Forest ecosystems in the Eastern USA are threatened by acid deposition rates that have increased dramatically since industrialization. We utilized two watersheds at the Fernow Experimental Forest in West Virginia to examine long-term effects of acidification on ecological processes. One watershed has been treated with ammonium sulfate (approximately twice the ambient deposition rate) since 1989 to simulate elevated acidic deposition, while the other served as a control. Prior to treatment, both watersheds were similar in age and species composition. Ten dominant overstory Prunus serotina and Liriodendron tulipifera trees were selected and cored from each watershed to measure bolewood concentrations of essential elements through time. In addition, changes in tree species basal area were analyzed utilizing 50 long-term growth plots. Results of this experiment show lower calcium and magnesium concentration and increased acidic cation concentration for both species in the treated watershed, indicating a negative treatment effect. Growth response, measured through relative growth rates of cored trees and changes in basal area from growth plots, was not as conclusive and appeared to differ by species. The resulting difference in species response indicates that acidification sensitivity is something that land managers should consider when managing forests affected by acidification.

A photodegradation technology based on the combination of ultraviolet radiation with ozone (UV/O₃) for degrading tri(chloropropyl) phosphate (TCPP) was developed in the present study. Parameters affecting the degradation of TCPP were optimized, and the developed technology was successfully applied to degrade TCPP in two real wastewater samples. The results showed that reaction time, ozone concentration, the initial acidity of reaction solution, and the initial concentration of TCPP in aqueous solution contributed to the degradation efficiency of TCPP. Under the optimized disposal conditions, 100 mg/L of TCPP aqueous solution with a pH value of 7 can be degraded effectively in 60 min with an ozone concentration of 66.2 mg/L. In detail, the yield rates of Cl⁻and PO₄³⁻was high up to 98.9 and 98.2 %, respectively; and total organic carbon (TOC) removal rate was high up to 94.3 %. Method application demonstrated that TCPP can be degraded effectively in pond water. However, only 83.2 and 61.9 % of Cl⁻and PO₄³⁻were produced, and the TOC removal rate was only 81.3 % after 60 min exposure in the effluent discharged from a wastewater treatment plant. Therefore, the presence of interferences may hinder the degradation of TCPP in real wastewater, but its potential application for real wastewater is promising in the future after appropriate domestication and evaluation.

The degradation of methyl orange (MO) in aqueous solution by microwave irradiation in the presence of granular-active carbon (GAC) was investigated. It was found that a synergistic rather than an additive effect of microwave irradiation and GAC contributes to the high-degradation efficiency. The ultraviolet and visible spectrum (UV–vis), infrared spectroscopy (IR), and scanning electron microscopy (SEM) measurements were conducted to trace the MO degradation process. It was demonstrated that the decrease in performance of GAC after repetitive use is largely attributed to the adsorption of some intermediate products on the surface of GAC. The regeneration of the spent GAC under microwave radiation was also investigated. The results show that the activity of spent GAC can be effectively recovered by microwave radiation and 74.1 % of its initial activity remains after six reaction cycles.

Nuisance odors generation from waste and wastewater treatment plants are a cause of public discomfort and complaints. This situation impairs the air quality and represents a growing social and public health problem, especially in developing countries. Several modeling approaches have been developed and successfully implemented in the frame of a wastewater treatment plant for both the biological treatment and physicochemical processes. The mathematical modeling of the odor generation process is still considered a quite complex issue, mainly due to the fact that olfactory nuisance can be caused by many different chemical compounds and the perception of odors is influenced by subjective thresholds. Moreover, the impact of odor sources on air quality is highly conditioned by complex atmospheric dispersion processes. This review presents a critical state-of-art and assessment where information related to odor emissions impact studies as well as modeling applications are compiled and discussed.

Base cation weathering (BCw) rate is one of the most influential yet difficult to estimate parameters in the calculation of critical acid loads of nitrogen (N) and sulfur (S) deposition for terrestrial systems. Only the clay correlation–substrate method, a simple empirical model, has been used for estimating BCw rates for forest ecosystems in the conterminous USA and may not be suitable for application at all sites without calibration or revision. An alternate model, PROFILE, may offer an improved method to estimate BCw rates. It is a transferable, process-based model that simulates the weathering rates of groups of minerals. The objective of this study was to evaluate PROFILE using national datasets as a method to estimate BCw rates for forests in the USA, focusing on Pennsylvania (PA) as the first test state. The model paired with national datasets was successfully applied at 51 forested sites across PA. Weathering rates ranged from 119 to 9,245 eq ha⁻¹ year⁻¹ and were consistent with soil properties and regional geology. Comparisons of terrestrial critical acid loads with 2002 N and S deposition showed critical load exceedances at 53 % of the sites. This trial evaluation of PROFILE paired with national datasets in PA establishes that there are sufficient data to support the estimation of BCw rates and determination of critical acid loads for forests in the USA. However, the paired method should be applied in other locations to further evaluate the performance of the model in different regions of the country.

