Environmental Science and Pollution Research

Your mycotoxins in water paper

Subject: Reply to letter to the Editor (ESPR-D-18-05279) about our manuscript

Biochemical impacts in adult and juvenile farmed European seabass and gilthead seabream from semi-intensive aquaculture of southern European estuarine systems Abstract The nutritional value and developmental variations of cultured fish were assessed for European seabass and gilthead seabream specimens reared in semi-intensive aquaculture systems in two Portuguese estuaries. Quantification of total protein and of carbohydrate and fatty acid profiles was carried out to determine differences between the composition of the same species in two development stages reared in four distinct farms. A significant influence of the rearing site on the nutritional composition of the same species was found for adult European seabass regarding saturated, monounsaturated and highly unsaturated fatty acids contents, both between estuaries and within each estuary. In gilthead seabream, saturated, monounsaturated, polyunsaturated and highly unsaturated fatty acids content were also influenced by the rearing site. Carbohydrate analysis showed a significant influence of the rearing site on free sugar and polysaccharide content in fish of both species, and there was no influence on the species' protein content. Differences in fatty acid and carbohydrate content among juvenile and adult stages were found for all the groups studied. The present study supported the existing evidence that semi-intensive rearing systems are subjected to the variability of extrinsic factors in the rearing sites, influencing the nutritional value of the same species, namely regarding lipid and carbohydrate profiles, depending on the production site. From a consumer's perspective, such differences may come as a disadvantage of the rearing method, as it is expected for a product to provide equal nutritional properties and benefits regardless its origin, especially within the same country.

Lower cadmium accumulation and higher antioxidative capacity in edible parts of Brassica campestris L . seedlings applied with glutathione under cadmium toxicity Abstract Glutathione (GSH) is involved in not only plant developmental processes but also plant responses to abiotic stresses. A hydroponic experiment was performed to explore the protective roles of exogenous GSH in mitigating cadmium (Cd) stress in Brassica campestris L. seedlings by analyzing the morphological and physiological parameters. Results showed that Cd caused severe growth inhibition and Cd accumulation. However, application of GSH significantly mitigated toxic symptoms induced by Cd, including the improvement of the photosynthesis-, plant growth-, and root morphology-related parameters in seedlings under Cd stress. These responses were associated with a striking increase in activities of representative antioxidative enzymes and contents of corresponding non-enzymatic antioxidants. In vivo imaging of O2.- and H2O2, and the detection of lipid peroxidation further demonstrated that increased ability by GSH for Brassica campestris L. seedlings to endure Cd stress was consistent with a striking elevation of ratios of reduced to oxidized glutathione (GSH/GSSG) and ascorbic acid to dehydroascorbic acid (AsA/DHA). Additionally, GSH application increased Cd retained in roots, thus significantly decreased its translocation from root to shoot, ultimately decreased Cd accumulation in shoots. Taken together, our results proved evidence for GSH in ameliorating Cd toxicity via reducing Cd accumulation in shoots and increasing oxidation resistance. Accordingly, application of GSH could be a high-efficiency and promising strategy to decrease Cd concentration in edible parts of Brassica campestris L. in agricultural production.

Highly efficient removal of Cr(VI) and Cu(II) by biochar derived from Artemisia argyi stem Abstract In this work, a novel biochar was prepared from the Artemisia argyi stem at 300 °C (AS300), 450 °C (AS450), and 600 °C (AS600). The structural properties of these biochars were characterized with various tools. The sorption kinetic processes of Cr(VI) and Cu(II) onto these biochars were better described by the pseudo-second order. The sorption isotherm processes of Cr(VI) onto these biochars were better described by the Freundlich model while the adsorption processes of Cu(II) were consistent with the Langmuir model. Batch sorption experiments showed that AS600 had the maximum adsorption capacity to Cr(VI) and Cu(II) with 161.92 and 155.96 mg/g, respectively. AS600 was selected for the follow-up batch and dynamic adsorption experiments. Results showed that AS600 had larger adsorption capacity for Cr(VI) at lower pH while the larger adsorption capacity for Cu(II) was found at higher pH. The effect of ionic strength on the adsorption of Cu(II) by AS600 was greater than that on the adsorption of Cr(VI). Dynamic adsorption experiments showed that Cu(II) had a higher affinity for the adsorption sites on the AS600 compared with Cr(VI). The adsorption mechanisms mainly involved electrostatic attraction, ion exchange, pore filling, and chemical bonding effect. Graphical abstract

