Concern over the enrichment of agricultural runoff with phosphorus (P) from land applied livestock manures has prompted the development of manure amendments that minimize P solubility. In this study, we amended poultry, dairy, and swine manures with two rare earth chlorides, lanthanum chloride (LaCl 3 ·7H 2 O) and ytterbium chloride (YbCl 3 ·6H 2 O), to evaluate their effects on P solubility in the manure following incubation in the laboratory as well as on the fate of P and rare earth elements (REEs) when manures were surface‐applied to packed soil boxes and subjected to simulated rainfall. In terms of manure P solubility, La:water‐extractable P (WEP) ratios close to 1:1 resulted in maximum WEP reduction of 95% in dairy manure and 98% in dry poultry litter. Results from the runoff study showed that REE applications to dry manures such as poultry litter were less effective in reducing dissolved reactive phosphorus (DRP) in runoff than in liquid manures and slurries, which was likely due to mixing limitations. The most effective reductions of DRP in runoff by REEs were observed in the alkaline pH soil, although reductions of DRP in runoff from the acidic soil were still >50%. Particulate REEs were strongly associated with particulate P in runoff, suggesting a potentially useful role in tracking the fate of P and other manure constituents from manure‐amended soils. Finally, REEs that remained in soil following runoff had a tendency to precipitate WEP, especially in soils receiving manure amendments. The findings have valuable applications in water quality protection and the evaluation of P site assessment indices.
Sediments recovered from the flooded mine workings of the Penn Mine, a Cu-Zn mine abandoned since the early 1960s, were cultured for anaerobic bacteria over a range of pH (4.0 to 7.5). The molecular biology of sediments and cultures was studied to determine whether sulfate-reducing bacteria (SRB) were active in moderately acidic conditions present in the underground mine workings. Here we document multiple, independent analyses and show evidence that sulfate reduction and associated metal attenuation are occurring in the pH-4 mine environment. Water-chemistry analyses of the mine water reveal: (1) preferential complexation and precipitation by H2S of Cu and Cd, relative to Zn; (2) stable isotope ratios of 34S/32S and 18O/16O in dissolved SO4 that are 2-3 per thousand heavier in the mine water, relative to those in surface waters; (3) reduction/oxidation conditions and dissolved gas concentrations consistent with conditions to support anaerobic processes such as sulfate reduction. Scanning electron microscope (SEM) analyses of sediment show 1.5-micrometer, spherical ZnS precipitates. Phospholipid fatty acid (PLFA) and denaturing gradient gel electrophoresis (DGGE) analyses of Penn Mine sediment show a high biomass level with a moderately diverse community structure composed primarily of iron- and sulfate-reducing bacteria. Cultures of sediment from the mine produced dissolved sulfide at pH values near 7 and near 4, forming precipitates of either iron sulfide or elemental sulfur. DGGE coupled with sequence and phylogenetic analysis of 16S rDNA gene segments showed populations of Desulfosporosinus and Desulfitobacterium in Penn Mine sediment and laboratory cultures.
Reuse of wastewater for aquaculture improves the efficient use of water and promotes sustainability but the potential effects of endocrine disrupting compounds including estrogens in wastewater are an emerging challenge that needs to be addressed. We examined the biological effects of wastewater-borne estrogens on African catfish (Clarias gariepinus) raised in a wastewater stabilization pond (WSP) of a functioning municipal wastewater treatment plant, a wastewater polishing pond (WWP) of a dysfunctional treatment plant, and a reference pond (RP) unimpacted by wastewater, located in Ghana. Measurements of estrogen concentrations in pond water by liquid chromatography/tandem mass spectrometry showed that mean 17 β-estradiol concentrations were higher in the wastewater ponds (WWP, 6.6 ng/L ± 2.7 ng/L; WSP, 4.9 ng/L ± 1.0) than the reference (RP, 3.4 ± 1.1 ng/L). Estrone concentrations were found to be highest in the WSP (7.8 ng/L ± 1.7) and lowest in the WWP (2.2 ng/L ± 2.4) with the RP intermediate (4.7 ± 5.0). Fish serum estrogenicity assayed by E-SCREEN was significantly higher in female vs. male catfish in the RP and WSP but not in the WWP (p ≤ 0.05). Histological examination of liver and gonad tissue showed no apparent signs of intersex or pathology in any ponds. The similarities in various measures of body indices between fish of this study and African catfish from freshwater systems suggest that aquaculture may be a suitable reuse option for treated municipal wastewater.
