Wastewater Treatment Infrastructure Research Articles

INSTRUMENTS FOR INTEGRATED WATER RESOURCES MANAGEMENT: WATER QUALITY MODELING FOR SUSTAINABLE WASTEWATER MANAGEMENT

This study presents the development and use of a hydraulic-coupled water quality model for the simulation of Biochemical Oxygen Demand (BOD) concentrations in the Bahlui River, a small river located in northeastern Romania. This river experiences the typical pollution problems for many Romanian water bodies: heavy pollution from both diffuse and point sources, low connectivity to wastewater systems in rural areas and moderate removal of pollutants in municipal wastewater treatment plants. The model was used to generate an image of the BOD regime of the Bahlui River, and to simulate two wastewater infrastructure development scenarios: the first one considered the improvement of the municipal wastewater treatment facilities, and the second scenario considered that all the point sources along the river discharge BOD- containing wastewaters within appropriate limits. Simulation results for the two scenarios indicated that upgrading the wastewater treatment infrastructure does not necessarily lead to major improvements in river quality, and subsequently, other wastewater management options have to be considered to achieve the Water Framework Directive objectives. The study shows how even with limited data a useful model can be developed to assess the contribution of different sources and evaluate strategies for water quality improvement. The application of models is rather new in Romanian water resources management but can help stakeholders to get more insight on the system behavior and find integrated and effective solutions

Wastewater Management and Marcellus Shale Gas Development: Trends, Drivers, and Planning Implications

Extraction of natural gas from tight shale formations, which occur globally, has been made possible by recent technological advances, including hydraulic fracturing with horizontal drilling. Shale gas development is being lauded as a potential energy and geopolitical “game-changer.” However, widespread concern exists with respect to possible environmental consequences of this development, particularly impacts on water resources. In the United States, where most shale gas extraction has occurred thus far, the Marcellus Shale is now the largest natural gas producing play. To date, over 6,000,000 m3 of wastewater has been generated in the process of extracting natural gas from this shale in the state on Pennsylvania (PA) alone. Here we examine wastewater management practices and trends for this shale play, as well as the tracking and transport of shale gas liquid waste streams in PA. Between 2008 and 2011, state regulations and policies, along with low natural gas prices, have led to increased wastewater reuse, decreased POTW use, and more complete data tracking, while the average distance traveled by wastewater has decreased by over 30%. Regional differences in wastewater management are influenced by industrial treatment capacity, as well as proximity to injection disposal capacity. Using lessons from the Marcellus Shale, we suggest that nations, states, and regulatory agencies facing new unconventional shale development implement wastewater reporting and tracking systems, assess local and regional wastewater treatment infrastructure in terms of capacity and capability, promote well-regulated on-site treatment technologies, and review and update wastewater management regulations and policies.

Embodied Energy and Carbon Footprint of Wastewater Treatment Infrastructure: Water Reuse and Energy Recovery in Rural Bolivia

Embodied Energy and Carbon Footprint of Wastewater Treatment Infrastructure: Water Reuse and Energy Recovery in Rural Bolivia

Quantitative Tools to Determine the Expected Performance of Wastewater Soil Treatment Units Guidance Manual, Toolkit User's Guide and Visual-Graphic Tools

Quantitative Tools to Determine the Expected Performance of Wastewater Soil Treatment Units Guidance Manual, Toolkit User's Guide and Visual-Graphic Tools

Life cycle assessment of coated white board: a case study in China

Life cycle assessment was carried out using IMPACT2002+ to estimate the environmental impact of coated white board production, which is common in China. Normalized results showed that the potential impacts of respiratory inorganics, terrestrial ecotoxicity, global warming, and non-renewable energy had a dominant contributions to overall environmental impact. Specifically, emissions from chemical and energy production processes exhibited higher potential impact (more than 80% of the total contribution) on the environment than that of emissions generated from transport, landfill, wastewater treatment, and paper plants infrastructure. Energy recovery from black liquor and energy generation based on natural gas are key factors in reducing overall environmental potential impact. The current paper presents improvements on the environmental performance of a coated white board production site in China.

