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. Laboratory tests confirmed the quick wash process selectively removed and recovered up to 90% of the total (TP) from fresh pig manure solids while leaving significant amounts of nitrogen (N) in the washed manure residue. As a result of manure P extraction, the washed solid residue became environmentally safer for land application with a more balanced N:P ratio for crop production. The recovered P can be recycled and used as fertilizer for crop production while minimizing manure P losses into the environment.
•P was selectively extracted from solid pig manure using acid wash solutions.•The washed manure had a balanced N:P ratio, environmentally safe for land application.•P was recovered by precipitation from the liquid extract by lime and polymer addition.•Up to 90% of the total P was recovered from fresh pig manure solids.•Recovered P can be recycled and used as fertilizer for crop production.
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•Gas permeable membranes were tested to capture NH3 gas lost from poultry waste.•Flat ePTFE membrane manifolds with circulating acid were placed in enclosures.•Headspace NH3 reduction ...was 70–97% of the volatilized NH3 from poultry waste.•About 88–100% of the N lost from poultry waste was recovered as liquid NH4 salt.•Benefits: cleaner air inside houses, lower ventilation costs, and NH4 nutrient solution.
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. The potential benefits of this technology include cleaner air inside poultry houses, reduced ventilation costs, and a concentrated liquid ammonium salt that can be used as a plant nutrient solution.
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► It was evaluated the use of PVA cryogels to encapsulate anammox sludge NRRL B-50286. ► Pellets were tested in CSTR with synthetic and partially nitrified swine wastewater. ► Anammox ...reaction was achieved for more than 5months (2.92mg-N/g-pellet/d). ► Availability of ammonium and nitrite do not become limiting unless below 5mg-N/L. ► Resilience to inhibition at high nitrite levels was confirmed (244–270mg-N/L).
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 11.8mg-TSS/g-pellet of enriched anammox sludge NRRL B-50286 (Candidatus Brocadia caroliniensis) in 4-mm cubes. They were tested with synthetic and partially nitrified swine wastewater using continuous stirred-tank reactors packed at 20% (w/v). The immobilized gel was retained inside the reactor by a screen that eliminated the need of sludge recycling. The stoichiometry of anammox reaction was maintained for more than 5months under non-sterile conditions. The process was not limited by substrates availability unless quite low N concentration (<5mg/L) achieving >93% removal efficiency. In mass balances, >80% of the potential N conversion activity was achieved (2920mg-N/kg-pellet/d). In addition, the immobilized bacteria were resilient to inhibition at high nitrite concentrations (244–270mg-N/L).
•Sources and particle sizes of biochars influenced biochar mineralization and stability.•Stability of biochar in soil is salient feature to evaluate its use as C sequestration tool.•Biochar processed ...into pellets and dust-sized had significant effect on its mineralization.•Site specific application is an effective use of biochar as a soil amendment.
Biochar produced during pyrolysis has the potential to enhance soil fertility and reduce greenhouse gas emissions. The influence of biochar properties (e.g., particle size) on both short- and long-term carbon (C) mineralization of biochar remains unclear. There is minimal information on the potential effects of biochar particle sizes on their breakdowns by soil microorganism, so it is unknown if the particle size of biochar influences C mineralization rate and/or stability in soils. In order to evaluate the effect of different sources (BS) and particle sizes (BF) of biochar on C loss and/or stability in soils, an incubation study on C mineralization of different biochar sources and particle sizes was established using two soils (ST): Norfolk soil (fine loamy, kaolinitic, thermic, typic Kandiudults) and Coxville soil (fine loamy kaolinitic, thermic, Paleaquults). In separate incubation vessels, these soils were amended with one of two manure-based biochars (poultry litters, PL; swine solids, SS) or one of two lignocellulosic-based biochars (switchgrass, SG; pine chips, PC) which were processed into two particle sizes (dust, <0.42mm; pellet, >2mm). The amount of CO2 evolved varied significantly between soils (p⩽0.0001); particle sizes (p⩽0.0001) and the interactions of biochar source (p⩽0.001) and forms of biochars (p⩽0.0001) with soil types. Averaged across soils and sources of biochar, CO2-C evolved from dust-sized biochar (281mgkg−1) was significantly higher than pellet-sized biochar (226mgkg−1). Coxville soils with SS biochar produced the greatest average CO2-C of 428mgkg−1 and Norfolk soils with PC had the lowest CO2-C production (93mgkg−1). Measured rates of carbon mineralization also varied with soils and sources of biochar (Norfolk: PL>SS>SG⩾PC; Coxville: PC>SG>SS>PL). The average net CO2-C evolved from the Coxville soils (385mgkg−1) was about threefold more than the CO2-C evolved from the Norfolk soils (123mgkg−1). Our results suggest different particle sizes and sources of biochar as well as soil type influence biochar stability.
