Nitrate Removal in a Restored Spring‐Fed Wetland,Pennsylvania, USA1

ABSTRACT:  In 2001, the 1.04‐ha Hornbaker wetland in south‐central Pennsylvania was restored by blocking an artificial drainage ditch to increase water storage and hydraulic retention time (HRT). A primary goal was to diminish downstream delivery of nitrate that enters the wetland from a limestone spring, its main source of inflow. Wetland inflow and outflow were monitored weekly for two years to assess nitrate flux, water temperature, pH, and specific conductivity. In Year 2, spring discharge was measured weekly to allow calculation of nitrate loads and hydraulic retention time. Surface runoff was confirmed to be a small fraction of wetland inflows via rainfall‐runoff modeling with TR‐55. The full dataset (n = 102) was screened to remove 13 weeks in which spring discharge constituted < 85% of total inflows because of high precipitation and surface runoff. Over two years (n = 89), mean nitrate‐nitrogen concentrations were 7.89 mg/l in inflow and 3.68 mg/l in outflow, with a mean nitrate removal of 4.19 mg/l. During Year 2 (n = 47), for which nitrate load data were available, the wetland removed an average of 2.32 kg N/day, 65% of the load. Nitrate removal was significantly correlated with HRT, water temperature, and the concentration of nitrate in inflow and was significantly greater during the growing season (5.36 mg/l, 64%) than during the non‐growing season (3.23 mg/l, 43%). This study indicates that hydrologic restoration of formerly drained wetlands can provide substantial water quality benefits and that the hydrologic characteristics of spring‐fed wetlands, in particular, support effective nitrogen removal.     

Soil Remediation Techniques at Uncontrolled Hazardous Waste Sites

The A&WMA Critical Review entitled “Soil Remediation Techniques at Uncontrolled Hazardous Waste Sites” was presented by Ronald C. Sims, Department of Civil and Environmental Engineering, Utah State University, Logan, Utah. Dr. Sims presented his review at the 83rd Air & Waste Management Association Annual Meeting, held in Pittsburgh, Pennsylvania in June 1990. Prepared discussions presented during the Critical Review session are published here, along with some closing remarks by Dr. Sims. Ronald Harkov, Chairman of the Critical Review Subcommittee of the Publications Committee, served as moderator of the 1990 A&WMA Critical Review session.     

Co-composting of spent coffee ground with olive mill wastewater sludge and poultry manure and effect of Trametes versicolor inoculation on the compost maturity

The co-composting of spent coffee grounds, olive mill wastewater sludge and poultry manure was investigated on a semi-industrial scale. In order to reduce the toxicity of the phenolic fraction and to improve the degree of composting humification, composts were inoculated with the white-rot fungus Trametes versicolor in the early stages of the maturation phase.During composting, a range of physico-chemical parameters (temperature and both organic matter and C/N reduction), total organic carbon, total nitrogen, elemental composition, lignin degradation and spectroscopic characteristics of the humic acids (HAs) were determined; impacts of the composting process on germination index of Hordeum vulgare and Lactuca sativa were assessed. The coffee waste proved to be a highly compostable feedstock, resulting in mature final compost with a germination index of 120% in less than 5 months composting. In addition, inoculation with T. versicolor led to a greater degree of aromatization of HA than in the control pile. Moreover, in the inoculated mixture, lignin degradation was three times greater and HA increased by 30% (P < 0.05), compared to the control pile. In the T. versicolor inoculated mixture, the averages of C and N were significantly enhanced in the HA molecules (P < 0.05), by 26% and 22%, respectively. This improvement in the degree of humification was confirmed by the ratio of optical densities of HA solutions at 465 and 665 nm which was lower for HA from the treated mixture (4.5) than that from the control pile (5.4).     

Enhanced aerobic bioremediation of a gasohol release in a fractured bedrock aquifer

In January 2005, a gasoline tanker carrying approximately 8,500 gallons of gasohol (gasoline containing 10 percent ethanol) overturned and caught fire in the front yard of a residence. Emergency response crews responded to the accident, extinguished the fire, and recovered residual gasoline on the ground surface. Soil impacted by the release was then removed and disposed of off‐site and free‐phase gasohol was recovered using a combination of vacuum recovery, pumping, and bailing to the extent practicable. Following free product recovery efforts, a feasibility evaluation was completed to select a technology to address the remaining dissolved‐phase contaminants that resulted in biosparging pilot testing and, ultimately, the installation of a full‐scale biosparging system. The full‐scale system has been operating for approximately 21 months, and contaminant concentrations within the heart of the plume have decreased dramatically over a short period of time—in most cases, to below applicable cleanup standards. Despite the complex hydrogeologic conditions and significant initial concentrations, biosparging has proven to be an effective technology to remediate this gasohol release, and it is anticipated that drinking‐water standards can be achieved following two to three years of biosparging (i.e., an additional 3 to 15 months of operations). © 2010 Wiley Periodicals, Inc.     

