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The presence of diclofenac, a frequently used analgesic drug in the environment, can be harmful to a variety of organisms like algae, crustaceans and fish. In this study, a bacterial strain of Klebsiella sp. KSC (Gen Bank, accession number KX500307) able to biodegrade high concentration of diclofenac was isolated from livestock soil and identified. The exposure of Klebsiella sp. KSC to 70 mg/L of diclofenac resulted in diclofenac mineralization after 72 h. This is the first study that points out substantial biodegradation of high concentration of diclofenac (70 mg/L) in less than 72 h; and this shows the potential of this strain to be bioaugmented in contaminated sites or to bioreactors. The chemical structure of twelve biotransformation products of diclofenac are proposed. Its transformation pathway may involve hydroxylation, dehydroxylation, decarboxylation and dechlorination of the central ring of diclofenac. Acute ecotoxicity assay with Vibrio fischeri test showed that the main biotransformation product (TP298) of diclofenac by Klebsiella sp . KSC was less toxic than the parent compound. [ABSTRACT FROM AUTHOR]

There is a growing need to recover degraded soils to restore their essential ecosystem services and limit damages of anthropic activities onto these systems. Safe and sustainable solutions for long-term recovery must be designed, ideally by recycling existing resources. Using ash from combustion of residual forest biomass at the pulp and paper industry is an interesting and sustainable strategy to recover mining soils. However, formulations must be found to limit the potential toxicity associated with soluble salts and chloride that ash contains. Here, we assessed the effectiveness of three field ash-based amendments for the recovery of three highly acidic soils from Portuguese abandoned mines. Three amendments were tested: an un-stabilized mixture of ash and biological sludge, granulated ash, and granulated ash mixed with composted sludge. One year after application in open field plots (in the scope of LIFE No_Waste project), soil health restoration was evaluated through (i) soil physico-chemical characterization and (ii) soil habitat functions though standardized ecotoxicological tests. This study highlights that stabilized materials provided nutrients, organic matter and alkalinity that corrected soil pH and decreased metal bioavailability, while controlling the release of soluble salts and chloride from ash. This soil improvement correlated with improved soil model organisms' reproduction and survival. For similar amendment, the native soil properties studied (as soil native electrical conductivity) affected the level of organism response. This work provides evidence that ash stabilization, formulation and supplementation with organic matter could be sustainable strategies to restore highly degraded mining soils and to recover their ecological functions. It further highlights the importance of analyzing combined effects on soil physico-chemical properties and ecological function recovery to assess restoration strategy efficiencies in complex multi-stressor environments. • Ash-based formulations improved physico-chemical conditions in highly degraded mining soils. • Invertebrate reproduction benefits from stabilized ash granules and composted sludge application. • Organic carbon addition with composted sludge promotes E. crypticus reproduction. • Ash granulation reduced EC and soluble chloride-related hazard for model invertebrates. Ash-based amendments are a promising strategy to contribute to the recovery of mining soils' capacity to support ecosystems function and to recycling nutrients in relevant waste streams. [ABSTRACT FROM AUTHOR]

Abstract: The presence of heavy metals in the sludges produced in wastewater treatment plants restricts their use for agricultural purposes. This study compares different types of sludges (aerobic, anaerobic, unstabilised and sludge from a waste stabilisation pond) in order to assess the extractability of heavy metals using simple extraction, water and DTPA. The stabilisation treatment undergone by the sludges influenced the heavy metals extractability. The least mineralised sludges (unstabilised and aerobic) showed higher metal extractability. The sewage sludges were subjected to chemical characterisation and toxicity testing (ecotoxicity and phytotoxicity assays) in absence of substrate, to provide a preliminary assessment of their suitability for land application. The ecotoxicity assays confirmed that no sludge constituted a hazardous waste. The sludge extracts had significant adverse effect on the germination index (GI) of barley (Hordeum vulgare L.) and cress (Lepidium sativum L.), a fact which indicates that some characteristics affected root growth. [Copyright &y& Elsevier]

Circular economy (CE) is defined as a system in which the value of products, materials and resources is maintained for as long as possible, minimizing their consumption and the generation of waste. Within the CE framework, anaerobic digestion (AD) represents an attractive technology, as it uses waste to produce biogas as renewable energy and stabilizes the sewage sludge for land application. In this way, this technology contributes to "closing the loop" between energy consumption, food production and the disposal of the subsequent waste. However, these potential benefits may be limited by negative impacts related to the land disposal of the stabilized sewage sludge. For example, the presence of micropollutants (MPs) in the input sludge and the inability of current AD methods to remove them are recognized potential risks for human health and for the environment. The aim of this review is to provide an overview of the different MPs present in the raw sewage sludge and stabilized sewage sludge (biosolids) with AD, to assess their potential adverse effects, and to highlight possible remediation strategies. This review will focus on three important groups: pharmaceuticals and personal care products (PPCPs), metallic trace elements, and polycyclic aromatic hydrocarbons (PAHs). The resulting toxicity of the biosolids will depend on the operational characteristics of AD and on the physicochemical properties of the different MPs. These two factors ultimately determine their final concentration, their persistence and bioaccumulative potential, and the formation of metabolites, which sometimes can be more toxic than the corresponding parental compounds. ga1 • MPs contained in sewage sludge are associated with negative effects for the human health and the environment. • Anaerobic digestion allows to "closet he loop" of biosolids with biogas production and the land disposal. • Due to the persistency, toxicity and bioaccumulative capacity of MPs, their potential risks should be evaluating. [ABSTRACT FROM AUTHOR]

• Hydra viridissima were exposed to polymethylmethacrylate nanoplastics (PMMA-NPLs). • The 96 h-LC 50 for H. viridissima was 84.0 mg PMMA-NPLs /L (∼40 nm). • PMMA-NPLs caused malformations in hydra tentacles at concentrations < 40 mg/L. • PMMA-NPLs (< 40 mg/L) delayed hydra regeneration. • Feeding rate was not affected by exposure to PMMA-NPLs. The current understanding of nanoplastics (NPLs) toxicity to freshwater biota, especially the potential toxic effects of polymethylmethacrylate (PMMA), remains limited. Thus, the present work intended to add knowledge about the ecotoxicity of ∼40 nm PMMA-NPLs focusing on lethality, morphology, feeding and regeneration capacity of the freshwater cnidarian Hydra viridissima, after an exposure period of 96 h. Results showed that high concentrations of PMMA-NPLs can impair the survival of H. viridissima , with an estimated 96 h-LC 50 of 84.0 mg PMMA-NPLs/L. Several morphological alterations were detected at concentrations below 40 PMMA-NPLs mg/L, namely partial or total loss of tentacles, which, however, did not induce significant alterations on the feeding rates. Morphological alterations not previously reported in the literature were also found after the 96 h exposure, such as double or elbow-like tentacles. Exposure to 40 mg PMMA-NPLs/L significantly impacted hydra regeneration, with organisms exposed to PMMA-NPLs presenting significant slower regeneration rates comparatively to controls, but with no impacts on the feeding rates. Overall, this work highlights the need to assess the effects of NPLs in freshwater biota. Hydra viridissima species was sensitive in a wide range of endpoints showing its value as a biological model to study the effects of small plastic particles. [ABSTRACT FROM AUTHOR]