Cuttings of black willow (Salix nigra), a naturally occurring wetland species, are used for restoration and streambank stabilization. As an adaptation to their wetland habitat, this species develops aerenchyma tissue to avoid root anoxia. To determine the effects of combined copper and ultraviolet-B radiation exposure on aerenchyma tissue (measured as root porosity), black willow cuttings were grown hydroponically and exposed to three ultraviolet-B (UV-B) intensities and three Cu concentrations in a completely randomized 3 × 3 factorial design. While both UV-B (F 2,42 = 11.45; p = 0.0001) and Cu (F 2,42 = 6.14; p = 0.0046) exposure increased root porosity, total biomass decreased in response to both UV-B (F 2,43 = 3.36; p = 0.0441) and to Cu (F 2,43 = 4.03; p = 0.0249). Root biomass decreased only in response to Cu (F 2,41 = 3.41; p = 0.0427) resulting in a decrease in the root/shoot ratio (F 2,42 = 3.5; p = 0.0393). Copper exposure also resulted in a decrease in the number of leaves/shoot (F 2,42 = 7.03; P = 0.0023). No UV-B and Cu interaction was found. While the present research indicates the negative effects of Cu contamination and elevated UV-B intensities on S. nigra, it also points out potential mechanisms that S. nigra uses to alleviate these stresses.

The capability of Chromolaena odorata (L) to grow in the presence of different concentrations of three heavy metals in crude oil-contaminated soil and its capability to remediate the contaminated soil was investigated using pot experiments. C. odorata plants were transplanted into contaminated soil containing 50,000 mg kg−1 crude oil and between 100 and 2,000 mg kg−1 of cadmium, nickel, and zinc and watered weekly with water containing 5% NPK fertilizer for 180 days. C. odorata did not show any growth inhibition in 50,000 mg kg−1 crude oil. Plants in experiments containing 2,000 mg kg−1 Cd showed little adverse effect compared to those in Zn-treated soil. Plants in 1,000 and 2,000 mg kg−1 Ni experiments showed more adverse effects. After 180 days, reduction in heavy metals were: 100 mg kg−1 experiments, Zn (35%), Cd (33%), and Ni (23%); 500 mg kg−1, Zn (37%), Cd (41%), and Ni (25%); 1,000 mg kg−1, Zn (65%), Cd (55%), and Ni (44%); and 2,000 mg kg−1, Zn (63%), Cd (62%), and Ni (47%). The results showed that the plants accumulated more of the Zn than Cd and Ni. Accumulation of Zn and Cd was highest in the 2,000 mg kg−1 experiments and Ni in the 500 mg kg−1 experiments. Crude oil was reduced by 82% in the experiments that did not contain heavy metals and by up to 80% in the heavy metal-treated soil. The control experiments showed a reduction of up to 47% in crude oil concentration, which was attributed to microbial action and natural attenuation. These results show that C. odorata (L) has the capability of thriving and phytoaccumulating heavy metals in contaminated soils while facilitating the removal of the contaminant crude oil. It also shows that the plant’s capability to mediate the removal of crude oil in contaminated soil is not significantly affected by the concentrations of metals in the soil.

Sediment and porewater samples from an enclosed bay receiving stormwater discharge (Skutviken) near the centre of Luleå, northern Sweden were analysed for major and trace elements and 16 polycyclic aromatic hydrocarbons (PAHs). Among the studied metals Cd, Cu, Pb and Zn were enriched at Skutviken. Also, the PAH content was enriched, in particular for phenantrene, anthracene, fluoranthene and pyrene which are regarded as common constituents in stormwater. The use of trace metal ratios provided indications about pollutant sources for the sediment. Cs-137 dating was used to determine historical changes in metal and PAH fixation in the sediment. The bay Skutviken is enclosed through the construction of a road bank since 1962. The enclosure led to reduced water circulation in the bay that promotes the occurrence of anoxic conditions with sulphate reduction within the bay. As a consequence of these conditions, metals are trapped in the sediments as sulphides. This study suggests that enclosed bays with restricted water circulation may be efficient traps for urban pollutants, reducing the present-day input of pollutants to the sea. In areas with postglacial land uplift, where such bays are common, bay sediments are a potential future source of pollutants when uplift results in erosion and oxidation of the sediments.

