Temporal dynamics of the soil resistome and microbiome irrigated with treated wastewater containing clarithromycin.

Clarithromycin, a common antibiotic found in domestic wastewater, persists even after treatment and can transfer to soils when treated wastewater (TWW) is used for irrigation. This residual antibiotic may exert selection pressure, promoting the spread of antibiotic resistance. While Predicted No Effect Concentrations (PNECs) are used in liquid media to predict resistance risks, PNEC values for soils, especially for clarithromycin, are lacking.

Effect of intermittent water flow on biodegradation of organic micropollutants in the hyporheic zone.

Water scarcity in the Mediterranean area has increased the number of intermittent rivers. Recently, hyporheic zones (HZ) of intermittent rivers have gained attention since a substantial part of the stream's natural purification capacity is located within these zones. Thus, understanding the flow dynamics in HZs is crucial for gaining insights into the degradation of organic micropollutants.

RISMEAU dataset: Pharmaceuticals and biocides concentrations in urban and agricultural sludge, amended soil and leachate and their environmental impacts.

The RISMEAU project ( - Risks related to residues of pharmaceuticals and biocides, and antimicrobial resistance of human and veterinary origin on the water resources of the 2083 km Arve catchment located in the French Alps) was implanted from 2018 to 2024 on the SIPIBEL observatory. It was devoted to the evaluation of (i) transfers of and processes related to pharmaceutical residues and biocides from both urban sludge and manure spread on fields as fertilisers, and (ii) the environmental impacts of land spreading, in particular the ecotoxicological risks and antimicrobial resistance dissemination. The methodology was based on the physico-chemical, ecotoxicological and antimicrobial resistance (AMR - assessed by molecular biology) characterisation of leachate and soil matrices samples, and focused on organic waste products application at locally representative agronomic rates.

Potentialities of semi-continuous anaerobic digestion for mitigating antibiotics in sludge.

The behavior and removal of roxithromycin (ROX), oxytetracycline (OTC), chlortetracycline (CTC), and enrofloxacin (ENR) were investigated during the steady state of sludge anaerobic digestion (AD) in semi-continuous mode (37 °C). Sludge was spiked at realistic concentrations (50 μg/L of each antibiotic) and then used to feed the bioreactor for 80 days. Antibiotics were extracted from the substrate and digested sludge samples by accelerated solvent extraction (ASE).

Temporal dynamic of soil microbial communities and antibiotic resistance markers exposed to increasing concentrations of sulfamethoxazole.

The reuse of treated wastewater (TWW) for irrigation is widely applied to alleviate pressure on freshwater resources. However, TWW contains antibiotics that once in soils, can exert selective pressure, promoting the emergence and spread of antimicrobial resistance (AMR) in the environment. Current environmental risk assessments for antibiotic residues rely on indicators such as Predicted No Effect Concentrations (PNECs), usually determined in liquid media.

Role of endogenous soil microorganisms in controlling antimicrobial resistance after the exposure to treated wastewater.

The reuse of treated wastewater (TWW) for irrigation appears to be a relevant solution to the challenges of growing water demand and scarcity. However, TWW contains not only micro-pollutants including pharmaceutical residues but also antibiotic resistant bacteria. The reuse of TWW could contribute to the dissemination of antimicrobial resistance in the environment.

Retention time and organic loading rate as anaerobic co-digestion key-factors for better digestate valorization practices: C and N dynamics in soils.

The growing use of anaerobic co-digestion (AcoD) in processing organic waste has led to a significant digestate production. To effectively recycle digestate back into soils, it is crucial to understand how operational variables in the AcoD process influence the conversion of organic matter (OM). To address this, a combination of biochemical fractionation and various soil incubation tests were employed to assess the stability of OM in digestates generated from anaerobic continuous reactors fed with a food waste-hay mixture and operating at different hydraulic retention times (HRT) and organic loading rates (OLR).

Assessing the chronic toxicity of spreading organic amendments on agricultural soil: Tests on earthworms and plants.

