Regulating water reuse for agricultural irrigation: risks related to organic micro-contaminants

Abstract

In recent years, more and more countries see irrigation using reclaimed water as an opportunity to secure and enhance agricultural production. Despite the benefits of water reuse, the scientific community raised several concerns and challenges for human health and the environment. This includes chemical risks. Effluents from urban wastewater treatment plants usually contain a wide range of organic chemicals. Such chemicals remaining in the water after the treatment process may cause hazards for human health, contaminate surrounding soil and water resources, and even compromise drinking water sources. Once crops on irrigated sites are exposed to chemicals, the potential transport to and accumulation in the edible parts of fruits and vegetables need to be controlled to rule out their introduction into the food chain. Finally, problems concerning the release of wastewater-borne antibiotics into the environment are starting to gain attention. For these reasons, agricultural irrigation should face more stringent quality requirements in order to minimize chemical risks. Combinations of measures reducing chemicals at the source, technical and natural water treatment processes especially to remove chemicals with persistent, bioaccumulative and toxic (PBT), or persistent, mobile and toxic (PMT) properties, good agricultural practices, and supplementary preventive measures (e.g. knowledge transfer to the stakeholders involved) will be necessary to bring about and ensure safe irrigation in the future. While internationally many regulations and guidelines for water reuse have successfully been implemented, questions remain whether the current knowledge regarding chemical risks is sufficiently considered in the regulatory context. The introduction of a new regulation for water reuse, as attempted in the European Union, poses a good opportunity to better take chemicals risks into account.

How microbial community composition, sorption and simultaneous application of six pharmaceuticals affect their dissipation in soils

“…Treated wastewater is often utilized to irrigate agricultural land in countries suffering from water deficiency that have a warm and dry climate, such as countries in the Middle East and Southern Europe (e.g., Carter et al, 2019;Lesser et al, 2018;Picó et al, 2020). Reclaimed wastewater is also increasingly utilized for irrigation in countries that have not previously suffered from a water shortage but face a change in a rainfall distribution throughout a year and a scarcity of water during vegetation seasons due to climate change (e.g., Helmecke et al, 2020). Another product of wastewater management is sewage sludge, which is frequently used as amendment to increase organic matter and nutrient content in soils (e.g., Ivanová et al, 2018;Verlicchi and Zambello, 2015).…”

Worldwide Regulations and Guidelines for Agricultural Water Reuse: A Critical Review

“…There is also a group of constituents that may be removed or reduced using the advanced treatment processes (e.g., metals, TDS) [166]. Finally, there are the emerging constituents that are present in micro or nanogram/L, which may pose negative health and environmental concerns [167]. These compounds sometimes cannot be removed effectively even with advanced treatment processes [4].…”

Graywater Reuse: The Effects on Income and Agricultural Production Sustainability of Family Farming Systems in the Semiarid Region of Ceará, Brazil

“…In addition, it is the first paper (at the national and international level) which tries to ascertain the impacts of the reuse of graywater on income and sustainability of agricultural production for family farmers. Previous research usually addressed the reuse of water for irrigation in three main approaches: i) risk factors (biological, chemical, sanitary, soil salinization, eutrophication) (Toze, 2006;Moretti et al, 2019;Egbuikwem, Mierzwa and Saroj , 2020), ii) technical aspects (Dolar et al, 2019;Rizzo et al, 2019), and iii) regulations (Helmecke, Fries and Schulte, 2020;Mukherjee and Jensen, 2020). Ricart and Rico (2019) draw attention to the role of social scientists in the elaboration of studies capable of offering subsidies to decisions makers in the elaboration of strategies which may provide sustainability of agricultural production and an increase in the income of family farmers.…”