Life cycle assessment and economic analysis of anaerobic membrane bioreactor whole-plant configurations for resource recovery from domestic wastewater.

The use of the anaerobic membrane bioreactor (AnMBR) process for domestic wastewater treatment presents an opportunity to mitigate environmental, social, and economic impacts currently incurred from energy-intensive conventional aerobic activated sludge processes. Previous studies have performed detailed evaluations on improving AnMBR process subcomponents to maximize energy recovery and dissolved methane recovery. Few studies have broadly evaluated the role of chemical use, membrane fouling management, and dissolved methane removal technologies. A life cycle assessment was conducted to holistically compare multiple AnMBR-based domestic wastewater treatment trains to conventional activated sludge (CAS) treatment. These treatment trains included different scouring methods to mitigate membrane fouling (gas-sparging and granular activated carbon-fluidizing) with consideration of upstream treatment (primary sedimentation vs. screening only), downstream treatment (dissolved methane removal and nutrient removal) and sludge management (anaerobic digestion and lime stabilization). This study determined two process subcomponents (sulfide and phosphorus removal and sludge management) that drove chemical use and residuals generation, and in turn the environmental and cost impacts. Furthermore, integrating primary sedimentation and a vacuum degassing tank for dissolved methane removal maximized net energy recovery. Sustainability impacts were further mitigated by operating at a higher flux and temperature, as well as by substituting biological sulfide removal for chemical coagulation.

Comparative Optimism: Relative Risk Perception and Behavioral Response to Lead Exposure.

Despite their true exposure, individuals with Comparative Optimism consider themselves less prone to the adverse health effects of pollution. Since individuals' response to a given environmental risk is affected by their appraisal of the risk, those with Comparative Optimism may be less likely to engage in prescribed behaviors or to do so at the urgency required of the given risk. Such limited or delayed response can amplify the risk instead of reducing it. Thus, there is a need to understand if Comparative Optimism applies to pollutants with irreversible adverse health effects as it would impose a higher burden. There is also a need to know which segments of the population are prone to Comparative Optimism and how it manifests in terms of activities that can enhance exposure. Doing so will allow public health professionals address gaps in risk communication and management efforts and help improve environmental health outcomes. Using survey data, we assess the presence, behavioral and socioeconomic predictors, and implications of Comparative Optimism for communicating and managing lead exposure risk in an urban setting. Our results indicate that a large share of the population has Comparative Optimism for lead exposure, despite living in a city that has a relatively higher lead poisoning burden. We also found that ethnicity, income, length of stay at residence, among others, predict Comparative Optimism, suggesting that Comparative Optimism may predict elevated blood lead level.

Evaluation of the role of risk perception in stakeholder engagement to prevent lead exposure in an urban setting.

Stakeholder engagement is a vital sustainable remediation practice for obtaining useful feedback and identifying societal needs. Evaluating and integrating risk perception of stakeholders into remediation and outreach efforts allows for greater insight, increases the likelihood of success and ultimately, benefits the community by protecting its members from environmental hazards. In this study, we identified risk perception factors that influenced residents' level of concern for mitigating their exposure to elevated concentrations of lead in household paint and historic fill material. Risk perception factors were assessed by an in-person survey conducted in public green spaces. The analysis of survey participants' responses indicated that their perception of risk to exposed lead was mostly influenced by the presence of hazardous materials in close proximity to their residence, the ability to address pollution, and awareness, interest, and individual accountability in mitigating environmental risks. Responses also revealed that residents considered risk of lead and soil pollution as less menacing than the presence of more immediate and perceptible risks posed by factors such as air and water pollution. In addition, the community seemed to exhibit "optimism bias" and did not identify itself at high risk to susceptible and immediate hazards, including lead exposure. This lack of concern over lead exposure created a significant obstacle to community participation in state-led education and outreach programs. By integrating risk perception analysis and increasing stakeholder engagement, we can bring more attention to this issue, educate the public about the threat of lead pollution, and efficiently use financial resources to implement a more sustainable solution.

Early decision framework for integrating sustainable risk management for complex remediation sites: Drivers, barriers, and performance metrics.

As the environmental remediation industry matures, remaining sites often have significant underlying technical challenges and financial constraints. More often than not, significant remediation efforts at these "complex" sites have not achieved stringent, promulgated cleanup goals. Decisions then have to be made about whether and how to commit additional resources towards achieving those goals, which are often not achievable nor required to protect receptors. Guidance on cleanup approaches focused on evaluating and managing site-specific conditions and risks, rather than uniformly meeting contaminant cleanup criteria in all media, is available to aid in this decision. Although these risk-based cleanup approaches, such as alternative endpoints and adaptive management strategies, have been developed, they are under-utilized due to environmental, socio-economic, and risk perception barriers. Also, these approaches are usually implemented late in the project life cycle after unsuccessful remedial attempts to achieve stringent cleanup criteria. In this article, we address these barriers by developing an early decision framework to identify if site characteristics support sustainable risk management, and develop performance metrics and tools to evaluate and implement successful risk-based cleanup approaches. In addition, we address uncertainty and risk perception challenges by aligning risk-based cleanup approaches with the concepts of risk management and sustainable remediation. This approach was developed in the context of lessons learned from implementing remediation at complex sites, but as a framework can, and should, be applied to all sites undergoing remediation.

Comparison of international approaches to sustainable remediation.

Since mid-to-late 2000s growing interest for sustainable remediation has emerged in initiatives from several international and national organisations as well as other initiatives from networks and forums. This reflects a realisation that risk-management activities can about bring environmental, social, and economic impacts (positive or negative) in addition to achieving risk-based remediation goals. These ideas have begun to develop as a new discipline of "sustainable remediation". The various initiatives have now published a number of frameworks, standards, white papers, road maps and operative guidelines. The similarities and differences in the approaches by these outputs and general trends have been identified. The comparison is based on a set of criteria developed in discussion with members of these various initiatives, and identifies a range of similarities between their publications. Overall the comparison demonstrates a high level of consensus across definitions and principles, which leads to the conclusion that there is a shared understanding of what sustainable remediation is both across countries and stakeholder groups. Publications do differ in points of detail, in particular about the operational aspects of sustainable remediation assessment. These differences likely result from differences in context and legal framework. As this analysis was carried out its findings were debated with members of the various international initiatives, many of whom have been included as authors. Hence the outcomes described in this paper can be seen as the result of a sort of multi-level debate among international experts (authors) and so can offer a starting point to new sustainable remediation initiatives (for example in other countries) that aim to start developing their own documents.

Inaction on Lead Despite the Relevant Knowledge: Predictors, Covariates, and Outreach Implications.

Testing residential soil and paint for lead provides actionable information. By showing where and how much lead exists on the residence, it allows one to quantify risk and determine the best ways to reduce exposure along with the corresponding health and financial costs. For these reasons, several federal and state programs offer outreach to audiences on the benefits of testing residential soil and paint for lead. Not all individuals who know about lead's adverse health effects, however, test their residence for lead, potentially limiting the actionable information that could have helped to reduce their exposure. Such individuals represent a challenge to outreach programs and the broader public health objectives. There is, thus, a need to understand who such individuals are and why they behave this way, allowing us to develop a specialized outreach program that addresses the problem by targeting the relevant sub-population. Using survey data, we quantitatively determine the profiles of individuals who, despite knowing about lead's adverse health effects, are unlikely to test their residence for lead, finding statistically significant socio-economic predictors and behavioral covariates. We also find a geographic component to it, further helping outreach professionals learn how to allocate their limited resources.