Organic UV filters that have been widely used in sunscreens and other personal care products have drawn much public concern because of their widespread contamination in the environment and their potential ecological risks to ecosystems. We selected three UV filters with high frequency of detection in the environment, namely butyl methoxy dibenzoylmethane (BM-DBM), ethylhexyl dimethyl p-aminobenzoate (OD-PABA), and 4-methylbenzylidene camphor (4-MBC), to investigate the sorption and degradation behaviors of these compounds in lab-scale water-sediment systems set up with natural water and sediment samples collected from different rivers and lakes (i.e., Yangtze River, Qinhuai River, Xuanwu Lake, and Mochou Lake) in Nanjing, East China. The sorption isotherms of these UV filters were well described by the Freundlich equation (C ₛ = K f × C w ⁿ). The sorption of three UV filters in four sediments was all linear or close to it, with n values between 0.92 and 1.13. A moderate to strong sorption affinity was observed for these compounds, and the sorption appears to be irreversible. For the combined sorption and degradation studies, sorption was found to be a primary mechanism for the disappearance of these UV filters from the water phase, and biotransformation appears to be the predominant factor for the degradation of the target compounds in the water-sediment systems. All three UV filters were found to be slightly resistant to the microbes in these systems, with DT₅₀ₜₒₜₐₗ and DT₉₀ₜₒₜₐₗ values—the disappearance time (DT) describes the time in which the initial total mass of the UV filters in the whole system is reduced by 50 and 90 %—ranging between 18 and 31 days and 68 and 101 days, respectively.

Aluminum (Al) is a major constraint to crop productivity in acid soils, whereas water deficit severely limits crop production in arid and semi-arid regions of the world. The objective of the present study was to examine the effects of both stresses, Al excess and water deficit, individually and in combination on the production of the reactive oxygen species (ROS) superoxide anion (O₂˙⁻), hydrogen peroxide (H₂O₂), hydroxyl radical, and lipid peroxidation and the activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and guaiacol peroxidase (GPX) in the seedlings of two rice (Oryza sativa L.) cvs. Malviya-36 (sensitive to water deficit and Al) and Vandana (tolerant to water deficit and Al). When 15-day grown seedlings were exposed to water deficit (created with 15 % polyethylene glycol, PEG-6000) or Al (1 mM AlCl₃) treatment or both treatments together for 24–72 h, the lengths and fresh weights of root/shoot declined in the seedlings of the sensitive cultivar, whereas in the tolerant seedlings, either little or insignificant decline in these parameters was observed due to the treatments. Biochemical determinations and histochemical studies revealed that under a similar level of water deficit, Al, or combined treatment, seedlings of sensitive cultivar showed a higher level of production of O₂˙⁻, H₂O₂, hydroxyl radical, and lipid peroxides compared to the tolerant seedlings. Seedlings of tolerant cultivars, both in roots and shoots, had constitutively higher activity levels of antioxidative enzymes SOD, CAT, and GPX and showed a greater increase in activity under water deficit or Al treatment alone or in combination compared to the similarly treated seedlings of sensitive cultivar. Our results suggest that a lower constitutive level of ROS and a high antioxidative enzyme capacity are associated with tolerance to both water deficit and Al excess in rice seedlings.

The by-product char of the fast pyrolysis of a green macroalga Enteromorpha compressa was used to remove copper from an aqueous solution. The surface area and the amount of cation exchange capacity (CEC) were increased by steam activation, resulting in enhanced adsorption capacity. Although chemical activation using a KOH solution increased the pore volume and surface area dramatically, it decreased the adsorption capacity because of activating in the KOH solution and washing decreased CEC. Ion exchange between the Cu ions and cations (Na⁺, K⁺, Ca²⁺, and Mg²⁺) as well as adsorption onto the functional groups on the char surface appeared to be important mechanisms for the removal of Cu. A pseudo-second-order kinetic model and Langmuir isotherm model could interpret the kinetics and equilibrium of the Cu adsorption on the E. compressa char. The maximum amount of Cu adsorption on the char was 137 mg g⁻¹.

