The objective of the present study was to investigate the short-term effects of benzo(a)pyrene (BaP) on juvenile sea bass (Dicentrarchus labrax L.) using a multiparameter approach. At the end of the 96 h of exposure to a range of BaP concentrations (2–256 μg l⁻¹) in laboratorial conditions, a suite of biomarkers involved in biotransformation pathways, oxidative stress and damage, neurotransmission and energetic metabolism were analysed. Levels of BaP metabolites in bile and BaP-type compounds in tissues were also included as biomarkers of exposure, and the post-exposure swimming velocity was used as a toxicity endpoint at a higher level of biological organisation. In addition, a time-series experiment on the levels of bile BaP metabolites was also performed. Increased levels of BaP metabolites in bile and BaP-type compounds in liver and brain of exposed fish were found, indicating BaP uptake, metabolisation and distribution by different tissues. BaP induced oxidative stress and damage, but no significant effects on the post-exposure swimming velocity, neurotransmission and energetic pathways were found. An increase in the levels of BaP metabolites in bile over time was also observed, reaching a threshold similar at all the concentrations tested. Overall, this integrative multiparameter study reflecting different biological responses of D. labrax was suitable to assess the effects caused by the short-term exposure to BaP and may be useful in the marine environmental risk assessment of polycyclic aromatic hydrocarbons pollution. The observed toxic effects also highlight the relevance of short-term exposure to relatively high concentrations of chemicals, as can occur in the case of punctual heavy chemical releases, such as oil spills in the marine environment.

A new speciation model developed and implemented in Polymath was found to be successful in predicting struvite precipitation in soils. Struvite (NH4MgPO4) has been identified as a mineral for the recovery of nitrogen (N) and phosphorus (P). Predicting struvite precipitation potential in soil is important for optimal quantification of nutrient species. Polymath and Visual Minteq models were used for prediction of several solid phases in the soil. One approach to immobilize P for solid-phase formation is by co-blending. Immobilization was achieved through the blending of an Al-based water treatment residual (Al-WTR) and with Ca–Mg-based materials [slag and magnesium oxide (MgO)]. The results suggest that Polymath model revealed solid Phases of dicalcium phosphate pentahydrate (DCPP), magnesium hydroxide (MHO), magnesium orthophosphate (v) docosahydrate (MP22), magnesium orthophosphate (v) octahydrate (MP8), and struvite, which were lacking in the modeling from Visual Minteq. Residual leachate from the co-blended amendments; Soil+WTR+Slag, Soil+WTR+MgO, Soil+MgO, Soil+Slag, Soil+WTR, and the control (without amendment) had struvite of 353, 199, 119, 90, 37, and 12 mg l-1, respectively. This implies that struvite, a phosphate mineral can be precipitated in the soil and could be released as nutrients for plant uptake. Struvite precipitation in soil and for reuse may reduce cost and may be a safe practice for sustainable environmental nutrient management.

The present study investigates the heterogenic distribution of nine polycyclic aromatic hydrocarbons (PAHs) in soil on a microscale. For this purpose, we developed a method allowing for the detailed analysis of PAHs in minute amounts of soil (5 to 25 mg). A certified reference soil with a known PAH content and a diffusely polluted Danish surface soil from central Copenhagen were used in the study. In order to separate soil heterogeneity from analytical variation, we attempted to establish the least amount of soil in which homogeneous and reproducible results could be obtained for the PAHs in question. The results demonstrated that for fluoranthene, analytical results in accordance with the certified reference values could be obtained in quantities of 10 mg of soil or more. For phenanthrene and pyrene, certified reference values could be obtained in quantities of 25 mg of soil or more. Similar results were obtained with the Nyboder soil, using the reference soil for quality and quantity assurance. For quantification of all nine PAHs, a minimum of 100 mg of soil was needed for both soils. In order to obtain an expression for the degree of heterogeneity of PAHs in the soils, a subsample variation was calculated based on overall sample variation and analytical measurements variation. The results demonstrate that the PAHs in the Nyboder soil are much more heterogeneously distributed than the PAHs in the reference soil due to much larger subsample variations. Furthermore, strong relationships between different physico-chemical properties and subsample variation were found. These included molecular weight, water solubility, log octanol/water partition coefficient, and soil–water distribution coefficient of the investigated PAHs, demonstrating that the heterogeneity of PAHs in the Nyboder soil is significantly influenced by such parameters.

