The Huai River is one of the major drinking water resources in Bengbu City of China’s eastern Anhui Province. The study focused on extracting information for spatial distributions of heavy metal(loid)s (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) based on the contents of pollutants in 20 surface sediments. Geoaccumulation index and Hakanson potential ecological index were used to calculate the ecological risk of sediment environment in this paper. The I gₑₒ results indicated that the sediments were moderately contaminated by Hg and Pb. The potential ecological risk sequence of the metals was Hg > Cd > Pb > Cu > Ni > Cr > Zn > As. Among the metal(loid)s, Hg was the main source of pollution that contributed ∼76% towards the potential ecological risk, followed by Cd. Finally, multivariate statistical analysis methods were conducted to identify the potential causes of pollution and provide basis for environment treatment in Bengbu Reach. The results depicted that Pb may be mainly derived from the traffic emission and manufacturing industry, while Hg may be originated from agricultural emissions.

A three-dimensional quantitative structure activity relationship (3D-QSAR) model is built by using a comparative molecular similarity indices analysis (CoMSIA) technique with an experimentally determined logarithm of bioconcentration factors (logBCFs) for 36 phenols in fish. Meanwhile, with the pentachlorophenol (PCP) molecule as target molecules, contributions of the molecular fields indicate that the electrostatic fields are the main influences on the bioconcentration of the PCP molecule. Based on the analytical results of CoMSIA contour map of PCP and PCP molecular docking with SOD protease (PDB ID: 4A7T), the R₆ substituent positions of PCP were modified to give seven new modified PCP molecules with low bioconcentration in this paper. The energy barrier calculation of the new modified PCP molecular reaction pathways can infer the order of the substitution reaction s as –SCl > –CH₂Cl > –COCl > –CCl₃ > –CH=CH₂ > –NO₂ > –SH. These calculations, combined with anaerobic biodegradation, ecotoxic effect, and mobility of new modified PCP molecules, enable a new environmentally friendly compound when the Cl at the R₆ position of PCP was replaced with –COCl substituent with low bioconcentration (reduced by 32.89%), ecotoxic effect basically unchanged (increased by 1.37%), anaerobic biodegradation increased (increased by 24.81%), and mobility basically unchanged (reduced by 0.94%) to be designed.

The degradation of paracetamol (PCT) and ciprofloxacin (CIP) was compared in relation to the generation of dihydroxylated products, Fe(III) reduction and reaction rate in the presence of dihydroxybenzene (DHB) compounds, or under irradiation with free iron (Fe³⁺) or citrate complex (Fecit) in Fenton or photo-Fenton process. The formation of hydroquinone (HQ) was observed only during PCT degradation in the dark, which increased drastically the rate of PCT degradation, since HQ formed was able to reduce Fe³⁺ and contributed to PCT degradation efficiency. When HQ was initially added, PCT and CIP degradation rate in the dark was much higher in comparison to the absence of HQ, due to the higher and faster formation of Fe²⁺ at the beginning of reaction. In the absence of HQ, no CIP degradation was observed; however, when HQ was added after 30 min, the degradation rate increased drastically. Ten PCT hydroxylated intermediates were identified in the absence of HQ, which could contribute for Fe(III) reduction and consequently to the degradation in a similar way as HQ. During CIP degradation, only one product of hydroxyl radical attack on benzene ring and substitution of the fluorine atom was identified when HQ was added to the reaction medium.

