palaeo‐depositional settings in the Central High Atlas. Authigenic uranium enrichment is used as a proxy for oxygen‐depleted depositional conditions, and may thus indicate potential organic‐rich lithologies. Of the four measured sections, only one (the Amellago section, which represents the deepest marine setting) shows relative authigenic uranium enrichment. Complementary TOC analyses (with maximum values of 3.24%) over this interval confirm an associated enrichment trend in organic matter. The organic matter recovered from the outcrop samples is however highly oxidised, and thus the absolute value is not regarded as being a true record of the rocks' organic content. It is concluded from this study that early Toarcian potential source rocks were deposited within restricted sub‐basins in the Central High Atlas. It is therefore possible that organic‐rich deposits of Toarcian age are present in similar palaeogeographic settings in other areas of Morocco. This increases the exploration potential of Moroccan basins in which Jurassic deposits are potential source rocks.