Hydrophobic organic compounds are common in the environment, especially in water bodies like rivers and lakes. Generally, due to their physico-chemical characteristics, mainly to hydrophobicity, these compounds are adsorbed by suspended material or other compartments which provide compatibility. Thus, compounds such as polycyclic aromatic hydrocarbons (PAHs) are rapidly adsorbed onto suspended material or even naturally occurring biofilms in water bodies. Biofilms can be defined as complex structures with cells and aggregates of cells. The extracellular polymers present empty spaces that can be filled by water. The biofilm is a sessile microbial community with several kinds of organisms such as bacteria, protozoa, fungi, algae, and extracellular polymeric substances, which may be found on almost any surface exposed to water. Here, biofilms were used to monitor the presence of PAHs in the Barigui River in Curitiba, Brazil. For the measurements and collection of representative microcoenoses, a biofilm sampling device was designed consisting of six glass plates installed in an open polyvinyl chloride pipe of 30 cm diameter and 60 cm length. The sampling device was exposed in the Barigui River for 2 weeks campaigns. The formed biofilm was treated and chemical analysis was performed for PAHs determination. The results showed that biofilms can trap most of the PAHs, especially those with high K ₒw values (octanol–water partition coefficient). Four campaigns were conducted. The total PAHs concentration ranged from 11,204.34 ± 560.12 to 45,846.90 ± 2,290.45 ng/g. According to the isomers ratio, the main source of PAHs in the first and second campaign was of pyrolytic origin, in other words, the PAHs were by-products from burning of light-refined oil products (gasoline and diesel oil). Meanwhile, the other campaigns revealed that the main source is of petrogenic origin. However, the possibility of both sources is not discarded considering the scenario studied and the records of sediments samples. Most of the investigations carried out focused on the loading of river sediments and suspended solids, but the biofilms might detect the amount that could be taken up by benthic organisms, for instance.

One of the main environmental impacts of concentrated animal feeding operations is the soil degradation in vicinity with the livestock breeding facilities due to substances such as ammonia emitted from the various stages of the process. Owing to the high temperatures of the Mediterranean ecosystems, the evolution of gasses is more extensive and the soil degradation is consequently more severe than those obtained in northern Europe. In this research, the soil degradation effects of a large meat-producing, processing, and packaging unit have been investigated. The investigated intensive hog farming operation (IHFO) is located at a limestone soil coastal area with sea to the north and hills to the south. Soil samples of the upper mineral soil were taken in various distances and directions from the IHFO boundaries. Thirteen experimental cycles were carried out in the duration of 1.5 years starting in March 2009 until October 2010. The soil samples were analyzed on pH and electrical conductivity (EC) values as well as NH4 + and NO3 − concentrations. Significantly higher concentrations of the two nitrogen forms were observed on samples at increasing proximity downwind from the farm (south). Southern soil average NH4 + and NO3 − concentrations ranged between 0.4–118 μg NH4 +-N g−1 soil and 6.1–88.4 μg NO3 −-N g−1 soil, respectively. The variation of emitted gasses depositions was clearly reflected in the average pH and EC values. Average pH and EC values downwind from IHFO boundaries varied between 7.1–8.2 and 140–268 μS/cm, respectively.

The removal of nutrients in wastewater is a critical issue in water treatment because released nutrients can cause serious adverse effects in water systems or the aquatic environment. In this study, a high-performing polymeric anion-exchange resin was developed for the removal of nutrients from wastewater. The resins were prepared by chloromethylation followed by amination under preferred conditions. The resins were investigated for the removal of nutrients such as phosphate, nitrate, and fluoride from water. The density of functional groups on the synthesized resin was approximately 33 % higher than on commercialized resins, and the specific surface area of synthesized resin was increased by approximately tenfold compared with commercialized resins. The adsorption capacity of synthesized resins (AMP16-FeCl₃) for anions was 285.8 mg/g, which was approximately three times higher than the capacity of commercialized resin (AMP16-OH). A study of the effects of the types of counterions and functional groups found that resins having hydroxide ion as a counterion showed higher capacity and selectivity for phosphate ion and that dimethylethanolamine as a resin functional group of resin was more efficient than trimethylamine.