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. This review article analyzes and discusses current and innovative management practices for soil legacy P. Specifically, we address the use of biochar as an emerging novel technology that reduces P movement and bioavailability in legacy P soils. We illustrate that properties of biochar can be affected by pyrolysis temperature and by various activating chemical compounds and by-products. Our approach consists of engineering biochars, using an activation process on poultry litter feedstock before pyrolysis to enhance the binding or precipitation of legacy P. Finally, this review article describes previous examples of biochar activation and offers new approaches to the production of biochars with enhanced P sorption capabilities.
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. The application rate for SG and USG based on a corn yield goal of 112 kg ha−1 was 40 Mg ha−1. Inorganic N was added at the rate of 100 kg N ha−1, also based on a corn yield of 7.03 tons ha−1. Experimental treatments were: control (CONT) soil; control with N (CONT + N); switchgrass residues (USG); USG with N (USG + N); switchgrass biochars at 250 °C (250SG); SG at 250 °C with N (250SG + N); SG at 500 °C (500SG); and SG at 500 °C with N (500SG + N). Cumulative and net CO2–C evolution was increased by the additions of SG and USG especially when supplemented with N. Soils treated with 250SG (8.6 mg kg−1) had the least concentration of total inorganic nitrogen (TIN) while the greatest amount of TIN was observed from the CONT + N (19.0 mg kg−1). Our results suggest that application of SG in the short term may cause N immobilization resulting in the reduction of TIN.
•Carbon dioxide evolution was increased by the additions of switchgrass biochars and residues.•Application of switchgrass biochar may cause N immobilization.•Biochar application may need supplemental N to avoid crop growth retardation.
Long-term preservation of anammox bacteria Rothrock, Michael J.; Vanotti, Matias B.; Szögi, Ariel A. ...
Applied microbiology and biotechnology,
10/2011, Letnik:
92, Številka:
1
Journal Article
Recenzirano
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. Of the different preservation treatments tested, only anammox biomass preserved via freezing in liquid nitrogen followed by lyophilization in skim milk media without glycerol achieved stoichiometric ratios for the anammox reaction similar to the biomass in both the parent bioreactor and in the freshly harvested control treatment. A freezing temperature of −60°C alone, or in conjunction with lyophilization, resulted in the partial recovery of the anammox bacteria, with an equal mixture of anammox and nitrifying bacteria in the reactivated biomass. To our knowledge, this is the first report of the successful reactivation of anammox biomass preserved via sub-zero freezing and/or lyophilization. The simple preservation protocol developed from this study could be beneficial to accelerate the integration of anammox-based processes into current treatment systems through a highly efficient starting anammox biomass.