The incineration fly ash (IFA), molten fly ash (MFA), thermal power plant fly ash (TPP-FA), and nonferrous metal processing plant ash (MMA) have been screened in terms of the following rare-termed metal contents: B, Ce, Co, Dy, Eu, Ga, Gd, Hf, In, Li, Lu, Mn, Nb, Nd, Ni, Pr, Rb, Sb, Se, Sm, Sr, Ta, Tb, Te, Ti, Tm, V, W, Y, and Yb. The pseudo-potential for recycling of the waste ashes, as compared to the cumulative concentration in the crust (mg kg⁻¹), was determined as follows: MMA > IFA > MFA > TPP-FA. The comparison with the crude ore contents indicates that the MMA is the best resource for reprocessing. The recovery of the target metals using aminopolycarboxylate chelants (APCs) has been attempted at varying experimental conditions and ultrasound-induced environment. A better APC-induced extraction yield can be achieved at 0.10 mol L⁻¹ concentration of chelant, or if the system temperature was maintained between 60 to 80 °C. Nevertheless, the mechanochemical reaction induced by the ultrasound irradiation has been, so far, the better option for rare metal dissolution with chelants as it can be conducted at a minimum chelant concentration (0.01 mol L⁻¹) and at room temperature (25 ± 0.5 °C).

A new cotton-based hydrogel nanocomposite was successfully prepared by free radical graft copolymerization of acrylamide (AAm) and acrylonitrile (AN) onto fabric followed by insertion of Ag nanoparticles. Ammonium persulfate (APS) was used as an initiator in the presence of a cross-linker, methylene bisacrylamide (MBA). Fourier transform infrared, thermogravimetric analysis, scanning electron microscopy, X-ray diffraction, and transmission electron microscopy were employed to confirm the structure of the hydrogel nanocomposite. Initially, the affecting variables onto graft polymerization (i.e. AAm, AN, MBA, APS, and silver concentrations) were systematically optimized to achieve a hydrogel with swelling capacity as high as possible. The resulted nanocomposite exhibits superhydrophilic and superhydrophobic properties. Therefore, the grafted fabric selectively separated water from oil/water mixtures with high separation efficiency. The influences of filter type, percentage of coated hydrogel on cotton, presence of silver nanoparticles, pH of solution, extracted oil type, as well as hydrogel nanocomposite on the separation efficiency of filters were also studied in detail. Moreover, pH of zero point charge (pHzₚc) of the hydrogel nanocomposite was determined by alkaline titration method, and a value of 6.5 was obtained.

The Tubarão River rises in Santa Catarina, Brazil, and has been historically affected by coal mining activities around its springhead. To evaluate its water conditions, an investigation regarding a possible decontamination gradient associated with the increased river flow toward the estuary, as well as the influence of seasonality over this gradient was performed through a series of biomarkers (vitellogenin, comet assay, lipid peroxidation, protein carbonylation, gluthatione, gluthatione S-transferase, acetylcholinesterase, light microscopy in liver, and scanning electron microscopy in gills) and chemical analysis (polycyclic aromatic hydrocarbons (PAHs) in bile and metal analysis in sediment) in the cichlid Geophagus brasiliensis. Two collections (summer and winter) were made in four distinct sites along the river, while sediments were sampled between those seasons. As expected, the contamination linked exclusively to mining activities was not observed, possibly due to punctual inputs of contaminants. The decontamination gradient was not observed, although seasonality seemed to have a critical role in the responses of biomarkers and availability of contaminants. In the summer, the fish presented higher histopathological damages and lower concentrations of PAHs, while in the winter they showed both higher genetic damage and accumulation of PAHs. The Tubarão suffers impacts from diverse activities, representing health risks for wild and human populations.

A study on the surface modification of uncontaminated sediment dredged for new port development with surfactant was performed, and the effectiveness of surface modified sediment for in-situ capping to control pollutant (N, P) release from the contaminated coastal sediments into seawater was also investigated. From this experiment, the adsorbed amount of surfactants on the surface of sediment particles was increased with the increase in the surfactant concentration. A more feasible method for the sediment modification with surfactants was mechanical shaking for 3 h, compared to sonication for 30 min or microwave radiation for 3 min. The adsorption capacities of the sediments modified with cationic surfactant (hexadecyltrimethylammonium bromide [HDTMA]) were 40 mg g⁻¹ for ammonia-nitrogen, 16 mg g⁻¹ for nitrate-nitrogen, 31 mg g⁻¹ for phosphorus, which are higher those of the sediment modified with anionic (SDS) and nonionic surfactants (TX-100). The capping layer with the sediment modified with HDTMA in column experiment was effective for inhibiting the release of nitrogen and phosphorus from the contaminated sediment into overlying seawater, indicating that the cationic surfactant modified sediment is reusable as a good in-situ capping material for contaminated coastal sediment.

Perfluorinated chemicals (PFCs) are extremely persistent and have been found extensively in the environment and wildlife. Oceans are the final sink for many persistent organic pollutants (POPs) including PFCs. However, to date, there has been a lack of studies that investigated the environmental consequences of PFCs on marine organisms. To fill in this gap, environmental toxicity of two dominant PFCs, perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), was examined in a sentinel species, green mussel Perna viridis, using a series of biomarkers corresponding to different biological levels (molecular, cellular, and physiological). Correlations among these biomarkers were also investigated. The results showed that the tested compounds can induce a series adverse effect at different biological levels, including oxidative stress, DNA damage, membrane instability, suppressed filtration rate, and reduced body weight. Correlation analysis revealed that excess production of reactive oxygen species could be the major toxic pathway. An indirect mode of toxic action was also explored where adverse impacts could be secondary effects of PFC exposure. The joint analysis of biomarkers from multiple biological levels resulted in a comprehensive understanding of how PFC exposure can influence the health of organisms. The correlations of these biomarkers also provided a new perspective of the ecological consequences of PFCs.