Restoration of riparian buffers is an important component of nutrient reduction strategies in the Chesapeake Bay watershed. In 1998, Maryland adopted a Conservation Reserve Enhancement Program (CREP), which provides financial incentives to take agricultural land out of production to plant streamside vegetation. Between 1998 and 2005, 1-30% of streamside vegetation (average = 11%), was restored to forest or managed grass in 15 agriculturally dominated sub-basins in the Choptank River basin, a tributary of Chesapeake Bay. Pre-existing forested buffers represented 10-48% of the streamside (average = 33%), for a total of 12-61% buffered streamsides (average = 44%). Using multi-year water quality data collected before and after CREP implementation (1986, 2003-2006), we were unable to detect significant effects of CREP on baseflow nutrient concentrations based on the area of restored buffer, the percentage of restored streamside, or the percentage of total riparian buffer in the sub-basins (p > 0.05). Although CREP increased the average buffered streamside from 33% in the 1990s to 44% by 2005, N and P concentrations have not changed or have increased in some streams over the last 20 years. Reductions may not have occurred for the following reasons: (1) buffer age, width, and connectivity (gaps) between buffers are also important to nutrient reductions; (2) agricultural nutrient inputs may have increased during this period; and (3) riparian buffer restoration was not extensive enough by 2005 to have measurable affects on the stream water quality in these sub-basins. Significant effects of CREP may yet be resolved as the current CREP buffers mature; however, water quality data through 2006 in the Choptank basin do not yet show any significant effects.

Recent studies have shown that the lower basin of the Salado River is highly polluted with copper and chromium. In order to evaluate the effect of those metals on Notodiaptomus conifer, a representative calanoid copepod, we carried out two (acute and chronic) experimental assays. In the first one, the 24- and 48-h EC₅₀ values were determined in nauplii and adults. Chronic assays were conducted to evaluate the time of development for nauplii, time of development for each copepodite stage, total development time, growth, number of ovigerous females, fecundity, and time required to produce the first egg sac. Additionally, the effect of those metals on the equiproportional model proposed for copepods was evaluated. Acute experiments reveled that juveniles were more sensible than adults. Although growth was not seriously affected by metal exposition, development time was delayed and reproductive variables were altered with the increase of metal concentrations. The deviation from the equiproportional model proposed for copepods proved to be a useful parameter to provide relevant information on toxicity of both metals along development time. In comparison with other zooplanktonic species, the highest sensitivity of N. conifer to copper and chromium makes it a suitable bioindicator in ecotoxicological tests.

A pot experiment was conducted to study the effects of high concentrations of available Cu and Pb in soil originated from the vicinity of a copper foundry in Poland (Cu, 2,585–3,725 mg kg−1 d.wt.; Pb, 1,459–1,812 mg kg−1 d.wt.) on the growth and chemical constituents of Betula pendula seedlings. Control plants grew in unpolluted forest soil. Dry matter accumulation in the plants during the growing season and root/leaf mineral content were determined. Colonization of birch roots by ectomycorrhizal (ECM) fungi also was evaluated, as was soil dehydrogenase activity for influence of the metals on soil microorganisms. The heavy metals negatively affected seedling growth, ECM colonization, and soil dehydrogenase activity. A reverse relationship was found between ECM abundance and heavy metal concentrations in birch leaves, indicating the potential of mycorrhizas to protect the aboveground part of young silver birch seedlings from elevated environmental levels of Cu and Pb.

The photodegradation of azo dyes aqueous solution has been investigated using TiO₂ as catalyst in sunlight. The effect of amount of catalyst, concentration of dye, and pH value on the degradation of Direct Blue 78 was observed. A complete degradation of 100 mg/L Direct Blue 78 solution under solar irradiation was achieved in 6 h at pH 3.0, dosage of TiO₂ 1.0 g/L. A possible pathway for the photodegradation of Direct Blue 78 in sunlight was proposed.

Water retention and transport in soils is dependent upon the surface tension of the aqueous phase. Surfactants present in aqueous solution reduce the surface tension of aqueous phase. In soil-water systems, this can result in water drainage and reductions in field capacity and hydraulic conductivity. In this investigation, the surface tension of surfactant solutions mixed with soil—in a constant fixed ratio—was measured as a function of surfactant concentration. Two anionic surfactants were used: sodium dodecyl sulphate and sodium bis (2-ethylhexyl) sulfosuccinate. Two soils were also used—a clay soil and a sandy soil. The key observation made by this investigation was that the addition of soil to the surfactant solution provided a further component of surface tension reduction. Neither soil sample reduced the surface tension of water when surfactant was absent from the aqueous phase, though both soils released soil organic matter at low surfactant concentrations as shown by measurement of the chemical oxygen demand of the supernatant solutions. Furthermore, both surfactants were shown to be weakly adsorbed by soil as shown by the use of a methylene blue assay. It is therefore proposed that the additional reduction in surface tension arises from synergistic interactions between the surfactants and dissolved soil organic matter.

