The aim of the study was to determine the effectiveness of soil application of manure, clay, charcoal, zeolite, and calcium oxide in remediation of soil polluted with cobalt (0, 20, 40, 80, 160, 320 mg Co kg⁻¹ of soil). The following were determined: weight of harvested plants as well as the content of cobalt in grain, straw, and roots of oat. In addition, tolerance index (Ti), cobalt bioconcentration (BCF), translocation (TF), and transfer (TFr) coefficients were derived. In the series without amendments, the increasing doses of cobalt had a significant effect by decreasing the yields of oat grain and straw and the mass of its roots. Also, lower tolerance index values were noted in the objects polluted with cobalt, especially with its highest dose. The application of manure had the strongest effect on increasing the mass of particular organs of the test plant, while the application of charcoal led to a significant decrease in this respect. The application of all substances to the soil, and especially manure and calcium oxide, resulted in higher tolerance index Ti values. The growing contamination of soil with cobalt caused a significant increase in the content of this element in oat and in the values of the translocation coefficient, in contrast to the effects noted with respect to the bioconcentration and transfer coefficients. All the substances applied to soil reduced the content of cobalt and its bioconcentration in oat straw, in opposition to grain and roots, limited its translocation, but elevated the transfer of this element from soil to plants. Soil contamination with cobalt promoted the accumulation of lead and copper in grain, cadmium, lead, nickel, zinc, manganese, and iron in straw, as well as cadmium, nickel, zinc, and manganese in oat roots. As the cobalt dose increased, the content of other trace elements in oat organs either decreased or did not show any unambiguous changes. Of all the tested substances, the strongest influence on the content of trace elements was produced by calcium oxide in straw and roots and by zeolite in roots, whereas the weakest effect was generated by manure in oat grain. Oat is not the best plant for phytoremediation of soils contaminated with cobalt.

Since the ban of tributyltin in antifouling paints, many alternative biocides have been introduced to prevent settlement and growth of marine organisms on ship hulls. Zinc pyrithione (ZnPT) is one of the most frequently used alternative biocides in antifouling paints. This paper reviewed the overall chemical properties, toxicological characteristics, and environmental fates of ZnPT, as well as the analytical challenges of studying pertinent processes. ZnPT is generally toxic to a wide range of marine organisms, including algae, bivalves, sea urchins, polychaetes, crustaceans, and fish, typically at μg/L levels. ZnPT can be transchelated into other compounds in the presence of metal ions, and photodegrades when exposed to UV light. ZnPT is also reported to be biodegraded or hydrolyzed forming several metabolites of their own toxicity and stability. However, ZnPT accumulates in the water column or sediment, if it does not degrade at certain environmental conditions. To determine potential risks caused by ZnPT in the marine environment, studies have evaluated the environmental distribution of ZnPT with various chromatographic or voltammetry methods. Unfortunately, rapid transchelation and degradation of ZnPT in both the marine environment and laboratory interfered with most of the methods employed, making it difficult to evaluate its environmental distribution. More robust and sensitive analytical methods need to be developed to reliably describe the environmental release and distribution of ZnPT. To comprehensively understand the risk posed by the input of ZnPT into the marine environment, total degradation processes and its potential products also need to be adequately addressed.

Over the last few decades, many classes of micropollutants have been detected in aquatic environments worldwide and paracetamol is one of the micropollutant agents detected in the aquatic environment. New treatment methods based on biologically produced metal and metal oxides have been developed for micropollutant removal. Biogenic manganese oxides are also one of the most important biogenic metal oxide species. In this study, biogenic manganese oxides produced by manganese-adapted Pseudomonas putida NRRL B-14878 were used for removing paracetamol. A complete removal of paracetamol could be achieved within 216 h at pH 7, biogenic manganese oxide amount of 5 g/L, and paracetamol concentration of 2 mg/L. Response surface methodology (RSM) was applied to determine interaction between solution pH, paracetamol concentration, and biogenic manganese oxide amount being individual variables and to optimize operating conditions. According to results of variance analysis (ANOVA), the second-order polynomial model was statistically significant and coefficient of determination value was high. The optimal conditions were obtained as the solution pH of 6.81, the paracetamol concentration of 9.82 mg/L, and the biogenic manganese oxide amount of 6.36 g/L. Transformation products including the dimers, higher-degree oligomers, 3-hydroxyacetaminophen, 4-aminophenol, 4-methoxyphenol, 1,4-dimethoxybenzene, and butenedioic acid were identified by LC-MS/MS. The results of this work indicate that biogenic manganese oxide is an effective material for removing micropollutants.

