Particle Image Velocimetry (PIV) was used to study the settling of activated sludge flocs under turbulent flow conditions. Experimental results showed that a larger particle diameter led to a higher settling velocity while the higher turbulence intensity led to lower settling velocity. Based on the measurements a mathematical relation has been derived which correlates the settling velocity for individual sludge flocs under turbulent conditions through a modified Vesilind equation. Settling velocity shows a power-type relation to sludge particle diameter and an exponential-type relation with turbulence intensity and sludge concentration.

The aim of this paper is to realize fully the hybrid respirometric measurement principle with high accuracy and measuring frequency. Based on the knowledge of the difficulty in implementing “ultimate” hybrid respirometer and the drawbacks of the simpler hybrid respirometer, a novel implementation of the hybrid respirometric measurement principle was developed. It was verified that the new hybrid respirometer possessed the advantage of “ultimate” hybrid respirometer while its DO electrodes suffered no effect of flow rate change. Also the accurate and constant temperature of the whole set-up was solved. For the purpose of enhancing the availability of the respirometer proposed in this paper, software with friendly user interface was developed, in which advanced arithmetic and median filter were adopted. Finally the new hybrid respirometer system was evaluated and the accuracy and reliability were satisfied.

Based on batch settling tests, a model describing the compression settling process of activated sludge was developed and validated by experiments. Furthermore, a theoretical equation for determining the critical point when the compression settling stage commences, and a new velocity function for the compression settling were deduced from the model. By combining the new model and the conservation of mass, it was proved that the Vesilind function was also capable of describing the compression settling velocity on condition that the appropriate parameters were estimated. Dividing the complete settling process of activated sludge into the zone settling and compression settling stages, and describing them by the Vesilind function with different parameter sets was more reasonable for characterizing the complete settling process of activated sludge. The method was applied to predict the sludge blanket height during batch settling tests, and the results showed that the settling processes could be simulated well.

论述了三峡水库几个重要水环境问题。对近年来三峡水库水污染控制科学研究工作进行回顾，评述了一些重要研究成果。就三峡水库水质模拟、水体富营养化、水库泥沙截留淤积和重金属污染等问题进行了深入探讨。基于国际水协会最新推出的河流水质模型，提出了三峡水库水环境模拟研究的观点和方法；基于湖泊（水库）生态动力学模型原理，在对水体中磷元素预测的基础上，从营养盐含量、水深、流速、温度因素等与富营养化非线性映射关系出，初步建立三峡水库水体富营养化人工神经网络模型，对三峡水库水体富营养化潜势进行研究,分析讨论了一些初步结果；论述了水库泥沙截留淤积及其与水体中污染物，特别是重金属污染的相互作用；建议了近期内应予以重视的一些三峡水库重要水环境科学问题。

The integration of methanogenesis with denitrification and anaerobic ammoniumoxidation (ANAMMOX) was studied in an expanded granular sludge bed (EGSB) reactor in this work. Experimental results from the continuous treatment of wastewater with nitrite and ammonium, which lasted for 107 days, emonstrated that wastewater with high nitrite and ammonium could be anaerobically treated in an expanded granular sludge bed reactor. More than 91% to 97% of COD were removed at up to about 3.9g CODP (L