In this study, we have investigated the effects of three lipopeptides (fengycin, surfactin and mycosubtilin) produced by different strains of Bacillus subtilis against the phytopathogenic fungi Fusarium oxysporum f. sp. iridacearum, which affects the ornamental bulb plant populations of Iris sp. The antifungal effects were tested using minimum inhibitory concentration assay, determination of mycelium growth and spore germination inhibition rates. Also, in vivo tests on infected rhizomes and scanning electron microscopy were employed. Mycosubtilin alone and in combination with fengycin or/and surfactin showed potent inhibitory activity at concentrations as low as 5 μg ml⁻¹ which is 100 times lower compared to Topsin M, a common chemical fungicide frequently used against fusariosis in ornamental plants. An enhancement of mycosubtilin antifungal activity was observed when it was used in combination with surfactin due to a synergistic effect. At a concentration of 20 μg ml⁻¹, mycosubtilin inhibited the growth of the mycelium up to 49% and the spore germination ability up to 26% in comparison to control. In addition, significant changes on the macro- and micro-morphology have been observed. The antifungal activity is related to the inhibition of spore germination and the irreversible damage of the hyphae cell wall. To the best of our knowledge, this is the first attempt to propose the lipopeptides as biopesticides against the fusariosis of ornamental plants.

Plastic pollution is an emerging threat with severe implications on animals’ and environmental health. Nevertheless, interactions of plastic particles with both microbial structure and metabolism are a new research challenge that needs to be elucidated yet. To improve knowledge on the effects played by microplastics on free-living and fish gut-associated microbial community in aquatic environments, a 90-day study was performed in three replicated mesocosms (control-CTRL, native polyvinyl chloride-MPV and weathered polyvinyl chloride-MPI), where sea bass specimens were hosted. In CTRL mesocosm, fish was fed with no-plastic-added food, whilst in MPV and MPI food was supplemented with native or exposed to polluted waters polyvinylchloride pellets, respectively. Particulate organic carbon (POC) and nitrogen, total and culturable bacteria, extracellular enzymatic activities, and microbial community substrate utilization profiles were analyzed. POC values were lower in MPI than MPV and CRTL mesocosms. Microplastics did not affect severely bacterial metabolism, although enzymatic activities decreased and microbes utilized a lower number of carbon substrates in MPI than MPV and CTRL. No shifts in the bacterial community composition of fish gut microflora were observed by denaturing gradient gel electrophoresis fingerprinting analysis.

Metal oxide nanoparticles are widely used in industries, and peak level can be confirmed in their surroundings. In the present study, the sub-lethal effects of CuO-NPs from low to high concentration as 0.5 to 1.5 mg/L were observed in tilapia (Oreochromis mossambicus). Accumulation of copper from CuO-NPs was increased with the increase in doses, and maximum accumulation was found in the gill than liver and muscles. The increased lipid peroxidation level was observed in the gill as compared to liver, and the similar results were obtained in catalase and glutathione while superoxide dismutase level was higher in the liver than gills. In histological alterations, gill edema, curved tips, fusion of gill lamellae, and thickening of primary and secondary gill lamellae were observed. Necrosis and apoptosis with condensed nuclear bodies and pyknotic nuclei were observed in the liver at the highest dose concentration. In a genotoxic study, the highest value of % tail DNA and olive tail movement was observed with increasing concentrations. Copper oxide nanoparticles has greater potential to accumulate in the soft tissues, which may cause respiratory distress such as oxidative stress, induction of antioxidant defense by raising glutathione, organ pathology, and genotoxicity.

Municipal sludge, composed of numerous types of organic matter with a gel structure, has high water content, low permeability coefficient, and poor mechanical properties. Fenton oxidation-assisted vacuum preloading method for municipal sludge treatment was proposed. First, the municipal sludge was oxidized and treated with Fenton’s reagent; then, drainage consolidation was performed on the sludge with the vacuum preloading method. The optimal dosage of Fenton’s reagent for municipal sludge was determined. Comparative experiments of the one-dimensional consolidation of municipal sludge treated with Fenton’s reagent and the drainage consolidation by Fenton oxidation-assisted vacuum preloading were conducted. The results reveal that the specific resistance of municipal sludge decreases upon Fenton oxidation by approximately 98.6% at the optimal dosage of 22%, sludge water content decreases from 82.14 to 66.67%, volume reduces by ~ 40%, and unconfined compressive strength increases to 55 kPa.