In this study, we have developed real-time PCR assays using SYBR Green chemistry to detect all known alleles of bla KPC, bla NDM, and bla OXA₋₄₈-like carbapenemase genes in water, sediment, and biofilm samples collected from hospital and wastewater treatment plant (WWTP) effluents and rivers receiving chronic WWTP discharges. The amplification of bla KPC, bla NDM, and bla OXA₋₄₈ DNA was linear over 7 log dilutions (R ² between 0.995 and 0.997) and showing efficiencies ranging from 92.6% to 100.3%. The analytical sensitivity indicated that the reaction for bla KPC, bla NDM, and bla OXA₋₄₈-like genes was able to detect 35, 16, and 19 copy numbers per assay, respectively. The three carbapenemase genes were detected in hospital effluents, whereas only the bla KPC and bla NDM genes were detected in biofilm and sediment samples collected from wastewater-impacted rivers. The detection of bla KPC, bla NDM, and bla OXA₋₄₈-like genes in different matrices suggests that carbapenem-resistant bacteria occur in both planktonic and benthic habitats thus expanding the range of resistance reservoirs for last-resort antibiotics. We believe that these real-time PCR assays would be a powerful tool for the rapid detection and quantification of bla KPC, bla NDM, and bla OXA₋₄₈-like genes in complex environmental samples.

The San Antonio Bay is a protected natural coastal area of Argentina that has been exposed to mining wastes over the last three decades. Iron and trace metals of potential concern to biota and human health (Cd, Pb, Cu, and Zn) were investigated in the sediments from the bay and in the soils of the Pile (mining wastes). Concentrations of Cd (45 mg kg⁻¹), Pb (42,853 mg kg⁻¹), Cu (24,505 mg kg⁻¹), and Zn (28,686 mg kg⁻¹) in the soils Pile exceeded guidelines for agricultural, residential, and industrial land uses. Risk assessment due to exposure to contaminated soils (Pile) was performed. Hazard quotients were superior to non-risk (HQ >1) for all trace metals, while accumulative hazard quotient index indicated a high risk for children (HI = 93) and moderate for adults (HI = 9). In the bay, sediments closest to the Pile (mudflat and salt marsh) exceeded sediment quality guidelines for protection of biota. Results of different acid extraction methods suggest that most of the pseudototal content was potentially mobile. Principal component analysis indicated that the sites near the Pile (Encerrado channel) were more polluted than the distal ones. Tissues of Spartina spp. located within Encerrado channel showed the highest metal levels among all studied sites. These results show that the problem still persists and the mining wastes are the sources of the pollution. Furthermore, the Encerrado channel is a highly impacted area, as it is shown by their metal enriched sediments.

This study explored the effects of supplemental dietary extra virgin olive oil (EVOO), gallic acid (GA), or lemongrass essential oil (LGEO) on growth performance, nutrient digestibility, carcass traits, lipid peroxidation, hematological, and antioxidative status in growing rabbits under heat stress conditions. A total of 48 male growing New Zealand White rabbits were randomly divided into four equal groups, which received a basal diet without any supplementation or supplemented with 15 g EVOO, 500 mg GA, or 400 mg LGEO/kg of diet, for eight consecutive weeks. Results revealed that the overall mean of temperature humidity index was 84.67 ± 0.35, reflecting a state of severe heat stress. Moreover, dietary supplementation with EVOO, GA, or LGEO significantly increased live body weight and daily body weight gain but decreased both feed conversion ratio and daily water consumption. Additionally, a significant increase in both organic matter and crude protein digestibility besides a remarkable elevation in the nutritive values of digestible crude protein, total digestible nutrients, and digestible energy, as well as an increase in the numbers of WBCs, lymphocytes, and heterophils was significant in EVOO-supplemented rabbits. Supplementation with EVOO, GA, or LGEO in the heat-stressed growing rabbit’s diet enhanced catalase activity and reduced glutathione content, whereas EVOO-treated rabbits had the highest values. Also, malondialdehyde activity was reduced in response to all tested additives. In conclusion, these findings suggested that addition of EVOO, GA, or LGEO in growing rabbit’s diet could be used effectively to alleviate negative impacts of heat stress load on performance, nutrient digestibility, oxidative status, and hemato-biochemical features. Furthermore, among these additives, EVOO achieved the best effects.