NYSDEC's DER‐31/Green Remediation Policy Influences Tool Development and Global Program

The New York State Department of Environmental Conservation (NYSDEC) Division of Environmental Remediation (DER) issued a program policy focused on the overall sustainability of hazardous waste site cleanups on August 11, 2010. This DER‐31/Green Remediation program policy (DER‐31) was issued in accordance with 6 New York Codes, Rules and Regulations (NYCRR) Part 375 Environmental Remediation Programs. DER‐31 represents one of the first government‐issued green and sustainable remediation (GSR) policies in the United States. Consistent with other DER policies, DER‐31's provisions are broadly considered to be an expectation/requirement. GSR experts from within AECOM's Remediation Services (RS) Practice Area developed and implemented a GSR program designed to comply with DER‐31 provisions and have now broadly incorporated GSR into our New York remediation projects. Lessons learned from this experience in New York have influenced AECOM's global GSR program and implementation procedures and prompted the development of a new GSR tool (GSRx^TM) for identifying and assessing GSR best management practices (BMPs), which has also been employed globally. © 2013 Wiley Periodicals, Inc.     

Consumer-resource body-size relationships in natural food webs

It has been suggested that differences in body size between consumer and resource species may have important implications for interaction strengths, population dynamics, and eventually food web structure, function, and evolution. Still, the general distribution of consumer-'resource body-size ratios in real ecosystems, and whether they vary systematically among habitats or broad taxonomic groups, is poorly understood. Using a unique global database on consumer and resource body sizes, we show that the mean body-size ratios of aquatic herbivorous and detritivorous consumers are several orders of magnitude larger than those of carnivorous predators. Carnivorous predator-prey body-size ratios vary across different habitats and predator and prey types (invertebrates, ectotherm, and endotherm vertebrates). Predator-prey body-size ratios are on average significantly higher (1) in freshwater habitats than in marine or terrestrial habitats, (2) for vertebrate than for invertebrate predators, and (3) for invertebrate than for ectotherm vertebrate prey. If recent studies that relate body-size ratios to interaction strengths are general, our results suggest that mean consumer-resource interaction strengths may vary systematically across different habitat categories and consumer types.     

Kelp (<Emphasis Type="Italic">Laminaria digitata</Emphasis>) increases germination and affects rooting and plant vigour in crops and native plants from an arable grassland in the Outer Hebrides,Scotland

Kelp and other seaweeds are traditionally used in many parts of the world as a soil amendment on arable fields. Seaweeds contain biochemical compounds that can act as plant growth regulators in terrestrial plants. In a low-intensity arable grassland in northwest Scotland an organic fertilizer, kelp (Laminaria digitata) has been used for hundreds of years, due to its anticipated positive effect as a soil conditioner and provider of plant nutrients. In this study the effects of kelp on germination and rooting of crops and native plants from this area were investigated in soil-free media. Germination was studied by incubation in the presence of kelp solutions. Rooting of plant cuttings was assessed after a pulse treatment with kelp solutions, and indole-3 acetic acid (IAA) as a reference plant growth regulator. Germination percentage of Plantago lanceolata, Trifolium repens and Avena strigosa seeds increased significantly when incubated with 0.05% kelp solutions. Total root weight and the individual weight of roots produced in cuttings of Vigna radiata and P. lanceolata were significantly increased when exposed to a 0.5% solution of kelp. Plant vigour, assessed visually, decreased significantly for P. lanceolata exposed to kelp at concentrations of 0.5 and 5.0% indicating the presence of a threshold level for an inhibitory effect of kelp at these concentrations, which may be due to high salinity. The results confirmed the presence of plant growth regulators in kelp, and indicates that amendment with kelp may potentially affect plant community composition. The threshold levels where some plants responded negatively to kelp amendment were close to or lower than the theoretical concentrations of kelp in soil water at field conditions with the current doses used on the machair, indicating that care should be taken in either administering kelp at the appropriate dose or leaching out salt before application.     

Facial asymmetry is negatively related to condition in female macaque monkeys

The face is an important visual trait in social communication across many species. In evolutionary terms, there are large and obvious selective advantages in detecting healthy partners, both in terms of avoiding individuals with poor health to minimise contagion and in mating with individuals with high health to help ensure healthy offspring. Many models of sexual selection suggest that an individual's phenotype provides cues to their quality. Fluctuating asymmetry is a trait that is proposed to be an honest indicator of quality, and previous studies have demonstrated that rhesus monkeys gaze longer at symmetric faces, suggesting preferences for such faces. The current study examined the relationship between measured facial symmetry and measures of health in a captive population of female rhesus macaque monkeys. We measured asymmetry from landmarks marked on front-on facial photographs and computed measures of health based on veterinary health and condition ratings, number of minor and major wounds sustained and gain in weight over the first 4?years of life. Analysis revealed that facial asymmetry was negatively related to condition-related health measures, with symmetric individuals being healthier than more asymmetric individuals. Facial asymmetry appears to be an honest indicator of health in rhesus macaques, and asymmetry may then be used by conspecifics in mate-choice situations. More broadly, our data support the notion that faces are valuable sources of information in non-human primates and that sexual selection based on facial information is potentially important across the primate lineage.     

Plant growth rates and seed size: a re-evaluation

Small-seeded plant species are often reported to have high relative growth rate or RGR. However, because RGR declines as plants grow larger, small-seeded species could achieve higher RGR simply by virtue of their small size. In contrast, size-standardized growth rate or SGR factors out these size effects. Differences in SGR can thus only be due to differences in morphology, allocation, or physiology. We used nonlinear regression to calculate SGR for comparison with RGR for 10 groups of species spanning a wide range of life forms. We found that RGR was negatively correlated with seed mass in nearly all groups, but the relationship between SGR and seed mass was highly variable. We conclude that small-seeded species only sometimes possess additional adaptations for rapid growth over and above their general size advantage.