陶瓷污泥中微量镉催化光度法测定

利用还原型若丹明B(RRhB)与KClO3的显色反应,对含镉(Ⅱ)陶瓷污泥中痕量镉(Ⅱ)进行测定。结果表明,在pH5.3HAc-NaAc缓冲溶液中具有高灵敏的显色反应,产物的最大吸收波长为560nm,方法的检出限为3.0×10-8gCd2 /L,催化程度与镉(Ⅱ)量在0～0.045mg/L范围内符合比耳定律,加标回收率为97.4%～103.8%(n=6)。结合KI—MIBK萃取分离,满意地测定了陶瓷污泥中的微量镉。     

污泥调理剂

综述了污泥调理中常用的化学调理剂及其各自的优缺点,着重介绍了因具有安全、无毒、可生物降解、无二次污染等独特的性质而倍受人们的关注的生物絮凝剂。     

MBR中溶解氧和污泥负荷对污泥产量的影响

采用MBR处理人工配制生活污水,考察反应器中可控因子溶解氧(DO)、污泥负荷(F/M)对系统污泥产率的影响。试验中分别考察了DO为1mg/L、3mg/L和5mg/L以及污泥负荷为0.3gCOD/gMLSS·d、0.6gCOD/gMLSS·d和0.9gCOD/gMLSS·d时系统的污泥产率变化情况。根据试验结果发现在相同污泥负荷条件下,随着MBR中DO的升高,污泥产率呈现降低的趋势;在同一个DO水平下,系统的污泥产率随着污泥负荷的升高而升高。以菌胶团内DO和基质浓度的分布为基础,对DO和污泥负荷影响系统污泥产率的现象进行了理论分析。     

动态膜在错流微滤系统中的应用

利用6000目的高岭土作为动态膜涂膜材料,在相同的条件下过滤活性污泥和二级出水.实验结果显示,动态膜过滤在出水水质和通量方面明显优于直接过滤,而处理二级出水在膜通量方面没有优势.清洗实验结果表明动态膜能有效降低膜内部污染,并能恢复到新膜通量的90%.污泥浓度越大,通量越小.提高膜面流速和增加压力都能有效的提高膜通量,但提高膜面流速更经济.     

污水厂污泥制备吸附剂及其脱硫机理研究

以城市和石化污水厂生化活性污泥及剩余污泥为原料,采用不同方法制备烟气脱硫吸附剂,对影响产物吸附性能的因素进行了研究。结果表明城市污水厂剩余污泥利用热解炭化法制备的吸附剂脱硫性能较好,其吸附过程可用Freundlich模型来描述,SO2-O2-N2体系吸附机理主要为物理吸附,SO2-O2-H2O(g)-N2体系SO2发生了催化氧化,以化学吸附为主。     

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.     

Dewatering behaviour of water treatment sludges associated with contaminated site remediation in Antarctica

Sludge reduction and dewatering is an important aspect of water and waste water treatment. This is especially true in the case of Australia's Antarctic contaminated site remediation program, where the reduction in volume of wastes to be returned to Australia can lead to significant transport and handling cost savings. The dewatering characterisation of water treatment sludges from an Antarctic contaminated site was conducted using a theory of suspension dewatering developed by Buscall, Landman and White. This theory uses fundamental material properties of compressibility and permeability to determine the diffusivity of a suspension. Diffusivity is a useful property that can be used to directly compare the dewaterability of various sludges. In this investigation, several water treatment sludges were collected and characterised in the field to determine the impact of temperature and additives on compressibility, permeability and diffusivity. The Antarctic sludges were found to be less compressible and less permeable than materials such as mineral suspensions and alum water treatment sludges. Compressibility was found to decrease with the addition of powdered coagulation aids such as bentonite and chitosan.     

Assessment by Microscopy of the Coverage of Sludge Flocs by a Nano‐scale Surface Layer

Flocs are irregularly shaped suspended particles of complex structure and composition that occur naturally in aquatic systems. In water treatment facilities, the settling of flocs is extremely important. Transmission electron microscopy was used to quantify the formation of a nano‐scale surface layer on flocs from two laboratory bioreactors modelling a biological wastewater treatment facility. By comparing different floc populations, we demonstrated that flocs that settled quickly out of wastewater had a significant amount of this layer, whereas those with little nano‐scale surface layer had poor settling properties. This morphological feature of floc ultrastructure may permit engineering manipulations that promote floc settling.     

Preparation of carbon-based adsorbents from sewage sludge pyrolysis to remove metals from water

The objective of this study was to evaluate the use of cheap carbon-based adsorbents from sewage sludge pyrolysis to remove Na⁺, K⁺, Ca²⁺ and Mg²⁺ from saline water. Four model solutions of NaCl, KCl, CaCl₂ and MgCl₂ that simulated seawater composition were used. The model solutions were 456.54 mmol_c L⁻¹ NaCl, 9.72 mmol_c L⁻¹ KCl, 19.96 mmol_c L⁻¹ CaCl₂ and 111.09 mmol_c L⁻¹ MgCl₂. Two carbon adsorbents, one with chemical activation, were prepared by a new method and evaluated for ion adsorption. The results indicated that carbon adsorbent without chemical activation was the most effective in removing ions from different solutions and the removal of metals followed the sequence: Na⁺ (76.78−69.66) >K⁺ (66.0−57.80) >Mg²⁺ (44.84−42.85) >Ca²⁺ (35.12−12.38). Results showed that it is to possible prepare carbon-based adsorbents from sewage sludge following inexpensive and environmentally acceptable methods.     

改善剩余活性污泥过滤性能的研究

本文采用FeCl_3、Al_2(SO_4)_3和聚丙烯酰胺三种混凝剂,研究了混凝剂剂量与剩余活性污泥比阻值的关系,优化出最佳混凝剂种类和剂量,对降低污泥处理的运行费用具有实际指导意义。