To probe the overflow pollution of separate storm drains with inappropriate sewage entries, in terms of the relationship between sewage entries and the corresponding dry-weather and wet-weather overflow, the monitoring activities were conducted in a storm drainage system in the Shanghai downtown area (374 ha). In this study site, samples from inappropriately entered dry-weather sewage and the overflow due to storm pumps operation on dry-weather and wet-weather days were collected and then monitored for six water quality constituents. It was found that overflow concentrations of dry-weather period could be higher than those of wet-weather period; under wet-weather period, the overflow concentrations of storm drains were close to or even higher than that of combined sewers. Relatively strong first flush mostly occurred under heavy rain that satisfied critical rainfall amount, maximum rainfall intensity, and maximum pumping discharge, while almost no first flush effect or only weak first flush effect was found for the other rainfall events. Such phenomenon was attributed to lower in-line pipe storage as compared to that of the combined sewers, and serious sediment accumulation within the storm pipes due to sewage entry. For this kind of system, treating a continuous overflow rate is a better strategy than treating the maximum amount of early part of the overflow. Correcting the key inappropriate sewage entries into storm drains should also be focused.

Causticized calcium carbonate (CCC), a solid waste derived from kraft black recovery process, can be used as an alternative for the conventional precipitated calcium carbonate (PCC). However, the application of the CCC has been limited due to its low sizing efficiency in its filled paper. In this study, the characteristics of the CCC were studied aiming to improve the alkyl ketene dimer (AKD) sizing performances of the CCC filled papers, and the results were compared with those from PCC filled papers. The results showed that the CCC had higher pore structure, higher specific surface area, and more negative charge density than the PCC, thus leading to a higher cationic AKD adsorption onto the CCC filler. The lower AKD sizing efficiency in the CCC filled paper can be explained by the combination of higher AKD adsorption and migration, both of which resulted in preferred AKD adsorption onto/into the CCC fillers, rather than the cellulose fibers. Based on the above, the prior addition of polyamide-polyamine epichlorhydrin (PAE) resin to the CCC filler system was proposed to remedy the related issues, thus improving the sizing efficiency.

We assess here, through an experimental simulation using lead nitrate, the response to lead deposition of three common Mediterranean bryophyte species in the family Pottiaceae. Five concentrations of lead nitrate (from 0 to 10⁻³ M) were sprayed for 4 months on plants belonging to Tortula muralis (reported as toxitolerant), Syntrichia ruralis (medium-tolerant), and Tortula subulata (less tolerant). The three species showed a remarkably high tolerance to lead nitrate, with a low incidence of damage even at concentrations as high as 10⁻⁴ M. The maximum concentration (10⁻³ M), although resulting eventually in serious damages in the gametophyte of the three species (high mortality rates in S. ruralis and T. subulata, or a significant percentage of damaged tissue in T. muralis), did not prevent the production of sporophytes in the two species with fertile samples (T. muralis and T. subulata). Growth parameters show limited value as bioindicators of lead deposition, as they only show clear effects at very high concentrations. Besides, we identified the existence of a lead exclusion strategy mediated by mucilage using histochemical analyses and scanning electron microscopy combined with energy-dispersive X-ray spectroscopy. This mechanism can hamper the usefulness of these mosses in quantitative estimation of lead deposition.

We evaluated the effect of compost amendment and/or bacterial inoculants on the growth and metal accumulation of Salix caprea (clone BOKU 01 AT-004) and Nicotiana tabacum (in vitro-bred clone NBCu10-8). Soil was collected from an abandoned Pb/Zn mine and rhizobacterial inoculants were previously isolated from plants growing at the same site. Plants were grown in untreated or compost-amended (5% w/w) soil and were inoculated with five rhizobacterial strains. Non-inoculated plants were also established as a control. Compost addition increased the shoot DW yield of N. tabacum but not S. caprea, while it decreased soil metal availability and lowered shoot Cd/Zn concentrations in tobacco plants. Compost amendment enhanced the shoot Cd/Zn removal due to the growth promotion of N. tabacum or to the increase in metal concentration in S. caprea leaves. Bacterial inoculants increased photosynthetic efficiency (particularly in N. tabacum) and sometimes modified soil metal availability, but this did not lead to a significant increase in Cd/Zn removal. Compost amendment was more effective in improving the Cd and Zn phytoextraction efficiency than bioaugmentation.