Modulation of photosynthetic parameters, sugar metabolism, polyamine and ion contents by silicon amendments in wheat ( Triticum aestivum L.) seedlings exposed to arsenic Abstract The objective of the present investigation was to consider the effectiveness of exogenous silicate supplementation in reviving the arsenate imposed alterations on pigment content, Hill activity, photosynthetic parameters, sugar metabolism, polyamine, and ion contents in wheat (Triticum aestivum L. cv. PBW-343) seedlings. Experiments were conducted under different levels of arsenate (0, 25 μM, 50 μM, and 100 μM) in combination with silicate (0, 5 mM) in a hydroponic environment with modified Hoagland's solution for 21 days to determine the ameliorative role of silicon (Si). Arsenate exposure led to a decline in chlorophyll content by 28% and Hill activity by 30% on an average along with photosynthetic parameters. Activity of starch phosphorylase increased causing a subsequent decrease in starch contents by 26%. Degradation of starch enhanced sugar contents by 61% in the test cultivar. Dose-dependant increments in the activities of carbohydrate metabolizing enzymes viz., sucrose synthase, sucrose phosphate synthase, and acid invertase were also noted. Putrescine content was significantly enhanced along with a consequent decline in spermidine and spermine contents. The macro- and micronutrient contents declined proportionally with arsenate imposition. Conversely, silicate amendments irrespective of all arsenate concentrations brought about considerable alterations in all parameters tested with respect to arsenate treatment alone. Marked improvement in pigment content and Hill activity also improved the gas exchange parameters. Soluble sugar contents decreased and starch contents were enhanced. Increase in polyamine contents improved the ionic balance in the test cultivar as well. This study highlights the potentiality of silicon in ameliorating the ecotoxicological risks associated with arsenic pollution and the probable ability of silicon to offer an approach in mitigating arsenate-induced stress leading to restoration of growth and metabolism in wheat seedlings.

Study on the purification effect of aeration-enhanced horizontal subsurface-flow constructed wetland on polluted urban river water Abstract The issue of urban river pollution has attracted great attention due to high concentrations of ammonia nitrogen (NH4+-N) and low concentrations of dissolved oxygen (DO) in polluted water bodies. In order to investigate the effects of aeration-enhanced horizontal subsurface-flow constructed wetlands on polluted river water, unaerated aeration (NA), continuous aeration (CA), and intermittent aeration (IA) constructed wetlands were established. The purification effects of the wetland on various pollutants and the form of effluent nitrogen, influences of temperature on the removal rates of pollutants, the change of redox potential—oxidation reduction potential (ORP)—and the difference of dissolved oxygen (DO) between influent and effluent were investigated. The results indicated that aeration enhancement can improve the purification efficiencies of chemical oxygen demand (COD) and NH4+-N in constructed wetlands. The purification efficiencies of TN in IA and CA constructed wetlands were 91.9% and 53.7%, respectively, indicating that IA is the optimized aeration method for removal of various pollutants in wetlands. Changes of DO and ORP in effluent under IA and CA suggested improvement of aeration on the water environment. Meanwhile, DO was more sensitive to temperature compared with ORP. Additionally, a study of the nitrogen content in effluent suggested that the aeration method had a significant influence on the nitrogen content in effluent. The removal rates of both NH4+-N and TN degraded as the temperature dropped. The results also demonstrated that the removal rate of NH4+-N under aeration condition was more sensitive to temperature than that under NA condition and the effect of temperature on the removal rate of NH4+-N was greater than that of TN.

