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Reports that the common assumption that phosphorus occurs exclusively as phosphate in the environment is deserving of increased scrutiny. How if a sample contained reduced phosphorus compounds (P in an oxidation state of less than +5), standard methods of phosphorus determination would incorrectly classify the compounds mostly as organic P, although significant fractions were sometimes misclassified as orthophosphates and condensed P.

The evolution of phosphine gas during the anaerobic batch fermentation of fresh swine manure was detected and correlated to the production of methane and hydrogen sulphide. A close temporal relationship between phosphine liberation and methane formation was found. However, the gaseous phosphine released from manure during fermentation only represents a tiny fraction of the overall phosphine balance. The majority of phosphine is captured in solid manure constituents. This matrix-bound phosphine is eliminated by more than 50% during anaerobic batchfermentation. Seasonally determined phosphine concentrations in biogas and manure from two large-scale manure treatment plants also revealed net losses of phosphine in fermentation. Consequently, manure hasto be considered more as a sink of phosphine rather than a phosphine-generating medium. Furthermore, a close relationship between phosphine in the feed of swine and manure of these swine was observed, implying that phosphine residues in the feed (possibly as a result of grain fumigation) represent an important source of phosphine in manure technologies that is relevant before the faecals of swine enter manure treatment plants' [ABSTRACT FROM AUTHOR]

Objectives: Insight into modifiable factors related to falls risk in older adults living in residential aged care facilities (RACFs) is necessary to tailor preventive strategies for this high-risk population. Associations between physical activity (PA), physical performance and psycho-cognitive functioning have been understudied in aged care residents. This study investigated associations between PA, and both physical performance and psycho-cognitive functioning in older adults living in RACFs., Design: Cross-sectional study., Methods: Forty-four residents aged 85±8years were recruited from four RACFs located in Southeast Queensland. PA was assessed as the average time spent walking in hours/day using activPAL3™. Physical performance tests included balance, gait speed, dual-task ability, reaction time, coordination, grip strength, and leg strength and power. Psycho-cognitive questionnaires included quality of life, balance confidence, fear of falling and cognitive functioning. Associations between PA and each outcome measure were analysed using linear or ordinal regression models., Results: The average time spent walking was 0.5±0.4h/day. Higher levels of PA were significantly associated with better balance (compared with low PA, medium: B=1.6; high: B=1.3) and dual-task ability (OR=7.9 per 0.5h/day increase). No statistically significant associations were found between PA and the other physical and psycho-cognitive measures., Conclusions: More physically active residents scored higher on balance and dual-task ability, which are key predictors of falls risk. This suggests that physical activity programs targeting balance and dual-task ability could help prevent falls in aged care residents., (Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)

Atmospheric phosphine (PH(3)) fluxes from typical types of wetlands and PH(3) concentrations in adjacent atmospheric air were measured. The seasonal distribution of PH(3) in marsh and paddy fields were observed. Positive PH(3) fluxes are significantly related to high air temperature (summer season) and increased vegetation. It is concluded that vegetation speeds up the liberation of PH(3) from soils, while water coverage might function as a diffusion barrier from soils or sediments to the atmosphere. The concentrations of atmospheric PH(3) (ng m(-3)) above different wetlands decrease in the order of paddy fields (51.8 ± 3.1) > marsh (46.5 ± 20.5) > lake (37.0 ± 22.7) > coastal wetland (1.71 ± 0.73). Highest atmospheric PH(3) levels in marsh are found in summer. In paddy fields, atmospheric PH(3) concentrations in flourishing stages are higher than those in slowly growing stages., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

The main objective of this research was to test the hypothesis that bioavailable protein and, more specifically, the sulfur-containing amino acids within the protein, can be degraded by proteolytic enzymes to produce odor-causing compounds--mainly volatile sulfur compounds (VSCs)--during biosolids storage. To achieve these objectives, samples of digester effluent and cake solids were collected at 11 different wastewater treatment plants in North America, and the samples were analyzed for protein and amino acid content and general protein-degrading enzyme activity. At the same time, cake samples were stored using headspace bottles, the concentration of VSCs were measured using gas chromatography, and olfactometry measurements were made by a trained odor panel. The results showed that the bound cake protein content and methionine content was well-correlated with VSC production and the detection threshold measured by the odor panel.

