Advanced oxidation processes (AOPs) are among the most efficient methods for wastewater treatment. To achieve the degradation of persistent organic pollutants (POPs), AOPs have been developed that employ Fenton reactions promoted by ultrasound (US) or microwaves (MW). Integrated methods combining AOPs with biological treatments are also of great interest. The present paper describes such an integrated approach for the decontamination of water from nonylphenol (NP), a common pollutant that accumulates in aquatic organisms and is quite resistant to biodegradation. Polluted water (containing 1,000 ppm of NP) was sequentially subjected to a sonochemical Fenton reaction and biosorption by the filamentous fungus Paecilomyces lilacinus. Although these methods can be used separately, the sequential approach proved more advantageous. In 1 h the sonochemical oxidation, carried out in a 300 kHz US-reactor equipped with a cooling system, halved NP content in polluted water, as determined by GC-MS analysis. The water was then inoculated with pure cultures of the fungus, whose mycelial biomass further reduced NP content in 7 days. Thus an initial NP concentration of 1,000 ppm was reduced approximately by 90%.

The canopy budget model simulates the interaction of major ions within forest canopies based on throughfall and precipitation measurements. The model has been used for estimating dry deposition and canopy exchange fluxes in a wide range of forest ecosystems, but different approaches have been reported. We give an overview of model variations with respect to the time step, type of open-field precipitation data, and tracer ion, and discuss the strengths and weaknesses of different assumptions on ion exchange within forest canopies. To examine the effect of model assumptions on the calculated fluxes, nine approaches were applied to data from two deciduous forest plots located in regions with contrasting atmospheric deposition, i.e. a beech (Fagus sylvatica L.) plot in Belgium and a mixed sugar maple (Acer saccharum Marsh.) plot in Quebec.For both forest plots, a semi-annual time step in the model gave similar results as an annual time step. Na⁺ was found to be more suitable as a tracer ion in the filtering approach than Cl⁻ or [Formula: see text]. Using bulk instead of wet-only precipitation underestimated the potentially acidifying deposition. To compute canopy uptake of [Formula: see text] and H⁺, ion exchange with K⁺, Ca²⁺, and Mg²⁺ as well as simultaneous cation and anion leaching should be considered. Different equations to allocate [Formula: see text] vs H⁺ uptake had most effect on the estimated fluxes of the cation that was less important at a plot. More research is needed on the relative uptake efficiency of H⁺, [Formula: see text], and [Formula: see text] for varying tree species and environmental conditions.

We sampled and analyzed individually, edible dorsal muscle from largemouth bass (LMB), Micropterus salmoides (n = 138) and yellow perch (YP), Perca flavescens (n = 97) from 15 lakes to investigate potential local impacts of mercury emission point sources in northeastern Massachusetts (MA), USA. This area was identified in three separate modeling exercises as a mercury deposition hotspot. In 1995, 55% of mercury emissions to the environment from all MA sources came from three municipal solid waste combustors (trash incinerators) and one large regional medical waste incinerator in the study area. We determined the mercury accumulation history in sediments of a lake centrally located in the study area. Recent maximum mercury accumulation rates in the sediment of the lake of ~ 88 μg/m²/year were highly elevated on a watershed area adjusted basis compared to other lakes in the Northeast and Minnesota. Fish from the study area lakes had significantly (p = 0.05) greater total mercury concentrations than fish from 24 more rural, non-source-impacted lakes in other regions of the state (LMB n = 238, YP n = 381) (LMB: 1.5–2.5 x; YP: 1.5 x). The integration of this extensive fish tissue data set, depositional modeling projections, historical record of mercury accumulation in sediments of a lake in the area, and knowledge of substantial mercury emissions to the atmosphere in the area support designation of this area as a mercury depositional and biological concentration hotspot in the late 1990s, and provides further evidence that major mercury point sources may be associated with significant local impacts on fisheries resources.