Nutritional and toxicity constraints of phytoplankton from a Brazilian reservoir to the fitness of cladoceran species Abstract Camorim is a small, eutrophic reservoir in Rio de Janeiro, Brazil, with a phytoplankton community dominated most of the year by the filamentous diatom Aulacoseira spp. and the toxic cyanobacterium Cylindrospermopsis raciborskii. As filamentous species can be a poor food for grazers, we hypothesize that phytoplankton from this reservoir would constrain cladoceran fitness due to nutritional limitation and/or toxicity when animals fed mixtures of cultured green algae and natural seston. Clones of different cladoceran species were exposed either to seston from Camorim reservoir sampled in different seasons or to a C. raciborskii strain (CYLCAM-2) isolated from the reservoir. In short-term assays, cladocerans were exposed to either 100% seston or mixtures of 50% seston added to green algae (200 μg C L−1), and their survivorship and somatic growth were measured for 4 days. In life table assays, neonates were exposed to the same seston treatments over 14 days and age at first reproduction, survivorship, fecundity, total offspring, and the intrinsic rate of natural increase (r) were assessed. In general, seston negatively affected cladoceran survivorship and fitness (r), but this response was seasonally and species specific. Stronger effects of CYLCAM-2 than those caused by seston on survivorship, somatic growth, and r were found for all cladoceran species, especially when the proportion of CYLCAM-2 was higher than 50% in relation to green algae in a fixed total food concentration. Our results suggest that both nutritional (C/P and morphology) and toxicity factors can act to impair cladoceran fitness and help explain the absence of cladocerans in Camorim reservoir.

Environmental improvement in the printing industry: the case study of self-adhesive labels Abstract Labels are used for marketing, technical information, local of production and environmental declarations of products. The aim of the study was to evaluate the life cycle of two sets of front and back adhesive labels made with different liners: polyethylene terephthalate (PET) and glassine paper. The study is a pioneering initiative in the labelling industry using life cycle assessment, especially in Brazil. The attributional life cycle assessment method was based on the ISO 14044 standard and covered the entire life cycle, cradle to grave. Primary data for key suppliers, printing facility and label use composed the foreground data, while the ecoinvent database composed the background data. The material efficiency was assessed through mass balance. The impact assessment methods were cumulative energy demand for non-renewable energy and ILCD 2011 midpoint for the environmental categories. The glassine liner is heavier than the PET which resulted in larger environmental indicator values for production, transportation and waste treatment. On the other hand, energy demand of label set with glassine liner was lower than the PET. Furthermore, the hotspot analysis of each impact category was presented per process and substance. The label set made with glassine liner tended to present larger environmental indicator values in most categories, 13 of the 16 assessed, compared to the label set made with PET liner, despite the uncertainties. Contribution analysis identified that the pre-manufacturing step presented larger environmental indicator values than manufacturing, use and post-use steps along the label set life cycle. Therefore, environmental improvement opportunities were evaluated through scenarios of end of life, recycled inputs, domestic suppliers, waste prevention and product redesign. Moreover, the life cycle assessment was useful for diagnosing the energy and environmental profiles of self-adhesive labels and planning cleaner production measures that avoid environmental tradeoffs.

Adsorption of pharmaceuticals from biologically treated municipal wastewater using paper mill sludge-based activated carbon Abstract A waste-based alternative activated carbon (AAC) was produced from paper mill sludge under optimized conditions. Aiming its application in tertiary wastewater treatment, AAC was used for the removal of carbamazepine, sulfamethoxazole, and paroxetine from biologically treated municipal wastewater. Kinetic and equilibrium adsorption experiments were run under batch operation conditions. For comparison purposes, they were also performed in ultrapure water and using a high-performance commercial AC (CAC). Adsorption kinetics was fast for the three pharmaceuticals and similar onto AAC and CAC in either wastewater or ultrapure water. However, matrix effects were observed in the equilibrium results, being more remarkable for AAC. These effects were evidenced by Langmuir maximum adsorption capacities (qm, mg g−1): for AAC, the lowest and highest qm were 194 ± 10 (SMX) and 287 ± 9 (PAR), in ultrapure water, and 47 ± 1 (SMX) and 407 ± 14 (PAR), in wastewater, while for CAC, the lowest and highest qm were 118 ± 7 (SMX) and 190 ± 16 (PAR) in ultrapure water and 123 ± 5 (SMX) and 160 ± 7 (CBZ) in wastewater. It was found that the matrix pH played a key role in these differences by controlling the surface electrostatic interactions between pharmaceutical and AC. Overall, it was evidenced the need of adsorption results in real matrices and demonstrated that AAC is a promising option to be implemented in tertiary wastewater treatments for pharmaceuticals' removal. Graphical abstract Production of an alternative activated carbon (AC) comparing favourably with a commercial AC in the removal of neutral and positive pharmaceuticals from wastewater