The integrated algal pond system (IAPS) is a passive wastewater treatment technology that can be used to remediate liquid waste from domestic, industrial and agricultural sources. The system exploits the mutualistic interaction between microalgae and bacteria to generate water of a quality suitable for discharge and/or reuse. During the treatment process, biomass in the form of microalgal–bacterial flocs (MaB-flocs) is generated, and this can be harvested and beneficiated in downstream processing. Here, we review literature on MaB-floc and extracellular polymeric substance (EPS) formation and discuss how essential microalgal–bacterial mutualism is at effecting IAPS-based wastewater treatment. Aggregation of microalgae and bacteria into MaB-flocs is clearly an outcome of EPS production by these microorganisms and arises for purposes of chemical and developmental interaction, protection, communication, aggregation and adhesion. The polymeric compounds which form the scaffold of this extracellular matrix comprise polysaccharides, proteins, uronic acid and nucleic acid. Natural EPS can be used as bioflocculant in water purification and in the dewatering and settling of sludge and is therefore an ideal natural replacement for commercially available synthetic polymers. Additionally, EPS are considered high value and can be used in many commercial applications. Thus, and to ensure sustained MaB-floc production in IAPS-based wastewater treatment plants, it is important that correct levels of EPS are maintained to facilitate settling and biomass recovery. Furthermore, it is the associated environmental and operational conditions that most impact EPS production and in turn, MaB-floc formation, and quality of the final IAPS-treated water.

The biosphere is polluted with metals due to burning of fossil fuels, pesticides, fertilizers, and mining. The metals interfere with soil conservations such as contaminating aqueous waste streams and groundwater, and the evidence of this has been recorded since 1900. Heavy metals also impact human health; therefore, the emancipation of the environment from these environmental pollutants is critical. Traditionally, techniques to remove these metals include soil washing, removal, and excavation. Metal-accumulating plants could be utilized to remove these metal pollutants which would be an alternative option that would simultaneously benefit commercially and at the same time clean the environment from these pollutants. Commercial application of pollutant metals includes biofortification, phytomining, phytoremediation, and intercropping. This review discusses about the metal-accumulating plants, mechanism of metal accumulation, enhancement of metal accumulation, potential commercial applications, research trends, and research progress to enhance the metal accumulation, benefits, and limitations of metal accumulators. The review identified that the metal accumulator plants only survive in low or medium polluted environments with heavy metals. Also, more research is required about metal accumulators in terms of genetics, breeding potential, agronomics, and the disease spectrum. Moreover, metal accumulators’ ability to uptake metals need to be optimized by enhancing metal transportation, transformation, tolerance to toxicity, and volatilization in the plant. This review would benefit the industries and environment management authorities as it provides up-to-date research information about the metal accumulators, limitation of the technology, and what could be done to improve the metal enhancement in the future.

Sodium diclofenac (DCF) is a common analgesic and anti-inflammatory drug, which has become an environmental problem due to its growth and accumulation into water bodies. In this work, commercial (with excipients) and analytical (pure) DCF mineralization was studied by means of heterogeneous catalytic ozonation. The process was carried out with magnetite (Fe₃O₄) as a catalyst, which preserves its physical and chemical properties during the process. The best results of mineralization were obtained after a 40-min treatment of 35 mg/L analytical DCF solution, with a 0.5 g/L catalyst concentration. These results showed the highest organic load decrease, measured as dissolved organic carbon (DOC) and chemical oxygen demand (COD), with 94 and 89%, respectively. In addition, the percentage of organic load decrease was compared between the conventional and the catalyzed process. Besides, reaction products were identified by gas chromatography–mass spectrometry (GC-MS) and the catalytic properties were identified by Mössbauer spectroscopy, which showed the catalyst maintained its nature after the process. Finally, the results obtained show that the heterogeneous catalytic process could be an efficient degradation treatment for emerging contaminants such as DCF.

