Effective management of water resources is crucial for global food security and sustainable development. In this Review, we explore the potential benefits and challenges associated with treated wastewater (TW) reuse for irrigation. Currently, 400 km³ yr⁻¹ of wastewater is generated globally, but <20% is treated, and of that TW, only 2–15% is reused for irrigation depending on region. The main limitation of TW for irrigation is the inability of current treatment technologies to completely remove all micropollutants and contaminants of emerging concern, some of which have unknown impacts on crops, environment and health. However, advanced water treatment and reuse schemes, supported by water quality monitoring and regulations, can provide a stable water supply for agricultural production, as demonstrated in regions such as the USA and Israel. Such schemes could potentially serve a net energy source, as the embedded energy in wastewater exceeds treatment needs by 9 to 10 times. Agriculturally useful nutrients such as nitrogen, phosphorus and potassium could be also recovered and reused. TW reuse for irrigation could act as a major contributor to a circular economy and sustainable development, but the first steps will be funding and implementation of advanced and sustainable treatment technologies and social acceptance.

Multiple lineages of SARS-CoV-2 have been identified featuring distinct sets of genetic changes that confer to the virus higher transmissibility and ability to evade existing immunity. The continuous evolution of SARS-CoV-2 may pose challenges for current treatment options and diagnostic tools. In this study, we have first evaluated the performance of the 14 WHO-recommended real-time reverse transcription (RT)-PCR assays currently in use for the detection of SARS-CoV-2 and found that only one assay has reduced performance against Omicron. We then developed a new duplex real-time RT-PCR assay based on the amplification of two ultra-conserved elements present within the SARS-CoV-2 genome. The new duplex assay successfully detects all of the tested SARS-CoV-2 variants of concern (including Omicron sub-lineages BA.4 and BA.5) from both clinical and wastewater samples with high sensitivity and specificity. The assay also functions as a one-step droplet digital RT-PCR assay. This new assay, in addition to clinical testing, could be adopted in surveillance programs for the routine monitoring of SARS-CoV-2’s presence in a population in wastewater samples. Positive results with our assay in conjunction with negative results from an Omicron-specific assay may provide timely indication of the emergence of a novel SARS-CoV-2 variant in a certain community and thereby aid public health interventions.

In this study, weekly grab samples extracted by solid-phase extraction (SPE) and stir bar sorptive extraction (SBSE) were compared for the analysis of 230 pesticides in surface waters. Samples were collected from three different locations around Melbourne, Australia. Analysis was performed using Gas Chromatography Quadrupole Time of Flight High Resolution Mass Spectrometry (GC-QToF-HRMS). The two extraction techniques were compared, among others, for their limits of detection, recovery, extraction, and quantification efficiency of pesticides, as well as spatial and temporal differences in detected compounds. The target compounds screened were pesticides belonging mainly to the categories of fungicides, insecticides, and herbicides. Although SBSE extracted more pesticides at two out of three sites, SPE extracted total concentrations up to four times higher than SBSE over all sampling sites. The log K_OW of detected pesticides only partially explained the differences in detection, with SBSE performing better in the absorption of hydrophobic compounds. In addition, matrix effects, in particular turbidity, appeared to hinder extraction of contaminants, especially for SBSE. Spatially, SBSE detected 10 pesticides more than SPE at two locations, while the opposite was true at the third location, where turbidity was higher. The types of pesticides detected varied slightly between techniques and locations. The study highlights the complementarity of SBSE and SPE for monitoring pesticides in natural environments. SBSE is an easy-to-use technique and allows for extraction of a higher number of pesticides at trace level, but it might not be the preferred option for highly turbid waters. SPE requires more tedious and complex sample processing but allows for a more accurate quantification of a broader range of pesticides.

The Urban Water Atlas for Europe constitutes an original overview of Urban Water Management in Europe, explaining and illustrating water in an unprecedented way and reflecting how water, the essence of life, flows through the arteries of our cities. Leading experts in water sciences and technologies, together with climate change researchers, have joined artists and children in order to show how thirsty our cities really are and how we can cope with their growing demand for the most precious resource of our planet. The result is the first major publication of the Science and Knowledge Service of the European Commission, the JRC, which within a movement stemming from its Sci-Art Programme seeks to explore the important opportunities arising from the cross-fertilisation between science and art. The Atlas itself establishes the benchmark for over 40 cities, both European and from farther afield, in 30 different countries, in a manner which permits a vast range of municipalities to confront one of the greatest global challenges by employing local solutions in order to ensure a supply of water for all. It contains 95 scientific indicators and parameters, over 700 graphs, original illustrations and never seen before photographs and combines the work of 40 contributors from 22 organisations. Yet, the true value of this publication lies in the process of ensuring that the underlying scientific knowledge is available for societal uptake. The resolving of conflicts which stem from an exclusive self-understanding of traditional natural sciences, the difficulty to communicate the purpose of technological solutions and the challenge to engage in peer-to-peer discussion between the sciences, politics and the citizen constitute worthy lessons for both environmental experts and their social science counterparts.

Pesticide contamination poses significant threats to both humans and the environment, with residues frequently detected in surface waters worldwide. This study compares the effectiveness of passive samplers (POCIS and Chemcatcher) and grab sampling coupled with Stir-Bar Sorptive Extraction (SBSE) and Solid-Phase Extraction (SPE) for monitoring pesticides in surface waters. The comparative study was conducted at three sites in Victoria, Australia, representing different land uses. A total of 230 pesticides were screened, with 79 different pesticides detected overall. SBSE extracted the highest number of pesticides from grab samples, followed by SPE and passive samplers. The study highlights the complementarity of different sampling and extraction techniques in detecting a wide range of pesticides. The study also explores the suitability of these techniques for citizen science applications, emphasizing the importance of selecting appropriate methods based on specific research objectives and available resources. The findings underscore the need for a tiered approach, combining passive samplers for initial screening and grab sampling for quantitative analysis, to develop a robust monitoring strategy for protecting water quality.