Elements uptake, histological distributions as well as mycorrhizal and physiological statuses of Atriplex halimus were determined on trace metal and metalloid polluted soils from the surrounding spray zones of a former lead smelter in the South-East coast of Marseille (France). Analyses of heavy metal and arsenic distribution in soil and plant organs showed that A. halimus tolerance is largely due to exclusion mechanisms. No specific heavy metal concentration in leaf or root tissues was observed. However, accumulation of salts (NaCl, KCl, Mg and Ca salts) on leaf bladders and peripheral tissues of roots was observed and may compete with metal element absorption. Occurrence of endomycorrhizal structures was detected in roots and may contribute to lower element transfer from root into the aerial parts of plants. The non-destructive measurements of leaf epidermal chlorophylls, flavonols and phenols showed a healthy state of the A. halimus population on the metal and metalloid polluted sites. Considering the low metal bioaccumulation and translocation factors along with a reduced metal stress diagnosis, A. halimus appeared as a good candidate for phytostabilization of trace metals and metalloids and notably arsenic in contaminated soils of the Mediterranean spray zone. However, its invasive potential has to be determined before an intensive in situ use.

Cadmium (Cd) is a toxic and nonessential element. Because of its toxicity, Cd soil contamination is a major environmental risk to living organisms. Several studies have reported on the successful use of biochar to immobilize Cd in soil as it reduces Cd accumulation in plant parts. This research reports on the contrasting effect of biochar on enhancing Cd uptake by plants. A cassava stem biochar produced through low-temperature pyrolysis was applied to natural Cd-contaminated soil that also had a high zinc (Zn) concentration. Vigna radiata L. (a green bean) was grown in treatments receiving three biochar rates, i.e., 5, 10, and 15 %, respectively. The results showed that the 10 % biochar-amended soil had a positive effect on promoting plant growth and seed yield. Unfortunately, 15 % biochar-amended soil caused an adverse effect to plant growth. Cadmium uptake by plants increased with increasing biochar application rate. Zinc uptake by plants tended to decrease with biochar application. Cadmium and Zn bioavailability in soil was significantly reduced with an increasing biochar application rate. The results also showed that the biochar-amended soil could be an alternative and cost-effective method to promote plant growth and decrease Cd mobility in soil. The ratio of Cd concentration in plant root to soil was higher than 1, while the translocation factor from root to shoot was less than 1. These results indicate that the cultivation of V. radiata L. coupled with biochar application is an appropriate method to enhance Cd phytostabilization efficiency of V. radiata L. in Cd-polluted sites.

A bentonite-based hydrogel was chemically modified to prepare a new effective adsorbent for the removal of phosphate from aqueous solutions using batch equilibrium experiments at the laboratory scale. The efficiency of the phosphate adsorption by the modified adsorbents followed the order: Al-Fe-hydrogel > Al-hydrogel > Fe-hydrogel > Rewoquate surfactant-hydrogel ≅ Irasoft surfactant-hydrogel > raw hydrogel. The amount of Fe and Al, as determined in proportion to the cation exchange capacity (CEC) of the hydrogel, was the most important parameter for optimizing the modification process by pillaring solutions. The results showed that the phosphate adsorption was rapid and pH independent. The removal of phosphate reached up to 99 % at the optimized conditions. The adsorption data were well fitted by Langmuir and Freundlich models. According to the Langmuir model, the maximum adsorption capacity of the phosphate on the Fe-Al-hydrogel was 14.29 mg L⁻¹. The removal of phosphate from an urban wastewater using the modified adsorbent was more than 99 %. The Fe-Al-hydrogel selectively adsorbed the phosphate from the solutions containing sulphate, bicarbonate, chloride, and nitrate. Based on the obtained results, the synthesized adsorbent could be used effectively to decontaminate the phosphate polluted water.

Three-dimensional graphene-based materials promise oil spill cleanup in water at throughputs much higher than state-of-the-art oil–water separation materials.

Based on the enhancing effect of chitosan (CS) on luminol-dissolved oxygen chemiluminescence (CL) reaction, a flow injection (FI) luminol–CS CL system was established. It was found that the increase of CL intensity was proportional to the concentrations of CS ranging from 0.7 to 10.0 μmol l⁻¹. In the presence of chlortoluron (CTU), the CL intensity of luminol–CS system could be obviously inhibited and the decrements of CL intensity were linearly proportional to the logarithm of CTU concentrations ranging from 0.01 to 70.0 ng ml⁻¹, giving the limit of detection 3.0 pg ml⁻¹ (3σ). At a flow rate of 2.0 ml min⁻¹, the whole process including sampling and washing could be accomplished within 36 s, offering a sample throughput of 100 h⁻¹. The proposed FI–CL method was successfully applied to the determination of CTU in soil samples with recoveries ranging from 95.0 % to 105.3 % and the relative standard deviations (RSDs) of less than 4.0 %.

