Resource added for the Environmental Engineering Waste and Water Technology program 105062.

As a result of changes in hydrology, the former mesotrophic, shallow lake Naardermeer, has been eutrophicated during the last decades. To compensate for shortage of water, eutrophicated water with different chemical characteristics has been supplied. In order to determine the effects of alkalinity, acidity and external sulphate and phosphorus load on eutrophication processes, developments in water chemistry have been studied in enclosures. A decrease of the phosphorus load of the lake did not improve water quality on the short term. This observation was confirmed by this enclosure experiment. Reduction of alkalinity did improve water quality, particularly by reductions of turbidity and chlorophyll-a content. The significant increase in sulphate load in the water layer led to deterioriation of the water quality and an increased biomass of sessile algae by internal eutrophication, probably as a result of increased sulphate reduction in the sediment. Therefore, it seems that lowering of sulphate concentrations in the inlet water after the removal of phosphorus is necessary to improve the water chemistry. The best option, however, is to restore the former hydrological conditions after which the system will be fed only by seepage of groundwater poor in nutrients and sulphate.

A study was carried out in order to estimate the presence of enteric and non-enteric indicators in the water distribution systems of Western Greece and to evaluate different methods for culture and isolation of coliforms in that region, under several incubation conditions and using different media. According to the different media and techniques used, the numbers of water samples found unsafe for consumption represented 21, 17 and 10% of the total, when mT7 agar, M-Endo agar LES (Membrane Filtration technique) and Most Probable Number (MPN) techniques were used, respectively. In one third of the samples oxidase positive microorganisms were present, which were almost eliminated by using anaerobic incubation of the media. Faecal streptococci were found only in 5% of the samples tested. The MPN technique proved to be significantly less efficient in recovering the coliform colonies than the Membrane Filtration (MF) technique (x² = 125.758 < 182.405). The use of m-Endo agar LES and mT7 agar showed no statistically significant difference in detecting total coliforms (x² = 162.55 > 162.422). However, a larger mean number of colonies per sample developed on mT7 agar, indicating that the latter medium should be used in our region for the detection of total coliforms.

The work reported here deals with the study of interception/deposition and translocation of ⁸⁵Sr, ¹³¹I, and¹³⁷ Cs in three different types of vegetables i.e. beans (Phasoolus vulgaris), spinach (Spinicia olericia) and radish (Raphanous sative) following redionuclides release to the environment. Activity was injected in the experimental chamber in the form of aerosols having a size distribution of 0.3–1.0 µm (AMAD). Plant samples were collected soon after the injection for the evaluation of interception/deposition factors (IF/DF) for the different parts of the plants, as well as for the whole plant and the washable fraction of the deposited activity and its variation with time. The evaluated IF/DF shows a minimum value of 0.12 m³ kg⁻¹ for ⁸⁵Sr in case of spinach whole plant and maximum value of 1.93 m³ kg⁻¹ for ¹³¹I in case of beans whole plant. Translocation factors (TF) have also been evaluated for the activity that migrates from the above soil plant parts to the root and its variation with time. The evaluated TF shows a range of 7.27 × 10⁻³ to 136 × 10⁻³.

The Henry's law constant of trichloroacetic acid [K′H (mol kg⁻¹ atm⁻¹) for the equilibrium CCl₃COOH₍g₎ ⇌ CCl₃COOH₍ₐq₎] has been determined from measured partial pressures over aqueous solutions at 298.15 K and 308.15 K. Its value is given by: ln(K′H) = (11.21 ± 0.5) – 8.66 × 10³ (l/Tᵣ – l/T) where T (K) is temperature and Tᵣ is equal to 298.15 K, for an aqueous phase dissociation constant (Kₐ) of 0.55 mol kg⁻¹ determined from literature osmotic coefficient and electromotive force data. Accuracy is estimated to be 4–30% in the product K′HKₐ. Trichloroacetic acid is highly soluble and will partition strongly into aqueous atmospheric aerosols, and completely into fog and cloud water. Its occurrence and transport in the environment are therefore to be associated primarily with liquid phases.

A pilot-plant-scale study of combined sulfur dioxide/nitrogen oxides (SO₂/NOₓ) removal has been performed by the Dravo Lime Company at the Cincinnati Gas and Electric Company's Miami Fort Station in North Bend, Ohio. This study used Dravo's patented Thiosorbic® lime process along with Argonne National Laboratory's (ANL's) patented process for combined SO₂/NOₓ removal using the chelate ferrous·ethylenediaminetetraacetate (Fe·EDTA). For approximately nine months, scrubbing tests were carried out, and waste samples were collected. Waste testing at ANL involved two types of long-term chemical stability experiments. In one test, the gas-phase composition above several different samples was studied by mass spectrometry over 22 months. Unexpectedly, production of carbon dioxide and hydrogen sulfide was observed in some of the samples. The other experiment involved solid-phase leaching. Samples were stored for up to 14 months before leaching. Each leachate was tested for total Kjeldahl nitrogen and for the nitrogen-containing ions nitrite, nitrate, and ammonium. Significant amounts of ammonium ions were found in two of the samples. Total leachable nitrogen was found to stabilize after about the first 7 months of storage.

From 1990 to 1994, a total of 21 sediment cores and 37 grab sediment samples were collected from the Milwaukee Harbor Estuary. Each sediment core was sectioned and dated using ²¹⁰Pb and¹³⁷ Cs radioisotope techniques. A total of 305 samples were analyzed for sixteen polycyclic aromatic compounds (PAHs). Grain size distribution, porosity, and total organic carbon content as measured by loss on ignition were also determined. The results provide a historical overview of the impact of industrialization in the Milwaukee area. Although highly variable, the concentration profile of PAHs show, in general, peaks in the 1950's through 1980's. The PAH concentrations have declined since then for most sediment cores. The current levels of total PAHs in most surface sediment samples range from 25 to 200 ppm. A few cores, some of which were collected in 1994, have an elevated PAH concentration at the surface. Toxicity of the surface sediments was evaluated by comparing with the benchmark values developed by the United States National Oceanic and Atmospheric Administration (NOAA). The most heavily contaminated area was found in the Kinnickinnic River between the Becher Street Bridge and the Wisconsin Wrecking Company Wharf. The highest total PAH concentration determined from seven vibra cores collected in this area ranges from 380 to 1000 ppm. The former Wisconsin Solvay Coke Company may have been a major point source of PAHs until the 1970's. Highway traffic and various industrial discharges also contribute to the sediment PAHs in this area.