Magnesium activation affects the properties and phosphate sorption capacity of poultry litter biochar.

Biochars with a high affinity for phosphorus (P) are promising soil amendments for reducing P in agricultural run-off. Poultry litter (PL) is an abundant biochar feedstock. However, PL-derived biochars are typically high in soluble P and therefore require chemical modification to become effective P sorbents.

Evaluation of a pH- and time-dependent model for the sorption of heavy metal cations by poultry litter-derived biochar.

Common isotherm and kinetic models cannot describe the pH-dependent sorption of heavy metal cations by biochar. In this paper, we evaluated a pH-dependent, equilibrium/kinetic model for describing the sorption of cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) by poultry litter-derived biochar (PLB). We performed sorption experiments across a range of solution pH, initial metal concentration, and reaction time.

Evaluation of phosphorus runoff from sandy soils under conservation tillage with surface broadcasted recovered phosphates.

Potential new sources of phosphorus (P) fertilizer are the recovered P from livestock wastewater through chemical precipitation and the ash from combusting animal manures. Although most of the research on P losses from conservation tillage include high water-soluble P compounds from commercial fertilizer sources, information on the use of non-conventional, low water-soluble, recycled P sources is scarce. Particularly for sandy soils of the United States (US) Southeastern Coastal Plain region, research driven information on P loss into the environment is needed to determine recommendations for a direct use of new recycled P sources as crop P fertilizers.

The Occurrence of Legacy P Soils and Potential Mitigation Practices Using Activated Biochar.

The long-term application of manures in watersheds with dense animal production has increased soil phosphorus (P) concentration, exceeding plant and soil assimilative capacities. The P accumulated in soils that are heavily manured and contain excess extractable soil P concentrations is known as legacy P. Runoff and leaching can transport legacy P to ground water and surface water bodies, contributing to water quality impairment and environmental pollution, such as eutrophication.

Biomass production, metal and nutrient content in sorghum plants grown on soils amended with sewage sludge.

Sludge generation from wastewater treatment plants in Uruguay has increased in recent years. Agricultural soils may be a final destination. A greenhouse experiment was conducted to quantify the effect of this sludge on 1) plant biomass production and nutrient concentration of sorghum ( var.

Earthworms increase the potential for enzymatic bio-activation of biochars made from co-pyrolyzing animal manures and plastic wastes.

We assessed the enzymatic activation of four different biochars produced from pyrolyzing swine manure and poultry litter, and by co-pyrolyzing these livestock residues with agricultural spent mulch plastic film wastes (plastichars). Enzymatic activation consisted of incubating biochars in soil inoculated with earthworms (Lumbricus terrestris), which acted as biological vectors to facilitate retention of extracellular enzymes onto biochar surface. The activity of carboxylesterase ‒a pesticide-detoxifying enzyme‒ was measured in non-bioturbed soils (reference), linings of the burrows created by earthworms, casts (feces) and biochar particles recovered from the soil.

A simple mathematical method to estimate ammonia emission from in-house windrowing of poultry litter.

In-house windrowing between flocks is an emerging sanitary management practice to partially disinfect the built-up litter in broiler houses. However, this practice may also increase ammonia (NH) emission from the litter due to the increase in litter temperature. The objectives of this study were to develop mathematical models to estimate NH emission rates from broiler houses practicing in-house windrowing between flocks.

Improved water quality and reduction of odorous compounds in anaerobic lagoon columns receiving pre-treated pig wastewater.

Large volumes of wastewater from confined pig production are stored in anaerobic lagoons. Control methods are needed to reduce air pollution by foul odors released from these lagoons. In a pilot-scale experiment, we evaluated the effect of pig wastewater pre-treatment on reducing the concentration of selected malodor compounds in lagoons receiving liquid from: (1) flocculant enhanced solid-liquid separation (SS), and (2) solid-liquid separation plus biological N treatment using nitrification-denitrification (SS+NDN).

