The onset of the COVID-19 pandemic posed many global challenges, mainly in the healthcare sector; however, the impacts on other vital sectors cannot be overlooked. The waste sector was one of the significantly impacted sectors during the pandemic, as it dramatically changed the dynamics of waste generation. Inadequate waste management practices during COVID-19 shed light on the opportunities for developing systematic, sustainable, and resilient waste infrastructure in the future. This study aimed to exploit the learnings of COVID-19 to identify any potential opportunities in post-pandemic waste infrastructure. A comprehensive review on existing case studies was conducted to understand the waste generation dynamics and the waste management strategies during COVID-19. Infectious medical waste from healthcare facilities had the largest influx of waste compared with non-medical waste from residential and other sectors. This study then identified five key opportunities from a long-term operational perspective: considering healthcare waste sector as a critical area of focus; encouraging the integration and decentralization of waste management facilities; developing systematic and novel approaches and tools for quantifying waste; shifting towards a circular economy approach; and modernizing policies to improve the effectiveness of the post-pandemic waste management infrastructure.

Natural source zone depletion (NSZD) is an emerging technique for sustainable and cost-effective bioremediation of light non-aqueous phase liquid (LNAPL) in oil spill sites. Depending on regulatory objectives, NSZD has the potential to be used as either the primary or sole LNAPL management technique. To achieve this goal, NSZD rate (i.e., rate of bulk LNAPL mass depletion) should be quantified accurately and precisely. NSZD has certain characteristic features that have been used as surrogates to quantify the NSZD rates. This review highlights the most recent trends in technology development for NSZD data collection and rate estimation, with a focus on the operational and technical advantages and limitations of the associated techniques. So far, four principal techniques are developed, including concentration gradient (CG), dynamic closed chamber (DCC), CO₂ trap and thermal monitoring. Discussions revolving around two techniques, “CO₂ trap” and “thermal monitoring”, are expanded due to the particular attention to them in the current industry. The gaps of knowledge relevant to the NSZD monitoring techniques are identified and the issues which merit further research are outlined. It is hoped that this review can provide researchers and practitioners with sufficient information to opt the best practice for the research and application of NSZD for the management of LNAPL impacted sites.

On-site waste management is considered as an important part of the sustainable construction process in any construction project. In fact, almost all Leadership in Energy and Environmental Design (LEED) projects require considerable effort in waste management as part of the requirement to obtain the LEED credits and rating. However, sustainable waste management is achievable only if the process is cost effective in addition to the underlying societal and environmental benefits. Planning on-site waste management process is essential to achieve economic benefits. However proper planning and execution is not possible without prediction of construction waste quantities linked to the project execution plan. The paper presents a novel method of grouping factors, thus reducing the number of variables for statistical analysis which requires for establishing relationships between quantity of waste and many factors such as labour, material and environmental related factors. . The research outlined in the paper considers the principles of "Activity Based Waste Generation" which enables the prediction of total waste from a project (i.e. cumulative waste from each of the activities). The presented methodology is part of the research on "developing a planning tool for construction waste management" which involves site monitoring, and data collections from several building construction projects in Calgary, Alberta.