The concentrations of selected metals—Cr, Ni, Cu, Zn, Cd, and Pb—were determined in the samples of Hypogymnia physodes lichen and Pleurozium schreberi moss collected in Polish and Czech Euroregions Praded and Glacensis. More specifically, the samples were collected in Bory Stobrawskie, Bory Niemodlińskie, and Kotlina Kłodzka (Poland) and in Jeseniki (Czech Republic). The concentration of metals in the samples was measured using the atomic absorption spectrometry (flame AAS technique and electrothermal atomization AAS technique). The results were used to calculate the comparison factor (CF) that quantifies the difference in concentration of a given bioavailable analyte × accumulated in lichens and mosses: CF = 2 (c x,lichen − c x,moss) (c x,lichen + c x,moss)−1. The values of CF greater than 0.62 indicate the most probable location of heavy metals deposited in the considered area. In this work, the method was used to show a significant contribution of urban emissions to the deposition of heavy metals in the area of Bory Stobrawskie and in the vicinity of Kłodzko City.

The levels of 131I and six natural radionuclides (238U, 226Ra, 210Pb, 228Ra, 224Ra, and 40K) were determined in sewage sludge samples obtained from an urban wastewater treatment plant that services a medium-sized town in Spain. Secondary treatment of wastewater consisting of anaerobic, anoxic, and oxic stages is collectively called A2O processing. Radio analytical determinations were performed by gamma spectrometry using a high-purity germanium detector. This technique has proven useful in identifying local radioactive pollution. This type of pollution was consistently detected throughout the year, with several increases associated with authorized discharges from hospitals. Finally, we examined the radiation dose that workers are exposed to due to the presence of 131I in the sludge. We found inhalation risk to be negligible, with external radiation as the main source of exposure to 131I.

This study applied the Model of Acidification of Groundwater in Catchments (MAGIC) to estimate the sensitivity of 66 watersheds in the Southern Blue Ridge Province of the Southern Appalachian Mountains, United States, to changes in atmospheric sulfur (S) deposition. MAGIC predicted that stream acid neutralizing capacity (ANC) values were above 20 μeq/L in all modeled watersheds in 1860. Hindcast simulations suggested that the median historical acidification of the modeled streams was a loss of about 25 μeq/L of ANC between 1860 and 2005. Although the model projected substantial changes in soil and stream chemistry since pre-industrial times, simulated future changes in response to emission controls were small. Results suggested that modeled watersheds would not change to a large degree with respect to stream ANC or soil % base saturation over the next century in response to a rather large decrease in atmospheric S deposition. Nevertheless, the magnitude of the relatively small simulated future changes in stream and soil chemistry depended on the extent to which S emissions are reduced. This projection of minimal recovery in response to large future S emissions reductions is important for designing appropriate management strategies for acid-impacted water and soil resources. Exploratory analyses were conducted to put some of the major modeling uncertainties into perspective.

A wide variety of veterinary antibiotics (VAs) has been detected in environmental water samples, and this is of potential environmental concern due to their adverse effects. In particular, the potential for development of antibiotic-resistant bacteria has raised social concerns leading to intensive investigation regarding the influence of antibiotics on human and ecosystem health. One of the main sources of antibiotic effluence to the environment is livestock manures that often contain elevated levels of VAs that survive normal digestive procedures following medication in animal husbandry because unlike human waste, waste generated on farms does not undergo tertiary wastewater treatment, and consequently, the concentration of antibiotics entering the environment is expected to be larger from farming practices. Animal feed is often supplemented with VAs to promote growth and parasite resistance in the medicated animals, and this practice typically resulted in higher use of VAs and consequential excretion from livestock through urine and feces. The excretion rate varied depending on the type of VA used with around 75, 90, and 50–100% being excreted for chlortetracycline, sulfamethazine, and tyolsin, respectively. The excreted VAs that initially present in livestock manures were degraded more than 90% when proper composting practice was used, and hence, this can be employed as a management strategy to decrease VA environmental loads. The reduction of VA concentrations during composting was mainly attributed to abiotic processes rather than biotic degradation. The VAs released to soils by the application of manure and manure-based composts can be degraded or inactivated to various degrees through abiotic process such as adsorption to soil components. Depending on the antibiotic species and soil properties, residues can be transferred to groundwater and surface water through leaching and runoff and can potentially be taken up by plants.

