Kappa-Carrageenan-based hydrogel for leachate wastewater treatment and resource recovery

Resource recovery from and management of wastewater in rural South Africa: Possibilities and practices

Chapter 1 - Wastewater to R3 – resource recovery, recycling, and reuse efficiency in urban wastewater treatment plants

Developing countries still lag in transitioning wastewater treatment plants towards resource recovery. This study assessed the challenges hindering and opportunities enabling the implementation of resource recovery from municipal wastewater treatment in Zvishavane town, Zimbabwe using the descriptive case study research design to collect data from selected key informant interviewees. Findings highlighted that resource recovery from Zvishavane’s Mabula wastewater treatment plant was at a nascent but dormant stage. Policy, economic, technological factors and lack of expertise were identified as limiting the transition towards resource recovery in Zvishavane. On the other hand, findings indicated that several enabling factors could enable the transition of the Mabula wastewater treatment plant into a resource recovery facility. These included the presence of entrepreneurs working in the resource recovery sector, university-utility collaboration and a vast raw material base. A stakeholder interaction model was developed to create pathways towards resource recovery in Zvishavane.

Quantitative assessment of energy and resource recovery in wastewater treatment plants based on plant-wide simulations

Osmotic membrane bioreactor (OMBR), which integrates forward osmosis (FO) with biological treatment process, has been recently developed to advance wastewater treatment and reuse. During OMBR operation, driven by osmotic pressure gradient, biologically treated water transports from the mixed liquor, through a semi-permeable FO membrane, into a highly concentrated draw solution. Compared to conventional MBR, OMBR has several advantages, including better product water quality, lower fouling propensity, and higher fouling reversibility. OMBR can be operated in the osmotic dilution mode when the draw solution, such as liquid fertilizers or seawater, can be reused or discharged directly. In most cases, OMBR is integrated with an additional process, commonly including reverse osmosis, membrane distillation, and electrodialysis, to form hybrid systems for sustainably reconcentrating draw solutions and producing clean water for reuse. In addition, several membrane processes, such as microfiltration, ultrafiltration, and electrodialysis, are combined with OMBR to address its inherent issue, salinity build-up in the bioreactor, and achieve resource (e.g., nutrients and energy) recovery. This review aims to provide a comprehensive understanding on the performance of OMBR and its hybrid systems in wastewater reuse and resource recovery. OMBR analogs and their performance are also systematically introduced. Key technical challenges and their potential solutions to the further development of OMBR and its hybrid systems are highlighted. This review sheds light on future research for the further development of OMBR and its hybrid systems.

In developing countries, there is often a lack of a comprehensive data set that supports the development of coherent policies on resource recovery from wastewater treatment. This paper aims to contribute to the elaboration of resource recovery projects by providing accurate and updated data from wastewater treatment plants such as those located in the region of the Macrometropolis of Sao Paulo. The authors discuss possibilities of improvement of resource recovery for this illustrative example. Comprehensive analyses were performed based on data from 143 municipal wastewater treatment plants to understand the situation regarding resource recovery implementation in this region. The results show that just 26% of the plants perform at least one resource recovery practice. The predominant resource recovery practice is internal water reuse, and recovery is concentrated more in large plants than in medium and small ones. The sludge is disposed in landfills except for three plants, which perform sludge recycling for compost. Some plant managers reported interest in recovering energy from biogas, in expanding water reuse and in recovering sludge for fertilizer production or for building materials. Several aspects that have been regarded as relevant to the implementation of resource recovery processes in previous literature are discussed, such as the size of the plant, related legislation as well as treatment technologies and configurations. Finally, the authors propose a generic framework with several steps that can help to achieve resource recovery implementation. Therefore, the results can provide support for planning of resource recovery projects for large cities in developing countries.

Planning the centralization level in wastewater collection and treatment: A review of assessment methods

Chapter 5 - Microbial desalination cell based wastewater treatment and resource recovery: Various challenges

Wastewater treatment technology selection under various influent conditions and effluent standards based on life cycle assessment

Environmental synergies in decentralized wastewater treatment at a hotel resort.

Perspective trends of osmotic membrane bioreactor hybrid system for a circular economy

Considering the current resources scarcity, Wastewater Treatment Plants (WWTP) should be adapted to become more sustainable. For example, it is possible to recover resources present in municipal wastewater. However, regional studies about integration of resource recovery processes at different scales or about the main barriers to implementation in developing countries are missing in the literature. Also, there is a need for planning methodologies to identify the most sustainable solution in each context. Understanding the current situation is an essential step to support planning and accelerate resource recovery implementation. To address these issues this thesis aims to guide planning, technology and policy development towards resource recovery from municipal WWTP in large cities of developing countries. This thesis presents a comprehensive knowledge base for wastewater treatment plant managers and decision-makers leading to a better understanding of resource recovery solutions and the actions needed to facilitate implementation. The methodology comprised critical literature reviews and two case studies. Secondary data from literature and primary data (obtained through questionnaires) were collected and analysed. Megacities in developing countries are analysed in the papers, with the focus on the Macrometropolis of Sao Paulo, which is the most populous area in the Southern Hemisphere. The current situation shows a low implementation of resource recovery practices in the region, and local conditions affect the implementation of water reuse, and nutrients and energy recovery. A framework consisting of eleven steps is proposed to support planning and decision-making on resource recovery from wastewater. This new tool was tested and can be applied by decision-makers in wastewater sector for better operation and management. Market, legislation, local economic development, and cooperation with stakeholders are relevant aspects covered in the analysis. There is a great potential to expand wastewater treatment integrated with nutrient and energy recovery strategies in developing countries. Potentials for phosphorus and energy recovery were estimated and some recovery scenarios are recommended. In conclusion, the findings can help planning and elaboration of resource recovery projects in wastewater treatment in urban areas and stimulate creation of public policies. The main research gaps identified in this thesis can guide further research and technological development in this field. (Less)

16 - Bio and bio-based hybrid techniques for municipal wastewater treatment and resource recovery

Chapter 2 - Energy and resources recovery from wastewater treatment systems

Quantifying benefits of resource recovery from sanitation provision in a developing world setting