Little is known about the fate of arsenic (As) in land-applied litter from chickens that have been fed roxarsone, an organic feed additive containing As. This study seeks to elucidate the transfer of As in runoff from ditch-drained soils of the poultry-producing region of the Delmarva Peninsula by tracking As and phosphorus (P) export from seven drainage ditches over two water-years (1 July 2005 to 30 June 2007). Annual losses of As from ditches ranged from 0.004 to 0.071 kg ha(-1) while P losses ranged from 0.33 to 18.56 kg ha(-1), with the largest loads associated with a litter storage shed that served as a point source. Event-based As and P losses in ditch flow fluctuated by a factor of 162 and 1882, respectively. The two elements were correlated in flow from the ditch draining a litter storage shed (r = 0.99), and in sediment extracts in soils near the litter shed (r = 0.73), pointing to similar behavior under point source conditions. Indeed, As and P exhibited similar behavior within storms for all ditches, characterized by relatively high initial concentrations subject to rapid concentration declines before peak flow, consistent with dilution of a finite source. However, As and P concentrations varied significantly between ditches and showed considerable temporal variability within ditches, with no clear seasonal trends or associations with current management strategies. The results suggest that similar management strategies might be effective for As and P point sources, but that field management practices geared toward controlling nonpoint source P losses may not readily transfer to the control of As losses.
Poultry production on Delmarva is a primary source of poultry litter used to fertilize farmland to support staple crop production. This trend over long period of time may cause a build-up of trace elements such as As, Hg and Zn in soils, which can contaminate water resources at relatively low levels. Additionally, the widespread adoption of no-till farming on Delmarva and the usual practice of surface application of poultry litter have led to elevated trace elements transport in surface run-off. Three poultry litter amendment treatments – broadcast (conventional no-till), subsurface application and broadcast/disked were compared in this study with an unamended control (no litter). Immediately after litter application, lysimeters (61 x 61 x 61cm) were collected from each of the treatment areas, set at 3% slope and subjected to rainfall simulation (1 hr, 6.06 cm/hr) 15 and 42 days after litter application. Runoff samples were analyzed for dissolved and particulate trace elements (arsenic, selenium, mercury, and zinc). USDA-ARS subsurface (subsurfer) application and broadcasting followed by disking lowered losses of As and Zn in surface runoff by about 2-fold as compared to the broadcast application after the first rainfall simulation. However, the differences disappeared by the second rainfall event. No differences were observed between treatments in losses of Hg and Se in runoff for both rainfall events. These results suggest that incorporation of poultry litter by subsurface application or broadcast followed by disking would help lower trace elements of concern such as As in surface runoff.