Increasing Resource Efficiency through Residential Greywater Use

To support population growth, a viable fresh water supply, supporting water and wastewater treatment infrastructure, and electric capacity is needed. Historically the answer to growing demand was to build more reservoirs, however; viable potential sites are not plentiful. In addition, infrastructure for water supply and treatment is difficult, expensive, and time-consuming to develop. Greywater use offers the opportunity to stretch our water supply and electrical capacity through dual water use and less treatment. Greywater may offer a viable solution to increasing water supplies in the near term as we plan and development new water resources. This research identifies the potential impacts of greywater toilets on a large scale in two communities that are considering building additional water storage capacity. The use of greywater toilet systems in new and existing homes in these communities could potentially support new residential growth for 3.4 years in these areas. This could reduce the pressure on the existing water system while the new water supply infrastructure and electrical capacity are developed. This time extension may also support water saving technology development, thus further reducing water demand. A case study identifies possible savings from greywater toilets in reducing the demand on existing water resources.

Financing Water Quality Management

In a context of greater pressure on water resources, ensuring continued and adequate access to safe water supplies will require the investment of significant funds and expertise in public sewerage and water and wastewater treatment infrastructure. After a short introduction, this paper examines the recent trends in the development of wastewater infrastructure. It then discusses the investment needs and reviews the potential sources of funding, before turning to recent trends in private-sector participation in water and wastewater treatment infrastructure and the framework conditions to make this participation work in the public interest.

Mixed culture polyhydroxyalkanoates production from sugar molasses: The use of a 2-stage CSTR system for culture selection

Polyhydroxyalkanoates (PHAs) are promising biodegradable polymers. The use of mixed microbial cultures (MMC) and low cost feedstocks have a positive impact on the cost-effectiveness of the process. It has typically been carried out in Sequencing Batch Reactors (SBR). In this study, a 2-stage CSTR system (under Feast and Famine conditions) was used to effectively select for PHA-storing organisms using fermented molasses as feedstock. The effect of influent substrate concentration (60–120 Cmmol VFA/L) and HRT ratio between the reactors (0.2–0.5 h/h) on the system’s selection efficiency was assessed. It was shown that Feast reactor residual substrate concentration impacted on the selective pressure for PHA storage (due to substrate-dependent kinetic limitation). Moreover, a residual substrate concentration coming from the Feast to the Famine reactor did not jeopardize the physiological adaptation required for enhanced PHA storage. The culture reached a maximum PHA content of 61%. This success opens new perspectives to the use of wastewater treatment infrastructure for PHA production, thus valorizing either excess sludge or wastewaters.

An innovative sustainability assessment for urban wastewater infrastructure and its application in Chengdu, China

Sustainability assessments are an increasingly common tool for measuring progress towards sustainable development. Despite their popularity, sustainability assessments and the indicators that compose them are said to have had little impact on the policy arena. In this paper we discuss four attributes that we contend will improve the use of sustainability assessments to guide decision making: non-compartmentalization, site specificity, built-in guidance for target setting, and ability to measure active sustainability. We present a novel assessment tool for wastewater treatment infrastructure that illustrates these attributes. The assessment is composed of two-dimensional indicators we call “burden to capacity” ratios, that reveal and quantify the local value of resources embodied in wastewater and treatment byproducts, and the tradeoffs between designing systems for disposal versus reuse. We apply the sustainability assessment framework to an existing treatment plant in Chengdu, China and discuss the results.

Charting a Path for Innovative Toilet Technology Using Multicriteria Decision Analysis

Practical and theoretically sound methods for analyzing innovative environmental technologies are needed to inform public and private decisions regarding research and development, risk management, and stakeholder communication. By integrating scientific assessments with a characterization of values, multicriteria decision analysis (MCDA) supports the ranking of alternative technology pathways on the basis of technical, financial, and social concerns. We applied MCDAto evaluate the use of NoMix urine separating toilets for managing environmental risk and postponing expensive upgrades to a large wastewater treatment plant near Zürich, Switzerland. Results indicate that, given current priorities, no single, fixed course of action (including the status quo) will be desirable to all stakeholders over the considered time horizon. However, a path forward is suggested that is not significantly disadvantageous to any stakeholder now and leaves open future options, allowing society to achieve overall greater benefits if priorities change, new environmental risks are revealed, or technology improves. While our analysis focuses on a particular catchment in Switzerland, many communities worldwide are faced with an aging and inefficient wastewater treatment infrastructure while also experiencing growth and development. Our framework can help these communities balance the conflicting objectives of diverse stakeholders and gain insight into the role that urine separation can play in transitioning to a more comprehensive and sustainable urban water management system.