Efficacy of Metarhizium anisopliae strain (IMI330189) and Mad1 protein alone or in combination by feeding method to overcome immune-related enzymes and Toll-like pathway genes was investigated in migratory locust. M. anisopliae (IMI330189) is a potent and entomopathogenic fungal strain could be effectively used against insect pests. Similarly, Mad1 protein adheres to insect cuticle, causing virulence to insects. We confirmed maximum 55% of mortality when M. anisopliae (IMI330189) and Mad1 was applied in combination. Similarly, increased PO activity was observed in locust with combined dose of Mad1 + IMI330189 whereas PO, POD, and SOD activities reduced using Mad1 independently. Four Toll-like signaling pathway genes (MyD88, Cactus, Pelle, and CaN) were investigated from midgut and body of the migratory locust after 72 h of treatments. Subsequently, the expression of MyD88 in the midgut and body significantly decreased with the application of Mad1 and Mad1 + IMI330189. Performance of these treatments was absolutely non-consistent in both parts of insects. Meanwhile, IMI330189 significantly raised the expression of Cactus in both midgut and body. However, the combined treatment (Mad1 + IMI330189) significantly reduced the Cactus expression in both body parts. Pelle expression was significantly increased in the midgut with the application of independent treatment of Mad1 and IMI330189 whereas the combined treatment (Mad1 + IMI330189) suppressed the Pelle expression in midgut. Its expression level was absolutely higher in body with the application of IMI330189 and Mad1 + IMI330189 only. On the other hand, Mad1 significantly increased the expression of CaN in midgut. However, all three treatments significantly affected and suppressed the expression of CaN gene in body of locust. This shows that the applications of M. anisopliae and Mad1 protein significantly affected Toll signaling pathway genes, which ultimately increased level of susceptibility of locust. However, their effect was significantly different in both parts of locust which recommends that the Toll-related genes are conserved in midgut instead of locust body.

Pollution caused by heavy metals affects all forms of life. The aim of the study was to determine the content of toxic (Sr, Ni, Pb, V, Cd, U, Rb, As) and essential (Na, K, Ca, Mg, Zn, Cu, Se, Mn, Cr, Mo, Co) metals in the bone and whole blood samples, in regard to clinical means of long- and short-term exposure, respectively. For this purpose, the cortical and trabecular parts of femoral neck, as well as the blood samples, were collected to quantify bone-important metals by inductively coupled plasma (ICP)-based techniques. According to principal component analysis (PCA), the most influential metal discriminating blood samples was Cu, while all other quantified elements were present in higher amounts in the bones. Additionally, trabecular bones (TBs) could be characterized by higher content of Mo, Cr, V, Mn, Co, As, and Ni compared to cortical bones (CBs). Linear discrimination analysis (LDA) was successfully applied to distinguish trabecular bone from the cortical bone. Significant correlation between essential Ca and toxic Sr with other elements was found and discussed. This study provides novel data on the effects of metal pollutants on bone health hazards. The results obtained for investigating metals may serve as a baseline for further clinical investigations in the orthopedic fields.

A tailing impoundment situated in the mining district of La Carolina (Spain), which stores waste resulting from the washing of Pb and Ag sulphides, was studied 30 years after it was abandoned. Fibre optic sensors were installed to record humidity, temperature, electrical conductivity and oxygen content in the pores down to a depth of 35.5 m. The oxygen profiles show an oxidised thickness of 5 m, meaning that the speed of the advancing oxidation front is estimated as 15 cm year⁻¹. Sediment samples were obtained from different depths, and parameters such as pH, carbonates and metal(loid)s, among others, were analysed. High concentrations of As (> 500 mg kg⁻¹), Fe (> 34,000 mg kg⁻¹), Mn (> 900 mg kg⁻¹), Pb (> 8000 mg kg⁻¹) and Zn (> 5000 mg kg⁻¹) were found. A piezometer was installed to enable the water inside the tailing pond to be sampled, and this presented high contents of SO₄²⁻ (> 2400 mg L⁻¹), Fe (> 28,000 μg L⁻¹), Mn (> 7800 μg L⁻¹) and Zn (> 7000 μg L⁻¹), suggesting that the mineral leaching was related to the oscillations in the water table. The water from two drainage adits situated at the foot of the impoundment was also analysed, as well as surface water both upstream and downstream from it. The speciation-saturation models applied for these water samples indicated that in spite of the contamination potential of the impoundment, the deterioration in the quality of the river water is mainly due to the discharge from mining drains and the dissolution processes of precipitates accumulated along the riverbanks.