An improved understanding of factors that influence the survival and/or growth of Escherichia coli (E. coli) in soil is essential to allow the formation of land management practices to control the spread of the pathogenic strains of the bacteria, whose transmission to fresh produce is a threat to food safety. Persistence of E. coli in soils held at different water potentials and with carbon additions then subjected to post-freezing incubation temperatures and in the presence of Klebsiella terrigena (K. terrigena) were investigated. Soil samples adjusted to different water potentials (-0.03, -0.1 and -1.5 MPa) were inoculated with a multi-antibiotic resistant strain of E. coli (E. coli 2+), which allowed recovery of the organism from soil samples. In addition to manipulation of water content, different C levels were added and samples were frozen for varying lengths of time, thawed and incubated. In freezing studies, initial soil moisture content significantly affected E. coil 2+ survival in soils following thawing, resulting in lower survival rate (k) at water potential of -0.03 than at -0.1 and -1.5 MPa. The effect of length of freezing time was significant only at -0.03 MPa. Glucose addition at 1.25 mg C g⁻¹ improved survival rate versus glucose at 0.125. The low level glucose increased die-off rate versus no addition, suggesting that unless amendments provide C above a certain threshold level, they might facilitate the death of the bacteria. E. coli 2+ survival improved in the presence of K. terrigena at 6°C but not at 23°C. Persistence of E. coli under the interactive influence of various environmental factors highlights the urgency and importance of understanding its potential for transmission to fresh produce and water bodies.

The dust fall in a region is closely related to upwind sources. Dust fall from sandstorms has a strong influence on industry, agriculture, and daily life. Hohhot, the capital of Inner Mongolia Autonomous Region, is downwind of the Inner Mongolia Plateau and experiences frequent sandstorms during the spring monsoon season. This study investigated the relationship between dust fall in the Hohhot area and surface soils on the Inner Mongolia Plateau. Samples of dust fall from Hohhot and surface soils from the plateau were analyzed for major and trace elements. The SiO₂ content of dust fall from sandstorms differs from that of the plateau soils by only 2.77%, indicating that the main dust fall source for Hohhot is surface soils from the plateau. Dust samples from coal smoke, roads, and buildings were used for comparison. The As content in dust fall from sandstorms is greater than that found in the plateau soils and in dust from non-sandstorm days. This indicates that As is added to the sand during transport from the plateau by coal factories near Hohhot. The second most important dust source is traffic, as evidenced by Pb contents. Preventing erosion of sand upwind of Hohhot during the spring monsoon is key to improving and managing air quality in the Hohhot region. This can be accomplished through management of the farm grassland areas.

An experiment of Randomized Block Design was conducted during 2005 in a greenhouse of the University of Ioannina, Department of Environmental Management and Natural Resources, in order to study the effect of the Treated Municipal Wastewater (TMWW) on the interrelationships of macro, micronutrients, heavy metals and physical and chemical properties of a soil cultivated with Brassica oleracea var. italica (broccoli). The experimental design included the following treatments: (a) TMWW, (b) Fresh irrigation water or “control”, in six replications, with a total number of 2 x 6 = 12 plots of 2.5 x 1.8 = 4.5 m² size. The following were found. Numerous interactions are taking place in the soil under the effect of TMWW, between: (a) macro-, micronutrients, and heavy metals, i.e. (N, P, K, Ca, Mg, Zn, Mn, Fe, B, Cu)x(Ni (Co, Pb, Cd) and (b) between all the above metals and the soil properties i.e. (nutrients and heavy metals)x(pH,CaCO₃, O.M) These interactions could have an important impact on plant growth and the environment, as they can either supply the plants with nutrients, due to their synergistic effects or they can contribute to the decrease or inactivation (fixation) of some undesirable soil heavy metals, owing to their antagonism. Examples of these interactions are studied, and their significance in plants and the environment, is examined, under the effect of the TMWW reuse.

Acid mine drainage (AMD), a legacy of coal and mineral extraction, contaminates streams with complex mixtures of acid and heavy metals that are usually partitioned between the water column and substrate. Understanding the conditions under which sediments retain toxicity after the water column is cleared is important for predicting the long term success of remediation efforts. We conducted laboratory and field experiments to evaluate the relative contribution of acidity versus metals to the toxicity of AMD contaminated sediment towards aquatic macroinvertebrates. Laboratory bioassays showed that precipitate-coated substrate from AMD-impacted sites were toxic to Ctenodaphnia magna and reduced growth of mayflies (Ephemeroptera: Heptageniidae). Toxicity correlated more with acidity released from the sediment than with metals. After transplantation to a clean stream, the same Al- and Fe-contaminated substrate were not toxic to daphnia and was readily colonized by benthic macroinvertebrates within 5 weeks.