Recycling organic wastes on agricultural soils improves the soil quality, but the environmental and health impact of these organic amendments closely depends on their origins, their bio-physicochemical characteristics and the considered organisms potentially affected. The aim of this study was to assess the potential chronic ecotoxicity of spreading organic amendments on agricultural soils. To do this, we characterized three different organic amendments: sewage sludge from an urban wastewater treatment plant, cow manure and liquid dairy manure.

Consideration of unmeasured micropollutants released from WWTP for potential impact estimations.

During wastewater treatment, micropollutants are only partly eliminated and may present a risk for human health and aquatic ecosystems. The potential impacts these substances may have are currently underestimated due to the lack in available concentrations that lie below the limit of quantification (LOQ) for an important set of micropollutants. Here, the potential impacts due to 261 organic micropollutants on human health and aquatic environments were investigated at the scale of France.

Deciphering the contribution of microbial biomass to the properties of dissolved and particulate organic matter in anaerobic digestates.

The recalcitrant structures either from substrate or microbial biomass contained in digestates after anaerobic digestion (AD) highly influence digestate valorization. To properly assess the microbial biomass contribution to the digested organic matter (OM), a combination of characterization methods and the use of various substrate types in anaerobic continuous reactors was required. The use of totally biodegradable substrates allowed detecting soluble microbial products via fluorescence spectroscopy at emission wavelengths of 420 and 460 nm while the protein-like signature was enhanced by the whey protein.

Predicting the Stability of Organic Matter Originating from Different Waste Treatment Procedures.

Recycling organic wastes into farmland faces a double challenge: increasing the carbon storage of soil while mitigating CO emission from soil. Predicting the stability of organic matter (OM) in wastes and treatment products can be helpful in dealing with this contradiction. This work proposed a modeling approach integrating an OM characterization protocol into partial least squares (PLS) regression.

Reclaimed wastewater reuse in irrigation: Role of biofilms in the fate of antibiotics and spread of antimicrobial resistance.

Reclaimed wastewater associated biofilms are made up from diverse class of microbial communities that are continuously exposed to antibiotic residues. The presence of antibiotic resistance bacteria (ARB) and their associated antibiotic resistance genes (ARGs) ensures also a continuous selection pressure on biofilms that could be seen as hotspots for antibiotic resistance dissemination but can also play a role in antibiotic degradation. In this study, the antibiotic degradation and the abundance of four ARGs (qnrS, sul1, blaTEM, ermB), and two mobile genetic elements (MGEs) including IS613 and intl1, were followed in reclaimed wastewater and biofilm samples collected at the beginning and after 2 weeks of six antibiotics exposure (10 µg L).

Combining sequential extraction and 3D fluorescence to investigate the behavior of antibiotic and polycyclic aromatic hydrocarbons during solar drying of sewage sludge.

Solar drying and liming are commonly used for sludge treatment, but little is known about their efficiency on antibiotics and Polycyclic Aromatic Hydrocarbons (PAHs) removal. This study aimed to investigate the removal of antibiotics and PAHs during solar drying of Limed Sludge (LS) and Non-Limed Sludge (NLS). Thus, organic matter fractionation and 3D fluorescence were used to assess the accessibility and the complexity of organic matter.

Prediction of organic matter accessibility and complexity in anaerobic digestates.

Further characterization to properly assess the fate of organic matter quality during anaerobic digestion and organic carbon mineralization in soils is required. Organic matter quality based on its accessibility and complexity was employed to successfully classify 28 substrate/digestate pairs through principal components and hierarchical clustering analysis. The two first components explained 58.

Assessment of pesticides volatilization potential based on their molecular properties using the TyPol tool.

Following treatment, amounts of pesticides can reach the atmosphere because of spray drift, volatilization from soil or plants, and/or wind erosion. Monitoring and risk assessment of air contamination by pesticides is a recent issue and more insights on pesticide transfer to atmosphere are needed. Thus, the objective of this work was to better understand and assess pesticides emission potential to air through volatilization.

Relative Weight of Organic Waste Origin on Compost and Digestate 16S rRNA Gene Bacterial Profilings and Related Functional Inferences.

Even though organic waste (OW) recycling via anaerobic digestion (AD) and composting are increasingly used, little is known about the impact of OW origin (fecal matters and food and vegetable wastes) on the end products' bacterial contents. The hypothesis of a predictable bacterial community structure in the end products according to the OW origin was tested. Nine OW treatment plants were selected to assess the genetic structure of bacterial communities found in raw OW according to their content in agricultural and urban wastes and to estimate their modifications through AD and composting.

