Osteophagia by Nasutitermes guayanae (Blattodea:Isoptera: Termitidae) on human bone remains in theAndean Amazon, Caquetá, Colombia / Osteofagia por Nasutitermes guayanae (Blattodea, Isoptera, Termitidae)sobre restos óseos humanos en la Amazonia Andina, Caquetá, Colombia

We present the first report of Nasutitermes guayanae feeding on human bone remains found in an urban area of the municipality of Florencia, Caquetá, Colombia, in the Colombian Amazon piedmont. The record indicates an expansion in the diet of these termites. The observation suggests that the association of N. guayanae with decomposing bodies may be a possible tool for the estimation of postmortem intervals.

Presentamos el primer reporte de Nasutitermes guayanae alimentándose de restos óseos humanos encontrados en un área urbana del município de Florencia, Caquetá, Colombia, en el Piedemonte Amazónico colombiano. El registro indica una expasión en la dieta de esas térmitas. La observación sugiere que la asociación de N. guayanae con cuerpos en descomposición puede ser una posible herramienta para la estimación de intervalos postmortem.

Osteophagia by Nasutitermes guayanae (Blattodea:Isoptera: Termitidae) on human bone remains in theAndean Amazon, Caquetá, Colombia / Osteofagia por Nasutitermes guayanae (Blattodea, Isoptera, Termitidae)sobre restos óseos humanos en la Amazonia Andina, Caquetá, Colombia

We present the first report of Nasutitermes guayanae feeding on human bone remains found in an urban area of the municipality of Florencia, Caquetá, Colombia, in the Colombian Amazon piedmont. The record indicates an expansion in the diet of these termites. The observation suggests that the association of N. guayanae with decomposing bodies may be a possible tool for the estimation of postmortem intervals.(AU)

Presentamos el primer reporte de Nasutitermes guayanae alimentándose de restos óseos humanos encontrados en un área urbana del município de Florencia, Caquetá, Colombia, en el Piedemonte Amazónico colombiano. El registro indica una expasión en la dieta de esas térmitas. La observación sugiere que la asociación de N. guayanae con cuerpos en descomposición puede ser una posible herramienta para la estimación de intervalos postmortem.(AU)

Agronomic efficiency and profitability of cotton on integrated use of phosphorus and plant microbes / Eficiência e rentabilidade agronômica do algodão no uso integrado de fósforo e micróbios vegetais

Cotton crop, plays a significant role in Pakistan's economy by ruling a prominent place in edible oil and local textile industry. Phosphorus (P) inaccessibility and deficiency of soil organic matter are the key restraints for low crop productivity in cotton. Therefore, a two years field study was designed during 2014-15, to explore the influence of phosphate solubilizing bacteria (PSB), farmyard manure (FYM), poultry manure (PM) and inanimate sources of P on various physiological, growth, yield and quality parameters of cotton crop at CCRI Multan. Field responses of seeds inoculated with two distinctive phosphate solubilizing bacteria (PSB) strains viz. S0 = control, S1 =strain-1, S2 = strain-2 and eight organic, inorganic P sources viz., P0= control, P1 = 80 kg ha-1 P from inorganic source, P2 = 80 kg ha-1 P from FYM, P3 = 80 kg ha-1 P from PM, P4 = 40 kg ha-1 P from FYM + 40 kg ha-1 P from inorganic source, P5 = 40 kg ha-1 P from PM + 40 kg ha-1 P from inorganic source, P6 = 80 kg ha-1 P from FYM + 40 kg ha-1 P from inorganic source, P7 = 80 kg ha-1 P from PM + 40 kg ha-1 P from inorganic source and P8 = 40 kg ha-1 P from FYM + 40 kg ha-1 P from PM were evaluated. Results revealed that inoculation of seeds with PSB and collective use of inorganic and organic sources of P had considerably increased the yield contributing attributes in cotton. However, the treatment P7 (80 kg P ha-1 from PM + 40 kg P ha-1 from inorganic source) in coincidence with seeds inoculated with PSB (S1) produced taller plant, maximum boll weight, significantly higher LAI and CGR. Significantly higher seed cotton yield, lint yield, fiber length and maximum BCR of 1.95 and 1.81 was also obtained from the P7 treatment during both crop-growing seasons. In conclusion, combined use of 80 kg P ha-1 from PM + 40 kg P ha-1 from inorganic source and cotton seeds inoculated with strain-1 improved phosphorus uptake ensuing in greater consumption of photo-assimilates for maximum growth and yield.