We examined long-term changes in soil solution chemistry associated with experimental, whole watershed-acidification at the Bear Brook Watershed in Maine (BBWM). At BBWM, the West Bear (WB) watershed has been treated with bimonthly additions of ((NH₄)₂ SO₄) since 1989. The adjacent East Bear (EB) watershed serves as a biogeochemical reference. Soil solution chemistry in the EB watershed was relatively stable from 1989–2007, with the exception of declining SO₄–S concentrations associated with a progressive decline in SO₄–S deposition during this period. Soil solution chemistry in WB reflected a progressive change in acid-neutralization mechanisms from base cation buffering to Al buffering associated with treatment during this period. Total dissolved Al concentrations progressively increased over time and were ~4× higher in 2007 than in 1989. Treatment of WB was also associated with long-term increases in soil solution H⁺, SO₄–S, and NO₃–N, whereas soil solution dissolved organic carbon (DOC) was unresponsive to treatment. For solutes such as Ca, H⁺, and SO₄–S, changes in stream chemistry were generally parallel to changes in soil solution chemistry, indicating a close coupling of terrestrial and aquatic processes that regulate the chemistry of solutions in this first-order stream watershed. For other solutes such as Al and DOC, solute concentrations were higher in soil solutions compared with streams, suggesting that sorption and transformation processes along hydrologic flow-paths were important in regulating the chemistry of solutions and the transport of these solutes.

We investigated the potential application of pyrolysis treatment to a mixture of woody biomass and a metal-contaminated soil as an alternative eco-friendly option to stabilize metals in soils. Our specific objective was to test the optimum combination of high heating temperature (HHT) and heating time to effectively encapsulate metals in a contaminated soil into a biochar. For this purpose, we used a laboratory bench batch reactor to react a mixture of multi-element metal contaminated soil with 0% (control) 5%, 10%, and 15% (w/w) sawdust. Each mixture was reacted at 200°C and 400°C HHT for 1 and 2 h heating times. Physicochemical and morphological characterization along with standard EPA Synthetic Precipitation Leaching Procedure (SPLP) test were conducted to assess the effectiveness of the heat treatment to immobilize the metals in the contaminated soil. Compared to controls, we recorded up to 93% reduction in Cd and Zn leachability after 1 h heat treatment at 400°C, with the addition of 5–10% biomass. Pb leaching was reduced by 43% by the same treatment but without the addition of biomass. At lower pyrolysis temperature (200°C), however, there was a substantial increase in both As and Zn leaching compared to the untreated controls. Our study suggests that several factors such as the type of metal, heating temperature, heating period, and the addition of biomass influence the efficiency of pyrolysis to immobilize metals in the contaminated soil.

The objectives of this study were to characterize and map the spatial distribution of As, Cd, Cu, Pb, and Zn in topsoil at Rayong Province, a rapidly developing city, and to evaluate the associated health risks. A total of 130 soil samples were collected by a stratified random sampling technique. The soil samples were digested by HNO₃, HCl and H₂O₂, and heavy metals were determined by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). Descriptive statistics and geostatistics were used to analyze the data, and the kriging method was used for data interpolation. The results show that the mean values of most heavy metals in the soil, except for As, were lower than Thailand's soil quality standard for habitat and agriculture purposes and the worldwide background level. Highly significant correlations were found for As/Cd, As/Cu, As/Pb, As/Zn, Cd/Cu, Cd/Pb, Cd/Zn, Cu/Pb, Cu/Zn, and Pb/Zn. In addition, most heavy metals showed significantly positive correlations with the reference element (Fe). Spherical, Gaussian and exponential models were selected for the semivariogram analysis of the heavy metals in the Rayong soil. As, Cd, Cu, and Pb were fitted with the spherical model, and Zn was fitted with the exponential model. The total hazard index (HIs) from the heavy metals in the Rayong soil found in both children and adults were in the order of As > Pb > Cu > Cd > Zn. The hazard index of As in the children was higher than 1. The major health risk areas are mainly located in the eastern part of the study area where the land is used for agriculture and in the southwestern areas where industrial activities take place.

This study investigated the encapsulation and photocatalysis of chlorophenol compounds in water using porphyrin-(polystyrene-b-2-dimethylaminoethyl acrylate) star polymer. The chloride ions generated during photocatalytic process were identified and quantified. 2,4,6-Trichlorophenol, pentachlorophenol, and 2,4-dichlorophenol were satisfactorily decomposed in the photoreactor using porphyrin-(polystyrene-b-2-dimethylaminoethyl acrylate) star polymer, with removal efficiencies of 2,454, 498, and 760 mg/g of porphyrin-(polystyrene-b-2-dimethylaminoethyl acrylate) star polymer. The half-life times reached around 30 min, with the exception of that for 2,4-dichlorophenol. The star polymer-impregnated porphyrin is a promising photocatalyst for the removal of chlorophenols.