Managing the NYC Watershed WWTP Upgrade Program - "Re-tooling an Entire Watershed's Wastewater Treatment Infrastructure" Overview and Case Study

Managing the NYC Watershed WWTP Upgrade Program - "Re-tooling an Entire Watershed's Wastewater Treatment Infrastructure" Overview and Case Study

A suitability evaluation tool for siting wastewater treatment facilities in new urban developments

This paper describes the development of a spatial decision-support tool based on soft computing that assists the optimal siting of wastewater treatment technologies within the context of new urban developments, through the creation of suitability maps. The tool is based on multi-criteria decision analysis and fuzzy logic, allowing the inclusion of both uncertainty and of the decision-makers' attitude towards risk in the decision-making process. The paper describes the attributes influencing the siting of wastewater treatment infrastructure and presents a method for using these to generate composite siting suitability maps for a given development site and propose specific locations maximizing the combined suitability index. Extensive sensitivity analysis has been undertaken and the results discussed. The proposed system architecture integrates three widely used software platforms (ArcView GIS, Matlab and MS Excel) into a flexible and user-friendly decision-support tool that can easily be adapted to different spatial decision environments.

Managing climate change risks in New York City’s water system: assessment and adaptation planning

Managing risk by adapting long-lived infrastructure to the effects of climate change must become a regular part of planning for water supply, sewer, wastewater treatment, and other urban infrastructure during this century. The New York City Department of Environmental Protection (NYCDEP), the agency responsible for managing New York City’s (NYC) water supply, sewer, and wastewater treatment systems, has developed a climate risk management framework through its Climate Change Task Force, a government-university collaborative effort. Its purpose is to ensure that NYCDEP’s strategic and capital planning take into account the potential risks of climate change—sea-level rise, higher temperature, increases in extreme events, changes in drought and flood frequency and intensity, and changing precipitation patterns—on NYC’s water systems. This approach will enable NYCDEP and other agencies to incorporate adaptations to the risks of climate change into their management, investment, and policy decisions over the long term as a regular part of their planning activities. The framework includes a 9-step Adaptation Assessment procedure. Potential climate change adaptations are divided into management, infrastructure, and policy categories, and are assessed by their relevance in terms of climate change time-frame (immediate, medium, and long term), the capital cycle, costs, and other risks. The approach focuses on the water supply, sewer, and wastewater treatment systems of NYC, but has wide application for other urban areas, especially those in coastal locations.

Neural network prediction of concrete degradation by sulphuric acid attack

Microbiologically induced corrosion is a leading cause of the deterioration of wastewater collection, transmission and treatment infrastructure around the world. This paper examines the feasibility of using artificial neural networks (ANNs) to predict the compressive strength of concrete and its degradation under exposure to sulphuric acid of various concentrations. A database incorporating 78 concrete mixtures performed by the authors was developed to train and test the ANN models. Data were arranged in a patterned format in such a manner that each pattern contains input variables (concrete mixture parameters) and the corresponding output vector (weight loss of concrete by H2SO4 attack and compressive strength at different ages). Results show that the ANN model I successfully predicted the weight loss of concrete specimens subjected to sulphuric acid attack, not only for mixtures used in the training process, but also for new mixtures unfamiliar to the ANN model designed within the practical range of the input parameters used in the training process. Root-mean-squared error (RMSE) and average absolute error (AAE) for ANN predictions of weight loss due to sulphuric acid attack were 0.013 and 8.45%, respectively. The ANN model II accurately predicted the compressive strength of the various concrete mixtures at different ages with RMSE and AAE of 2.35 MPa and 4.49%, respectively. A parametric study shows that both models I and II can successfully capture the sensitivity of output variables to changes in input parameters.

