Pyrolysis-induced phosphorus transformations for biosolids from diverse sources.

Biosolids have been long used as a soil amendment to promote nutrient recovery. The readily releasable forms of nutrients present in this biowaste, such as phosphorus (P), along with their over application, can be detrimental to the environment, causing eutrophication. Pyrolysis, the thermal decomposition of organic materials at elevated temperature and low oxygen, seems to be a promising strategy to lower P release from biowastes such as biosolids.

Valorization of farm pond biomass as fertilizer for reducing basin-scale phosphorus losses.

Long-term fertilizer phosphorus (P) inputs are causing phosphorous saturation of agricultural soils globally. The saturation is spreading to the edge-of-the-farm stormwater detention systems (SDSs) from where the legacy P is potentially being released to downstream surface waters. We use site-specific and literature data for P-saturated SDSs, to develop and evaluate the biogeochemical and economic feasibility of a P recycling program that targets both low (LIC, sugarcane) and high intensity cropping (HIC, fresh-produce) systems within a watershed.

Arsenic release from Floridan Aquifer rock during incubations simulating aquifer storage and recovery operations.

While aquifer storage and recovery (ASR) is becoming widely accepted as a way to address water supply shortages, there are concerns that it may lead to release of harmful trace elements such as arsenic (As). Thus, mechanisms of As release from limestone during ASR operations were investigated using 110-day laboratory incubations of core material collected from the Floridan Aquifer, with treatment additions of labile or refractory dissolved organic matter (DOM) or microbes. During the first experimental phase, core materials were equilibrated with native groundwater lacking in DO to simulate initial non-perturbed anaerobic aquifer conditions.

Physicochemical and sorptive properties of biochars derived from woody and herbaceous biomass.

It is unclear how the properties of biochar control its ability to sorb metals. In this work, physicochemical properties of a variety of biochars, made from four types of feedstock at three pyrolysis temperatures (300, 450 and 600°C) were compared to their ability to sorb arsenic (As) and lead (Pb) in aqueous solutions. Experimental results showed that both feedstock types and pyrolysis temperature affected biochar's production rate, i.

Manganese oxide-modified biochars: preparation, characterization, and sorption of arsenate and lead.

This work explored two modification methods to improve biochar's ability to sorb arsenic (As) and lead (Pb). In one, pine wood feedstock was pyrolyzed in the presence of MnCl2·4H2O (MPB) and in the other it was impregnated with birnessite via precipitation following pyrolysis (BPB). The resulting biochars were characterized using thermogravimetry, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and energy-dispersive X-ray analyses.

Biochar amendment affects leaching potential of copper and nutrient release behavior in contaminated sandy soils.

Copper (Cu) contamination to soil and water is a worldwide concern. Biochar has been suggested to remediate degraded soils. In this study, column leaching and chemical characterization were conducted to assess effects of biochar amendment on Cu immobilization and subsequent nutrient release in Cu-contaminated Alfisol and Spodosol.

Removal of arsenic by magnetic biochar prepared from pinewood and natural hematite.

There is a need for the development of low-cost adsorbents to removal arsenic (As) from aqueous solutions. In this work, a magnetic biochar was synthesized by pyrolyzing a mixture of naturally-occurring hematite mineral and pinewood biomass. The resulting biochar composite was characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDS).

Interaction effects of climate and land use/land cover change on soil organic carbon sequestration.

Historically, Florida soils stored the largest amount of soil organic carbon (SOC) among the conterminous U.S. states (2.

Ionic strength reduction and flow interruption enhanced colloid-facilitated Hg transport in contaminated soils.

The effects of ionic strength (IS) reduction (5-0.05mM) and flow interruption (FI, flow stopped for 7d) on colloid and Hg release in the leachate were examined in column experiment. Two Hg contaminated soils (13.

Particulate copper in soils and surface runoff from contaminated sandy soils under citrus production.

Soil contamination by copper (Cu) is a worldwide concern. Laboratory incubation and soil Cu characterization were conducted to examine the effects of external Cu loading and liming on Cu speciation in both bulk soil and particulates of an Alfisol and Spodosol under citrus production. Also, drainage water from the sites was evaluated for dissolved and particulate forms of Cu.

Orthophosphate Leaching in St. Augustinegrass and Zoysiagrass Grown in Sandy Soil under Field Conditions.

Phosphorus (P) is required to maintain healthy, high-quality, warm-season turf. However, excessive P applications to soils with poor P retention capabilities may lead to leaching losses to groundwater. This field study was conducted to determine the maximum P fertilizer application rate to (Walt.

Nutrient removal using biosorption activated media: preliminary biogeochemical assessment of an innovative stormwater infiltration basin.

Soil beneath a stormwater infiltration basin receiving runoff from a 23 ha predominantly residential watershed in north-central Florida, USA, was amended using biosorption activated media (BAM) to study the effectiveness of this technology in reducing inputs of nitrogen and phosphorus to groundwater. The functionalized soil amendment BAM consists of a 1.0:1.

Soil property control of biogeochemical processes beneath two subtropical stormwater infiltration basins.

Substantially different biogeochemical processes affecting nitrogen fate and transport were observed beneath two stormwater infiltration basins in north-central Florida. Differences are related to soil textural properties that deeply link hydroclimatic conditions with soil moisture variations in a humid, subtropical climate. During 2008, shallow groundwater beneath the basin with predominantly clayey soils (median, 41% silt+clay) exhibited decreases in dissolved oxygen from 3.

Spectroscopic models of soil organic carbon in Florida, USA.

