Biological assessment of bisphenol A degradation in water following direct photolysis and UV advanced oxidation

Endocrine disrupting compounds (EDCs) are exogenous environmental chemicals that can interfere with normal hormone function and present a potential threat to both environmental and human health. The fate, distribution and degradation of EDCs is a subject of considerable investigation. To date, several studies have demonstrated that conventional water treatment processes are ineffective for removal of most EDCs and in some instances produce multiple unknown transformation products. In this study we have investigated the use of direct photolysis with low-pressure (LP) Hg UV lamps and UV+hydrogen peroxide (H(2)O(2)) advanced oxidation process (AOP) for the degradation of a prototypic endocrine disrupter, bisphenol A (BPA), in laboratory water. Removal rates of BPA and formation of degradation products were determined by high performance liquid chromatography (HPLC) analysis. Changes in estrogenic activity were evaluated using both in vitro yeast estrogen screen (YES) and in vivo vitellogenin (VTG) assays with Japanese medaka fish (Oryzias latipes). Our results demonstrate that UV alone did not effectively degrade BPA. However, UV in combination with H(2)O(2) significantly removed BPA parent compound and aqueous estrogenic activity in vitro and in vivo. Removal rates of in vivo estrogenic activity were significantly lower than those observed in vitro, demonstrating differential sensitivities of these bioassays and that certain UV/AOP metabolites may retain estrogenic activity. Furthermore, the UV/H(2)O(2) AOP was effective for reducing larval lethality in treated BPA solutions, suggesting BPA degradation occurred and that the degradation process did not result in the production of acutely toxic intermediates.     

Assessing the efficacy of dredged materials from lake panasoffkee,Florida: Implication to environment and agriculture

BACKGROUND, AIMS AND SCOPE: Current dredged material disposal alternatives have several limitations. Options for dealing with dredged materials include leaving them alone, capping them with clean sediments, placing them in confined facilities, disposing of them at upland sites, treating them chemically, or using them for wetlands creation or other beneficial uses The ability to reuse lake-dredge materials (LDM) for agricultural purposes is important because it reduces the need for offshore disposal and provides an alternative to disposal of the materials in landfills. Often these materials can be obtained at little or no cost to the farmers or landowners. Thus, forage production offers an alternative to waste management since nutrients in the LDM are recycled into crops that are not directly consumed by humans. The objective of this study (Part 2) were to: (1) assess dredge materials from Lake Panasoffkee, Florida as a soil amendment to establish bahiagrass (BG) in a subtropical beef cattle pasture in Sumter County, Florida; and (2) determine the effect of LDM application on the crude protein (CP) and nutrient uptake of BG. This series of two papers aims at providing assessment of the efficacy of lake-dredged materials especially its implication to environment (soil quality, Part 1) and agriculture (forage quality and pasture establishment, Part 2). METHODS: The experimental treatments that were evaluated consisted of different ratios of natural soil (NS) to LDM: LDM0 (100% NS:0% LDM); LDM25 (75% NS:25% LDM); LDM50 (50% NS:50% LDM); LDM75 (25% NS:75% LDM); and LDM100 (0% NS:100% LDM). Bahiagrass plots at its early establishment were cut to a 5-cm stubble height on Julian days 112 and harvested to the same stubble height on Julian days 238 and on Julian days 546 following the double-ring method. Field layout was based on the principle of a completely randomized block design with four replications. Plant samples harvested at 546 Julian days were ground to pass through a 1-mm mesh screen in a Wiley mill. Ground forage was analyzed for crude protein. Ground forage samples were also analyzed for tissue P, K, Ca, Mg, Mn, Cu, Fe, Al, and Mo concentrations using an ICP spectroscopy. The effects of dredged materials addition on forage yield and on crude protein and nutrient uptake that were taken at 546 Julian days were analyzed statistically following the PROC ANOVA procedures. RESULTS AND DISCUSSION: Part 1 of this study demonstrated that the heavy and trace metal contents of LDM were below the probable effect levels and threshold effect levels. As such, the agricultural or livestock industry could utilize these LDM to produce forages. Resuits showed consistently and significantly (p < 0.001) higher BG biomass production and CP from plots amended with LDM than those of BG planted on plots with 0% LDM. Forage yield of BG during its establishment increased linearly (Forage Yield = 1724.3 + 25.64*LDM; R2 = 0.83; p < or = 0.0001) with increasing rates of LDM application. The CP of BG also varied significantly with varying levels of LDM applications. The tissues of BG with 100% LDM had the greatest CP content while the lowest CP content was from the control plots (LDM0). The CP of BG increased linearly with increasing rates of LDM application. The crude protein response to BG application can be described by a linear equation: Crude Protein = 10.38 + 0.052*LDM; R2 = 0.85 p < or = 0.0001. Addition of LDM had increased the levels of Ca by about 1811% when compared with the level of soil Ca among plots with no LDM application. Liming the field could have some direct and indirect effects on the chemical status of the soils. The physiological functions performed by Ca in plants are not clearly defined, but it has been suggested that Ca favors the formation of and increases the protein content of mitochondria. CONCLUSIONS: Beneficial uses of dredged materials from LP, Florida are both economical and environmental. Often these materials can be obtained at little or no cost to the farmers or landowners. Results showed that dredged materials can be used as soil amendments (lime and fertilizer) for early establishment of BG in beef cattle pastures. Environmentally, dredging of sediments that are rich in CaCO3 should restore the 19.4-sq km LP by removing natural sediments from the lake bottom to improve the fishery, water quality, and navigation of the lake. The nutritional uptake of BG grown in unfertile sandy soils of Sumter County was enhanced significantly (p < or = 0.001) by LDM addition. Uptake of TKN, TP, K, Ca, and Mg were remarkably increased as a result of LDM. RECOMMENDATION AND OUTLOOK: Land application of LDM from LP may not only provide substantial benefits that will enhance the environment, community, and society in south Florida, but also in other parts of the world especially those areas with forage-based beef cattle pastures and similar climatic conditions. The heavy and trace metal contents of these materials were below the PEL and TEL (see Part 1). As such, the agricultural or livestock industry could utilize these LDM to produce forages. LDM should be regarded as a beneficial resource, as a part of the ecological system. Although our results have demonstrated the favorable and beneficial effects of added LDM on the early establishment of BG in pasture fields., further studies are still needed not only in pastures of south Florida, but also in other areas with subtropical or tropical climatic conditions to determine whether the environmental and ecological implications of LDM application are satisfied over the longer term.     

