Feasibility analysis of wastewater and solid waste systems for application in Indonesia

Indonesia is one of many developing countries with a backlog in achieving targets for the implementation of wastewater and solid waste collection, treatment and recovery systems. Therefore a technical and financial feasibility analysis of these systems was performed using Indonesia as an example. COD, BOD, nitrogen, phosphorus and pathogen removal efficiencies, energy requirements, sludge production, land use and resource recovery potential (phosphorus, energy, duckweed, compost, water) for on-site, community based and off-site wastewater systems were determined. Solid waste systems (conventional, centralized and decentralized resource recovery) were analyzed according to land requirement, compost and energy production and recovery of plastic and paper. In the financial analysis, investments, operational costs & benefits and Total Lifecycle Costs (TLC) of all investigated options were compared. Technical performance and TLC were used to guide system selection for implementation in different residential settings. An analysis was undertaken to determine the effect of price variations of recoverable resources and land prices on TLC. A 10-fold increase in land prices for land intensivewastewater systems resulted in a 5 times higher TLC,whereas a 4-fold increase in the recovered resource selling price resulted in maximum 1.3 times higher TLC. For solid waste, these impacts were reversed — land price and resource selling price variations resulted in a maximumdifference in TLC of 1.8 and 4 respectively. Technical and financial performance analysis can support decision makers in system selection and anticipate the impact of price variations on long-termoperation. The technical analysiswas based on published results of international research and the approach can be applied for other tropical, developing countries. All costs were converted to per capita unit costs and can be updated to assess other countries' estimated costs and benefits. Consequently, the approach can be used to guide wastewater and solid waste system planning in developing countries

A new approach to nationwide sanitation planning for developing countries : Case study of Indonesia

Many developing countries struggle to provide wastewater and solid waste services. The backlog in access has been partly attributed to the absence of a functional sanitation planning framework. Various planning tools are available; however a comprehensive framework that directly links a government policy to nationwide planning is missing. Therefore, we propose a framework to facilitate the nationwide planning process for the implementation of wastewater and solid waste services. The framework requires inputs from government planners and experts in the formulation of starting points and targets. Based on a limited number of indicators (population density, urban functions) three outputs are generated. The first output is a visualization of the spatial distribution of wastewater and solid waste systems to support regional priority setting in planning and create awareness. Secondly, the total number of people served, budget requirements and distribution of systems is determined. Thirdly, the required budget is allocated to the responsible institution to assure effective implementation. The determined budgets are specified by their beneficiaries, distinguishing urban, rural, poor and non-poor households. The framework was applied for Indonesia and outputs were adopted in the National Development Plan. The required budget to reach the Indonesian government's 2019 target was determined to be 25 billion US$over 5 years. The contribution from the national budget required a more than fivefold increase compared to the current budget allocation in Indonesia, corresponding to an increase from 0.5 to 2.7 billion US$ per year. The budget for campaigning, advocacy and institutional strengthening to enable implementation was determined to be 10% of the total budget. The proposed framework is not only suitable for Indonesia, but could also be applied to any developing country that aims to increase access to wastewater and solid waste facilities

Flexible design in water and wastewater engineering - Definitions literature and decision guide

Urban water and wastewater systems face uncertain developments including technological progress, climate change and urban development. To ensure the sustainability of these systems under dynamic conditions it has been proposed that technologies and infrastructure should be flexible, adaptive and robust. However, in literature it is often unclear what these technologies and infrastructure are. Furthermore, the terms flexible, adaptive and robust are often used interchangeably, despite important differences. In this paper we will i) define the terminology, ii) provide an overview of the status of flexible infrastructure design alternatives for water and wastewater networks and treatment, and iii) develop guidelines for the selection of flexible design alternatives. Results indicate that, with the exception of Net Present Valuation methods, there is little research available on the design and evaluation of technologies that can enable flexibility. Flexible design alternatives reviewed include robust design, phased design, modular design, modular/component platform design and design for remanufacturing. As developments in the water sector are driven by slow variables (climate change, urban development), rather than market forces, it is suggested that phased design or component platform designs are suitable for responding to change, while robust design is an option when operations face highly dynamic variability

