Upgrading the Activated-Sludge Process for Total Nitrogen Removal in Hong Kong

In order to protect the sensitive waters in Tolo harbour (Hong Kong), Sha Tin and Tai Po sewage-treatment works were first designed to remove 70% of the nitrogen load from the sewage. Since then, due to continuing serious eutrophication problems in the harbour, both plants have been modified to increase the removal efficiency to 90%.
The modifications were based on the Bardenpho process. However, the designers of the two plants adopted different approaches to process intensity, complexity and control of bacterial foam. At Sha Tin, the average monthly results have shown an increase of total nitrogen removal from 60–70% to about 80% since its completion. The addition of methanol was found to be ineffective on further enhancement of the denitrification rate due to difficulties in the apportioning of the second anoxic zone. The overall monthly results for Tai Po have also shown an increase in the removal rate to about 80%, even though 90% was achieved for a short period of time. The major problem encountered at the latter plant was that the process design did not provide an effective control on bacterial foaming, which had affected the smooth operation of the process.     

广义离散系统的周期解

首次对广义离散系统的周期解的存在性进行研究，给出了广义离散系统周期解存在的判据。     

磨损随机过程建模及实例分析

针对磨损过程的动态性和随机性,提出一种构件磨损随机过程建模方法,为磨损构件的可靠性分析和寿命预测提供基础。基于平稳随机过程,给出了磨损随机过程建模基本流程;以Ar-chard磨损公式为例,推导了任意时刻磨损量的分布函数,从而能够评估磨损构件的动态可靠度和概率失效时间;结合活塞气环的实测数据,建立磨损随机过程模型,并给出抗磨损可靠度随行驶里程的变化规律。通过算例发现,磨损随机过程模型与实际相符,而考虑稳态磨损过程的磨损率为随机变量,计算结果偏保守。这样,为工程构件磨损的定量评估探索新的途径。     

农村及偏远地区饮用水除氟研究

研究了农村及偏远地区地下饮用水的除氟方法及其工艺流程、发展中的除氟新方法及新材料;分析了现有饮用水除氟设施存在的问题及其原因;提出了适合于农村及偏远郊区的除氟方法及其设施的发展方向.     

某超贫钒钛磁铁矿选矿试验研究

对某超贫钒钛磁铁矿开展了选矿试验研究,在工艺矿物学研究的基础之上,采用预选和再磨弱磁选工艺,获得了铁精矿铁品位58.32%,回收率60.76%的试验指标。     

高原铁矿选矿厂预选工艺的研究与应用

主要介绍了金钢矿业乔普卡铁矿新建高原铁矿选矿厂预选工艺的研究与应用情况,通过对预选工艺的设计和优化,使生产流程更加顺畅,提高了生产效率,实现了流程运行的科学性、高效性与稳定性,形成了一套具有高原特色的新型铁矿选矿生产工艺,可为高原铁矿的选矿提供借鉴。     

湖南某铜矿选矿无碱新工艺研究

针对铜品位0.850%的湖南某铜矿,进行了矿石多元素分析和物相分析,进行了各种条件试验,确定了无碱新工艺优先浮铜流程,可获得铜精矿含铜22.338%、铜回收率89.09%的选矿指标。     

An inverse solution of the lifetime-oriented design problem

This paper presents a new solution of the lifetime-oriented design problem. This solution is based on a point-to-point allocation between the space of the design parameters and the space of structural responses. Each point in the space of the design parameters defines a feasible or non-feasible design, and all feasible designs guarantee compliance with a predetermined lifetime. From the set of feasible designs, one or more designs may be selected with the aid of technical or economic criteria. The presented solution permits the consideration of non-statistical data uncertainty, thereby leading to an uncertain lifetime. Because of the unavoidable information deficit, for example incomplete data in practical problems, the application of non-statistical data uncertainty is more realistic than the application of stochastic data models. The selection of feasible design variants is based on methods of explorative data analysis.     

Optimal intervention strategies for multiple objects affected by manifest and latent deterioration processes

In the existing infrastructure management systems, optimal interventions strategies (OISs) are determined for objects that deteriorate gradually (manifest deterioration process, MDPs), under the assumption that with appropriate inspection and intervention strategies the probability of failure of object can be neglected. Objects that deteriorate suddenly (latent deterioration process, LDPs), for example, due to scouring during a flood or earth movements during an earthquake are not considered. The determination of OISs for an object that deteriorates due to both MDPs and LDPs requires the consideration of both. The latter, however, means that the probability of failure of the object must be considered. In this article, a Markov model is presented that can be used to determine OISs for multiple objects of multiple types affected by uncorrelated MDPs and LDPs. The model is an extension of the model proposed by Mayet and Madanat (Incorporation of seismic considerations in bridge management systems. Computer-Aided Civil and Infrastructure Engineering, 17:185–193, 2002). In the model, a set of condition states (CSs) is used to describe the condition of objects of each type, where each set is composed of non-failure CSs and failure CSs. The probabilities of going from each non-failure CS to each failure CS are estimated using normalised fragility curves, and the probabilities of going from each non-failure CS to each non-failure CS are initially estimated using the Markov deterioration prediction model of Kobayashi, Kaito, and Lethanh (A Bayesian estimation method to improve deterioration prediction for infrastructure system with Markov chain model. International Journal of Architecture, Engineering and Construction, 1:1–13, 2012a) and later adjusted taking into consideration the probabilities of entering the failure CSs. The use of the model is demonstrated using a road link comprising one road section and one bridge.