Transport modeling of copper and cadmium with linear and nonlinear retardation factors

The predictive accuracy of using the one-dimensional advection–dispersion equation to evaluate the fate and transport of solute in a soil column is usually dependent on the proper determination of chemical retardation factors. Typically, the distribution coefficient (K_d) obtained by fitting the linear sorption isotherm has been extensively used to consider general geochemical reactions on solute transport in a low-concentration range. However, the linear distribution coefficient cannot be adequately utilized to describe the solute fate at a higher concentration level. This study employed the nonlinear equilibrium-controlled sorption parameters to determine the retardation factor used in column leaching experiments. Copper and cadmium transportation in a lateritic silty-clay soil column was examined. Through the explicit finite-difference calculations with a third-order total-variation-diminishing (TVD) numerical solution scheme, all results of the theoretical copper and cadmium breakthrough curves (BTCs) simulated by using the Freundlich nonlinear retardation factors revealed good agreement with the experimental observations.     

Effects of major nutrient additions on metal uptake in phytoplankton

We examined the influences of major nutrients (N, P, Si) on the accumulation of three trace metals [Cd, Se(IV), and Zn] in four species of marine phytoplankton (diatom, green alga, dinoflagellate, prasinophyte). Relative metal uptake was quantified by the kinetic measurements of metal concentration factor over a short exposure period. Our study demonstrated that nutrient addition significantly influenced the metal uptake rate and the cell growth rate in all four phytoplankton species. An increase in ambient N concentration considerably enhanced metal uptake by the cells. The dry weight concentration factor increased by 2.4-14.9 times for Cd, 1.1-4.0 times for Se, and 1.1-5.4 times for Zn in all four phytoplankton species with an addition of 176.4 microM N. The effects of P or Si addition on metal uptake and cell growth were less pronounced than the effects of N addition. Under most circumstances the rate of metal uptake increased exponentially with increasing cell growth rate constant. Only Se(IV) uptake in the diatom Phaeodactylum tricornutum was not correlated with cell growth rate. Se(IV) was not accumulated by the green algae Chlorella autotrophica at a high P concentration (7.2 microM), but appreciable accumulation was documented in cells inoculated without P addition. Our study therefore demonstrated that nutrient enrichments in many coastal waters can considerably affect trace metal uptake in phytoplankton and presumably metal trophic transfer in marine food chains.     

