筛分技术在城市河道疏浚污泥处置中的应用研究

对筛分技术应用于城市河道污泥进行探索研究,在对城市河道污泥的工程特性分析的基础上,对不同的筛分设备用于城市河道污泥进行全面分析,并将筛分技术应用于工程实践中,取得了良好的效果,为城市河道污泥预处置中遇到的难题提供了良好借鉴。     

Predictive control of an activated sludge process: An application to the Viikinmäki wastewater treatment plant

In this work, we discuss the application of multivariable predictive control for the activated sludge process in a full-scale municipal wastewater treatment plant. Emphasis is given to the selection of a control configuration that contributes to minimising the economic costs while improving the removal efficiency of the nitrogen compounds. For this task, a simple dynamic matrix control algorithm is favoured for controlling the nitrogen concentrations at the end of the biological process. The behaviour of the activated sludge process is reproduced in a commercial simulator that acts as a real-time testing platform and that is also used for identifying the multivariable input–output models for the predictive controller. For demonstrating the effectiveness of the proposed approach, different control configurations are considered and compared against the aeration control strategies currently used at the plant. Based on the simulation results, this work shows the potentiality of the dynamic matrix control which is able to decrease the energy consumption costs and, at the same time, reduce the ammonia peaks and nitrate concentration in the effluent.     

城市污水处理厂节能水平评估标准探讨

以我国现行典型城市污水处理厂实际运行情况为依托,结合国内外经验成果,在筛选影响城市污水处理厂节能水平重要因子的前提下,初步提出采用打分形式对城市污水处理厂节能水平进行评估的设想,从而建立城市污水处理厂节能水平等级划分标准。     

Breakthrough Technologies for the Biorefining of Organic Solid and Liquid Wastes

Organic solid and liquid wastes contain large amounts of energy, nutrients, and water, and should not be perceived as merely waste. Recycling, composting, and combustion of non-recyclables have been practiced for decades to capture the energy and values from municipal solid wastes. Treatment and disposal have been the primary management strategy for wastewater. As new technologies are emerging, alternative options for the utilization of both solid wastes and wastewater have become available. Considering the complexity of the chemical, physical, and biological properties of these wastes, multiple technologies may be required to maximize the energy and value recovery from the wastes. For this purpose, biorefining tends to be an appropriate approach to completely utilize the energy and value available in wastes. Research has demonstrated that non-recyclable waste materials and bio-solids can be converted into usable heat, electricity, fuel, and chemicals through a variety of processes, and the liquid waste streams have the potential to support crop and algae growth and provide other energy recovery and food production options. In this paper, we propose new biorefining schemes aimed at organic solid and liquid wastes from municipal sources, food and biological processing plants, and animal production facilities. Four new breakthrough technologies—namely, vacuum-assisted thermophilic anaerobic digestion, extended aquaponics, oily wastes to biodiesel via glycerolysis, and microwave-assisted thermochemical conversion—can be incorporated into the biorefining schemes, thereby enabling the complete utilization of those wastes for the production of chemicals, fertilizer, energy (biogas, syngas, biodiesel, and bio-oil), foods, and feeds, and resulting in clean water and a significant reduction in pollutant emissions.     

Structure of Crack in Thermally Dried Sludge Cake

We examined in this work the drying characteristics of wastewater sludge, considering the weight loss using an electronic balance and the morphology change of drying cake by an X-ray micro-computerized tomography scanner (micro-CT). The drying rates for sludge cake was 50-60% of the pure water test. The corresponding micro-CT images were scanned to explore the change in cake volume and development of internal crack over drying. The Otsu's method was applied to bilevel the scanned images, based on which the three-dimensional model for crack's internal structure was reconstructed. The cake porosity and the geometric factors of cracks, such as the compactness, the boundary fractal dimension, and the Sierpinski carpet fractal dimension, were evaluated. The shrinkage of cake volume and the development of internal crack occurred simultaneously. The skin layer formed by the former mechanism retards further drying. On the other hand, the internal cracks were shown to exhibit zigzagging with a noncircular cross section and fractal-like boundary, which should be able to enhance local drying. A possible role of change in crack structure on the rate of drying was discussed.     