Earlier reports show very low concentrations of phosphine in remote air of the lower troposphere of nonpolar regions, in the low ng m(-3) range during the night and in the pg m(-3) range during daylight around noon. In this study, abnormally and unexpectedly high phosphine concentrations (30.0-407.8 ng m(-3), 11 locations) were found in polar air samples collected on Millor Peninsula, eastern Antarctica and Fildes Peninsula, western Antarctica. The maximum concentration was measured in the atmosphere of penguin colonies. Field phosphine emission rates from four colonies were 8.99 ng m(-2) h(-1) (skua colony), 9.56 ng m(-2) h(-1) (gentoo penguin colony), 39.96 ng m-2 h-' (seal colony) and 63.58 ng m(-2) h(-1) (empire penguin colony), respectively. Our air sampling sites are located downwind of two large penguin colonies, indicating that penguin colony emission is the predominant source for atmospheric PH3 on Millor Peninsula. Laboratory scale incubation of ornithogenic soils amended by penguin guanos yielded a maximum PH3 production rate of 0.58 ng kg(-1) d(-1) specifically at low temperature (4 degrees C). Significant concentrations of phosphine occur in the atmosphere of coastal Antarctica and confirm the existence of a small gaseous link in the phosphorus cycle of the Antarctic tundra ecosystem.

Eleven dewatered sludge cakes collected from anaerobic digesters at different treatment plants were evaluated for the amount, type, and pattern of odorous gas production. All but one of the sludge cakes were from mesophilic anaerobic digesters. One was from a thermophilic digester. The pattern and quantities of sulfur gases were found to be unique for each of the samples with regard to the products produced, magnitude, and subsequent decline. The main odor-causing chemicals were volatile sulfur compounds, which included hydrogen sulfide, methanethiol, and dimethyl sulfide. Volatile sulfur compound production peaked in 3 to 8 days and then declined. The decline was a result of conversion of organic sulfur compounds to sulfide. In one side-by-side test, a high-solids centrifuge cake generated more odorous compounds than the low-solids centrifuge cake. The data show that anaerobic digestion does not eliminate the odor potential of anaerobically digested dewatered cakes.

The objectives of this research were to elucidate the mechanisms for production and degradation of volatile organic sulfur compounds (VOSCs), key odor causing compounds produced by biosolids. These compounds included methanethiol (MT), dimethyl sulfide (DMS), and dimethyl disulfide (DMDS). A series of experiments were used to probe various pathways hypothesized to produce and degrade these VOSCs. The production of MT was found to mainly occur from degradation of methionine and the methylation of hydrogen sulfide. DMS was formed through the methylation of MT. DMDS was formed by MT oxidation. All three of the VOSCs were readily degraded by methanogens and a cyclic pathway was proposed to describe the production and degradation of VOSCs. The research demonstrated that the main source of VOSCs was the biodegradation of protein within the biosolids and the results provided a framework for understanding the production of odor from anaerobically digested sludges before and after dewatering.

This study shows for the first time that overlooked mg/L concentrations of industrial dimethyl sulfoxide (DMSO) waste residues in sewage can cause "rotten cabbage" odor problems bydimethyl sulfide (DMS) in conventional municipal wastewater treatment. In laboratory studies, incubation of activated sludge with 1-10 mg/L DMSO in bottles produced dimethyl sulfide (DMS) at concentrations that exceeded the odor threshold by approximately 4 orders of magnitude in the headspace gas. Aeration at a rate of 6 m3 air/m3 sludge resulted in emission of the DMS into the exhaust air in a manner analogous to that of an activated sludge aeration tank. A field study atthe NEWPCP sewage treatment plant in Philadelphia found DMSO levels intermittently peaking as high as 2400 mg/L in sewage near an industrial discharger. After 3 h, the DMSO concentration in the influent to the aeration tank rose from a baseline level of less than 0.01 mg/L to a level of 5.6 mg/L and the DMS concentration in the mixed liquor rose from less than 0.01 to 0.2 mg/L. Finding this link between the intermittent occurrence of DMSO residues in influent of the treatment plant and the odorant DMS in the aeration tank was the keyto understanding and eliminating the intermittent "canned corn" or "rotten cabbage" odor emissions from the aeration tank that had randomly plagued this plant and its city neighborhood for two decades. Sewage authorities should consider having wastewater samples analyzed for DMSO and DMS to check for this possible odor problem and to determine whether DMSO emission thresholds should be established to limit odor generation at sewage treatment plants.