The fermentative production of L-lysine as an animal feed additive

A new and innovative process for the biotechnological production of L-lysine is presented, exemplified here by the fermentative production of the feed additive Biolys60. The novel feature of this product is that the entire manufacturing concept, i.e. the production strain, the raw materials, all process stages and the product specifications have been systematically tailored for optimal environmental compatibility and for minimum resource depletion and waste. The process completely dispenses with the need to discharge residual and waste material and reduces the handling of hazardous materials to a minimum. Since only a few process stages are involved, the method is economical to use and investment outlay is reduced. The process, which also leads to a higher grade product, is thus highly attractive in both ecological and economical terms. By boosting the nutrient value of the plant-based feedstuffs, the product itself makes an cost-effective contribution towards a more sustainable form of animal feeding and by reducing nitrogen emission levels promotes a more environmentally compatible form of animal husbandry.     

Analysis of pesticide runoff from mid-Texas estuaries and risk assessment implications for marine phytoplankton

During 1993, estuarine surface water samples were collected from the mid-Texas coast (Corpus Christi to Port Lavaca, TX). Agricultural watershed areas as well as tidal creeks immediately downstream were chosen as sampling sites along with adjoining bay sampling stations. Collections were made throughout the growing season (February to October 1993) before and after periods of significant (> 1.25 cm) rainfall. All samples were initially screened for the presence of pesticides using enzyme-linked immunosorbent assay (ELISA) test kits (EnviroGard) for triazine herbicides and carbamate insecticides. All samples were extracted and then analyzed using gas chromatography (GC) for quantification of atrazine. Only samples testing positive for carbamate insecticides via ELISA were further extracted for GC analysis to quantify aldicarb and carbofuran. Additionally, laboratory toxicity tests using phytoplankton were examined from published, peer-reviewed literature and compared with the atrazine field levels found in Texas. Results of ELISA screening indicated the presence of triazine herbicides in nearly all samples (>93%). GC analysis further confirmed the presence of atrazine concentrations ranging from <0.01-62.5 microg/L. Screening tests also found detectable levels of carbamate insecticides (aldicarb and carbofuran) that were also confirmed and quantified by GC. Comparison of measured concentrations of atrazine compared with published toxicity tests results indicated that there was a potential environmental risk for marine/estuarine phytoplankton in surface waters of Texas estuaries, particularly when the chronic nature of atrazine exposure is considered.     

Soil-to-plant and plant-to-cow's milk transfer of radiocaesium in alpine pastures: significance of seasonal variability

Because our present knowledge on the environmental behaviour of fallout radiocaesium in semi-natural environments is rather limited, the transfer of this radionuclide and of natural 40K, from soil-to-plant as well as from plant-to-cow's milk was investigated for a typical alpine pasture (site P). For comparison, a nearby alpine pasture (site K) not used for cattle grazing was also studied. Small seasonal effects were found for 137Cs in the plants, but they were different for the two pastures. Due to the presence of a large variety of different plant species on the pastures and soil adhesion on the vegetation from trampling cattle, the scattering of the data was very large, and the seasonal effects were observable only because of the large number of samples (N approximately 100) collected. The aggregated soil-to-plant transfer factor of 137Cs was for site P, on average, 0.002 +/- 0.001 m2 kg(-1). The plant-to-milk transfer coefficient was, on average, 0.02 day l(-1). The 137Cs concentration in the milk of the cows varied within the grazing period only between 1.4 and 2.9 Bq l(-1), with a significant maximum in the beginning of August. As a result of soil adhesion due to cattle trampling, significantly higher ash- and 137Cs contents of the plants were observed at site P as compared to site K. Possible consequences of the above observations with respect to a representative sampling design of vegetation and milk are discussed.     