Fate of emerging and priority micropollutants during the sewage sludge treatment - Part 2: Mass balances of organic contaminants on sludge treatments are challenging.

This paper analyzes the fate of 71 priority and emerging organic contaminants all along the treatment trains of sewage sludge treatment facilities in Paris including dewatering by centrifugation, thermal drying and anaerobic digestion. It aimed at proposing and applying a mass balances calculation methodology to each process and pollutant. This data validation strategy demonstrated the complexity to perform representative inlet/outlet sampling and analysis campaigns at industrial scales regarding organic compounds and to propose options to overcome this issue.

Impact assessment of a large panel of organic and inorganic micropollutants released by wastewater treatment plants at the scale of France.

Micropollutants emitted by Human activities represent a potential threat to our health and aquatic environment. Thousands of active substances are used and go to WWTP through wastewaters. During water treatment, incomplete elimination occurs.

The impact of biogas digestate typology on nutrient recovery for plant growth: Accessibility indicators for first fertilization prediction.

In recent years, anaerobic digestion of organic waste (OW) is rapidly appearing as a winning waste management strategy by producing energy and anaerobic digestates that can be used as fertilizers in agricultural soils. In this context, the management of the OW treatment process to maximize agro-system sustainability satisfying the crop nutrient demands represents the main goal. To investigate these traits, two protocols to assess the plant availability of digestate nitrogen (N) and phosphorus (P) were evaluated.

Process type is the key driver of the fate of organic micropollutants during industrial scale treatment of organic wastes.

Organic micropollutants (OMPs) such as polycyclic aromatic hydrocarbons, nonylphenols and pharmaceutical products are ubiquitous in organic wastes generated by most human activities. Those wastes are mainly recycled by land spreading, most often after treatments, such as liming, dewatering, composting or anaerobic digestion. It has been shown essentially at lab scales that biological treatments have an effect on the removal of some OMPs.

Humic-like substances extracted from different digestates: First trials of lettuce biostimulation in hydroponic culture.

Digestate valorization is a key challenge for the feasibility of Anaerobic Digestion plants. In this study, humic-like substances (HLS) extracted from two digestates (sewage sludge and manure) were used for the biostimulation of hydroponic cultures of Lactuca sativa (lettuce) at different doses and compared to a commercial reference of leonardite HLS. Aerial biomass increase averages ranged from 7 to 30 %, but the results presented a high coefficient of variation (around 20 %).

Modelling hydrolysis: Simultaneous versus sequential biodegradation of the hydrolysable fractions.

Hydrolysis is considered the limiting step during solid waste anaerobic digestion (including co-digestion of sludge and biosolids). Mechanisms of hydrolysis are mechanistically not well understood with detrimental impact on model predictive capability. The common approach to multiple substrates is to consider simultaneous degradation of the substrates.

First fertilizing-value typology of digestates: A decision-making tool for regulation.

Defined as the residue from anaerobic digestion (AD), digestate refers to a set of materials with varied biochemical compositions. The objective of this study was to establish a digestate typology according to its fertilizing-value with data from literature and internal unpublished databases. To establish a relatively big database allowing the application of advanced statistics, usual fertilizing-value parameters were used: dry matter, volatile solids, C/N, C/Organic-N, total N (TN), total ammoniacal nitrogen (TAN), TAN/TN, total P and total K.

Organic micropollutants' distribution within sludge organic matter fractions explains their dynamic during sewage sludge anaerobic digestion followed by composting.

The simultaneous fate of organic matter and 4 endocrine disruptors (3 polycyclic aromatic hydrocarbons (PAHs) (fluoranthene, benzo(b)fluoranthene, and benzo(a)pyrene) and nonylphenols (NP)) was studied during the anaerobic digestion followed by composting of sludge at lab-scale. Sludge organic matter was characterized, thanks to chemical fractionation and 3D fluorescence deciphering its accessibility and biodegradability. Total chemical oxygen demand (COD) removal was 41% and 56% during anaerobic digestion and composting, respectively.