Semi-centralised supply and treatment systems for (fast growing) urban areas

Mega cities with rapid growth are challenged by two main problems concerning water supply and sanitation. One is water scarcity because local demand exceeds local supply. The other is that the infrastructure for water supply and the collection and treatment of wastewater cannot keep up with the rapid growth of the mega cities. The transfer of conventional centralised water and wastewater systems from industrialised countries to mega cities does not seem appropriate, because of the rapid and almost unpredictable growth in mega cities on the one hand and the regional shortage of water which requires an economical use and reuse wherever possible on the other hand. The transition from centralised to semi-centralised supply and treatment systems (SESATS) may be one method of resolution to the grave discrepancy between the rapid growth of cities and the provision of supply and treatment infrastructure. One important aspect of planning semi-centralised wastewater collection and treatment infrastructure including intra-urban water reuse is the assessment of the optimal size. Therefore, factors and indicators, which have an effect on the scale of semi-centralised sanitation systems, have to be developed. Beside the introduction in SESATS some of these factors, criteria and indicators and their effects on the system's scale will be introduced in this paper.

Rethinking urban water systems – revisiting concepts in urban wastewater collection and treatment to ensure infrastructure sustainability

Technology and economic development has led to the growth of megacities and urban centres with populations in the millions. Such population expansion and densification increases the strain on wastewater collection and treatment infrastructure, which has been largely based on an end-of-line centralised model. However, in megacities new challenges arise, because provision of suitable sanitation is expensive and it requires infrastructure expansion through construction of extensive sewer networks and larger capacity wastewater treatment plants, which consume more energy. Alternative disposal techniques for solid and liquid waste generated during the treatment process are required, because disposal solutions are decreasing as landfill costs rise and environmental standards are tightened, the latter reducing opportunities for land reuse. Additionally, mass wastewater discharge can have a detrimental impact on the ecology of water bodies and on the health of downstream populations, and requires suitable treatment before disposal. These challenges have the potential to offset the savings that the economies of scale offered by the traditional wastewater collection and treatment systems can impart. The need for affordable and effective wastewater systems in megacities requires the re-evaluation of traditional systems and the re-engineering of water and wastewater transport and resource concepts. Alternative concepts in wastewater collection and treatment, such as decentralised treatment, allied with innovative solutions using current and new technology could play a role in providing affordable and sustainable solutions to deal with the wastewater issue. This paper investigates the scope that integrated wastewater treatment and localised water reuse (in-line treatment, sewer mining), resource recovery (biogas, biosolids), operational changes (timed discharge of sewers, vacuum sewers) and biotreatment (e.g. vermiculture, faecal coliform removal) can play to guarantee the longevity of wastewater infrastructure in megacities. These alternatives offer increased treatment efficiency, recovery of value-added products, and reduce infrastructure cost, whilst maintaining health standards and reducing environmental discharge.

Review of Water Resources Planning by Andrew A. Dzurik

This is the third edition of a basic text on the broad subject of water resources planning. The author has apparently added new material in the form of a Web site listing, some new text, and new tables to update dated material, such as a listing of models in use. All-in-all, however, the text appears to be little changed from the author’s first two editions. In any event, the author offers an interesting sample of water resources planning and management topics, written at a basic level. This is a very broad field, and, as the author acknowledges, it is difficult to stipulate prerequisites for learning in such a broad field. Prerequisites, according to the author, would be basic math and science, intellectual maturity, and an interest in the subject. The author is a professor of environmental engineering at the FSU-FAMU College of Engineering, located at Florida State University. He has served as a resident scholar with the Corps of Engineers where he obtained federal experience. He teaches and writes in the fields of water planning and environmental policy. As with the earlier editions, the current volume is a clear and straightforward presentation of a range of topics. These include hydrology, law, organization, legislation, the planning process, economics, applications, models, environmental issues, and future directions. Having also prepared a text on the same topic, this reviewer concurs in general with the book’s organization and scope but would differ on the details of the list of important topics. One surprise was the author’s chapter on ‘‘Federal Water Agencies and Legislation.’’ The reviewer expected to find text about agency structure, programs, and politics, but the chapter is really an extension of the previous one, and covers water and environmental law. The chapter’s introduction specifies that it is divided into two parts, but the second part dominates. Moreover, the chapter’s introduction specifies that it is an introduction to the federal ‘‘regulatory scheme,’’ but federal agency resource activities go beyond regulatory programs. The book apparently meets a demand for a clear presentation of the basic aspects of water resources planning. Its features that seem worthy of praise include broad coverage, a clear presentation, and the author’s success in writing to a wide audience. Also, the new inclusion of a listing of Web sites should be useful. Although the book is comprehensive in scope, a number of important topics are either left out or not covered in detail. For example, there is no coverage of irrigation, one of the most important water management topics in the West. Similarly, there is no coverage of planning for wastewater treatment infrastructure. Also, in the midst of one of the worst droughts in memory for parts of the country, there is no mention of droughts or drought contingency planning. Environmental issues in planning seem mostly relegated to a chapter on ‘‘other planning issues.’’ Knowing the author is more up-to-date than that, this reviewer suspects

