We investigated the effects of road deicer runoff on benthic macroinvertebrate communities in Korean freshwaters focusing on the effects of CaCl₂deicer. Quantitative field sampling was conducted at eight sites (lakes and streams) in South Korea, and toxicity tests were conducted on 48-h lethal and effective concentrations (LC₅₀and EC₅₀) of road deicer (CaCl₂74 %) and high-grade CaCl₂(96 %) on five selected macroinvertebrate species (Gammarus sobaegensis, Caridina denticulata denticulata, Glyptotendipes tokunagai, Cloeon dipterum, and Ecdyonurus levis). Although Cl⁻concentrations were significantly different between the seasons (before and after snowfall) at most of the study sites, community values (species richness, density, dominance index, and diversity index) were not significantly different between the seasons. In the bioassay, 2.85 g L⁻¹CaCl₂elicited abnormal swimming behavior of test organisms based on EC₅₀values. The LC₅₀values of the five test species ranged from 3.54 to 20.73 g L⁻¹. For all tested species, the LC₅₀of road deicer was higher than that of high-grade CaCl₂. This study shows that despite the heavy application of road deicers during the snowy season, the deicer may not directly affect benthic macroinvertebrate communities over short time periods because Cl⁻concentrations in the field sites (<0.025 g L⁻¹) were much lower than the LC₅₀values. Because the quantity of deicers used in this region continues to increase, long-term research into the effects of deicers on benthic macroinvertebrates is needed.

The effects of urbanization on runoff pollutant concentrations and pollutant loading were studied in three urban catchments of varying imperviousness and land use type in the city of Lahti, Finland. Imperviousness of the catchments were 19 % (“Low”), 62 % (“Intermediate”) and 89 % (“High”). During the 2-year study period, runoff quantity was measured continuously and samples were taken for water quality analysis. Besides imperviousness, land use type strongly affected pollutant concentrations: differences in total phosphorus (tot-P), Al, Cr, Zn and Pb concentrations were observed especially between the city centre catchments (High and Intermediate) and the residential catchment (Low), while total suspended solids (TSS), total nitrogen (tot-N), Mn, Co, Ni and Cu concentrations increased with increasing imperviousness. As for pollutant loads, imperviousness was strongly related to TSS, tot-P, Al, Mn, Zn, Cr, Co, Ni and Cu export. The effects of urbanization on runoff quality were season dependent: urbanization increased runoff volumes and, hence, pollutant loads, especially during warm seasons. Still, highest pollutant export in the catchments occurred during spring. Nevertheless, the warm period produced comparable loads to spring at the city centre catchments. Pollutant concentrations, especially in the city centre catchments, exceeded thresholds set for surface waters, indicating a need for runoff treatment in water quality protection.

Novel nanocomposite hydrogels based on wheat bran-g-poly(methacrylic acid) and nano-sized clinoptilolite have been successfully utilized for the removal of Pb(II), Cu(II), Cd(II), and Ni(II) cations from their aqueous solution. The experimental results were investigated using Freundlich, Langmuir, Temkin, and Dubinin–Radushkevich isotherm models. The pseudo-first-order, pseudo-second-order and interparticle diffusion kinetic models were studied in order to analyze the kinetic data. The kinetic data indicated that the rate of cation adsorption on nanocomposite hydrogels was fast that more than 80 % of the equilibrium adsorption capacity occurs within 15 min. The maximum monolayer adsorption capacity of the nanocomposite hydrogel, as obtained from the Langmuir adsorption isotherm, was found to be 166.7, 243.9, 175.4, and 166.6 mg g⁻¹ for Pb(II), Cu(II), Cd(II), and Ni(II), respectively. Thermodynamic parameters such as free energy (ΔG ⁰), enthalpy (ΔH ⁰), and entropy (ΔS ⁰) change were determined; the sorption process was found to be endothermic. The results of five times sequential adsorption–desorption cycle showed high adsorption efficiency and a good degree of desorption.

Nanoscale zero-valent iron (nZVI) was synthesized and used for the removal of Sb(III) and Sb(V) from aqueous solutions. Results showed that more than 90 % of antimony would be removed in 15 min and that all of antimony could be removed with appropriate nZVI dosage in 90 min. The influence of pH value and possible impurities was investigated. The pH of 4 was found as the optimum pH. Discussion and speculation about the mechanism were presented according to X-ray photoelectron spectroscopy and transmission electron microscopy data. A sheet-like structure was observed after a 90-min reaction, and antimony was detected on the surface by energy-dispersive X-ray spectroscopy. Both Sb(III) and Sb(V) partially reduced in the process. The presence of humic acid transformed the morphology of nZVI but barely influenced the removal efficiency. Competing ions showed diverse influence between Sb(III) and Sb(V). The overall results indicated that nZVI was an efficient and suitable material for the removal of antimony.

During this study, the effect of applying several types of treated domestic wastewater on the translocation and accumulation of organic and inorganic micropollutants in soil and radish plants (Raphanus sativus L.) was examined. Primary (PTW), secondary (STW) and tertiary (TTW) treated wastewater as well as tap water (TW) were used for the irrigation of radish plants for a period (transplantating and harvesting) of 67 days. Higher concentrations of polycyclic aromatic hydrocarbons (PAHs) were observed in soils irrigated with PTW. The concentration of PAHs in radish roots ranged between 107.6 ± 12.1 μg/kg for plants irrigated with TTW and 124.1 ± 17.7 μg/kg for plants irrigated with PTW. The root concentration factors (RCFs) expressed as the ratio of PAH concentration in the root mass (dry weight) to the residual concentration in the soil varied from 1.6 to 1.9 indicating a higher accumulation of PAHs in the edible part of radishes than soil. Heavy metals were not detected in the wastewaters utilised and, as a result, no accumulation was found in either the soil or plants in comparison with tap water. RCFs for heavy metals were calculated between 0.91 and 0.99, 0.49 and 0.66, 0.004 and 0.005 for Cu, Zn and Ni, respectively. The results showed that radishes have the ability to concentrate PAHs when they are present in the wastewater and this could have associated health risks.