A safra de algodão, desempenha um papel significativo na economia do Paquistão, ao ocupar um lugar de destaque no óleo comestível e na indústria têxtil local. A inacessibilidade e a deficiência de fósforo (P) da matéria orgânica do solo são as principais restrições para a baixa produtividade das culturas em algodão. Portanto, um estudo de campo de dois anos foi desenvolvido durante 2014-15, para explorar a influência de bactérias solubilizantes de fosfato (PSB), esterco de capoeira (FYM), esterco de aves (PM) e fontes inanimadas de P sobre vários fatores fisiológicos, crescimento, rendimento e parâmetros de qualidade da cultura do algodão no CCRI Multan. Respostas de campo de sementes inoculadas com duas cepas distintas de bactérias solubilizantes de fosfato (PSB) viz. S0 = controle, S1 = cepa-1, S2 = cepa-2 e oito fontes orgânicas de P inorgânicas viz., P0 = controle, P1 = 80 kg ha-1 P de fonte inorgânica, P2 = 80 kg ha-1 P de FYM, P3 = 80 kg ha-1 P de PM, P4 = 40 kg ha-1 P de FYM + 40 kg ha-1 P de fonte inorgânica, P5 = 40 kg ha-1 P de PM + 40 kg ha-1 P de fonte inorgânica, P6 = 80 kg ha-1 P de FYM + 40 kg ha-1 P de fonte inorgânica, P7 = 80 kg ha-1 P de PM + 40 kg ha-1 P de fonte inorgânica e P8 = 40 Foram avaliados kg ha-1 P da FYM + 40 kg ha-1 P da PM. Os resultados revelaram que a inoculação de sementes com PSB e o uso coletivo de fontes inorgânicas e orgânicas de P aumentaram consideravelmente os atributos que contribuem para a produtividade no algodão. No entanto, o tratamento P7 (80 kg P ha-1 da PM + 40 kg P ha-1 da fonte inorgânica) em coincidência com sementes inoculadas com PSB (S1) produziu planta mais alta, peso máximo de cápsula, IAF e CGR significativamente maiores. Produtividade significativamente maior do algodão, rendimento de fiapos, comprimento da fibra e BCR máximo de 1,95 e 1,81 também foi obtida a partir do tratamento P7 durante as duas épocas de cultivo. Em conclusão, o uso combinado de 80 kg P ha-1 de PM + 40 kg P ha-1 de fonte inorgânica e sementes de algodão inoculadas com a cepa-1 melhoraram a captação de fósforo, resultando em maior consumo de foto assimilados para obter crescimento e produtividade máximos.

Managing agricultural phosphorus to minimize water quality impacts

Eutrophication of surface waters remains a major use-impairment in many countries, which, in fresh waters, is accelerated by phosphorus (P) inputs from both point (e.g., municipal waste water treatment plants) and nonpoint sources (e.g., urban and agricultural runoff). As point sources tend to be easier to identify and control, greater attention has recently focused on reducing nonpoint sources of P. In Brazil, agricultural productivity has increased tremendously over the last decade as a consequence, to a large extent, of increases in the use of fertilizer and improved land management. For instance, adoption of the 4R approach (i.e., right rate, right time, right source, and right placement of P) to fertilizer management can decrease P runoff. Additionally, practices that lessen the risk of runoff and erosion, such as reduced tillage and cover crops will also lessen P runoff. Despite these measures P can still be released from soil and fluvial sediment stores as a result of the prior 10 to 20 years management. These legacy sources can mask the water quality benefits of present-day conservation efforts. Future remedial efforts should focus on developing risk assessment indices and nonpoint source models to identify and target conservation measures and to estimate their relative effectiveness. New fertilizer formulations may more closely tailor the timing of nutrient release to plant needs and potentially decrease P runoff. Even so, it must be remembered that appropriate and timely inputs of fertilizers are needed to maintain agricultural productivity and in some cases, financial support might also be required to help offset the costs of expensive conservation measures.