Ammonia and Nitrous Oxide Emissions from Broiler Houses with Downtime Windrowed Litter.

An emerging poultry manure management practice is in-house windrowing to disinfect the litter. However, this practice is likely to increase emissions of ammonia (NH) and nitrous oxide (NO) from the windrowed litter. The objective of this study was to quantitatively compare NH and NO emissions from broiler houses with and without in-house windrowing.

Recovery of ammonia and phosphate minerals from swine wastewater using gas-permeable membranes.

Gas-permeable membrane technology is useful to recover ammonia (NH) from liquid manures. In this study, phosphorus (P) recovery via MgCl precipitation was enhanced by combining it with NH recovery through gas-permeable membranes. Anaerobically digested swine wastewater containing approximately 2300 mg NH-N L and 450 mg P L was treated using submerged membranes plus low-rate aeration to recover the NH from within the liquid and MgCl to precipitate the P.

Carbon sequestration in a surface flow constructed wetland after 12 years of swine wastewater treatment.

Constructed wetlands used for the treatment of swine wastewater may potentially sequester significant amounts of carbon. In past studies, we evaluated the treatment efficiency of wastewater in a marsh-pond-marsh design wetland system. The functionality of this system was highly dependent on soil carbon content and organic matter turnover rate.

Enhancing recovery of ammonia from swine manure anaerobic digester effluent using gas-permeable membrane technology.

Gas-permeable membrane technology is useful to recover ammonia from manure. In this study, the technology was enhanced using aeration instead of alkali chemicals to increase pH and the ammonium (NH4(+)) recovery rate. Digested effluents from covered anaerobic swine lagoons containing 1465-2097 mg NH4(+)-N L(-1) were treated using submerged membranes (0.

Impact of switchgrass biochars with supplemental nitrogen on carbon-nitrogen mineralization in highly weathered Coastal Plain Ultisols.

Although an increase in soil fertility is the most frequently reported benefit linked to adding biochar to soils, there is still a need to pursue additional research that will improve our understanding on the impact of soil fertility enhancement because the effect could vary greatly between switchgrass (Panicum virgatum, L) residues (USG) and switchgrass biochars (SG). We hypothesized that SG with supplemental nitrogen (N) would deliver more positive effects on carbon (C) and N mineralization than USG. The objective of this study was to evaluate the effects of USG and SG, with or without supplemental inorganic N fertilizer on C and N mineralization in highly weathered Coastal Plain Ultisols.

Biochars impact on water infiltration and water quality through a compacted subsoil layer.

Soils in the SE USA Coastal Plain region frequently have a compacted subsoil layer (E horizon), which is a barrier for water infiltration. Four different biochars were evaluated to increase water infiltration through a compacted horizon from a Norfolk soil (fine-loamy, kaolinitic, thermic, Typic Kandiudult). In addition, we also evaluated biochars effect on water quality.

Leachate water quality of soils amended with different swine manure-based amendments.

In the face of the rising level of manure production from concentrated animal feeding operations (CAFOs), management options are being sought that can provide nutrient recycling for plant growth and improved soil conditions with minimal environmental impacts. Alternatives to direct manure application are composting and thermochemical conversion which can destroy pathogens and improve handling and storage. The effect of four forms of swine manure-based soil amendments (raw, compost, hydrochar, and pyrochar) on soil fertility and leachate water quality characteristics of a sandy soil were investigated in soil incubation experiments.

Soil physicochemical conditions, denitrification rates, and abundance in north Carolina coastal plain restored wetlands.

Over the last century, North Carolina has seen a severe reduction in the percentage of wetlands and a rise in negative environmental impacts related to this loss. To counter these effects, efforts have been enacted to mitigate wetland loss and create new wetland areas. The objective of this study was to assess the impact of hydrological restoration at several sites in the North Carolina coastal plain.

Phosphorus recovery from pig manure solids prior to land application.