Anticoagulants are biocides widely used as pest control agents in agriculture, urban infrastructures, and domestic applications for the control of rodents. Other anticoagulants such as warfarin and acenocoumarol are also used as drugs against thrombosis. After use, anticoagulants are discharged to sewage grids and enter wastewater treatment plants (WWTPs). Our hypothesis is that WWTP effluents can be a source of anticoagulants to receiving waters and that these can affect aquatic organisms and other nontarget species. Therefore, the objective of the present study was to determine the occurrence of 11 anticoagulants in WWTPs receiving urban and agricultural wastewaters. Warfarin was the most ubiquitous compound detected in influent waters and was partially eliminated during the activated sludge treatment, and low nanograms per liter concentration were found in the effluents. Other detected compounds were coumatetralyl, ferulenol, acenocoumarol, flocoumafen, brodifacoum, bromadiolone, and difenacoum at concentrations of 0.86–87.0 ng L⁻¹. Considering water volumes of each WWTP, daily emissions were estimated to be 0.02 to 21.8 g day⁻¹, and thus, WWTPs contribute to the loads of anticoagulants to receiving waters. However, low aquatic toxicity was observed using Daphnia magna as a model aquatic organism.

Nanoscale zero-valent iron (nZVI) has recently gained great interest in the scientific community as in situ reagent for installation of permeable reactive barriers in aquifer systems, since nZVI is highly reactive with chlorinated compounds and may render them to harmless substances. However, nZVI has a high tendency to agglomerate and sediment; therefore it shows very limited transport ranges. One new approach to overcome the limited transport of nZVI in porous media is using a suited carrier colloid. In this study we tested mobility of a carbon colloid supported nZVI particle “Carbo-Iron Colloids” (CIC) with a mean size of 0.63 μm in a column experiment of 40 cm length and an experiment in a two-dimensional (2D) aquifer test system with dimensions of 110 × 40 × 5 cm. Results show a breakthrough maximum of 82 % of the input concentration in the column experiment and 58 % in the 2D-aquifer test system. Detected residuals in porous media suggest a strong particle deposition in the first centimeters and few depositions in the porous media in the further travel path. Overall, this suggests a high mobility in porous media which might be a significant enhancement compared to bare or polyanionic stabilized nZVI.

Acetaminophen is globally one of the most prescribed drugs due to its antipyretic and analgesic properties. However, it is highly toxic when the dosage surpasses the detoxification capability of an exposed organism, with involvement of an already described oxidative stress pathway. To address the issue of the ecotoxicity of acetaminophen, we performed acute exposures of two aquatic plant species, Lemna gibba and Lemna minor, to this compound. The selected biomarkers were number of fronds, biomass, chlorophyll content, lipid peroxidation (TBARS assay), and proline content. Our results showed marked differences between the two species. Acetaminophen caused a significant decrease in the number of fronds (EC₅₀ = 446.6 mg/L), and the establishment of a dose-dependent peroxidative damage in L. minor, but not in L. gibba. No effects were reported in both species for the indicative parameters chlorophyll content and total biomass. However, the proline content in L. gibba was substantially reduced. The overall conclusions point to the occurrence of an oxidative stress scenario more prominent for L. minor. However, the mechanisms that allowed L. gibba to cope with acetaminophen exposure were distinct from those reported for L. minor, with the likely involvement of proline as antioxidant.

This paper explores the potential of a hazardous waste of difficult management, electric arc furnace dust (EAFD), as photocatalytic material. Starting from a real waste coming from a Spanish steel factory, chemical, mineralogical, and optical characterizations have been carried out. Direct trials on EAFD and mortar containing this waste have been performed to evaluate its potential as photocatalyst itself and within a cementitious material. The analysis of photocatalytic properties has been done by two different methods: degradation of NO ₓ and degradation of rhodamine (RhB). As a result, it can be said that EAFD exhibited photocatalytic activity for both configurations with UV and visible light, having the mortar enhanced photocatalytic activity for NO ₓ with respect to the EAFD itself. Additionally, in direct trials on the EAFD, it has been able to degrade RhB even in the dark, which has been attributed to transfer of electrons between the adsorbed RhB and the conduction band of some oxides in the dust.