Phosphorus (P) is essential for life and has a fundamental role in industry and the world food production system. The present work describes different technologies adopted for what is called the ...second-generation P recovery framework, that encompass the P obtained from residues and wastes. The second-generation P has a high potential to substitute the first-generation P comprising that originally mined from rock phosphates for agricultural production. Several physical, chemical, and biological processes are available for use in second-generation P recovery. They include both concentrating and recovery technologies: (1) chemical extraction using magnesium and calcium precipitating compounds yielding struvite, newberyite and calcium phosphates; (2) thermal treatments like combustion, hydrothermal carbonization, and pyrolysis; (3) nanofiltration and ion exchange methods; (4) electrochemical processes; and (5) biological processes such as composting, algae uptake, and phosphate accumulating microorganisms (PAOs). However, the best technology to use depends on the characteristic of the waste, the purpose of the process, the cost, and the availability of land. The exhaustion of deposits (economic problem) and the accumulation of P (environmental problem) are the main drivers to incentivize the P’s recovery from various wastes. Besides promoting the resource’s safety, the recovery of P introduces the residues as raw materials, closing the productive systems loop and reducing their environmental damage.
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 (NH4+–N) to nitrite nitrogen (NO2−–N) was 57% (1.32 g NO2−–N g–1 NH4+–N), which corresponds with the reaction ratio of the anaerobic ammonium oxidation (anammox). This target was successfully achieved at 32°C by controlling the inflow rate and the corresponding nitrogen loading rate (NLR). An average NLR of 1.47 g NH4+–N L−1 d−1 was applied to the partial nitritation sequencing batch reactor during a period of 70 d. The nitrite production rate obtained was 0.91 g NO2−–N L−1 d−1. No nitrate was produced. The PN effluent contained 1.38 g NO2−–N g−1 NH4+–N, which was within 5% of the target ratio. Under steady composition of the wastewater, the pH was shown to be a good indicator of the PN process performance. Furthermore, in a second sequencing batch reactor, the anaerobic ammonium oxidation process was effectively applied to the PN effluent, attaining a nitrogen conversion rate of 0.36 g N L−1 d−1 (14.3 mg N g−1 volatile suspended solids h−1).
Heat-shock protein B1 (HSPB1) is among the most well-known and versatile member of the evolutionarily conserved family of small heat-shock proteins. It has been implicated to serve a neuroprotective ...role against various neurological disorders via its modulatory activity on inflammation, yet its exact role in neuroinflammation is poorly understood. In order to shed light on the exact mechanism of inflammation modulation by HSPB1, we investigated the effect of HSPB1 on neuroinflammatory processes in an in vivo and in vitro model of acute brain injury.
In this study, we used a transgenic mouse strain overexpressing the human HSPB1 protein. In the in vivo experiments, 7-day-old transgenic and wild-type mice were treated with ethanol. Apoptotic cells were detected using TUNEL assay. The mRNA and protein levels of cytokines and glial cell markers were examined using RT-PCR and immunohistochemistry in the brain. We also established primary neuronal, astrocyte, and microglial cultures which were subjected to cytokine and ethanol treatments. TNFα and hHSPB1 levels were measured from the supernates by ELISA, and intracellular hHSPB1 expression was analyzed using fluorescent immunohistochemistry.
Following ethanol treatment, the brains of hHSPB1-overexpressing mice showed a significantly higher mRNA level of pro-inflammatory cytokines (Tnf, Il1b), microglia (Cd68, Arg1), and astrocyte (Gfap) markers compared to wild-type brains. Microglial activation, and 1 week later, reactive astrogliosis was higher in certain brain areas of ethanol-treated transgenic mice compared to those of wild-types. Despite the remarkably high expression of pro-apoptotic Tnf, hHSPB1-overexpressing mice did not exhibit higher level of apoptosis. Our data suggest that intracellular hHSPB1, showing the highest level in primary astrocytes, was responsible for the inflammation-regulating effects. Microglia cells were the main source of TNFα in our model. Microglia isolated from hHSPB1-overexpressing mice showed a significantly higher release of TNFα compared to wild-type cells under inflammatory conditions.
Our work provides novel in vivo evidence that hHSPB1 overexpression has a regulating effect on acute neuroinflammation by intensifying the expression of pro-inflammatory cytokines and enhancing glial cell activation, but not increasing neuronal apoptosis. These results suggest that hHSPB1 may play a complex role in the modulation of the ethanol-induced neuroinflammatory response.
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