Although current trends address towards prevention strategies, the organic fraction of municipal solid waste is greatly produced, especially in high-income contexts. Its recovery-oriented collection is a common practice, but a relevant portion of the biodegradable waste is not source selected. Mechanical and biological treatments (MBT) are the most common option to sort and stabilize the biodegradable matter ending in residual waste stream. Following the changes of the framework around waste management, this paper aimed at analyzing the quality of the mechanically selected organic waste produced in MBT plants, in order to discuss its recovery options. The material performance was obtained by its composition as well as by its main chemical and physical parameters; biological stability was also assessed by both aerobic and anaerobic methods. On this basis, the effectiveness of an aerobic biostabilization process was assessed at pilot scale. After 21 days of treatment, results proved that the biomass had reached an acceptable biostabilization level, with a potential Dynamic Respirometric Index (DRIP) value lower than the limit required for its use as daily or final landfill cover material. However, the final stabilization level was seen to be influenced by scaling factors and the 21 days of treatment turned to be not so adequate when applied in the existing full-scale facility.

This work sought to ascertain survival and possible changes in levels of glycogen, triglycerides, total lipids, cholesterol, protein, and lipid peroxidation in gills, liver, and muscle of bullfrog tadpoles (Lithobates catesbeianus) exposed to low concentrations of atrazine (2.5 μg L⁻¹), glyphosate (18 μg L⁻¹), and quinclorac (0.025 μg L⁻¹) at laboratorial conditions. Tadpoles showed a reduction of glycogen and triglyceride in all organs and an increase in lipid peroxidation (LPO) compared with control animals. Total lipid in gills and muscle increased in exposure to atrazine, and gills alone in exposure to glyphosate, but decreased in gills, liver, and muscle after quinclorac. Cholesterol increased in gills and liver after atrazine, in gills and muscle after glyphosate, and decreased in liver after quinclorac. Total protein in gills decreased after exposure to all herbicides, increased in muscle after atrazine, and in liver and muscle after quinclorac. These findings show that at concentrations of these herbicides tested can lead to an increase in energy expenditure to maintain homeostasis and survival of these animals despite the increase in lipid peroxidation levels in all organs analyzed. Responses observed can be one of the factors responsible for the decline in the number of amphibians around the world.

The management and treatment of contaminated sediment is a worldwide problem and poses major technical and economic challenges. Nowadays, various attempts have been committed to investigating a cost-effective way in contaminated sediment restoration. Among the remediation options, in situ capping turns out to be a less expensive, less disruptive, and more durable approach. However, by using the low adsorption capacity materials, traditional caps do not always fulfill the reduction of risks that can be destructive for human health, ecosystem, and even natural resources. Active caps, therefore, are designed to employ active materials (activated carbon, apatite, zeolite, organoclay, etc.) to strengthen their adsorption and degradation capacity. The active capping technology promises to be a permanent and cost-efficient solution to contaminated sediments. This paper provides a review on the types of active materials and the ways of these active materials employed in recent active capping studies. Cap design considerations including site-specific conditions, diffusion/advection, erosive forces, and active material selection that should be noticed in an eligible remediation project are also presented.

The short- and long-term influences of ferric iron (Fe(III)) on nutrients removal and nitrous oxide (N₂O) emission during SNDPR process were evaluated. According to the continuous cycle experiments, it was concluded that the addition of Fe(III) could lower the nitrogen removal of the following cycle during SNDPR process, which was mainly induced by the chemical removal of phosphorus. However, the impacts were transitory, and simultaneous nitrogen and phosphorus removal would recover from the inhibition of Fe(III) after running certain cycles. Moreover, the addition of Fe(III) could stimulate N₂O emission transitorily during SNDPR process. However, if Fe(III) was added into reactor continuously, the nitrogen removal would be improved, especially at low Fe load condition. It was because that the activity of NO reductase was enhanced by the addition of Fe. However, the low Fe load in reactor would induce more N₂O emission. When Fe(III) load was 40 mg/L in the reactor, the N₂O yield was 10 % higher than control. The TN removal was weakened when Fe(III) load reached to 60 mg/L, and the N₂O yield was lower than control, due to the inhibition of the high Fe load on denitrification enzymes.