Salvinia minima has been reported as a cadmium and lead hyperaccumulator being the adsorption and intracellular accumulation the main uptake mechanisms. However, its physicochemical properties, the effect of metal concentration and the presence of organic and inorganic compounds on its hyperaccumulating capacity are still unknown. Furthermore, the specific adsorption and accumulation mechanisms occurring in the plant are not clear yet. Thus, based on a compartmentalization analysis, a bioadsorption (BAF) and an intracellular accumulation factor (IAF) were calculated in order to differentiate and quantify these two mechanisms. The use of kinetic models allowed predicting the specific type of uptake mechanisms involved. Healthy plants were exposed to five lead concentrations ranging from 0.80 ± 0.0 to 28.40 ± 0.22 mg Pb²⁺l⁻¹ in batch systems. A synthetic wastewater, amended with propionic acid and magnesium sulfate, and deionized water were used as media. The BAF and IAF contributed to gain an in-depth insight into the hyperaccumulating lead capacity of S. minima. It is clear that such capacity is mainly due to adsorption (BAF 780–1980) most likely due to its exceptional physico-chemical characteristics such as a very high surface area (264 m² g⁻¹) and a high content of carboxylic groups (0.95 mmol H⁺g⁻¹ dw). Chemisorption was predicted as the responsible mechanism according to the pseudo-second order adsorption model. Surprisingly, the ability of S. minima to accumulate the metal into the cells (IAF 57–1007) was not inhibited at concentrations as high as 28.40±0.22 mg Pb²⁺l⁻¹.

The practice of contaminant transport and remediation has shown significant progress in recent years. However, despite the significant progress made, remediation efforts are often delayed by extremely long breakthrough curve tails that render efforts to bring the level of contaminants below the regulatory standards inefficient. One hypothesis is that these long tails are due to the reservoir-like slow diffusive processes in soil micropore zones. This study compares the effects of micropores at macroscopic and microscopic levels and establishes a link between these approaches for validation and calibration purposes. The link between macroscopic and microscopic levels is established through comparisons and testing of the two models while incorporating appropriate scale and boundary effects. Despite the differences in conceptual approaches and simulation time, the two approaches rendered meaningful results. The link helps forecast the effects of micropore zone transport processes in the subsurface efficiently and thus allows development of numerical tools that could contribute towards more efficient remediation design.

Bacteria, fungi and viruses are often encountered in aerosols and they can be pathogenic or cause allergies following inhalation. Wastewater treatment facilities have been found to generate bioaerosols, which are transported by the prevailing winds downstream to areas that can be up to several hundred meters away. Bioaerosol formation has a significant effect on air quality in the vicinity of the treatment plants. The amount and characteristics of the formed bioaerosols depend on the aeration system employed at the aeration tank of the wastewater treatment facility. In this work we determined Enterobacteria in air and wastewater samples at the main wastewater treatment facility of the city of Chania (Crete, Greece). Concentrations of airborne bacteria were measured near the aeration and sedimentation tanks. Samples of airborne bacteria were taken by using Merck's MAS-100 bioaerosol collector followed by incubation and enumeration of the colonies. The use of different growth media enabled the separation and enumeration of several classes of microorganisms. As part of this study, Enterobacteria in air samples were also determined by filtration sampling followed by analysis of the collected microorganisms using DAPI staining to determine total cell counts (both viable and non-viable cells). Fluorescence in situ hybridization (FISH) with specific 23S rRNA probes was also used in order to identify specific groups of microorganisms (well known pathogens) present in the bioaerosols. The analysis was also performed in wastewater taken from the aeration and secondary sedimentation tanks in an effort to correlate the airborne bacteria with those in the wastewater.