The effect of compact formulations on the environmental profile of Northern European granular laundry detergents Part II: Life Cycle assessment

The environmental profile of laundry detergents at three time points (1988, 1992, and 1998) were compared on the basis of two distinct, complementary approaches: Environmental Risk Assessment (ERA) and Life-Cycle Assessment (LCA). The results are presented in this paper and its accompanying paper in this issue (Part I: Product Environmental Risk Assessment). Life-Cycle Inventory (LCI) data from The Netherlands and Sweden were used for this retrospective analysis. The chosen time period studied (1988 - 1998) spans significant, multiple formulation and process change in laundry detergents, including the introduction of compact, then super-compact, granular detergents. Cradle-to-Gate LCAs based on 1 kg of finished product (from raw material supply to packaged finished product leaving the suppliers site) revealed no significant differences between the products themselves, as manufactured between 1988, 1992 and 1998. Cradle-to-Grave LCAs based on 1000 wash cycles (from raw material supply to disposal of used product) indicated that the consumption of raw materials and energy, as well as environmental emissions (air, water and solid waste), decreased after the introduction of compact detergents in 1988. The LCAs revealed that a number of category indicator values decreased (for acidification, aquatic toxicity greenhouse effects, eutrophication, toxicity, ozone depletion and smog). Furthermore, the results of the LCAs support the conclusion that the differences between The Netherlands and Sweden are due to (1) differences in electrical generation between the countries, (2) differences in energy consumption during consumer use, (3) differences in detergent dosage per wash and (4) differences in the wastewater treatment infrastructure.

Privatization, Participation, and the Planning Process: A Case Study of Wastewater Treatment Infrastructure

Two broad models of planning inform public administrators and planners. One is a public management model in which involvement in decision making is on a “need-to-know ” basis, and public participation and input are viewed as forces to be overcome. It echoes the private sector practice of flexible specialization in that it relies on quick decision making and noninclusive planning to reduce intraorganizational conflict. The other is a participatory planning model that invites many stakeholders to discuss and debate aspects of pending decisions. Emphasis is frequently placed on stakeholder concerns and equity issues. Current efforts to restructure local government service delivery through privatization and contracting-out potentially privilege the public management model over the participatory model. The City of Indianapolis recently contracted its wastewater treatment operations and management to a private consortium using the public management model. This article links several recent and unintended outcomes in the Indianapolis case to the planning model used.

Hollowing the Infrastructure: Revolving Loan Programs and Network Dynamics in the American States

Trends toward more complex intergovernmental programs and greater use of public-private arrangements carry implications for public management, since these developments signify challenges for administrators called upon to manage within hollowed institutional settings: interorganizational networks for effectuating policy. The implications of such shifts are explored by examining one important program change of the last decade: the move away from federal grant support for municipal wastewater treatment infrastructure and toward the creation of separate state revolving-loan funds (SRFs). National regulatory standards remain, but the central place of the EPA in the infrastructure effort has shifted largely into other hands, with consequences for the implementation of policy. Altered policy instruments stimulate the formation of more complex network patterns involving new actors who offer needed technologies. These changes carry implications for program operations and results. Evidence from the operations of SRFs suggests that these developments are significant and also that public management has become, if anything, even more consequential in such networked contexts.