Managing agricultural phosphorus to minimize water quality impacts

Eutrophication of surface waters remains a major use-impairment in many countries, which, in fresh waters, is accelerated by phosphorus (P) inputs from both point (e.g., municipal waste water treatment plants) and nonpoint sources (e.g., urban and agricultural runoff). As point sources tend to be easier to identify and control, greater attention has recently focused on reducing nonpoint sources of P. In Brazil, agricultural productivity has increased tremendously over the last decade as a consequence, to a large extent, of increases in the use of fertilizer and improved land management. For instance, adoption of the 4R approach (i.e., right rate, right time, right source, and right placement of P) to fertilizer management can decrease P runoff. Additionally, practices that lessen the risk of runoff and erosion, such as reduced tillage and cover crops will also lessen P runoff. Despite these measures P can still be released from soil and fluvial sediment stores as a result of the prior 10 to 20 years management. These legacy sources can mask the water quality benefits of present-day conservation efforts. Future remedial efforts should focus on developing risk assessment indices and nonpoint source models to identify and target conservation measures and to estimate their relative effectiveness. New fertilizer formulations may more closely tailor the timing of nutrient release to plant needs and potentially decrease P runoff. Even so, it must be remembered that appropriate and timely inputs of fertilizers are needed to maintain agricultural productivity and in some cases, financial support might also be required to help offset the costs of expensive conservation measures.(AU)

Nitrogen and phosphorus distribution in a constructed wetland fed with treated swine slurry from an anaerobic lagoon.

Nitrogen and phosphorus distribution in a constructed wetland fed with treated swine slurry from an anaerobic lagoon were studied. The methodology considered a daily meteorological monitoring site. During 2011 to 2012, water, soil and plants (Schoenoplectus californicus (C.A. Méyer) Sójak, Typha angustifolia (L.)) were seasonally sampled (spring and fall) into the constructed wetland. During study period, results showed that rainfall was the main factor of maintenance hydraulic conditions, while evapotranspiration was driver of variations in water storage level. Nitrogen and phosphorus removal from the water phase were up to 54% and 37%, respectively. Onto soil were adsorbed over 70% nitrogen and 65% phosphorus. Phosphorus was less mobile than nitrogen, since it was bound to oxides Fe-Mn. Inorganic nitrogen species were affected by level water and seasonal vegetable maturation. During spring, N-NH4(+) was the predominant soil species, while in the fall, N-NO3(-) was dominant near the belowground part of Sc and NH4(+) near to the belowground zone of Ta. In addition, nutrients uptake was less than 30% with 64% aboveground-spring and 85% belowground-fall for both plants. Findings showed nitrification process evidences when water levels are below 0.1 m.

Quality of the effluents of bullfrog tadpole ponds / Qualidade de efluentes de tanques de girino de rã-touro

The objective of this study was to determine the quality of the effluent from ponds populated with bullfrog tadpoles by evaluating the physical, chemical and microbiological parameters of the water. Samples were collected bi-weekly on the ponds located at the bullfrog culture sector in the Caunesp. The experimental design was completely randomized with two treatments (inlet and outlet water) and six repetitions (ponds). There was no difference (P>0.01) among treatments for conductivity, however, the values varied in different samples according to growth of tadpoles. The values of temperature, pH, dissolved oxygen and nitrate were higher (P 0.01) in the inlet, while total phosphorus, ammonia, Escherichia coli, chemical oxygen demand (COD), biochemical oxygen demand (BOD5) and turbidity had increased concentrations in the outlet water. The total phosphorus and BOD5 concentrations were higher than permitted by Brazilian environmental legislation. The management adopted to rear bullfrog tadpoles increased the nutrients in the water, with the highest concentrations of ammonia and total phosphorus deriving mainly from the uneaten feed and animal excretion, the latter being the main factor for water eutrophication.

O objetivo deste trabalho foi avaliar a qualidade do efluente de tanques de criação de girinos de rã-touro através da análise das variáveis físicas, químicas e microbiológica da água. As amostras foram coletadas quinzenalmente nos tanques do setor de ranicultura do Caunesp. O delineamento experimental utilizado foi inteiramente casualizado, com dois tratamentos (água de entrada e saída dos tanques) e seis repetições (tanques). Não houve diferença significativa (P>0,01) entre os tratamentos para condutividade, entretanto, os valores variaram nas diferentes coletas, conforme o crescimento dos girinos. Os valores de temperatura, pH, oxigênio dissolvido e nitrato foram maiores (P 0,01) na água de entrada, enquanto as concentrações de fósforo total, amônia, Escherichia coli, demanda química de oxigênio DQO, demanda bioquímica de oxigênio (DBO5) e turbidez tiveram um aumento na água de saída. As concentrações de fósforo total e DBO5 foram maiores do que o permitido pela legislação ambiental brasileira. O manejo realizado na criação de girinos provocou um aumento de nutrientes na água, sendo que as maiores concentrações de amônia e fósforo total foram provenientes, principalmente, da ração e das excretas dos animais.

