Antibiotic resistance dissemination in wastewater treatment plants: a challenge for the reuse of treated wastewater in agriculture

Abstract

The reuse of treated wastewater (TWW) has been considered a suitable alternative for agriculture and for achieving water security and management. However, this practice may contribute to the dissemination of antibiotic resistance genes (ARGs) into the environment, a matter of global concern. The aim of this study is to discuss the reuse of TWW in agriculture under the perspective of the risks associated to ARGs dissemination. An exhaustive bibliographic research was conducted for determining the capacity of reducing ARG loads for different wastewater treatment technologies (conventional, non-conventional and advanced technologies). Moreover, the distribution of ARG elements in crops irrigated with TWW was also reviewed for discussing the potential health risks associated to the TWW reuse. Reduction of ARG loads in conventional, non-conventional and advanced treatments fluctuated between 1.1 and 4.1, 0.1-2.1 and 0.1-9.5 log units, respectively. These variable ranges indicate that operational parameters, plant design, and water quality are fundamental parameters determining their performance and their capacity to reduce ARG dissemination. In the case of ARG distribution in crops and soil irrigated by TWW, higher abundances were observed in soil than edible parts of crops with ranges between (-0.7)-6.0 log copies/g of soil and (-0.9)-5.6 log copies/g of soil, respectively. The occurrence of ARGs in crops may represent a relevant human exposure to ARG-harbouring bacteria and therefore, a potential human health risk that requires the establishment of safe procedures and legislation for assuring a safe reuse of TWW.

Reclamation of Treated Wastewater for Irrigation in Chile: Perspectives of the Current State and Challenges

“…The term emerging compounds (ECs) includes a wide range of compounds with relevant biological activities, such as pharmaceutical and personal care products (PPCPs), endocrine disrupting compounds (EDs), and their transformation products and/or metabolites [109]. In nature, wastewater is the most common source of these compounds, and therefore generates concerns among scientists and policy makers in the context of water use or reuse [17].…”

“…On account of their toxicity and potential adverse effects on the environment and humans, their release into effluents must be minimized, particularly when wastewater reuse for crops irrigation is expected [110]. In the case of PPCPs, irrigation with treated wastewater can contribute to the dissemination of antibiotic resistance due to the low effectiveness of conventional and non-conventional WWTPs for removing antibiotics [109]. Antibiotics have been detected in treated wastewater in concentrations ranging from 55 to 22,000 ng/L [18].…”

“…Antibiotics have been detected in treated wastewater in concentrations ranging from 55 to 22,000 ng/L [18]. Therefore, irrigation with treated wastewater can affect soil and plant microbial communities and can contribute to this global concern endangering human health and the environment [109].…”

Antibiotic-Resistant Gene Behavior in Constructed Wetlands Treating Sewage: A Critical Review

“…For these reasons, conventional WWTPs do not reach optimal ARG reductions, and ARG abundance in the final effluent sometimes increases. For example, Bueno et al [21] reported an average increase of 1.43 log copies/mL for 17 ARGs in effluent from a WWTP that used an aerobic reactor and UV disinfection [3,16,22]. Similarly, Narciso-da-Rocha et al [23] evaluated the variations of bacterial community and ARG abundance in a conventional WWTP using activated sludge as a secondary treatment.…”

“…Constructed wetlands (CWs) are nonconventional treatment technologies that mimic the removal processes of natural wetlands, optimizing operational and design parameters to enhance the removal of contaminants [25]. These systems have proven to be a sustainable alternative to treat sewage in developed countries, as they efficiently remove organic matter and nutrients [22,25]. According to their hydrology, CWs can be classified as surface (SF) and subsurface flow (SSF).…”