Urban runoff (UR) is a promising new resource that may alleviate growing tensions in numerous arid and semi-arid regions of the world. However, it is precisely in these zones that the available UR quality characteristics are scarcer. This work aims to evaluate a wide set of parameters to establish a detailed approach to both the quality of UR in a midsized city in Central Mexico and the feasibility of using UR to recharge aquifers. UR from an institutional land use site was sampled during wet and dry seasons and assessed for suspended solids, organic matter, nutrients, microorganisms, metals, and persistent organic chemicals (i.e., polycyclic aromatic hydrocarbons, PAH). The results were analyzed using multivariate statistical methods to identify relationships among the variables, the sampling sites and the seasons. The soil erosion and the leaching of materials due to the water flow through vegetated areas were identified as the most influencing factor on the quality of the site runoff in both dry and wet seasons. Additionally, data were more heterogeneous during the dry season, and higher pollutant concentrations were found both during the dry season and in more pervious zones. We consider UR a promising water source for recharging aquifers in arid and semi-arid zones if a program is implemented that can integrate an adequate runoff treatment system, soil protection, and other non-structural measures.

Enzymatic conversion of fish frame waste of threadfin breams (Nemipterus japonicus) to protein hydrolysate could be a solution for minimizing the pollution issues related to seafood processing operations and a way for the value addition to processing by-products. Protein hydrolysates from fish frame waste (FW) of thread fin breams (N. japonicus) were prepared and evaluated for bioactive properties such as angiotensin-I-converting enzyme (ACE) inhibitory activity and antioxidant and functional properties as a function of degree of hydrolysis (DH). Two different plant proteases, papain and bromelain, were used to prepare fish protein hydrolysates (FPH) and designated as HP (hydrolysates prepared using papain) and HB (hydrolysates prepared using bromelain). The ACE inhibitory activity of HP samples was higher at 5 and 10 % DH than that of the HB samples at DH 15 %, and there was no significant difference (p < 0.05). Antioxidant properties (2, 2 diphenyl-1-picrylhydrazyl [DPPH] radical scavenging activity, ferric reducing power and lipid peroxidation inhibition) of hydrolysates increased with increase in DH. The HB samples at DH 15 % had significantly higher antioxidant properties than HP samples (p < 0.05). The solubility of HP and HB samples was high in a wide range of pH and increased with DH. The functional properties of HP and HB samples decreased significantly with increase in DH (p < 0.05). The fractionation of the HB–DH 15 % sample yielded three peptide fractions with the approximate molecular weight of peptides in the range of 7562–812 Da. Relatively, bromelain enzyme is more effective in producing the FPH with desirable bioactive and functional properties.

The extracellular polymeric substrate (EPS) extracted from Klebsiella sp. J1 was used to adsorb low concentrations of tetracycline, and the efficiency and mechanism of tetracycline adsorption by EPS from strain J1 were studied. Adsorption efficiency was evaluated at different conditions. Results showed that optimal adsorption efficiency was 71.68 % with 60 mg L⁻¹ of EPS from strain J1 and 90 μL of 10 % (w/v) CaCl₂ in 100 mL of tetracycline solution (80 μg L⁻¹) with pH of 8.0. Experimental data was fitted well with Langmuir, Freundlich isotherm, and pseudo-second-order models. Analyses of E value, Ea value, thermodynamics, zeta potential variation, and Fourier transform infrared spectroscopy (FTIR) spectra proved that chemisorption was the main adsorption type and bridging was the main adsorption mechanism. Thermodynamic analysis indicated that adsorptive reaction was exothermic from 20 to 40 °C. In addition, humic acid (HA) showed little effect on the tetracycline adsorption by MFX.