Soil phosphorus dynamics as affected by Congo grass and P fertilizer

Some plant species can change soil phosphorus (P) availability and this may be an important tool in managing tropical high fixing phosphorus soils. An experiment was conducted to evaluate phosphorus transformations in the soil and phosphatase activity during periods of Congo grass (Brachiaria ruziziensis, Germain et Evrard) growth in two tropical soils receiving 20, 40, 80, 160 mg dm-3 of inorganic P. Plants were grown for 84 days in 8-L pots. Acid phosphatase activity, P in the microbial mass, soil organic and inorganic P and P accumulation by Congo grass were evaluated. Phosphorus fertilization increased soil P availability, Congo grass yields and P accumulation in the plant. On average, less labile P forms in the soil were not changed by Congo grass; however, the P in the soil extracted with HCl (P-Ca - non labil form) decreased. This decrease may have resulted from the combination of the presence of grass and phosphatase capacity to dissolve less available P in the soil. Thus, soil exploration by Congo grass roots and the subsequent extraction of calcium phosphate may have increased the P concentration in the plant tissue. Despite the decrease in the P extracted from the soil with HCl resulting in increased labile P forms in the soil, the effect of Congo grass on the availability of P depends on the soil type.

Quality of the effluents of bullfrog tadpole ponds / Qualidade de efluentes de tanques de girino de rã-touro

The objective of this study was to determine the quality of the effluent from ponds populated with bullfrog tadpoles by evaluating the physical, chemical and microbiological parameters of the water. Samples were collected bi-weekly on the ponds located at the bullfrog culture sector in the Caunesp. The experimental design was completely randomized with two treatments (inlet and outlet water) and six repetitions (ponds). There was no difference (P>0.01) among treatments for conductivity, however, the values varied in different samples according to growth of tadpoles. The values of temperature, pH, dissolved oxygen and nitrate were higher (P 0.01) in the inlet, while total phosphorus, ammonia, Escherichia coli, chemical oxygen demand (COD), biochemical oxygen demand (BOD5) and turbidity had increased concentrations in the outlet water. The total phosphorus and BOD5 concentrations were higher than permitted by Brazilian environmental legislation. The management adopted to rear bullfrog tadpoles increased the nutrients in the water, with the highest concentrations of ammonia and total phosphorus deriving mainly from the uneaten feed and animal excretion, the latter being the main factor for water eutrophication.(AU)

O objetivo deste trabalho foi avaliar a qualidade do efluente de tanques de criação de girinos de rã-touro através da análise das variáveis físicas, químicas e microbiológica da água. As amostras foram coletadas quinzenalmente nos tanques do setor de ranicultura do Caunesp. O delineamento experimental utilizado foi inteiramente casualizado, com dois tratamentos (água de entrada e saída dos tanques) e seis repetições (tanques). Não houve diferença significativa (P>0,01) entre os tratamentos para condutividade, entretanto, os valores variaram nas diferentes coletas, conforme o crescimento dos girinos. Os valores de temperatura, pH, oxigênio dissolvido e nitrato foram maiores (P 0,01) na água de entrada, enquanto as concentrações de fósforo total, amônia, Escherichia coli, demanda química de oxigênio DQO, demanda bioquímica de oxigênio (DBO5) e turbidez tiveram um aumento na água de saída. As concentrações de fósforo total e DBO5 foram maiores do que o permitido pela legislação ambiental brasileira. O manejo realizado na criação de girinos provocou um aumento de nutrientes na água, sendo que as maiores concentrações de amônia e fósforo total foram provenientes, principalmente, da ração e das excretas dos animais.(AU)

Soil phosphorus dynamics as affected by Congo grass and P fertilizer

Some plant species can change soil phosphorus (P) availability and this may be an important tool in managing tropical high fixing phosphorus soils. An experiment was conducted to evaluate phosphorus transformations in the soil and phosphatase activity during periods of Congo grass (Brachiaria ruziziensis, Germain et Evrard) growth in two tropical soils receiving 20, 40, 80, 160 mg dm-3 of inorganic P. Plants were grown for 84 days in 8-L pots. Acid phosphatase activity, P in the microbial mass, soil organic and inorganic P and P accumulation by Congo grass were evaluated. Phosphorus fertilization increased soil P availability, Congo grass yields and P accumulation in the plant. On average, less labile P forms in the soil were not changed by Congo grass; however, the P in the soil extracted with HCl (P-Ca - non labil form) decreased. This decrease may have resulted from the combination of the presence of grass and phosphatase capacity to dissolve less available P in the soil. Thus, soil exploration by Congo grass roots and the subsequent extraction of calcium phosphate may have increased the P concentration in the plant tissue. Despite the decrease in the P extracted from the soil with HCl resulting in increased labile P forms in the soil, the effect of Congo grass on the availability of P depends on the soil type.(AU)

Enamel demineralization and bracket bond strength when etching with acid and /or Er:YAG laser.