This study aimed to evaluate the relationship between physicochemical parameters and heavy metal (Cu, Ni, Pb, and Cd) concentrations from sediment, seawater, and its accumulation in tissues of oyster species (Crassostrea madrasensis and C. gryphoides) from the three sites (Chicalim Bay (CB), Nerul Creek (NC), Chapora Bay (ChB)) along the Goa coast (India). Results showed enrichment of Cu and Ni in sediment exceeding the effect range low (ERL) level. The higher concentrations of Cu and Ni in sediments and in suspended particulate matter (SPM) from all the study sites are indicative of severe contamination of estuarine and associated habitats. Moreover, particulate Ni (at all the sites), Cu (at NC and ChB), Pb (at NC), and Cd (at CB and NC) concentrations were recorded more than its total loadings in surface sediment. Concentration of Cu and Cd in oyster tissue was several folds higher than its concentration in ambience. Further, this study showed that the levels of metal in oysters and their ambient environment were higher during the monsoon season. Hence, the consumption of oysters needs to be considered carefully with respect to the health hazards posed by the elevated levels of metal contaminants in certain seasons. The present study concludes that metals associated with the particulate matter in water column are the main source of metal accumulation in oyster. It is also suggested that concentration of metal pollutants in coastal and estuarine water bodies should be monitored regularly to ensure the acceptable limits of metal concentrations.

Constructed wetlands (CWs) offer several advantages for treating waters; however, the successful application of these systems remains a challenge. Practical solutions to pollution through CWs remain incipient because wetlands are still studied as “black boxes”; further studies are required regarding the involvement of rhizosphere bacteria in the removal of pollutants. This research focused on increasing the performance of CWs treatment systems for the removal of inorganic and organic pollutants from domestic wastewater, by the application of native bioremediating rhizobacteria. A bacterial consortium (CAD/1S) was designed with four rhizobacteria strains isolated from Typha domingensis plants of natural wetlands. Each individual strain was identified by 16S ribosomal RNA (rRNA) gene sequencing. This consortium removed organic matter, ammonium, and phosphate with percentages over 70% from model wastewater. The evaluation of abiotic and biotic factors’ influence on pollutant removal indicated the best conditions to remove pollutants: a neutral pH, a 72-h contact time, and an inoculum from single growth of each strain. The subsequent bioaugmentation with the consortium of CWs at laboratory scale allowed 100%, greater than 70 and 55% removal of organic matter, ammonium, and phosphate, respectively. The set of results allowed the proposal of a new strategy for the improvement of CWs technology for the treatment of domestic wastewater pollutants.

Heavy metals can be serious pollutants of natural water bodies causing health risks to humans and aquatic organisms. The purpose of this study was to investigate the removal of five heavy metals from water by adsorption onto an iron industry blast furnace slag waste (point of zero charge (PZC) pH 6.0; main constituents, Ca and Fe) and a coal industry fly ash waste (PZC 3.0; main constituents, Si and Al). Batch study revealed that rising pH increased the adsorption of all metals with an abrupt increase at pH 4.0–7.0. The Langmuir adsorption maximum for fly ash at pH 6.5 was 3.4–5.1 mg/g with the adsorption capacity for the metals being in the order Pb > Cu > Cd, Zn, Cr. The corresponding values for furnace slag were 4.3 to 5.2 mg/g, and the order of adsorption capacities was Pb, Cu, Cd > Cr > Zn. Fixed-bed column study on furnace slag/sand mixture (1:1 w/w) revealed that the adsorption capacities were generally less in the mixed metal system (1.1–2.1 mg/g) than in the single metal system (3.4–3.5 mg/g). The data for both systems fitted well to the Thomas model, with the adsorption capacity being the highest for Pb and Cu in the single metal system and Pb and Cd in the mixed metal system. Our study showed that fly ash and blast furnace slag are effective low-cost adsorbents for the simultaneous removal of Pb, Cu, Cd, Cr and Zn from water.