Highlights Concern over nutrient runoff from agriculture has prompted research to limit phosphorus (P) mobility. Mine drainage residuals (MDRs) can reduce phosphorus solubility in soils, sediments and liquid manure slurries. MDR amendment resulted in lower dissolved phosphorus in runoff from sites treated with dairy manure slurry, but not with swine manure slurry. This study underscores the value of testing under field conditions before making recommendations. Abstract . Concern over nutrient runoff from agriculture has prompted considerable research on amendments to limit phosphorus (P) solubility of manure slurries and P mobility following land application of the slurry. The concept of solving one industry’s problem with another industry’s problem is attractive, but successful examples are uncommon. Mine drainage residual (MDR), generated from the process of neutralizing acid discharge from coal mines, has been shown to reduce soluble P in soils, sediments and manure slurries. We therefore sought to test whether amending manure slurries with MDR was effective at reducing P in runoff once that slurry was applied to agricultural soils. A series of simulated rainfall experiments revealed that amending dairy manure slurry with MDR resulted in significantly less flow weighted dissolved P concentrations and loads in runoff. However, the same effect was not observed with runoff from soils amended with swine manure slurry, despite a greater reduction of water extractable P in swine manure slurry with MDR addition than in dairy manure slurry. This study underscores the value of testing amendments under field conditions before making manure management recommendations. Keywords: Manure, Phosphorus, Mine drainage residual, Engineered treatment, Simulated rainfall.
Steroid estrogens contained in wastewater discharge from sewage treatment plants and agricultural run-off can alter endocrine function in exposed wildlife at part per trillion (ng/L) levels. Detection and quantification of estrogens in the environment at these levels pose numerous analytical challenges. This study aimed to develop a reproducible, accurate, and simple method for 17-estradiol (E2) quantification from environmental water samples. Extraction efficiencies of three solid phase extraction (SPE) cartridges; ENVI-Carb, Oasis HLB Glass and Oasis HLB Plus were tested by trial extractions of 500 mL ultrapure water spiked to 1 ng/mL, 10 ng/mL and 100 ng/mL. The Oasis HLB Plus cartridges yielded the best mean extraction efficiencies of 120.50 8.02 %; 113.23 9.77 % and 105.2 21.16 % for 100 ng/mL, 10 ng/mL and 1 ng/mL ultrapure water spikes respectively. Further tests of extractions efficiencies for field water samples showed reduced mean extraction efficiencies of 80.6 13.1 % for concentrations ranging from 40-15000 ng/L. This suggests the need for further clean-up of heavily loaded aqueous samples. Detection and quantification was by LC/MS using electrospray ionization (ESI) in negative ionization mode. Presence of precursor ion 271 (m/z) and product ion 183 (m/z) identified E2. A limit of quantification (LOQ) of 10 ng/L was established by finding the lowest point on the calibration curve whose signal-to-noise ratio was at least 3. Validation of the LOQ by analysis of 7 replicates of 40 ng/L field spikes by the SPE-LC/ESI/MS procedure yielded a mean recoveries of 81.98 8.5%.
Abstract Methyl tert ‐butyl ether (MTBE) and benzene have been measured since 1993 in a shallow, sandy aquifer contaminated by a mid‐1980s release of gasoline containing fuel oxygenates. In wells downgradient of the release area, MTBK was detected before benzene, reflecting a chromatographic‐like separation of these compounds in the direction of ground water flow. Higher concentrations of MTBE and benzene were measured in the deeper sampling ports of multilevel sampling wells located near the release area, and also up to 10 feet (3 m) below the water table surface in nested wells located farther from the release area. This distribution of higher concentrations at depth is caused by recharge events that deflect originally horizontal ground water flowlines. In the laboratory, microcosms containing aquifer material incubated with uniformly labeled 14 C‐MTBE under aerobic and anaerobic. Fe(III)‐reducing conditions indicated a low but measurable biodegradation potential (<3% 14 C‐MTBW as 14 CO 2 ) after a seven‐month incubation period, Tert ‐butyl alcohol (TBA), a proposed microbial‐MTBE transformation intermediate, was detected in MTBE‐contaminated wells, but TBA was also measured in unsaturated release area sediments. This suggests that TBA may have been present in the original fuel spilled and does not necessarily reflect microbial degradation of MTBE. Combined, these data suggest that milligram per liter to microgram per liter decreases in MTBE concentrations relative to benzene are caused by the natural attenuation processes of dilution and dispersion with less‐contaminated ground water in the direction of flow rather than biodegradation at this point source gasoline release site.