Land disposal of pig manure is an environmental concern due to an imbalance of the nitrogen to phosphorus (N:P) ratio for crop production, leading to excess phosphorus (P) in soils and potential risks of water pollution. A process called "quick wash" was investigated for its feasibility to extract and recover P from pig manure solids. This process consists of selective dissolution of P from solid manure into a liquid extract using mineral or organic acid solutions, and recovery of P from the liquid extract by adding lime and an organic polymer to form a P precipitate.

Water quality and nitrogen mass loss from anaerobic lagoon columns receiving pretreated influent.

Control methods are needed to abate NH losses from swine anaerobic lagoons to reduce the contribution of confined swine operations to air pollution. In a 15-mo meso-scale column study, we evaluated the effect of manure pretreatment on water quality, reduction of N losses, and sludge accumulation in swine lagoons using (i) enhanced solid-liquid separation with polymer (SS) and (ii) solid-liquid separation plus biological N treatment using nitrification-denitrification (SS + NDN). A conventional anaerobic lagoon was included as a control.

Recovery of ammonia from swine manure using gas-permeable membranes: effect of aeration.

The gas-permeable membrane process can recover ammonia from manure, reducing pollution whilst converting ammonia into an ammonium salt fertilizer. The process involves manure pH control to increase ammonium (NH4(+)) recovery rate that is normally carried out using an alkali. In this study a new strategy to avoid the use of alkali was tested applying low-rate aeration and nitrification inhibition.

Carbon mineralization in two ultisols amended with different sources and particle sizes of pyrolyzed biochar.

Biochar produced during pyrolysis has the potential to enhance soil fertility and reduce greenhouse gas emissions. The influence of biochar properties (e.g.

Recovery of ammonia from poultry litter using flat gas permeable membranes.

The use of flat gas-permeable membranes was investigated as components of a new process to capture and recover ammonia (NH3) in poultry houses. This process includes the passage of gaseous NH3 through a microporous hydrophobic membrane, capture with a circulating dilute acid on the other side of the membrane, and production of a concentrated ammonium (NH4) salt. Bench- and pilot-scale prototype systems using flat expanded polytetrafluoroethylene (ePTFE) membranes and a sulfuric acid solution consistently reduced headspace NH3 concentrations from 70% to 97% and recovered 88% to 100% of the NH3 volatilized from poultry litter.

Partial nitritation of swine wastewater in view of its coupling with the anammox process.

Partial nitritation (PN) of swine wastewater was investigated in a sequencing batch reactor (SBR) using a high-performance nitrifying sludge. Characteristics of the wastewater used were low content of biodegradable organic matter and a high alkalinity-to-ammonium ratio. The target oxidation of ammonium nitrogen (NH-N) to nitrite nitrogen (NO-N) was 57% (1.

Chemical phosphorus removal: a clean strategy for piggery wastewater management in Brazil.

The intensive production of animal protein is known to be an environmental polluting activity, especially if the wastewater produced is not managed properly. Swine production in Brazil is growing, and technologies to manage all pollutants present in the wastewater effluent are needed. This work presents a case of study of phosphorus (P) removal from piggery wastewater using Ca(OH)2, and demonstrates the feasibility of this strategy for P management.

Anammox sludge immobilized in polyvinyl alcohol (PVA) cryogel carriers.

This study evaluated the use of PVA cryogels to encapsulate slow-growing anammox bacteria for deammonification treatment of wastewater. The cryogel pellets were prepared by freezing-thawing at -8 °C. On average, pellets contained 11.

Long-term preservation of anammox bacteria.

Deposit of useful microorganisms in culture collections requires long-term preservation and successful reactivation techniques. The goal of this study was to develop a simple preservation protocol for the long-term storage and reactivation of the anammox biomass. To achieve this, anammox biomass was frozen or lyophilized at two different freezing temperatures (-60°C and in liquid nitrogen (-200°C)) in skim milk media (with and without glycerol), and the reactivation of anammox activity was monitored after a 4-month storage period.