Impairment of water quality is a major concern for streams and rivers in the central USA. Total maximum daily loads (TMDLs) establish a watershed framework and set management targets to alleviate pollution from both point and nonpoint sources. For this study, we have used a hydrologic modeling approach to holistically examine the effect of land use management, urban development, and agricultural practices on sediment and nutrient loadings in an agricultural watershed. Annualized Agricultural Nonpoint Source (AnnAGNPS) simulation indicates that while point source dischargers contribute 8% of total nitrogen (TN) and 24% of total phosphorus (TP) loadings to the Marmaton River, agricultural nonpoint sources are the leading pollution source contributing 55% of TN and 49% of TP loading. Based on TMDL analysis and model simulation, 3% of the watershed area (3,244 ha) needs to be targeted to control TN loading whereas 1% of the total area (1,319 ha) is required for TP reduction management. Managing the TN areas alone can achieve a 57% reduction in the TP load required for the TMDL, whereas managing the targeted TP areas can only provide 30% of the required TN reduction. Areas required both TN and TP management comprise 469 ha. Targeting these areas can achieve approximately 22% of the required TN reduction and 29% of the required TP reduction. Overall, 4,094 ha will require management to achieve water quality goals. This study demonstrates that a modeling approach is needed to effectively address TMDL issues and help identify targeted areas for management.

This study characterizes the effects of water-soil flooding volume ratio and flooding time on copper (Cu) desorption and toxicity following multiple floodings of field-collected soils from agricultural sites acquired under the Comprehensive Everglades Restoration Plan (CERP) in south Florida. Soils from four field sites were flooded with three water-soil ratios (2, 4, and 6 [water] to 1 [soil]) and held for 14 days to characterize the effects of volume ratio and flooding duration on Cu desorption (volume ratio and flooding duration study). Desorption of Cu was also characterized by flooding soils four times from seven field sites with a volume ratio of 2 (water) to 1 (soil) (multiple flooding study). Acute toxicity tests were also conducted using overlying waters from the first flooding event to characterize the effects of Cu on the survival of fathead minnows (Pimephales promelas), cladocerans (Daphnia magna), amphipods (Hyalella azteca), midges (Chironomus tentans), duckweed (Lemna minor), and Florida apple snails (Pomacea paludosa). Acute tests were also conducted with D. magna exposed to overlying water from the second and third flooding events. Results indicate that dissolved Cu concentrations in overlying water increased with flooding duration and decreased with volume ratio. In the multiple flooding study, initial Cu concentrations in soils ranged from 5 to 223 mg/kg (dw) and were similar to Cu concentration after four flooding events, indicating retention of Cu in soils. Copper desorption was dependent on soil Cu content and soil characteristics. Total Cu concentration in overlying water (Cuw) was a function of dissolved organic carbon (DOC), alkalinity, and soil Cu concentration (Cus): log(Cuw) = 1.2909 + 0.0279 (DOC) + 0.0026 (Cus) - 0.0038 (alkalinity). The model was validated and highly predictive. Most of the desorbed Cu in the water column complexed with organic matter in the soils and accounted for 99% of the total dissolved Cu. Although total dissolved Cu concentrations in overlying water did not significantly decrease with number of flooding events, concentrations of free Cu²⁺ increased with the number of flooding events, due to a decrease in DOC concentrations. The fraction of bioavailable Cu species (Cu²⁺, CuOH⁺, CuCO₃) was also less than 1% of the total Cu. Overlying water from the first flooding event was only acutely toxic to the Florida apple snail from one site. However, overlying water from the third flooding of six out of seven soils was acutely toxic to D. magna. The decrease in DOC concentrations and increase in bioavailable Cu²⁺ species may explain the changes in acute toxicity to D. magna. Results of this study reveal potential for high Cu bioavailability (Cu²⁺) and toxicity to aquatic biota overtime in inundated agricultural lands acquired under the CERP.

