Co-metabolic degradation of iomeprol by a Pseudomonas sp. and its application in biological aerated filter systems

Occurrence of iodinated contrast media (ICM) in water environments and their control strategies with a particular focus on iodinated by-products formation: A comprehensive review

Iodinated contrast media (ICM), one of the pharmaceutical and personal care products (PPCPs), are frequently detected in various water bodies due to the strong biochemical stability and recalcitrance to conventional water treatment. Additionally, ICM pose a risk of forming iodinated by-products that can be detrimental to the aquatic ecosystem. Consequently, effectively removing ICM from aqueous environments is a significant concern for environmental researchers. This article provides a comprehensive review of the structural characteristics of ICM, their primary source (e.g., domestic and hospital wastewater), detected concentrations in water environments, and ecological health hazards associated with them. The current wastewater treatment technologies for ICM control are also reviewed in detail with the aim of providing a reference for future research. Prior researches have demonstrated that traditional treatment processes (such as physical adsorption, biochemical method and chemical oxidation method) have inadequate efficiencies in the removal of ICM. Currently, the application of advanced oxidation processes to remove ICM has become extensive, but there are some issues like poor deiodination efficiency and the risk of forming toxic intermediates or iodinated by-products. Conversely, reduction technologies have a high deiodination rate, enabling the targeted removal of ICM. But the subsequent treatment issues related to iodine (such as I- and OI-) are often underestimated, potentially generating iodinated by-products during the subsequent treatment processes. Hence, we proposed using combined reduction-oxidation technologies to remove ICM and achieved synchronous control of iodinated by-products. In the future, it is recommended to study the degradation efficiency of ICM and the control efficiency of iodinated by-products by combining different reduction and oxidation processes.

Removal efficiency of emerging micropollutants in biofilter wastewater treatment plants in tropical areas

We studied the removal of 61 emerging micropollutants, including illicit drugs, in a biofilter wastewater treatment plant located in the French Indies (Martinique). Raw wastewater concentrations were the highest for paracetamol followed by caffeine, naproxen, ibuprofen, its metabolite 2-hydroxyibuprofen, atenolol, ketoprofen, furosemide, methylparaben, cocaine, benzoylecgonine, and 11-nor-delta-9-carboxytetrahydrocannabinol (THC-COOH). The calculated removals were better than those reported in the literature, while the cumulative removal efficacy (i.e., removal of the total mass load) was estimated to be 92 ± 4%. However, this good performance may be partly explained by the removal of paracetamol (also named acetaminophen) and caffeine, which represented 86.4% of the total mass load. Our results point to the adsorption of some molecules on sludge, thus raising the question about local soil pollution from sludge spreading.

Exploring the key microbial changes in the rhizosphere that affect the occurrence of tobacco root-knot nematodes

Root-knot nematode (RKN) disease is a soil-borne disease. However, most studies on RKN have focused on the screening of agents and the cultivation of resistant varieties, and reports on the interaction of RKNs with soil microorganisms are few. In this study, we performed Illumina high-throughput sequencing to analyze diseased and healthy soil and the microbial-community changes in rhizosphere soil after microbial treatment (Pseudomonas flurescens, Bacillus subtilis, Paecolomyces lilacinus). Results showed significant differences in the bacterial community richness and diversity between diseased and healthy soil and the presence of different microbial species. After treatment, the richness and diversity of microbial communities in soil, as well as the number and incidence of second-stage juvenile of RKNs, decreased. Through linear discriminant analysis effect size, Pearson correlation, and Venn diagram analysis, we screened five genera that were closely related to disease occurrence, among which Pseudomonas was most related to disease inhibition. Our results suggested that the occurrence of tobacco RKN was related to changes in soil microbial communities, and that the interactions among Pseudomonas, Bryobacter, Variibacter, Coniochaeta, and Metarhizium affected the health of rhizosphere soil.