CASS法处理含盐废水的研究

采用鱼品加工厂生产废水掺一定比例的海水作为试验用水,通过含盐量的不断增加研究系统的耐盐性,通过含盐量的降低和升高研究系统的抗盐度波动性。试验表明,当Cl-的质量浓度<6300mg/L时,CASS系统可正常运行;当Cl-的质量浓度<4500mg/L时,对于Cl-质量浓度梯度为3600mg/L的冲击,系统可以在1个运行周期内恢复正常运行。     

Solidification of electroplating sludge using alkali-activated pulverized fuel ash as cementitious binder

This work investigated the potential for utilization of alkali-activated PFA as solidification binder to treat electroplating sludge. The sludge was solidified using 30 wt.% of lime and 70 wt.% of PFA. Two alkali activators, Na₂SiO₃ and Na₂CO₃, were added at 0, 4, 6, and 8 wt.%. Results showed that early strength development of lime-PFA cements with Na₂SiO₃ and Na₂CO₃ was considerably higher than those without. Addition of electroplating sludge resulted in reduced strength. The strength reduction was greater when 4% Na₂SiO₃ activator was used than when 8% Na₂CO₃ activator was used. A higher pH of Na₂SiO₃ solution (pH=13.5) compared to that of Na₂CO₃ solution (pH=11.9) resulted in resolubilization of metal hydroxides from the electroplating sludge, which competed with calcium ion for soluble silicate. In addition, Pb, Cd, and Cu were not found in the toxicity characteristic leaching procedure (TCLP) leachates. Cr, Zn, and Fe were detected and in some cases Cr exceeded U.S. EPA allowable limits.     

山梨酸废水的生化处理

山梨酸生产废水有机浓度高、可生化性好、含盐量高。废水中CODCr为8000-16500mg/L，B/C≥0.5，含盐量≥15g/L。本工程通过淹没式厌氧生物滤池和膜分离活性污泥法处理，CODCr总去除率高达93%-99%，出水CODCr≤300mg/L，达到GB8978-1996《污水综合排放标准》行业二级排放标准，顺利通过当地环保部门的验收。     

好氧管式膜生物反应器处理高含盐有机废水的研究

采用好氧管式膜生物反应器处理不同含盐浓度的有机废水 ,研究结果表明 (1)进水COD浓度在 2 0 0 0～ 30 0 0mg/L时 ,出水COD在 179～ 2 2 3mg/L之间 ,COD平均去除率在 89.5 %以上 ;(2 )MBR处理高盐度有机废水耐冲击负荷的能力较强 ,出水水质稳定 ;(3)当膜的TMP =0 .1MPa,盐度为 1.0 %、1.5 %、2 .0 %时 ,管式膜的稳定运行通量分别为30、2 4、2 1L/ (m2 ·h) ,整个运行过程中没有进行膜清洗     

电镀污泥中铬的去除工艺优化

以某公司的电镀污泥为研究对象,针对污泥中含铬量高的特点,提出了去除铬的处理工艺.根据铬在污泥中存在的状态,采用硫酸作为浸出试剂.通过正交试验,考察了硫酸浓度、浸出时间、反应温度、搅拌速率等对铬去除率的影响,同时也对去除机理进行了探讨.X射线光电子能谱(XPS)显示,电镀污泥中铬的质量分数为22.05%;取此种污泥2g,用10mol/L的硫酸溶解,在固液比(质量分数)为15∶1,搅拌速率为800r/m,待反应90min后,可使污泥中各种形态的铬溶解于硫酸中,从而去除污泥中的铬.此种方法操作简单可行,污泥中铬的去除率可达90%以上.浸出的铬可进一步综合利用,剩余污泥也可安全填埋,有利于减少此类污泥对环境甚至生态系统的危害.