Zhenliang Liao

Combination of powdered activated carbon and powdered zeolite for enhancing ammonium removal in micro-polluted raw water

Even zeolite is promising in ammonia pollution disposing, its removal efficiency is frequently interfered by organics. As activated carbon has good removal efficiency on organic contaminants, combination of two adsorbents may allow their respective adsorption characteristics into full play. This paper provides a performance assessment of the combination for enhancing ammonium removal in micro-polluted raw water. Gel-filtration chromatography (GFC) was carried out to quantify the molecular weight (MW) range of organic contaminants that powdered activated carbon (PAC) and powdered zeolite (PZ) can remove. The polydispersity difference which also calculated from GFC may indicate the wider organic contaminants removal range of PAC and the relatively centralized removal range of PZ. The jar tests of combination dosing confirm a synergistic effect which promotes ammonium removing. Nevertheless, it also shows an antagonism hindering the due removal performance of the two adsorbents on CODMn, while it is not much evident on UV254. Furthermore, a comparison study with simulated coagulation-sedimentation process was conducted to evaluate the optimum dosing points (spatial and temporal) of PAC and PZ among follows: suction well, pipeline mixer, early and middle phase of flocculation. We suggest to dose both two adsorbents into the early phase of flocculation to maximize the versatile removal efficiency on turbidity, ammonium and organic contaminants.

Combined sewer overflow control with LID based on SWMM: an example in Shanghai, China

Although low impact development (LID) has been commonly applied across the developed countries for mitigating the negative impacts of combined sewer overflows (CSOs) on urban hydrological environment, it has not been widely used in developing countries yet. In this paper, a typical combined sewer system in an urbanized area of Shanghai, China was used to demonstrate how to design and choose CSO control solutions with LID using stormwater management model. We constructed and simulated three types of CSO control scenarios. Our findings support the notion that LID measures possess favorable capability on CSO reduction. Nevertheless, the green scenarios which are completely comprised by LID measures fail to achieve the maximal effectiveness on CSO reduction, while the gray-green scenarios (LID measure combined with gray measures) achieve it. The unit cost-effectiveness of each type of scenario sorts as: green scenario > gray-green scenario > gray scenario. Actually, as the storage tank is built in the case catchment, a complete application of green scenario is inaccessible here. Through comprehensive evaluation and comparison, the gray-green scenario F which used the combination of storage tank, bio-retention and rain barrels is considered as the most feasible one in this case.

The Mekong Game: Achieving an All-win Situation

In recent years, there have been many quarrels among countries of the Mekong River Basin surrounding use of the water resources of that river. In particular, China’s behavior of constructing dams upstream has resulted in objections by many people in all countries downstream. Cooperative game theory has been applied to solving issues of building and utilizing dams on trans-border rivers. The central question is how to allocate the surplus benefits generated by the dams. This paper proposes to achieve an all-win situation in use of Mekong water resources through cooperation. A game named “The Mekong Game” was designed for those Ph.D. students and resource persons to play on the PROSPER.NET’s workshop in 2010. For a hypothetical case in Mekong Game, the Shapley Value Method’s results were given, which could be regarded as one of equitable results in theory, and the Mekong Game’s process and outcomes are introduced in this paper. Participants were divided into six groups representing the six involved “countries.” The process of meeting an agreement with an all-win idea was simulated through three round-table negotiations. For the hypothetical case, different set of results under different situations were compared and discussed, including no dam(s), dam(s) without cooperation, dam(s) with cooperation but without compensation and re-allocation, Shapley Value Method, and Mekong Game (bargaining and negotiation). The results reveal: although it is hard to get theoretical optimal aftermath considering other complicated factors than those can be calculated, the all-win situation is still possible through bargaining and negotiation processes, which should be much better than all-lose situation such as the current one.

Integration of multi-technology on oil spill emergency preparedness.