Cloudwater samples have been collected for the first time at a high-elevation site in the US interior Southwest. Cloud samples were collected at the summit of Mt. Elden near Flagstaff, Arizona. The samples were analyzed for pH, ionic composition, trace metals, organic carbon content, and volatile organic compounds. All of the samples showed high pH values (5.12-6.66), which appear to be the result of soil/crustal acid-neutralizing components. Ammonium and nitrate were the dominant ionic species. Organic carbon concentrations ranged from 3 to 18 mg/l. Volatile aromatic compounds (toluene, ethylbenzene, and xylenes) were detected, although they did not contribute significantly to the dissolved organic matter (<1% of dissolved organic carbon). Still, their aqueous-phase concentrations were substantially higher than equilibrium partitioning from the gas phase would suggest. Metal concentrations were high when compared to other cloud studies in remote areas. Overall, with the exception of pH, the cloud chemistry showed marked inter-event variability. The source of the variability was investigated using NOAA HYSPLIT dispersion calculations. Like the cloud composition, the air mass back trajectories differed widely from event to event, and consistently, air masses that passed over highly urbanized areas had higher trace metal, organic, and ion concentrations than more pristine air masses.

The legacy of Chernobyl is not the only nuclear accident likely to confront Turkish territory, which is not far from other insecure power plants, especially the Metsamor. The main purpose of this study was to examine the possible impacts to Turkish territory of a hypothetical accident at the Metsamor Nuclear Plant. The research was performed based on two different methodologies: First, a 10-day trajectory analysis was carried out a set of long-term (30 years) meteorological data; second, a tracer study was performed using the MM5T online model for the selected episode. Trajectory and tracer studies showed that an accident at the Metsamor Nuclear Power Plant would influence all of Turkey. Furthermore, vulnerable regions in Turkey after the Chernobyl disaster were demonstrated as a new and first attempt in this study.

The adsorption of two taste- and odor-causing compounds, namely MIB (2-methyl isoborneol—C₁₁H₂₀O) and geosmin (C₁₂H₂₂O) on activated carbon was investigated in this study. The impact of adsorbent pore size distribution on adsorption of MIB and geosmin was evaluated through single solute and multicomponent adsorption of these compounds on three types of activated carbon fibers (ACFs) and one granular activated carbon (GAC). The ACFs (ACC-15, ACC-20, and ACC-25) with different degrees of activation had narrow pore size distributions and specific critical pore diameters whereas the GAC (F-400) had a wider pore size distribution and lesser microporosity. The effect of the presence of natural organic matter (NOM) on MIB and geosmin adsorption was also studied for both the single solute and binary systems. The Myers equation was used to evaluate the single solute isotherms as it converges to Henry's law at low coverage and also serves as an input for predicting multicomponent adsorption. The single solute adsorption isotherms fit the Myers equation well and pore size distribution significantly influenced adsorption on the ACFs and GAC. The ideal adsorbed solute theory (IAST), which is a well-established thermodynamic model for multicomponent adsorption, was used to predict the binary adsorption of MIB and geosmin. The IAST predicted well the binary adsorption on the ACFs and GAC. Binary adsorption isotherms were also conducted in the presence of oxygen (oxic) and absence of oxygen (anoxic). There were no significant differences in the binary isotherm between the oxic and anoxic conditions, indicating that adsorption was purely through physical adsorption and no oligomerization was taking place. Binary adsorptions for the four adsorbents were also conducted in the presence of humic acid to determine the effect of NOM and to compare with IAST predictions. The presence of NOM interestingly resulted in deviation from IAST behavior in case of two adsorbents, ACC-15 and F-400.

Municipal solid waste incineration (MSWI) bottom ash contains economically significant levels of silver and gold. Bottom ashes from incinerators at Amsterdam and Ludwigshafen were sampled, processed, and analyzed to determine the composition, size, and mass distribution of the precious metals. In order to establish accurate statistics of the gold particles, a sample of heavy non-ferrous metals produced from 15 tons of wet processed Amsterdam ash was analyzed by a new technology called magnetic density separation (MDS). Amsterdam's bottom ash contains approximately 10 ppm of silver and 0.4 ppm of gold, which was found in particulate form in all size fractions below 20 mm. The sample from Ludwigshafen was too small to give accurate values on the gold content, but the silver content was found to be identical to the value measured for the Amsterdam ash. Precious metal value in particles smaller than 2 mm seems to derive mainly from waste of electrical and electronic equipment (WEEE), whereas larger precious metal particles are from jewelry and constitute the major part of the economic value. Economical analysis shows that separation of precious metals from the ash may be viable with the presently high prices of non-ferrous metals. In order to recover the precious metals, bottom ash must first be classified into different size fractions. Then, the heavy non-ferrous (HNF) metals should be concentrated by physical separation (eddy current separation, density separation, etc.). Finally, MDS can separate gold from the other HNF metals (copper, zinc). Gold-enriched concentrates can be sold to the precious metal smelter and the copper-zinc fraction to a brass or copper smelter.

