Plant based phosphorus recovery from wastewater via algae and macrophytes.

At present, resource recovery by irrigation of wastewater to plants is usually driven by the value of the water resource rather than phosphorus recovery. Expanded irrigation for increased phosphorus recovery may be expected as the scarcity and price of phosphorus increases, but providing the necessary treatment, storage and conveyance comes at significant expense. An alternative to taking the wastewater to the plants is instead to take the plants to the wastewater. Algal ponds and macrophyte wetlands are already in widespread use for wastewater treatment and if harvested, would require less than one-tenth of the area to recover phosphorus compared to terrestrial crops/pastures. This area could be further decreased if the phosphorus content of the macrophytes and algae biomass was tripled from 1% to 3% via luxury uptake. While this and many other opportunities for plant based recovery of phosphorus exist, e.g. offshore cultivation, much of this technology development is still in its infancy. Research that enhances our understanding of how to maximise phosphorus uptake and harvest yields; and further add value to the biomass for reuse would see the recovery of phosphorus via plants become an important solution in the future.

Animal production for efficient phosphate utilization: from optimized feed to high efficiency livestock.

Phosphorus (P) is an essential nutrient for livestock but its efficiency of utilization is below 40%, contributing to environmental issues. In this review, we summarize recent approaches to optimize P availability in livestock diets and improve its utilization efficiency. Phase feeding could potentially reduce P excretion by 20%. Addition of phytase enzymes to diets increased P availability from 42 to 95%. Low phytate transgenic plants and transgenic animals increased P availability by 14% and 52-99%, respectively. In practice, a combination of phase feeding and enzymes has the highest potential for P reduction but legislation and ethics implications will prevent using transgenic animals in the short term. Functional and nutritional genomics may provide tools to improve efficiency in the future.

The phosphorus mass balance: identifying 'hotspots' in the food system as a roadmap to phosphorus security.

Phosphorus is a critical element on which all life depends. Global crop production depends on fertilisers derived from phosphate rock to maintain high crop yields. Population increase, changing dietary preferences towards more meat and dairy products, and the continuing intensification of global agriculture supporting this expansion will place increasing pressure on an uncertain, but finite supply of high-quality phosphate rock. Growing concern about phosphorus scarcity and security, coupled with the environmental impact of phosphorus pollution, has encouraged an increase in research exploring how phosphorus is used and lost in the food system-from mine to field to fork. An assessment of recent phosphorus flows analyses at different geographical scales identifies the key phosphorus 'hotspots', for example within the mining, agriculture or food processing sectors, where efficiency and reuse can be substantially improved through biotechnological approaches coupled with policy changes.

Phosphorus: a limiting nutrient for humanity?

Phosphorus is a chemical element that is essential to life because of its role in numerous key molecules, including DNA and RNA; indeed, organisms require large amounts of P to grow rapidly. However, the supply of P from the environment is often limiting to production, including to crops. Thus, large amounts of P are mined annually to produce fertilizer that is applied in support of the 'Green Revolution.' However, much of this fertilizer eventually ends up in rivers, lakes and oceans where it causes costly eutrophication. Furthermore, given increasing human population, expanding meat consumption, and proliferating bioenergy pressures, concerns have recently been raised about the long-term geological, economic, and geopolitical viability of mined P for fertilizer production. Together, these issues highlight the non-sustainable nature of current human P use. To achieve P sustainability, farms need to become more efficient in how they use P while society as a whole must develop technologies and practices to recycle P from the food chain. Such large-scale changes will probably require a radical restructuring of the entire food system, highlighting the need for prompt but sustained action.

Acute effects of different phosphorus sources on calcium and bone metabolism in young women: a whole-foods approach.

The recommended dietary phosphorus intake is exceeded in the typical Western diet. However, few studies have been conducted on the bioavailability and metabolic consequences of dietary phosphorus from different food sources. In this study, acute effects of dietary phosphorus from three different food sources and a phosphate supplement on calcium and bone metabolism were investigated. Sixteen healthy women aged 20-30 years were randomized to five controlled 24-hour study sessions, each subject serving as her own control. At the control session, calcium intake was ca. 250 mg and phosphorus intake ca. 500 mg. During the other four sessions, phosphorus intake was about 1,500 mg, 1,000 mg of which was obtained from meat, cheese, whole grains, or a phosphate supplement, respectively. The foods served were exactly the same during the phosphorus sessions and the control session; only phosphorus sources varied. Markers of calcium and bone metabolism were followed. Analysis of variance with repeated measures was used to compare the study sessions. Only the phosphate supplement increased serum parathyroid hormone (S-PTH) concentration compared with the control session (P = 0.031). Relative to the control session, meat increased markers of both bone formation (P = 0.045) and bone resorption (P = 0.049). Cheese decreased S-PTH (P = 0.0001) and bone resorption (P = 0.008). These data suggest that the metabolic response was different for different foods.