This paper focuses on the integration of technologies including Case-Based Reasoning (CBR), Genetic Algorithm (GA) and Artificial Neural Network (ANN) for establishing emergency preparedness for oil spill accidents. In CBR, the Frame method is used to define case representation, and the HEOM (Heterogeneous Euclidean-Overlap Metric) is improved to define the similarity of case properties. In GA, we introduce an Improved Genetic Algorithm (IGA) that achieves case adaptation, in which technologies include the Multi-Parameter Cascade Code method, the Small Section method for generation of an initial population, the Multi-Factor Integrated Fitness Function, and Niche technology for genetic operations including selection, crossover, and mutation. In ANN, a modified back-propagation algorithm is employed to train the algorithm to quickly improve system preparedness. Through the analysis of 32 fabricated oil spill cases, an oil spill emergency preparedness system based on the integration of CBR, GA and ANN is introduced. In particular, the development of ANN is presented and analyzed. The paper also discusses the efficacy of our integration approach.

CBR respond and preparedness system development for environmental emergency

Effective response and preparedness plans are important for successfully coping with environmental emergencies. ‘Quickness’ and ‘accuracy’ are the most important requirements of environmental emergency response and preparedness planning. We propose the use of case-based reasoning (CBR) technology to develop response and preparedness plans using these principles. Taking into account the characteristics of a real environmental emergency, the development is presented using the example of a CBR – Oil Spill Response and Preparedness System. This paper introduces the methodology, which includes system architecture, inputs and outputs, case structure, case retrieval, case adaptation, case evaluation and retention, and management of the case base. The following methods are presented to meet the requirements of environmental emergency response and preparedness planning: the Frame method for defining case representation; the modified Heterogeneous Euclidean-Overlap Metric method for defining the similarity function; and the Attribute Hierarchical Model method for assigning relative weights to attributes. The effectiveness and uncertainty of the methodology are also discussed.

Establishment of Water Environmental Data Mart

The concepts of data warehouse, data mart, on-line analytical processing (OLAP) are introduced into the domain of environmental decision support system. A water environmental data mart (WEDM) is developed with a citys water environmental operation database as data source, and with star schema as data framework. Two main parts are included in WEDM, the extract-cleanse-transform-load tool, and the universal OLAP tool whose functions include SQL, classifying statistic, and data visualization. The WEDM can provide multidimensional, multi-leveling, integrated, dynamic, flexible querying and analyzing, which is not offered by previous environmental operation database system. Three examples show the functions of proposing decision support information of WEDM.

An all-win game for Mekong

There have been many quarrels among countries of the Mekong River Basin surrounding about use of the water resources of the river in recent years. This paper is to achieve an all-win situation in use of Mekong water resources through cooperation. A game named “The Mekong Game” was designed for those Ph.D. students and resource persons to play on the PROSPER.NETs workshop. For a hypothetical case in Mekong Game, the Shapley Value Methods results were given, which could be regarded as one of equitable results in theory, and the Mekong Games process and outcomes are introduced in this paper. Participants were divided into six groups representing six involved “countries”. The process of meeting an agreement with an all-win idea was simulated through three round-table negotiations. The results reveal: although it is harder to get theoretical optimal aftermath considering other complicated factors than those which can be calculated, the all-win situation is still possible through bargaining and negotiation processes, which should be much better than all-lose situation such as the current one.

Development of Modeling Subsystem in Comprehensive Rehabilitation DSS of Suzhou Creek

The comprehensive rehabilitation project of Suzhou Creek has been one of the largest water environmental rehabilitation projects in Shanghai. In order to assess the effect of the comprehensive rehabilitation project on water quality of Suzhou Creek, a DSS (decision supporting system) which includes a modeling subsystem, a GIS subsystem and a data analysis subsystem is developed and put into application. In this paper, the development of the core part of the comprehensive rehabilitation DSS of Suzhou Creek, namely the modeling subsystem, is introduced. The modeling subsystem comprises of hydrodynamic model, water quality model, interface between them, interfaces with database, DSS and users. VB 6.0 is chosen as the developing platform. The modeling subsystem is capable of creating project schemes, editing project schemes, project schemes computing, displaying results and analyzing project schemes, thus can support users on making decisions of rehabilitation project of Suzhou Creek.