Environmental pollution has been on the rise in the past few decades owing to increased human activities on energy reservoirs, unsafe agricultural practices and rapid industrialization. Amongst the pollutants that are of environmental and public health concerns due to their toxicities are: heavy metals, nuclear wastes, pesticides, green house gases, and hydrocarbons. Remediation of polluted sites using microbial process (bioremediation) has proven effective and reliable due to its eco-friendly features. Bioremediation can either be carried out ex situ or in situ, depending on several factors, which include but not limited to cost, site characteristics, type and concentration of pollutants. Generally, ex situ techniques apparently are more expensive compared to in situ techniques as a result of additional cost attributable to excavation. However, cost of on-site installation of equipment, and inability to effectively visualize and control the subsurface of polluted sites are of major concerns when carrying out in situ bioremediation. Therefore, choosing appropriate bioremediation technique, which will effectively reduce pollutant concentrations to an innocuous state, is crucial for a successful bioremediation project. Furthermore, the two major approaches to enhance bioremediation are biostimulation and bioaugmentation provided that environmental factors, which determine the success of bioremediation, are maintained at optimal range. This review provides more insight into the two major bioremediation techniques, their principles, advantages, limitations and prospects.

Wastewater-based epidemiology (WBE) permits the sustainable surveillance of pathogens in large populations and does not discriminate between symptomatic and asymptomatic groups. WBE allows health authorities and policymakers to make swift decisions to limit the impact of local and regional disease outbreaks, minimise the spread of infection and mitigate the effects of pathogen importation. Biosensors are an exciting addition to conventional WBE analytical approaches. Combined with sentinel surveillance programs, biosensors can be reactive to novel variants of a virus in the community. However, progress developing biosensors for wastewater surveillance is severely limited compared to advances in clinical diagnostics, with a lack of well-developed biosensors currently being available. Whilst the field of biosensors is vast, this review focuses on trends in monitoring SARS-CoV-2 in wastewater over a key period (2020–2021). We explore the complexities involved in sampling within wastewater networks, the options for target selection, and reflect on the ethical considerations and limitations of this approach by highlighting the complex transdisciplinary connections needed. The outlook for WBE biosensors is assessed to be on a positive trajectory as current technical challenges are overcome. Finally, we outline the current status and where further development is needed to have a systematic feedback mechanism which would allow wastewater biosensors to be kept current and relevant to emergent pathogens.