Soil organic carbon (SOC) is an indicator of ecosystem quality and plays a major role in the biogeochemical cycles of major nutrients and water. Shortcomings exist to estimate SOC across large regions using rapid and cheap soil sensing approaches. Our objective was to estimate SOC in 7120 mineral and organic soil horizons in Florida using visible/near-infrared diffuse reflectance spectroscopy (VNIRS) calibrated by committee trees and partial least squares regression (PLSR).

Bench-scale recovery of phosphorus from flushed dairy manure wastewater.

Recovery of phosphorus (P) from flushed dairy manure in an easily-dewatered form would enable farmers to manage P as a resource rather than land-apply it in excess at environmental risk. The purpose of this study was to evaluate (i) the feasibility of P recovery and (ii) the form of recovered P from flushed dairy manure wastewater using crystallization in a fluidized-bed reactor. Wastewater was pumped directly from a dairy farm reservoir and continuously fed in parallel through four bench-scale fluidized-bed reactors deployed on-site.

Inhibition of calcium phosphate precipitation under environmentally-relevant conditions.

Precipitation of Ca phosphates plays an important role in controlling P activity and availability in environmental systems. The purpose of this study was to determine inhibitory effects on Ca phosphate precipitation by Mg(2+), SO(4)(2-), CO(3)(2-), humic acid, oxalic acid, biogenic Si, and Si-rich soil clay commonly found in soils, sediments, and waste streams. Precipitation rates were determined by measuring decrease of P concentration in solutions during the first 60 min; and precipitated solid phases identified using X-ray diffraction and electron microscopy.

Time dependency and irreversibility of water desorption by drinking-water treatment residuals: implications for sorption mechanisms.

Drinking-water treatment residuals (WTRs) are being evaluated as cost-effective sorption media for use in environmental remediation. Data from previous work have suggested that intraparticle phosphorus (P) diffusion into micropores is the rate-limiting mechanism of P sorption by WTRs. We used isothermal thermogravimetric analysis (TG) to study water desorption/resorption dynamics as they relate to steric diffusion rate limitations for prospective sorbates.

Physicochemical properties related to long-term phosphorus retention by drinking-water treatment residuals.

Drinking-water treatment residuals (WTRs) are nonhazardous materials that can be obtained free-of-charge from drinking-water treatment plants to reduce soluble phosphorus (P) concentrations in poorly P sorbing soils. Phosphorus sorption capacities of WTRs can vary 1-2 orders of magnitude, on the basis of short-term equilibration times (up to 7 d), but studies dealing with long-term (weeks to months) P retention by WTRs are lacking. Properties that most affect long-term P sorption capacities are pertinent to the efficacy of WTRs as amendments to stabilize P in soils.

Long-term phosphorus effects on evolving physicochemical properties of iron and aluminum hydroxides.

Iron (Fe) and aluminum (Al) hydroxides are highly reactive components in environmental processes, such as contaminant fate and transport. Phosphorus (P) sorption by these components can decrease environmental problems associated with excess accumulation of P in soils. The long-term stability of P sorbed by Fe/Al hydroxides is of major concern.

Phosphorus immobilization in micropores of drinking-water treatment residuals: implications for long-term stability.

Drinking-water treatment residuals (WTRs) can immobilize excess soil phosphorus (P), but little is known about the long-term P retention by WTRs. To evaluate the long-term P sorption characteristics of one Fe- and one Al-based WTR, physicochemical properties pertinent to time-dependency and hysteresis of P sorption were assessed. This study also investigated the P sorption mechanisms that could affect the long-term stability of sorbed P by WTRs.

Intraparticle phosphorus diffusion in a drinking water treatment residual at room temperature.

Phosphorus (P) has been recognized as one of the major limiting nutrients that are responsible for eutrophication of surface waters, worldwide. Efforts have been concentrated on reducing P loads reaching water bodies, via surface runoff and/or leaching through a soil profile. Use of drinking water treatment residuals (WTRs) is an emerging cost-effective practice to reduce soluble P in poorly P-sorbing soils or systems high in P.

Lead contamination in shooting range soils from abrasion of lead bullets and subsequent weathering.

Contamination of shooting range soils from the use of Pb bullets is under increasing scrutiny. Past research on Pb contamination of shooting ranges has focused on weathering reactions of Pb bullets in soil. The objective of this study was to determine the significance of abrasion of Pb bullets in contributing to soil Pb contamination.

Arsenic species and leachability in the fronds of the hyperaccumulator Chinese brake (Pteris vittata L.).

Arsenic speciation is important not only for understanding the mechanisms of arsenic accumulation and detoxification by hyperaccumulators, but also for designing disposal options of arsenic-rich biomass. The primary objective of this research was to understand the speciation and leachability of arsenic in the fronds of Chinese brake (Pteris vittata L.), an arsenic hyperaccumulator, with an emphasis on the implications for arsenic-rich biomass disposal.

Lead transformation and distribution in the soils of shooting ranges in Florida, USA.

The use of lead bullets and shot at shooting ranges is under increasing scrutiny as a potentially significant source of Pb pollution. This study assessed Pb contamination in the soils of two shooting ranges (TRR and MPR) in Florida. Soil samples were collected from the two ranges and analyzed for total Pb to determine Pb contamination.

Weathering of lead bullets and their environmental effects at outdoor shooting ranges.

Lead contamination at shooting range soils is of great environmental concern. This study focused on weathering of lead bullets and its effect on the environment at five outdoor shooting ranges in Florida, USA. Soil, plant, and water samples were collected from the ranges and analyzed for total Pb and/or toxicity characteristic leaching procedure (TCLP) Pb.