BACKGROUND: Enamel etching for brackets is usually done with phosphoric acid. Er:YAG lasers have been recently used for this purpose with conflicting results. The effects of lasers on tooth demineralization and the effects of different combinations of laser treatments and bonding agents were evaluated in this study. METHODS: The enamel contents of fluorine, calcium oxide and phosphorus pentoxide (P(2) O(5)) were analysed using acid etching, laser treatment or both. The tensile bond strength of metallic and ceramic brackets using Transbond XT and Fuji Ortho LC were also tested, using acid etching, laser treatment or a combination of both. RESULTS: All treatments reduced the contents of fluorine, P(2)O(5) and calcium oxide, and acid reduced P(2) O(5) levels more than laser. The bond strength with laser was weaker than with acid, and stronger when combining both. When using laser, the best adhesive was the Fuji Ortho LC. The combination of laser and acid produced the best results when using Transbond XT. CONCLUSIONS: The demineralization promoted by laser was lower than the one produced with acid. Laser treatment produced lower tensile stress strength than acid, but still enough to produce clinically efficient retention. The combination of laser and acid produced the best retention results.

Produção de biomassa e absorção de N e P pela Pfaffia glomerata (Spreng. ) Pedersen em função de doses de N e P em condições de casa de vegetação / Biomass production and N and P uptake by Pfaffia glomerata (Spreng. ) Pedersen according to N and P levels under greenhouse conditions

Com objetivo de avaliar a produção de biomassa e absorção de N e P pela Pfaffia glomerata em função de doses de N e P, foi realizado o presente trabalho, em casa de vegetação, utilizando como substrato Latossolo Vermelho distroférrico, coletado na camada de 0 - 20 cm. O delineamento foi inteiramente casualizado com três repetições e os tratamentos foram dispostos em esquema fatorial 5 x 5, sendo cinco doses de N (0, 125, 250, 375 e 500 mg vaso-1) e cinco doses de P (0, 125, 250, 375 e 500 mg vaso-1). As variáveis analisadas foram altura de plantas, massa fresca e seca da parte aérea e radicular e teores de N e P na parte aérea e radicular. Os resultados evidenciaram efeito interativo do N e P, em todas as variáveis analisadas, exceto com relação ao teor de P na parte aérea e radicular. A produção de biomassa e absorção de N e P pela Pfaffia glomerata foi influenciada pelas doses de N e P utilizadas no experimento e para a produtividade ótima das características avaliadas, as doses de N variaram entre 42,9 e 346,01 mg vaso-1 e as doses de P entre os valores de 72,02 e 500 mg vaso-1.

With the aim of evaluating biomass production and N and P uptake by Pfaffia glomerata according to N and P levels, the present study was carried out in a greenhouse, using as substrate Oxisol collected at the layer 0 - 20 cm. Experimental design was completely randomized, with three replicates and treatments arranged in 5 x 5 factorial arrangement, with five N levels (0, 125, 250, 375 and 500 mg pot-1) and five P levels (0, 125, 250, 375 and 500 mg pot-1). The assessed parameters were plant height, shoot and root fresh and dry matter, and N and P levels in shoot and roots. Results evidenced an interactive effect of N and P for all studied variables, except for N and P levels in shoot and roots. Biomass production and N and P uptake by Pfaffia glomerata were influenced by the N and P levels used in the experiment, whereas the optimal productivity was obtained with N levels ranging between 42.9 and 346.01 mg pot-1 and P levels between 72.02 and 500 mg pot-1.

