Potential Pitfalls in Wastewater Phosphorus Analysis and How to Avoid Them

Abstract

Due to the increasing adoption of nutrient discharge regulations, many research groups are stepping into new territory with phosphorus (P) measurements. Accurate reporting of P concentrations in effluent from novel wastewater treatment technologies is critical for protecting both environmental and human health. Analysis of P in wastewater is prone to pitfalls because of the (1) variety of chemical forms of P in wastewater (orthophosphate, condensed P, and organic P), (2) availability of different chemical assays for measuring different P forms, and (3) different conventions in the units for reporting P. Here, we present a case study highlighting how these pitfalls affect analysis and interpretation of P measurements. We show that, when used appropriately, commercially-available kits are indeed accurate tools for evaluating reactive P and total P concentrations. For both standard solutions and real wastewater, we systematically remove steps from the total P protocol to show how protocol deviations affect the results. While standard solutions are important for validating analytical methods, commercially-available wastewater standard solutions only contain P as orthophosphate (reactive P). We therefore demonstrate options for making a mixed-P standard solution containing acid-hydrolyzable and/or organic P compounds that can be used to validate both reactive P and total P assays.

Modeling, simulation and control of biological and chemical P-removal processes for membrane bioreactors (MBRs) from lab to full-scale applications: State of the art

“…1. There is no standardized and universally accepted approach for classifying the phosphorus fractions and there is urgent need to address this issue along with the standardizing notations of each fraction and corresponding testing method (Rosario et al, 2021). For convenience, TP is generally classified into three major classes i.e.…”

“…Therefore, it is recommended to revisit the phosphorus discharge limits and should be ideally based on PO 4 3− concentrations. However, literature review revealed that there is no standardized and globally accepted approach for classifying the phosphorus fractions and this presents an urgent need to address this issue along with the standardized notation of each fraction and corresponding testing method (Rosario et al, 2021). Despite overall effectiveness of different wastewater treatment technologies for TPremoval is well known, there is a dearth of studies documenting the effectiveness of various technologies for removal of specific fractions of phosphorus.…”

Learning from Failure in Environmental and Public Health Research

“…Failures in environmental and public health monitoring and measurement, including a discussion on how randomised controlled trials fail to capture the full complexity of WASH interventions within multi-sectoral systems, 10 why better standard procedures are needed for measuring phosphorous in wastewater, 11 how sharing soil testing data through mobile technology is a low priority for farmers in Ghana and Kenya, 12 and how plastic waste from water quality testing creates landfill, but there currently is no reliable method for reusing plastic filtres without impacting on measurement quality 13 ;…”

“…• • Failures in environmental and public health monitoring and measurement, including a discussion on how randomised controlled trials fail to capture the full complexity of WASH interventions within multi-sectoral systems, 10 why better standard procedures are needed for measuring phosphorous in wastewater, 11 how sharing soil testing data through mobile technology is a low priority for farmers in Ghana and Kenya, 12 and how plastic waste from water quality testing creates landfill, but there currently is no reliable method for reusing plastic filters without impacting on measurement quality 13 ; • • How we can learn from failures in environmental and public health and embed these lessons into our organisations. 14,15 Overall, the papers in this Collection demonstrate that failures happen everywhere: in the laboratory, when engaging with communities, in organisational leadership and even when talking about failure.…”