Avaliações da relação fósforo: flúor em suplementos minerais para bovinos comercializados na região nordeste do Paraná / Relation phosphorus: fluorine evaluations in mineral supplements for cattle commercialized in the northeast of the State of Paraná / Avaluaciones de la relación fosforo: fluor encontrados en suplementos minerales para vacunos, comercializados en la región noreste del estado de Paraná

Foram quantificados os teores de fósforo (P) e flúor (F) em doze diferentes amostras de suplementos minerais para bovinos, mais comercializados na região Nordeste do Estado do Paraná. Para a determinação do fósforo foi utilizado espectrofotômetro de colorimetria com região UV visível e, para a determinação do flúor, utilizou-se eletrodo de íon específico para o elemento e potenciômetro com escala em milivolts. Os resultados mostraram altos teores de flúor em duas amostras, e diferentes alterações na relação P:F, com variadas concentrações dos elementos, principalmente do fósforo, possibilitando a conclusão de que quase todas as formulações caracterizaram-se como incorretas pelas informações prestadas nos rótulos dos fabricantes e, irregulares na relação P:F calculada, quando comparada aos limites estabelecidos pela normatização em vigor no País.

We quantifi ed the contents of phosphorus (P) and fl uorine (F) in twelve mineral brands of supplements for cattle, more commercialized in the region northeast of the state of Paraná. For the phosphorus's determination was utilized spectrofotometry and for fl uorine was utilized equipment with specifi c ion and scale in milivolts. The results showed high contents of fl uorine in two samples, and alterations in the relation P: F, with varied concentrations of both elements, mainly of the phosphorus. The authors concluded that almost all formulations were incorrect according to the information from the manufactures' labels and, irregular in the relation P: F calculated, when compared to the limits established by Brazilian Government rules.

Fueron cuantifi cadas las concentraciones de Fósforo (P) y Fluor (f) en doce diferentes muestras de Suplementos Minerales para vacunos, entre los mas comercializados en la región noreste del Estado del Paraná. Para la determinación del Fosforo, fue utilizado un Espectofotómetro de Colormetria con región UV visible, y para la determinación del Fluor un electrodo de Ion Específi co para este elemento, aliado a un Potenciometro con lectura de variables en Milivolts. Los resultados mostraron altos porcentajes de Fluor en dos de las muestras, y en las otras, variadas alteraciones en la relación P:F, con diferentes concentraciones de estos elementos, principalmente del Fosforo. Esto posibilita la conclusión de que casi todas las formulaciones se caracterizaron como incorrectas por las informaciones que son apresentadas en las etiquetas de los fabricantes, ademas de irregulares na relación P:F calculada, en comparación con los límites establecidos por las Normas vigentes en el Brazil.

Consequences of the ban of by-products from terrestrial animals in livestock feeding in Germany and the European Union: alternatives, nutrient and energy cycles, plant production, and economic aspects.

Consequences of the ban of meat and bone meal (MBM) and animal fat with regard to livestock feeding, cropping, ecology and economy where investigated with an inter-disciplinary approach for Germany and the European Union. Calculations were made for different production systems with pigs and poultry on the basis of statistical data for the production and for the feed markets as well as from requirement data for the respective species and production system. (1.) The ban of MBM from feeding caused a need for alternative protein sources. If all the amount of protein from MBM is to be replaced by soybean meal, in Germany and the EU about 0.30 and 2.30 x 10(6) t would be needed each year (supplementary amino acids not considered). Alternatively, doubling the grain legume acreage in Germany to about 420,000 ha would supply a similar amount of protein. A wider application of phase feeding with adjusted dietary amino acid concentrations, however, would allow for saving protein to an extent which is similar to the amount of protein that was contributed by MBM in recent years. Thus, the ban is a minor problem in terms of ensuring amino acid supply. (2.) However, alternative plant ingredients cannot compensate for the gap in P supply that is caused by the ban. An additional demand for inorganic feed phosphates of about 14,000 and 110,000 t per year is given in Germany and the EU, respectively. So far, this gap is filled almost completely by increased mining of rock phosphates. Alternatively, a general application of microbial phytase to all diets would largely fill this gap. Until the ban, MBM contributed to 57% of the supplementation of P that was needed for pigs and poultry. The ban of MBM makes large amounts of P irreversibly disappearing from the food chain. (3.) Energy from slaughter offal and cadavers can be utilized in different technologies, in the course of which the efficiency of energy utilisation depends on the technology applied. It is efficient in the cement work or rotation furnace if heat is the main energy required. In contrast, the energetic efficiency of fermentation is low. (4.) Incineration or co-incineration of MBM and other by-products causes pollution gas emissions amounting to about 1.4 kg CO2 and 0.2 kg NOx per kg. The CO2 production as such is hardly disadvantageous, because heat and electrical energy can be generated by the combustion process. The prevention of dangerous gaseous emissions from MBM burning is current standard in the incineration plants in Germany and does not affect the environment inadmissibly. (5.) The effects of the MBM ban on the price for compound feed is not very significant. Obviously, substitution possibilities between different feed ingredients helped to exchange MBM without large price distortions. However, with each kg MBM not used in pig and poultry feeding economic losses of about 0.14 [symbol: see text] have to considered. In conclusion, the by far highest proportion of raw materials for MBM comes as by-products from the slaughter process. Coming this way, and assuring that further treatment is safe from the hygienic point of view, MBM and animal fat can be regarded as valuable sources of amino acids, minerals and energy in feeding pigs and poultry. Using them as feedstuffs could considerably contribute to the goal of keeping limited nutrients, phosphorus in particular, within the nutrient cycle and dealing responsible with limited resources.