Natural rock and mineral samples released trace amounts of phosphine during dissolution in mineral acid. An order of magnitude more phosphine (average 1982 ng PH3 kg rock and maximum 6673 ng PH3/kg rock) is released from pulverized rock samples (basalt, gneiss, granite, clay, quartzitic pebbles, or marble). Phosphine was correlated to hardness and mechanical pulverization energy of the rocks. The yield of PH3 ranged from 0 to 0.01% of the total P content of the dissolved rock. Strong circumstantial evidence was gathered for reduction of phosphate in the rock via mechanochemical or "tribochemical" weathering at quartz and calcite/marble inclusions. Artificial reproduction of this mechanism by rubbing quartz rods coated with apatite-phosphate to the point of visible triboluminescence, led to detection of more than 70 000 ng/kg PH3 in the apatite. This reaction pathway may be considered a mechano-chemical analogue of phosphate reduction from lightning or electrical discharges and may contribute to phosphine production via tectonic forces and processing of rocks.

Closed anaerobic batch-fermentation of eutrophic lake sediment samples was performed under variation of four environmental fermentation factors (pH, temperature, water/sediment ratio and disturbance) to learn how the quantity of phosphine will change and if the quantity of phosphine can increase. The fermentation conditions where matrix bound phosphine (MBP) increased (doubled from 3193+/-520 to about 7982+/-1003 ng/kg) were: a pH of 8 and of 10 (as compared to 1, 2, 4, 6, 12), a temperature of 20 and 30 degrees C (as compared to 4 and 40 degrees C), a water/sediment ratio of 3:1 (as compared to 1:1, 2:1, 5:1) and a disturbance of 100 r/min (as compared to 0 r/min), respectively. Although, over the full time course of fermentation, the balance of phosphine production became negative again or did remain almost unchanged under most conditions. A pH of 1 or disturbance of 150 r/min was significant factors to decrease phosphine over the long term. Free phosphine had been detected but was of minor importance (in the order of 60.9+/-10.1 ng/m(3)). Overall, the fermentation conditions which had been most favorable for microbial life (moderate temperature (20 and 30 degrees C) and pH 8) were also most favorable for a positive phosphine balance. This is an indication, but no biochemical proof that a natural (biogenic, microbial, biochemical) NET PRODUCTION of phosphine or DE NOVO PRODUCTION of phosphine has occurred. MBP concentrations in lake sediments were discussed as to be strongly dependent on a balance of natural generation and depletion processes, dependent of the simulated parameters.

The combination of ion chromatography (IC) and inductively coupled plasma emission spectroscopy (ICP-ES) was used forthe sensitive and specific detection of hypophosphite (PO2), phosphite (PO3), methylphosphonic acid (MPA), and phosphate (PO4). Application of this technique to a wide range of environmental samples proved that reduced phosphorus was present in some situations including process water from thermal phosphorus plants, drinking water contacting cast iron, and phosphorus corrosion inhibitor used in water treatment and in sewage wastewater. Preliminary testing did not detect high concentrations of reduced phosphorus and phosphine in situations where it was previously reported to be very important, including anaerobic digesters in wastewater treatment plants. The new IC-ICP-ES technique is a promising tool for use in corrosion and soil research where phosphites are likely to be present.

The effect of pH on phosphine formation during anaerobic cultivation of granular sludge was investigated. The sludge was taken from full-scale anaerobic reactors treating brewery wastewater. Acetate and phosphate were used as the carbon source and phosphorus source respectively. After 10 days cultivation in the dark, results showed that acidic conditions were more favorable for free phosphine production. At pH 5, the optimum concentration 86.42 ng PH3 m-3 of free phosphine was obtained. The level at pH 7 was reduced to 18.53 ng PH3 m-3, about 1/5 of the maximum. The maximum concentration of matrix-bound phosphine of 3.30 ng PH3 kg-1 wet sludge was achieved at pH 6. More than 83% of the total phosphine was matrix-bound phosphine, which accounted for 0.003-0.009 per thousand of the phosphate removal, while free phosphine comprised 0.00002-0.001 per thousand of the phosphate removal. Most of the phosphorus removal from solution was turned into chemical precipitation or was adsorbed by sludge. The mechanism of the phosphate reduction-step in the formation of phosphine production is still unknown. The promotion of phosphine formation by low pH is compatible with an acidic bio-corrosion mechanism of metal particles in the sludge or of metal phosphides which form phosphine at low pH.