A dose–response study was performed in four commercial clones, Baldo (Populus deltoides), Jean Pourtet (Populus nigra), I-214 (Populus x euramericana) and Villafranca (Populus alba), to investigate the best performing species in terms of metal content and high metal resistance (absence of symptoms) useful in biomass production on contaminated water/land by zinc. Zinc (1 μM as control and 1 mM) was applied for 4 weeks in a hydroponic system. Clone Villafranca was the least damaged, while the most sensitive was clone I-214. The highest zinc concentration in all different parts of plants analysed was recorded in Villafranca > I-214 > Baldo > Jean Pourtet. The higher translocation factor was seen in Baldo, the lowest in Villafranca. Analyses of leaf damage showed a reduction on Chl a in young leaves (96 %) in I-214 stressed plants, whereas in Villafranca, Chl a was about double compared to the control. Regarding other photosynthetic pigments, violaxanthin was significantly correlated to zinc concentration in old leaves. The responses of clones to zinc (Zn) stress were specific: Villafranca was the most resistant, while I-214 showed the highest biomass production under Zn excess. Since these two clones have useful and complementary traits for uptake and detoxification while maintaining high biomass production under Zn excess, they are interesting candidates for understanding the key resistance mechanisms.

This study was carried out to evaluate the linkages among herbaceous plant biomass (i.e., aboveground and litter biomasses) and diversity (Shannon-Wiener index) in riparian and non-riparian areas, land use, and lotic water quality (which included first- and second-order natural streams, a canal, and a reach of a lowland river). Herb stands selected were free from anthropogenic disturbances such as farming and construction activities for a period of 3 years (this was the dominant and peak frequency of disturbances of the study area). The results suggested that herb indicators are good representatives of the land use. However, land use explanations for herb indicators were complex and not universal for all lotic waters. The correlations between herb indicators and water quality were strong for the low-order natural streams. In these streams, herb indicators explained >36 % of the total variation with several statistically significant herb indicators. However, the large river section showed weak correlations. Furthermore, the canal’s hydrology (connectivity to sea) seemed to be more influential in shaping its water quality. This study demonstrated that the rehabilitation works with a span of 3–4 years using herbs in riparian and/or non-riparian areas could significantly improve water quality of low-order streams with natural origin.

A total of 179 surface sediment samples from shallow waters have been collected in Catalonia (Northwestern Mediterranean) from 2002 to 2010 to analyze heavy metals (Al, Cd, Cu, Hg, Pb, V, and Zn) concentrations, organic matter content, and sediment size in order (i) to find baseline values, (ii) to investigate metal contamination trends, and (iii) to identify its spatial and temporal distribution. Highest metals concentrations were registered in the Barcelona metropolitan area and in the mouth of Besòs and Llobregat Rivers for Zn, Cu, Pb, and Cd. Mercury was also abundant in these areas but the highest record was found close to Tarragona. The concentrations agree with those reported in other studies performed in big river’s mouths and industrialized areas. The absence of large industrial activity and urbanization outside Barcelona and Tarragona explains the low metal contents found at the other sampling sites. Based on enrichment factor (EF), Pb was the most enriched metal. Results will provide a useful aid for sustainable marine management in Catalonia.

An on-line preconcentration system using solid-phase extraction with polytetrafluoroethylene was used for the determination of mercury by cold vapor atomic absorption spectrometry. The system uses electronically controlled valves and operates in two simple steps using sorption and elution. The Hg(II) ammonium pyrrolidinedithiocarbamate complexes are retained in a minicolumn packed with the sorbent. The elution, transportation, and reduction of the analyte ions are promoted by a solution of sodium tetrahydroborate(III). After optimization, the developed method showed the following analytical characteristics: a limit of detection of 0.02 μg L⁻¹, linearity of 0.07 to 2.00 μg L⁻¹, enrichment factor of 35, and sampling frequency of 27 h⁻¹. The accuracy of the method was tested by analyzing the certified reference material BCR-060 Lagarosiphon major (aquatic plant). The proposed method was applied to the determination of mercury in water samples.

The adsorption capacities of six biosorbents (Pseudomonas aeruginosa, Pseudomonas fluorescens, Escherichia coli, Chlorella vulgaris, and Spirulina platensis) for Zn(II) ions under batch condition have been studied. The optimum pH range was found to be 5.0−6.0. The amount of adsorbed Zn(II) ions were between 18 and 128 mg/g. Characterization of biosorption equilibrium was evaluated with Langmuir and Dubinin-Radushkevich model using non-linear regression. The adsorption capacities of Ca-alginate, chitosan, and immobilized Spirulina platensis-maxima cells were also determined in packed-bed column in continuous system. The results show, free Spirulina cells have the highest adsorption capacity for Zn(II) ions (128 mg/g). The chitosan-Spirulina system has slightly decreased adsorption capacity 98 mg/g per dry weight content. Thomas and Yoon-Nelson models were fitted for the evaluation of experimental data.