Leaching and degradation of corn and soybean pesticides in an Oxisol of the Brazilian Cerrados

Pesticide pollution of ground and surface water is of growing concern in tropical countries. The objective of this pilot study was to evaluate the leaching potential of eight pesticides in a Brazilian Oxisol. In a field experiment near Cuiabá, Mato Grosso, atrazine, chlorpyrifos, lambda-cyhalothrin, endosulfane alpha, metolachlor, monocrotofos, simazine, and trifluraline were applied onto a Typic Haplustox. Dissipation in the topsoil, mobility within the soil profile and leaching of pesticides were studied for a period of 28 days after application. The dissipation half-life of pesticides in the topsoil ranged from 0.9 to 14 d for trifluraline and metolachlor, respectively. Dissipation curves were described by exponential functions for polar pesticides (atrazine, metolachlor, monocrotofos, simazine) and bi-exponential ones for apolar substances (chlorpyrifos, lambda-cyhalothrin, endosulfane alpha, trifluraline). Atrazine, simazine and metolachlor were moderately leached beyond 15 cm soil depth, whereas all other compounds remained within the top 15 cm of the soil. In lysimeter percolates (at 35 cm soil depth), 0.8-2.0% of the applied amounts of atrazine, simazine, and metolachlor were measured within 28 days after application. Of the other compounds less than 0.03% of the applied amounts was detected in the soil water percolates. The relative contamination potentials of pesticides, according to the lysimeter study, were ranked as follows: metolachlor > atrazine = simazine > monocrotofos > endsulfane alpha > chlorpyrifos > trifluraline > lambda-cyhalothrin. This order of the pesticides was also achieved by ranking them according to their effective sorption coefficient Ke, which is the ratio of Koc to field-dissipation half-life.     

Design and startup of a membrane-biological-reactor system at a Ford-engine plant for treating oily wastewater.

A wastewater-treatment facility at Ford (Dearborn, Michigan) was recently upgraded from chemical de-emulsification to ultrafiltration (UF) followed by a membrane-biological reactor (MBR). This paper describes the design, startup, and initial operational performance of the facility. Primary findings are as follows: (1) the MBR proved resilient; (2) the MBR removed approximately 90% of chemical-oxygen demand (COD) after primary UF; (3) the removal of total Kjeldahl nitrogen by MBR appeared to be more sensitive to operating conditions than COD removal; (4) nitrification and denitrification were established in one month; (5) the MBR removed oil and grease and phenolics to below detection levels consistently, in contrast to widely fluctuating concentrations in the past; (6) permeate fluxes of the primary and MBR UF were adversely affected by inadvertent use of a silicone-based defoamer; and (7) zinc concentrations in the effluent increased, which might have been a result of ethylenediaminetetraacetic acid used in membrane washing solutions and/or might have been within typical concentration ranges.     

Effects of increased deposition of atmospheric nitrogen on an upland moor: leaching of N species and soil solution chemistry

This study was designed to investigate the leaching response of an upland moorland to long-term (10 yr) ammonium nitrate additions of 40, 80 and 120 kg N ha(-1) yr(-1) and to relate this response to other indications of potential system damage, such as acidification and cation displacement. Results showed increases in nitrate leaching only in response to high rates of N input, in excess of 96 and 136 kg total N input ha(-1) yr(-1) for the organic Oh horizon and mineral Eag horizon, respectively. Individual N additions did not alter ammonium leaching from either horizon and ammonium was completely retained by the mineral horizon. Leaching of dissolved organic nitrogen (DON) from the Oh horizon was increased by the addition of 40 kg N ha(-1) yr(-1), but in spite of increases, retention of total dissolved nitrogen reached a maximum of 92% and 95% of 80 kg added N ha(-1) yr(-1) in the Oh and Eag horizons, respectively. Calcium concentrations and calcium/aluminium ratios were decreased in the Eag horizon solution with significant acidification mainly in the Oh horizon leachate. Nitrate leaching is currently regarded as an early indication of N saturation in forest systems. Litter C:N ratios were significantly lowered but values remained above a threshold predicted to increase leaching of N in forests.