Highway detention ponds can fill with sediments from runoff water loaded with traffic-related materials. Sediment disposal is problematic and various protocols are currently studied, including phytoremediation. Here we present a preliminary study on four highway detention ponds in southern France to identify key sediment characteristics. Our objectives were to characterize metal content and physicochemical properties of the sediments and to evaluate the role of charophytes, which grow spontaneously in ponds, on metal lability. Vegetated and non-vegetated areas were compared. The lability of Mn, Cu, Zn, and Pb complexes was greater in the presence of charophytes. No variation in grain size composition was observed between non-vegetated and vegetated areas. These results may be useful to implement a phytoremediation strategy using those spontaneous charophytes. Our results suggest that local factors may impact sediment characteristics: for instance, strong gusts of wind, typical of southern France climate, may blow particles (some of them not related to traffic) in and out of detention ponds.

In this report, the toxic effect of TCE (trichloroethylene), PCE (tetrachloroethylene), and potassium dichromate on P. subcapitata was investigated. The test was conducted at different concentrations of pollutants, starting from the European Community limit values defined for each analysed contaminant. Mixtures of pollutants were also tested to verify the combined effect of algae cells. Results suggest that both TCE and PCE were able to reduce P. subcapitata growth and metabolism starting from 0.05 and 0.02 mg L⁻¹ of contaminant, respectively. PCE seems to be substantially more toxic than TCE. Chromium produces a clear effect on algae growth and esterase activity only starting from 1 mg L⁻¹ of potassium dichromate; this result confirms the suitability of EU limit value. AFLP analysis showed that all tested pollutants produce DNA mutations probably due to oxygen radicals. Generally, chromium, at high concentrations, is more toxic and genotoxic that TCE or PCE. Test performed with a mixture of pollutants showed a synergic effect of chromium and organic compounds suggesting that the membrane damage induced from organic substances should increase the chromium cellular access.

Amine-functionalized SiO₂/TiO₂ photocatalytic films have been synthesized using the peroxo titanic acid (PTA) approach coupled with the sol-gel dip-coating method. The 3-aminopropyl-trimethoxysilane (APTMS) and methyltrimethoxysilane (MTMOS) were employed as the amine functional groups and silica precursor. The effects of the ratio of APTMS/MTMOS, PTA refluxed time, and pH of prepared sol on the characteristics and the formaldehyde degradation efficiency were investigated. Physicochemical properties of prepared photocatalysts were characterized with nitrogen adsorption-desorption isotherm measurement, SEM, X-ray diffraction (XRD), UV-vis spectrophotometer, and Fourier transform infrared (FTIR) spectroscopy. The XRD and FTIR results indicated that the obtained photocatalysts consisted of -NH₂ groups, SiO₂, and anatase TiO₂. The photocatalytic films showed high transmittance of 80-90% in the visible light region. The obtained film prepared with the APTMS/MTMOS ratio of 0.03, pH of 1.8, and 10 h of refluxed time possessed high specific surface area (604.0 m² g⁻¹) and 85% formaldehyde degradation efficiency. The enhancement of formaldehyde degradation efficiency was observed when increasing the PTA refluxed time. The repeatability of photocatalytic film was also tested, and the degradation efficiency was 92.0% of initial efficiency after seven cycles.

The potential of domestic wastewater treatment plants to contribute for the dissemination of ciprofloxacin-resistant bacteria was assessed. Differences on bacterial counts and percentage of resistance in the raw wastewater could not be explained on basis of the size of the plant or demographic characteristics of population served. In contrast, the treated effluent of the larger plants had significantly more heterotrophs and enterobacteria, including ciprofloxacin-resistant organisms, than the smaller (p < 0.01). Moreover, longer hydraulic retention times were associated with significantly higher percentages of resistant enterobacteria in the treated effluent (p < 0.05). Independently of the size or type of treatment used, domestic wastewater treatment plants discharged per day at least 10¹⁰-10¹⁴ colony forming units of ciprofloxacin-resistant bacteria into the receiving environment.

In this research, geological and hydrogeological studies were conducted to determine the source of high arsenic levels in the surficial aquifer of Simav Plain, Kutahya, Turkey. One of the two aquifer systems isolated in the study area was a deep confined aquifer composed of fractured metamorphic rocks that supply hot geothermal fluid. The other one was an unconfined alluvial aquifer, which developed within the graben area as a result of sediment deposition from the highlands. This aquifer serves as the primary water resource within the plain. A water quality sampling campaign conducted in 27 wells drilled in the surficial aquifer has yielded an average arsenic concentration of 99.1 µg/L with a maximum of 561.5 µg/L. Rock and sediment samples supported the fact that local metamorphic rocks contained significant amounts of sulfur minerals where arsenic-containing lenses are present inside. It was also determined that a Cu-Pb-Zn mine was operated in the past in the same formation. Arsenic-containing wastes of this mine were deposited near the Simav district center in an uncontrolled manner. This mined formation had arsenic levels reaching to levels as high as 660 mg/kg, which was found out to be the highest arsenic level in the area. Another potential arsenic source in the study area was the geothermal fluid that was used extensively in three geothermal fields with levels reaching to levels as high as 594 µg/L. Uncontrolled discharges of waste geothermal fluid and overexploitation of groundwater were also found to contribute to arsenic pollution in surface/subsurface waters of the plain. Thus, natural sources and anthropogenic influences of arsenic were found to create high concentrations in local water reserves of the area and influence human health. Consequently, death statistics from the 1995 to 2005 period collected from the area has revealed increased rates of gastrointestinal cancers above Turkish average.