Optimization and spatial pattern of large-scale aquifer thermal energy storage

Aquifer thermal energy storage (ATES) is a cost-effective technology that enables the reduction of energy use and CO2 emissions associated with the heating and cooling of buildings by storage and recovery of large quantities of thermal energy in the subsurface. Reducing the distance between wells in large-scale application of ATES increases the total amount of energy that can be provided by ATES in a given area. However, due to thermal interference the performance of individual systems can decrease. In this study a novel method is presented that can be used to (a) determine the impact of thermal interference on the economic and environmental performance of ATES and (b) optimize well distances in large-scale applications. The method is demonstrated using the hydrogeological conditions of Amsterdam, Netherlands. Results for this case study show that it is cost-effective to allow a limited amount of thermal interference, such that 30–40% more energy can be provided in a given area compared to the case in which all negative thermal interference is avoided. Sensitivity analysis indicates that optimal well distance is moderately insensitive to changes in hydrogeological and economic conditions. Maximum economic benefit compared to conventional heating and cooling systems on the other hand is sensitive, especially to changes in the gas price and storage temperatures

Potential demand for recoverable resources from Indonesian wastewater and solid waste

Projected population growth and urbanization will become a challenge for finite natural resources, their distribution and local availability. At the same time, 2.5 billion people do not have access to sanitation facilities. Indonesia is one of these rapidly growing countries with a poorly developed municipal wastewater and solid waste sector. Without an integrating concept to recover and reuse resources, "waste flows" are discarded and their potential value is ignored. Therefore, the Indonesian backlog may be an opportunity, since it allows for direct introduction of a circular resource approach. To foster a sustainable municipal wastewater and solid waste management, the 20 years' demand forecast of recoverable resources (phosphorus, compost, duckweed, plastic and paper) was analyzed. Phosphorus, compost and duckweed analysis was based on nutritional demand and not on market demand. Demand for recoverable plastic and paper related to the potential substitution of conventionally manufactured products. Phosphorus and compost demand analysis was based on (1) fertilizer requirements of 68 crops (staple food, horticulture and plantation), and (2) anticipated increase in production area of these crops. Duckweed demand as a protein-rich fish feed was analyzed based on the forecasted demand from aquaculture (tilapia and carp). The potentially recoverable (waste) plastic and paper to substitute conventional manufactured products were based on extrapolation of past trends in plastic and paper production in Indonesia. The potential contribution of recoverable products to the forecasted demand for 2035 was assessed for phosphorus (15%), compost (35%), duckweed (7%), plastic (66%) and paper (18%). A geographical discrepancy between potential recovery and demand location for phosphorus and compost was found. Therefore, the locations of potential markets should be considered in the planning and selection of wastewater and solid waste facilities. The presented methodology to assess the potential demand for recoverable resources from wastewater and solid waste may be applied in other countries as well

The urban harvest approach as framework and planning tool for improved water and resource cycles

Water and resource availability in sufficient quantity and quality for anthropogenic needs represents one of the main challenges in the coming decades. To prepare for upcoming challenges such as increased urbanization and climate change related consequences, innovative and improved resource management concepts are indispensable. In recent years we have developed and applied the Urban Harvest Approach (UHA). The UHA proposes to model and quantify the urban water cycle on different temporal and spatial scales. This approach allowed us to quantify the impact of the implementation of water saving measures and new water treatment concepts in cities. In this paper we will introduce the UHA and present for urban water cycles. Furthermore, we will show first results for an extension to energy cycles and highlight future research items (e.g., nutrients, water-energy-nexus). Key words | Resource cycles, Water management, Water-Energy Nexus, Decision-Suppor

Thermal performance and heat transport in aquifer thermal energy storage

Aquifer thermal energy storage (ATES) is used for seasonal storage of large quantities of thermal energy. Due to the increasing demand for sustainable energy, the number of ATES systems has increased rapidly, which has raised questions on the effect of ATES systems on their surroundings as well as their thermal performance. Furthermore, the increasing density of systems generates concern regarding thermal interference between the wells of one system and between neighboring systems. An assessment is made of (1) the thermal storage performance, and (2) the heat transport around the wells of an existing ATES system in the Netherlands. Reconstruction of flow rates and injection and extraction temperatures from hourly logs of operational data from 2005 to 2012 show that the average thermal recovery is 82% for cold storage and 68% for heat storage. Subsurface heat transport is monitored using distributed temperature sensing. Although the measurements reveal unequal distribution of flow rate over different parts of the well screen and preferential flow due to aquifer heterogeneity, sufficient well spacing has avoided thermal interference. However, oversizing of well spacing may limit the number of systems that ca