It is well established that the livestock sector is a major contributor to greenhouse gases (GHG) and ammonia (NH₃) emissions. In this paper, the evolution of livestock NH₃, methane (CH₄), nitrous oxide (N₂O) and particulate matter (PM) emissions is presented for the period 1960-2005 in Greece and the factors influencing the emission fluxes (such as livestock population changes, manure management systems in use) are examined and analyzed. Emission estimates are based on the updated EMEP/CORINAIR methodology together with the revised IPCC guidelines; newly published, Greece-specific emission factors are used. The emissions level from livestock is evaluated and compared with the corresponding emissions from other anthropogenic sources in Greece. Geographical analysis concerning the distribution of animals and the subsequent NH₃ emissions is performed. Main results indicate high levels of emissions from 1960 to 1995, while emissions from 1995 to 2005 show a stabilizing trend.

Environmental and energy performances of a water network system (WNS) utilizing water reuse are compared to those of a conventional water system (CWS) supplying only freshwater from the perspective of an entire economy and life cycle. Environmental input-output analysis (EIOA) is used to evaluate their air pollutant emissions and energy consumptions. The global warming potential and the emissions of carbon monoxide and of volatile organic compounds from the WNS are less than those from the CWS because of the decrease in the consumption of industrial water, while the emissions of sulfur dioxide and of nitrogen oxides and energy consumption from the WNS are greater because of the increase in electricity consumption for pumping. For perfectly environmentally-friendly water reuse, electricity consumption should be constrained or optimized in water network synthesis, and primary energy mix for electricity generation should be shifted towards renewable energy.

An experiment was set up to assess the factors affecting metal mobility in five wetland soils of the Scheldt estuary at different sampling depths when subjecting the soils to various water table levels. Pore water metal concentrations were monitored for 10 months at four sampling depths (10, 30, 60 and 90 cm) upon adjusting the water table level to 0, 40 and 80 cm below the surface of the soils. Nickel (Ni) release is facilitated by reductive conditions. These reductive conditions mainly occur below the water table. The fate of chromium (Cr) under reductive conditions seems to be promoted by the presence of dissolved organic matter. However, Cr fate seems to be inconsistent between the soils, as it is affected by a series of counteracting mechanisms. Copper (Cu), zinc (Zn) and especially cadmium (Cd) are all primarily released above the water table under high salinity conditions. These elements are also released below or just above the water table when organic matter is being decomposed, resulting in calcium (Ca), manganese (Mn), Ni and/or iron (Fe) release upon CO₂ accumulation and Fe/Mn oxide reduction, without being accompanied by sulphide production. Their mobility is low under reducing conditions, i.e. in the presence of sulphides, whereas the complexation by soluble organic matter especially seems to promote Cu mobility.

Pilot-scale experiments were performed to investigate the role of equalization basins used with constructed wetland systems for treatment of flue gas desulfurization (FGD) waters. Analysis of FGD water samples indicated that aqueous concentrations of Hg, As, and Se remained constant or changed very slightly in a pilot-scale equalization basin during a 24-h hydraulic retention time (HRT). No change in toxicity of FGD water occurred after one HRT. FGD particles were predominantly silt size, and approximately 99% of particles suspended in FGD water settled to the bottom of a 2.5-m-deep equalization basin during the first 4 h of the 24-h HRT. Approximately 90% of the total As, and smaller percentages of Hg and Se, in FGD water and particles were removed by particle settling in the equalization basin. Results of this investigation lend support to the use of equalization basins for treating FGD waters in constructed wetland treatment systems.