Advances in research on the use of biochar in soil for remediation: a review

Purpose: Soil contamination mainly from human activities remains a major environmental problem in the contemporary world. Significant work has been undertaken to position biochar as a readily-available material useful for the management of contaminants in various environmental media notably soil. Here, we review the increasing research on the use of biochar in soil for the remediation of some organic and inorganic contaminants.  Materials and methods: Bibliometric analysis was carried out within the past 10 years to determine the increasing trend in research related to biochar in soil for contaminant remediation. Five exemplar contaminants were reviewed in both laboratory and field-based studies. These included two inorganic (i.e., As and Pb) and three organic classes (i.e., sulfamethoxazole, atrazine, and PAHs). The contaminants were selected based on bibliometric data and as representatives of their various contaminant classes. For example, As and Pb are potentially toxic elements (anionic and cationic, respectively), while sulfamethoxazole, atrazine, and PAHs represent antibiotics, herbicides, and hydrocarbons, respectively.  Results and discussion: The interaction between biochar and contaminants in soil is largely driven by biochar precursor material and pyrolysis temperature as well as some characteristics of the contaminants such as octanol-water partition coefficient (KOW) and polarity. The structural and chemical characteristics of biochar in turn determine the major sorption mechanisms and define biochar’s suitability for contaminant sorption. Based on the reviewed literature, a soil treatment plan is suggested to guide the application of biochar in various soil types (paddy soils, brownfield, and mine soils) at different pH levels (4–5.5) and contaminant concentrations ( 50 mg kg−1).  Conclusions: Research on biochar has grown over the years with significant focus on its properties, and how these affect biochar’s ability to immobilize organic and inorganic contaminants in soil. Few of these studies have been field-based. More studies with greater focus on field-based soil remediation are therefore required to fully understand the behavior of biochar under natural circumstances. Other recommendations are made aimed at stimulating future research in areas where significant knowledge gaps exist

Presence of fluoroquinolones and sulfonamides in urban sewage sludge and their degradation as a result of composting

The concentrations of some widely used pharmaceuticals, namely fluoroquinolones (ciprofloxacin C17H18FN3O3, norfloxacin C16H18FN3O3 and ofloxacin C18H20FN3O4) and sulfonamides (sulfadimethoxine C12H14N4O4S and sulfamethoxazole C10H11N3O3S ) were determined in urban sewage sludge utilized for making compost. The levels of degradation of these pharmaceuticals resulting from sludge treatment were assessed. The concentrations of the studied pharmaceuticals sufficiently varied both in sewage sludge and in compost and due to this phenomenon the possible danger resulting from the presence of pharmaceuticals in sewage sludge, used for composting, can not be ignored. The concentrations of the studied pharmaceuticals were lower in compost, if compared to the relevant concentrations in sewage sludge. The highest pharmaceutical concentration in sewage sludge - 426 μg/kg - was detected in the case of ciprofloxacin. The highest concentrations present in compost were 22 μg/kg of norfloxacin and 20 μg/kg of ciprofloxacin. Results show that before using the sewage sludge for making compost or before using the compost a fertilizer for food plants, they should be carefully tested against the content of commonly used pharmaceuticals

Rejets hospitaliers d’antibiotiques et de bactéries fécales antibiorésistantes dans les rivières du bassin de la Seine: Antimicrobials and faecal bacteria resistant to antimicrobials in the rivers of the Seine River watershed: impacts of hospital effluents

Cette étude explore le niveau de contamination en antibiotiques et en bactéries fécales antibiorésistantes (Escherichia coli) dans les eaux usées d’un hôpital parisien, les eaux usées brutes et traitées de stations d’épuration municipales, et plusieurs cours d’eau du bassin de la Seine. La contamination des rivières est réelle, la concentration de certains antibiotiques atteignant jusqu’à plusieurs dixièmes de μg.L−1 et la fréquence de E. coli résistants à au moins un antibiotique se situant en moyenne à 42 %. Les effluents hospitaliers se caractérisent sans surprise par les concentrations en antibiotiques et les niveaux d’antibiorésistance les plus élevés (jusqu’à quelques dizaines de μg.L−1 et 71 % de E. coli antibiorésistants, respectivement). Néanmoins, il est évalué qu’à l’échelle du bassin de la Seine, l’impact des effluents hospitaliers sur la contamination des rivières est faible devant celui des effluents domestiques en ce qui concerne les antibiotiques, négligeable en ce qui concerne les bactéries fécales antibiorésistantes. En revanche, les concentrations en antibiotiques atteintes localement dans les effluents hospitaliers sont compatibles avec le maintien d’une pression de sélection sur les bactéries les plus sensibles, et les rejets de ces effluents contribuent à disséminer dans l’environnement des bactéries fécales avec un niveau de multirésistance nettement plus élevé qu’avec les effluents domestiques. ____________________________________________________________________________________ Hospital wastewaters contain large amounts of antimicrobial drugs and antimicrobial-resistant bacteria, which may eventually be discharged into the aquatic environment, raising the question of their impact on humans and ecosystems. In this study, the occurrence of 16 antimicrobials and the prevalence of antimicrobial resistance among the faecal bacteria Escherichia coli were studied in raw wastewaters from a large Parisian hospital, in raw and treated wastewaters from municipal wastewater treatment plants and in several streams and rivers from the Seine River watershed. Antimicrobial concentrations up to 544 ng·L−1 have been measured in the Seine River, while 42% of the E. coli found in the Seine hydrographical network were resistant to at least one antimicrobial. Unsurprisingly, hospital wastewaters displayed the highest concentrations of antimicrobials (up to 37.3 μg·L−1) and the highest prevalence of antimicrobial-resistant E. coli (71%). At the global scale of the whole watershed, when compared to municipal wastewaters, hospital wastewaters were estimated to have a minor contribution to the contamination of the rivers as regards antimicrobials, and a negligible contribution as regards antimicrobial-resistant faecal bacteria. On the other hand, some antimicrobials were found locally in hospital wastewaters at concentrations susceptible to exert a selective pressure on some bacteria of the microbial community, and faecal bacteria from hospital origin were much more multiple-resistant, which raises the issue of the dissemination of these bacteria or their genes into the environment.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Sources et devenir des médicaments dans le bassin versant de la Seine

[Departement_IRSTEA]Eaux [TR1_IRSTEA]ARCEAUEn 2006, la France se classait au deuxième rang des pays européens pour sa consommation d’antibiotiques avec 1295 tonnes consommées en médecine vétérinaire et 729 tonnes en médecine humaine (Goossens et al., 2005, AFSSA, 2006). Bien qu’il n’existe pas actuellement de réglementation concernant leur niveau de présence dans les rejets et l’environnement, ces données justifient l’intérêt et la nécessité de définir les sources et le mode de transfert de ces substances pharmaceutiques, afin d’obtenir une meilleure caractérisation de la présence de ces molécules et de leur comportement dans l’environnement. Au cours de la phase V du programme PIREN-Seine, un premier état des lieux de la contamination en médicaments de la Seine a été réalisé, ensuite nous nous sommes intéressés aux sources et aux devenir des antibiotiques dans le réseau hydrographique. Ce rapport présente les travaux d’Eau de Paris et résume les travaux de thèse de F. Tamtam (2008) et T. Dinh (soutenance prévue fin 2011)

Contamination de la Seine par les micropolluants organiques : Effet des conditions hydriques et de l'urbanisation

Contamination de la Seine par les micropolluants organiques : Effet des conditions hydriques et de l'urbanisatio