In the present study, oil in water emulsions (cₒᵢₗ = 100 ppm; dₒᵢₗ dᵣₒₚₗₑₜₛ < 2 μm) was purified with ozonation followed by microfiltration using polyethersulfone (PES) membrane (dₚₒᵣₑ = 0.2 μm). The effects of pre-ozonation on membrane microfiltration were investigated in detail both in case of ultrapure and model groundwater matrices, applying different durations (0, 5, 10, and 20 min) of pre-ozonation. Simultaneously, the effects of added inorganic water components on the combined method were investigated. Size distribution of oil droplets, zeta potentials, fluxes, and purification efficiencies were measured and fouling mechanisms were described in all cases. It was found that the matrix significantly affected the size distribution and adherence ability of oil droplets onto the membrane surface, therefore fouling mechanisms also were strongly dependent on the matrix. In case of low salt concentration, the total resistance was caused mainly by reversible resistance, which could be significantly reduced (eliminated) by pre-ozonation. In case of model groundwater matrix, nearly twice higher total resistance was measured, and irreversible resistance was dominant, because of the higher adhesion ability of the oil droplets onto the membrane surface. In this case, pre-ozonation resulted in much lower irreversible, but higher reversible resistance. Increased duration of pre-ozonation raised the total resistance and reduced the elimination efficiency (due to fragmented oil droplets and water soluble oxidation by-products) in both cases, therefore short pre-ozonation can be recommended both from economic and performance aspects.

Interaction of ciprofloxacin with the activated sludge of the sewage treatment plant is of importance for the ciprofloxacin migration and risk control. More than 96.0% ciprofloxacin was removed through the sludge adsorption. The sludge surface charge varied little with ciprofloxacin since most ciprofloxacin was dissociated into the neutral one. No obvious shift was observed for the soluble carbohydrate concentration and composition with the addition of ciprofloxacin, indicating the weak interaction between the carbohydrates and ciprofloxacin. The introduction of ciprofloxacin resulted in a reduction of the soluble protein concentration, a marked increase of the extracellular protein fluorescence intensities, and a dramatic emergence of new extracellular proteins. The alteration of the proteins highlights the strong interaction between the extracellular proteins and ciprofloxacin, and the consequent integration of certain soluble proteins and original unextractable inner layer extracellular proteins into the extractable extracellular proteins. Different types of interactions are suggested to dominate between the extracellular proteins and the differently dissociated ciprofloxacin.

Recently, the exposure to heavy metals through the consumption of vegetables has become a global concern. In this regard, the current study was aimed to measure the concentrations of lead (Pb) and cadmium (Cd) in the collected onion bulb samples as well as the surrounded soil using a flame atomic absorption spectrometer (FAAS). Additionally, the target hazard quotient (THQ) for males and females in all age groups of consumers were estimated by using Monte Carlo Simulation (MCS) method. Furthermore, the soil threshold values (STVs) were evaluated to investigate the heavy metal contents in the soil based on the established standard limits. In this context, 45 onion bulbs (HashtBandi region, 25 and Ravang region, 20) and 41 soil (HashtBandi region, 21 and Ravang region, 20) samples were collected (March–May of 2016). The average concentrations of Pb in the onions from HashtBandi and Ravang regions were determined as 0.0052 ± 0.0011 and 0.0061 ± 0.0022 mg/kg, and for Cd were 0.0095 ± 0.0024 and 0.0011 ± 0.0035 mg/kg, respectively. The average concentration of Pb in the soil from HashtBandi and Ravang regions were measured as 3.99 ± 3.77 and 2.03 ± 0.69 mg/kg, and for Cd, the corresponding values were determined as 2.21 ± 3.17 and 2.22 ± 0.92 mg/kg, respectively. The average concentration of Pb and Cd in both investigated onion bulb and soil were lower than Iranian national (onion bulb: Pb = 0.1 mg/kg, Cd = 0.05 mg/kg) and FAO/WHO (onion bulb: Pb = 0.3 mg/kg, Cd = 0.1 mg/kg; soil: Pb = 50 mg/kg, Cd = 0.3 mg/kg) standard limits. Moreover, the THQ and total target hazard quotient (TTHQ) for males and females in all age groups were less than 1 value. Therefore, no risk of the exposure to Pb and Cd as result of onion bulb consumption was reported. STVs for Pb and Cd in the HashtBandi region were calculated as 3.99 and 2.21 mg/kg, and Ravang as 2.03 and 2.22 mg/kg, respectively. Due to the higher calculated STVs for Cd while compared with the established standard limit for the soil, the further revisions regarding the heavy metal standard limits in the soil were recommended.