Dominance of Paris-type morphology on mycothallus of Lunularia cruciata colonised by Glomus proliferum / Predomínio da morfologia tipo-Paris em talo de Lunularia cruciata colonizado por Glomus proliferum

Microscopic evidence confirms that L. cruciata hosting G. proliferum shows major anatomical traits (arbuscules, coils, arbusculate coils and vesicles) generally associated arbuscular mycorrhizal roots and the anatomical morphology of intra-thalli mycelium is predominantly of the Paris-type. Colonised L. cruciata showed a reduction of biomass when compared with axenic plants suggesting a drain of resources towards the fungus and depletion of nutrients required for optimum plant growth. The behaviour of mycothalli regarding available KH2PO4 indicates that the nutritional stress threshold for phosphorus (P) is above the residual amount of P already present in PhytagelTM and in plant inoculum. These raise the possibility that in certain circumstances the relationship between L. cruciata and G. proliferum be parasitic rather than symbiotic and open the door for future studies to ascertain the nature of liverwort-AM fungi relationships.

Observações de microscopia ótica confirmam que L. cruciata colonizada por G. proliferum apresenta caracteres anatomicos (arbúsculos, hifas novelas, arbúsculos enovelados e vesículas) geralmente associadas a raízes micorrízicas arbusculares em que o micélio intra-tálico apresenta uma anatomia predominantemente do tipo Paris. L. cruciata colonizada apresentou redução de biomassa quando comparada com plantas axenicas, sugerindo dreno de recursos para o fungo e consequente redução de nutrientes necessários para o ótimo crescimento da planta. O comportamento do talo-colonizado em relação à disponibilidade de KH2PO4 no meio indica que o limiar de stress nutricional para fósforo se encontra acima do somatório das quantidades residuais deste elemento presentes no PhytagelTM e no inóculo. Os resultados aqui discutidos sugerem a possibilidade de, em certas circunstâncias, a relação entre L. cruciata e G. proliferum ter características de parasitismo e não de simbiose, abrindo novas perspectivas para futuros estudos na determinação da natureza da relação hepática-fungo arbuscular.

Evaluation of the influence of albumin on the mineralization of a glass by Atomic Force Microscopy.

Bioactive glasses have been used as a graft material that can stimulate the formation of a new bone. In vitro tests usually give sensible indications about the potential bioactivity of these glasses. In the present work the influence of egg albumin on the formation of a Ca-P precipitate on a glass of the system SiO(2)-CaO-MgO-P(2)O(5) was evaluated. The samples were immersed in simulated body fluid (SBF) that simulates the composition of human plasma, with and without albumin. After immersion in this solution for 7 and 14 days, the glass was characterized by X-Ray Diffraction (XRD) and Atomic Force Microscopy (AFM). AFM results of the samples after immersion in SBF with albumin show the development of a precipiate formed from the solution/substrate reaction. Glasses immersed in albumin-free SBF exhibit the formation of a thin layer easily detached from the substrate. XRD results indicate that the precipitate is essentially amorphous, evolving to octacalcium phosphate. As the formation of an adherent precipitate on the glass samples only occurred when the substrate was immersed in SBF with albumin, it is suggested that albumin improves the mineralization on the glasses.

Temporal and spatial variation of phosphate distribution in the sediment of a free water surface constructed wetland.

This study was aimed at determining the spatial and temporal variation of P distribution in sediment of an artificial wetland for sewage and industrial wastewater treatment, and the fraction that is potentially involved in the P exchange processes. Influent, effluent, macrophytes and sediment at the inlet, middle and outlet areas were sampled over 24 months. The P-fractionation in sediment was performed following the EDTA method. Eichhornia crassipes and Typha domingensis removed P efficiently when cover was high, but E. crassipes caused anoxic conditions. The increase in cover of T. domingensis may contribute to attain oxic conditions and to improve P removal. When macrophytes are not present or when cover is low, sediment seems to increase removal efficiency. A significant increase in the concentration of the fraction of Fe(OOH) approximately P and mainly that of CaCO(3) approximately P can be observed at the inlet. High pH, Ca(2+) and CO(3)(-)(2) concentrations in the influent suggest that P co-precipitates together with CaCO(3). Therefore, it seems that CaCO(3) approximately P represents the main precipitating mechanism. However, mineralization of organic matter maintained the sediment at a pH range lower than the high values prevailing in the influent. CO(3)(-)(2) could undergo partial dissolution and the released i-P(diss) could be readsorbed onto the Fe(OOH) approximately P fraction. Since the environment for P retention (high pH, Fe, Ca and ionic concentrations) is largely provided by the influent, the wetland may be expected to continue retaining P as far as the composition of the influent is maintained and there are available adsorption sites in the sediment.