Matrix-bound phosphine was determined in the Jiaozhou Bay coastal sediment, in prawn-pond bottom soil, in the eutrophic lake Wulongtan, in the sewage sludge and in paddy soil as well. Results showed that matrix-bound phosphine levels in freshwater and coastal sediment, as well as in sewage sludge, are significantly higher than that in paddy soil. The correlation between matrix bound phosphine concentrations and organic phosphorus contents in sediment samples is discussed.

Phosphine emission fluxes from paddy fields, phosphine ambient levels in air, and the vertical profile of matrix-bound phosphine in soil have been measured throughout the growing season of rice in Beijing, China. It was found that both the seasonal and diurnal emission fluxes and ambient levels fluctuate significantly. During the drainage period, phosphine released from the soil with the highest diurnal average flux on the first period of drainage (approx. 17.7 ng m(-2) h(-1)), whereas its highest ambient level (approx. 250 ng m(-3)) occurred at 06.00 h. During the flooded period, phosphine emission was low, and the peaks of phosphine emissions occurred at midnight. The average flux of PH3 emission for the whole season was found to be approximately 1.78 ng m(-2) h(-1). The mass fraction of matrix-bound phosphine is approximately 0.18 approximately 1.42 x 10(-7) (m/m) part of organic phosphorus or 3.4 approximately 9.2 x 10(-9) (m/m) part of total phosphorus in paddy soil. The amount of phosphine emitted to the atmosphere was only a small fraction of the phosphine that remained in the soil in the matrix-bound form. Soil serves both as the source and the sink of PH3.

Phosphine is a toxic agent and part of the phosphorus cycle. A hitherto unknown formation mechanism for phosphine in the environment was investigated. When iron samples containing iron phosphide were incubated in corrosive aquatic media affected by microbial metabolites, phosphine was liberated and measured by gas chromatography. Iron liberates phosphine especially in anoxic aquatic media under the influence of sulfide and an acidic pH. A phosphine-forming mechanism is suggested: Phosphate, an impurity of iron containing minerals, is reduced abioticly to iron phosphide. When iron is exposed to the environment (e.g. as outdoor equipment, scrap, contamination in iron milled food or as iron meteorites) and corrodes, the iron phosphide present in the iron is suspended in the medium and can hydrolyze to phosphine. Phosphine can accumulate to measurable quantities in anoxic microbial media, accelerating corrosion and preserving the phosphine formed from oxidation.

Oxide deposits found in combustion systems of landfill gas fired power stations contain relatively high concentrations of elements which form volatile species such as P, As, Sb and Sn. These deposits should be handled with care because of their potential toxicity. By contrast, deposits in biogas system engines were found to contain much lower levels of such elements. The enrichment of these elements can be attributed to a hypothetical multistage process. The elements form volatile species in the landfill body. They are selectively transported as part of the landfill gas into the gas-burning devices. Inside the burners, they are immobilized as nonvolatile oxides.

The possible liberation of highly toxic and mutagenic phosphine from putrefying media raises the question of its significance as a problem of hygiene. Free phosphine was established by gas chromatography as a universal trace component in gas emitted from the anaerobic biosphere. Sources of phosphine include landfills, compost processing, sewage sludge, animal slurry and river sediments. We detected maximum concentrations in the order of 20 ppb(v/v).

The degree of the emission of the mutagenic phosphane from animal slurry have become an issue of hygienic which so far has not been investigated. This work clearly detects spontaneously emitted free phosphane from animal slurry for the first time and correlates the degree of its emission with different disposal technologies. The subjects of the investigations are the simple storage process and processes involving biogas plants for the digestion both of pig and cattle slurry. Pig slurry generates about one magnitude more phosphane than cattle slurry. The maximum concentration detected in putrefaction gas was 14621 ppt(v/v). Putrefaction gas samples from fresh fecal slurry in primary (mediary storage) tanks followed by storage basins and sedimenters contains the highest concentrations. The mainly methanogenic biogas process generates the smallest concentrations but the highest fluxes of phosphane. Fluxes and concentrations in open basins are significantly higher during summer than in winter. The correlation of phosphane and dimethyldisulfide concentrations indicates that primary lytic processes play a role in the liberation of phosphane. Individual samples of the emission in air give a maximum value of 35 ppt. By comparison, measurement of phosphane in Hungarian digester gas from municipal sewage treatment show that maximum concentrations could be some orders of magnitude higher. Therefore the data base for phosphane from animal slurry must in future be expanded. The results of analysis so far achieved cannot be interpreted from either a human or veterinary medical viewpoint.