Measurements of number size distributions of submicron aerosols have been performed at the Eastern part of Mediterranean as part of an extensive measurement campaign to study photo-oxidants and aerosols (SUB-AERO Project). The measurements were made at the Finokalia station on the island of Crete (Greece) and onboard the research vessel “Aegaeon”. Two campaigns were performed during July 2000 and January 2001 using two scanning mobility particle sizers. The particle distributions measured in the range between 7.8 < d p < 327 nm during the summer measurements and between 7.5 < d p < 316 nm during the winter measurements, where d p is the mobility particle diameter. The concentration of ultrafine particles (7.5 < d p < 30 nm) was higher during the winter period and varied mainly between 5 × 10¹ and 2 × 10³ cm⁻³ with concentration peak values for this mode exceeding 1 × 10⁴ cm⁻³. During the summer campaign, an average number concentration of 1 × 10² cm⁻³ at Finokalia and about 5 × 10¹ cm⁻³ aboard the “Aegaeon” vessel was measured. An average concentration of 1 × 10³ cm⁻³ was measured for the particles in the size range between 30 and 100 nm, whereas in the size range 100-300 nm, the measured concentration ranged between 1 × 10² and 5 × 10³ cm⁻³. Diurnal patterns in number concentrations were observed in connection with the transport of air masses and local sources. During the winter period, three nucleation events were observed in connection with the appearance of a particle mode at 20 nm.

This laboratory-scale study explored the use of rice husk ash (RHA) as an admixture to stabilize and solidify the waste sludge from a chrome-tanning process. Various ratios of RHA and tannery sludge were used, ranging from 0.25 to 1.0 by weight of the cement content, resulting in an experimental matrix of 16 runs. It was observed that although the compressive strength of solidified sludge improved at longer curing times, the increase was moderate after 7 days of curing. In addition, higher RHA and/or sludge ratios progressively reduced the strength of the samples. On the other hand, curing time had a positive effect on chromium leachability since the leaching concentration decreased considerably with an increase in curing time, up to 28 days. Furthermore, both the RHA and/or sludge content affected leachability, producing acceptable results, from a Thai regulatory perspective, at ratios of 0.50 or lower. Finally, the solidified sludge can be disposed of in a secure landfill and/or used as a construction material in a number of applications.

Hydrochemical impacts of shallow rock industrial-scale mining activities close to sensitive constructed and natural wetlands were investigated. The shallow surficial groundwater and surface water in the Everglades Agricultural Area (EAA) were characterized. The chemical composition of sulfate and chloride in groundwater increased with depth. The average concentration of chloride averaged 182 mg L−1 at 6 m deep and increased gradually to 1,010 mg L−1 at 15 m deep, 1,550 mg L−1 at 30 m deep to reach 7,800 mg L−1 at 60 m deep. Comparatively, the surface water chemical composition in the surrounding areas showed much lower cationic and anionic charge. The specific conductivity and total dissolved solids of surface water in canals (close to the mining operations) are <900 μS cm−1 and <600 mg L−1, respectively, which should be compared to groundwater quality in wells from the EAA area (>2,000 μS cm−1 and >1,000 mg L−1, respectively). A steady-state groundwater fluid flow and transient solute transport modeling exercise was conducted to estimate surface/groundwater interactions. The modeled solute in surface water was transported downgradient through groundwaters, migrated approximately 30 m from the source area (after 5 years of operation), and needed more than 116 years to dissipate. An upward transport was also identified whereby chloride and sulfate, naturally present in deeper groundwaters, migrated approximately 200 m (after 1 year of mining) into the pristine shallower aquifer and reached the surface water with a concentration equaling 80% of that in the rock mining pit.