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Under the Indonesian PPSP (Accelerated Sanitation Development for Human Settlements Program) thousands of new DEWATS (Decentralized Wastewater Treatment Systems) may be realized in the coming five years. Taking the massive scale of planned implementation into consideration an evaluation of the technical and financial-economic aspects and users' involvement for three different types of DEWATS was performed. Evaluated systems included (1) Settler (Set)+Anaerobic Baffled Reactor (ABR)+Anaerobic Filter (AF), (2) Digester+Set+ABR+AF and (3) Settler, equalization, activated sludge, clarifier, filtration. All three systems complied with the current regulations. System 3 suggested the best overall performance on selected parameters in the monitored period. A clear reduction in specific investment costs per household was found with an increasing number of households per system. Only daily, regular operational costs were recovered from fees collected by the community, whereas costs for desludging, major repairs and capital and replacement costs were not. Surveys with users showed a different degree of involvement of local men and women in the planning stages of the project for the systems. Recommendations are provided to scale up the introduction of DEWATS in a more sustainable way in the framework of a city wide sanitation strategy.

A new type of hybrid constructed wetland (CW), consisting of both vertical-baffled flow wetland (VBFW) and horizontal subsurface flow wetland (HSFW), has been deployed in Southern China to naturally accelerate the removal of organic matter and nitrogen. The hybrid CW system is characterised by a combination of continuous baffled flow vertical wetland and 'S' pattern horizontal subsurface flow wetland with natural aeration ditches to increase the concentration of dissolved oxygen in the HSFW bed. An internal circulatory system from the HSFW effluent back to the VBFW may optionally be operated to enhance the biological denitrification effect. Cyperus alternifolius is the main macrophyte in the wetland bed. The performance of the hybrid CW was studied with a pilot-scale system and three full-scale systems for municipal sewage treatment in Southern China. The results suggest that this new hybrid CW can achieve removal efficiencies of chemical oxygen demand, suspended solids, ammonia nitrogen, total nitrogen, and total phosphorus of better than 83.6, 95.0, 71.7, 64.5 and 68.1% respectively, with a specific wetland bed area of 0.70-0.93 m(2) PE(-1). The mean effluent concentrations of these parameters would meet the regulatory discharge limits for wastewater treatment systems (GB18918, 2002) and reuse in the context of agricultural irrigation solutions in China.

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China is undergoing rapid urbanization and economic development. This requires a new approach on spatial planning and environmental infrastructure. In the presented project an example of this approach is given for the city of Changzhou (China) where a new residential area (Qinglong district) will be developed for 100.000 inhabitants. Key issue within the formulation of sustainable sanitation concepts is the integration and management of water, waste and energy in such a way that they will become beneficial to the establishment of the envisaged green city. Starting point was the closing of material cycles focusing on possibilities to recover and reuse valuable resources and energy from "waste" produced in an urban setting. Four different scenarios focusing on water, nutrient and energy recovery were compared with the baseline wastewater management practice. Besides environmental benefits, the economical benefits of sustainable sanitation concepts are attractive, the break even point with the baseline scenario, is already after 5 years, provided that recovered resources will be sold for a marketable price. We believe that presented concepts are applicable for a wide range of new urban development initiatives in China and similar rapidly developing densely populated regions worldwide.

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Absence of wastewater and solid waste facilities impacts the quality of life of many people in developing countries. Implementation of these facilities will benefit public health, water quality, livelihoods and property value. Additional benefits may result from the potential recovery of valuable resources from wastewater and solid waste, such as compost, energy, phosphorus, plastics and paper. Improving water quality through implementation of wastewater and solid waste interventions requires, among others, an analysis of i) sources of pollution, ii) mitigating measures and resource recovery potentials and their effect on water quality and health, and iii) benefits and costs of interventions. We present an integrated approach to evaluate costs and benefits of domestic and industrial wastewater and solid waste interventions. To support a policy maker in formulating a cost-and environmentally effective approach, we quantified the impact of these interventions on 1) water quality improvement, 2) resource recovery potential, and 3) monetized benefits versus costs. The integration of technical, hydrological, agronomical and socioeconomic elements to derive these three tangible outputs in a joint approach is a novelty. The approach is demonstrated using the heavily polluted Indonesian Upper Citarum River in the Bandung region. Domestic interventions, applying simple (anaerobic filter) technologies, were economically most attractive with a benefit cost ratio (BCR) of 3.2, but could not reach target water quality standards. To approach the target water quality, both advanced domestic (nutrient removal systems) and industrial wastewater treatment interventions were required, leading to a BCR of 2. We showed that benefits from selling recovered resources represent here an additional driver for improving water quality How to cite this paper: