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PubMed2002

The effect of aeration and non-aeration time on simultaneous organic, nitrogen and phosphorus removal using an intermittent aeration membrane bioreactor.

A laboratory-scale membrane bioreactor (MBR) was fed with synthetic wastewater to investigate the possibility of simultaneous removal of organic, nitrogen and phosphorus by intermittent aeration. The MBR consists of two compartments using a microfiltration membrane with 0.2 microm pore size and a surface area of 0.35 m2. Hydraulic retention time was set at 24 hours and solid retention time 25 days. MLSS concentration in the reactor was in the range of 2,500-3,800 mg/L. The MLSS internal recycling ratio was maintained at 100% influent flow rate. Intermittent aeration was applied in this study to provide an aerobic-anaerobic cycle. Three stages of operations were conducted to investigate the effect of aeration and non-aeration on simultaneous organic and nutrient removal. In Stage 1, time cycles of aeration and non-aeration were set at 90/150 min and 150/90 min in the first and second compartment, the removal efficiency was 97%, 94% and 70% for COD, nitrogen and phosphorus respectively. In Stage 2, time cycles of aeration and non-aeration were set at 60/120 min and 120/60 min in the first and second compartment, the removal efficiency was 97%, 96% and 71% for COD, nitrogen and phosphorus respectively. In Stage 3, time cycles of aeration and non-aeration were set at 120/120 min and 120/120 min in compartment 1 and 2, the removal efficiency was 98%, 96% and 78% for COD, nitrogen and phosphorus respectively. Results show that longer non-aeration time in the second compartment provided better performances of biological phosphorus removal.

Bioreactors↗
PubMed2003

Improving removal efficiency of organic matters by adding phosphorus in drinking water biofiltration treatment.

OBJECTIVE: To investigate phosphorus limitation and its effect on the removal efficiency of organic matters in drinking water biological treatment. METHODS: Bacterial growth potential (BGP) method and a pair of parallel pilot-scale biofilters were used for the two objectives, respectively. RESULTS: The addition of phosphorus could substantially increase the BGPs of the water samples and the effect was stronger than that of the addition of carbon. When nothing was added into the influents, both CODMn removals of the parallel biofilters (BF1 and BF2) were about 15%. When phosphate was added into its influent, BF1 performed a CODMn removal, 6.02 percentage points higher than the control filter (BF2) and its effluent had a higher biological stability. When the addition dose was < 20 micrograms.L-1, no phosphorus pollution would occur and there was a good linear relationship between the microbial utilization of phosphorus and the removal efficiency of organic matters. CONCLUSIONS: Phosphorus was a limiting nutrient and its limitation was stronger than that of carbon. The addition of phosphate was a practical way to improve the removal efficiency of organic matters in drinking water biological treatment.

Bacteria↗
PubMed2003

Cost effective and advanced phosphorus removal in membrane bioreactors for a decentralised wastewater technology.

Future stringent phosphorus regulations (down to 50 microg/L in some cases) together with the availability of more cost effective and/or innovative membrane processes, are the bases for this project. In contrast to conventional activated sludge plants, process parameters are not optimised and especially enhanced biological phosphorus (Bio-P) removal in membrane bioreactors (MBRs) are not proven yet. Current practice of P-removal in MBRs is the addition of coagulants in a co-precipitation mode. Enhanced biological phosphorus removal, when adapted to MBR technology, might be a cost-effective process. For very stringent effluent criteria additional P-adsorption on activated clay after membrane filtration can be also an interesting solution. The objective of this research project is to identify and test various phosphorus removal processes or process combinations, including MBR technologies. This should enable us to establish efficient and cost effective P-removal strategies for upgrading small sewage treatment units (up to 10,000 PE), as needed in some decentralised areas of Berlin. In particular, enhanced Bio-P removal technology was developed and optimised in MBR. Combinations of co-precipitation and post-adsorption will be tested when low P-values down to 50 microg/L are required in the effluent. One MBR bench-scale plant of 200 to 250 L and two MBR pilot plants of 1 to 3 m3 each were operated in parallel to a conventional wastewater treatment plant (Ruhleben WWTP, Berlin, Germany). The MBR bench-scale and pilot plants were operated under sludge ages of respectively 15 and 25 days. In both cases, Bio-P was possible, and phosphorus effluent concentration of about 0.1 mg/L could be achieved. A similar effluent quality was observed with the conventional WWTP. Investigations with lab columns indicated that P-adsorption could lead to concentrations down to 50 microg/L and no particle accumulation occurred in the filter media. The three tested materials exhibited great differences in break-through curves. Granulated ferric hydroxyde (GEH) showed higher capacity than activated alumina and FerroSorpPlus.

Adsorption↗
PubMed1992

Calcium and phosphorus metabolism in full-term infants.

Appropriate intake of dietary calcium and phosphorus is essential for the maintenance of mineral homeostasis and support of adequate bone mineralization in growing infants. Disturbances of calcium homeostasis such as newborn hypocalcemia, have been shown to be secondary to high oral phosphate intake. The incidence of hypocalcemic tetany has changed from epidemic proportions in newborns, who were formerly fed evaporated cow's milk formula, to the present sporadic occurrence in newborns who are now fed humanized cow's milk formula, with a calcium concentration of about 50 mg/dl and a phosphorus concentration of about 35 mg/dl. Human milk, provided vitamin D intake is adequate, has been shown to maintain calcium-phosphorus homeostasis and support adequate bone mineralization at least in the first 6 months of life. After this, the phosphorus content of breast milk could limit mineral accretion in exclusively breast fed infants. The present concentration of calcium and phosphorus in the humanized cow's milk formulas support adequate mineral homeostasis and bone mineralization throughout the first year of life. As bone calcium content is proportional to calcium intake, feeding whole cow's milk from early infancy onward is associated with abnormal bone mineralization. The adequacy of bone mineralization in infants fed soy formula is still controversial.

Bone Density↗
PubMed1992

Effects of dietary phosphorus and protein in dogs with chronic renal failure.

Four diets were formulated to contain: 16% protein and 0.4% phosphorus--diet 1; 16% protein and 1.4% phosphorus--diet 2; 32% protein and 0.4% phosphorus--diet 3; and 32% protein and 1.4% phosphorus--diet 4. Forty-eight dogs were fed diet 1 for 3 months after surgical reduction of renal mass, then were allotted to 4 groups of 12 dogs each, with equal mean values for glomerular filtration rate (GFR). Dog of groups 1-4 were fed diets 1-4, respectively, for 24 months. Data collected from the dogs during and at termination of the study were analyzed statistically for effects of dietary protein, phosphorus (P), time, and interactions between these factors. During the 24 months of study, 24 dogs developed uremia and were euthanatized for necropsy. Necropsy also was performed on the remaining 24 dogs after they were euthanatized at the end of the study. Dog survival was significantly enhanced by 0.4% P diets (vs 1.4% P diets), but survival was not significantly influenced by amount of dietary protein. The 0.4% P diets (vs 1.4% P diets) significantly increased the period that GFR remained stable before it decreased, but dietary protein did not have significant effect. Significant blood biochemical changes attributed to P, protein, and time were identified during the study. Terminally, plasma parathyroid hormone concentration was significantly increased from prediet values in all groups of dogs. Urine protein excretion was not significantly affected by dietary amount of either protein or P, when measured by either timed urine collection or urine protein-to-creatinine ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2004

[Accumulation pattern of dry matter, nitrogen, phosphorus, potassium and silicon in rice genotypes and their relationships].

The accumulation of dry matter, nitrogen, phosphorus, potassium and silicon in 30 rice genotypes and their relationships under field condition were studied. The results showed that dry matter accumulated at ripening stage linearly increased with increase of nitrogen, phosphorus, potassium and silicon accumulation with highly significant correlation coefficients at both early and late season. At the same time balance of nitrogen, phosphorus, potassium and silicon accumulation was beneficial for dry matter accumulation, which linearly increased with increase of nutrient balance index and decreased with increase of nutrient deviation index. The nitrogen, phosphorus, potassium and silicon were accumulated at the rate of 3.76:1:4.55:7.10 at early season and 2.88:1:4.54:8.09 at late season. During growth period, dry matter accumulation was the highest at middle stage, then late stage and early stage. But nitrogen accumulation was the highest at early stage, then middle stage and late stage. The dry matter accumulated before heading was mainly distributed in stem and leaf sheath, with the highest ratio of stem and leaf sheath to total dry matter at heading stage. In contrast, nitrogen accumulated before heading was mainly distributed in leaf blade, and the ratio of nitrogen in leaf blade to total nitrogen was higher than that of dry matter at either growth stages. Dry matter, nitrogen, phosphorus accumulated at ripening stage were mainly distributed in panicle with rates of 58.01%, 66.42% and 70.06%, respectively. But potassium accumulated at ripening stage was mainly distributed in stem and leaf sheath with the rate of 62.08%. Silicon was largely distributed in stem and leaf sheath at early season with the rate of 43.11%, but distributed largely in panicle at late season with the rate of 46.99%.

Genotype↗
PubMed2004

[Phosphorus intake in Poland in 1994-2000].

The aim of the study was the evaluation of the phosphorus intake in 8 types of households with different family number of persons in Poland during 1994-2000. The research was conducted on the basis on households budget food consumption data and tables of food composition and nutritional value. Phosphorus intake per capita per day was compared to RDA at the safe level. The intake of phosphorus was high in all investigated households and ranged between 65-144% above lower RDA limit and 34-96% for upper one. When the family number of persons increased, the intake decreased. The main food sources of phosphorus were: bread, meat and meat products, milk and milk drinks and vegetables and mushrooms. The bread has a highest share in phosphorus supply in households maintained from non-earned sources and the lowest for the non-manual labour position one.

Agaricales↗
PubMed2004

Assessment on the pollution of nitrogen and phosphorus of Beijing surface water based on GIS system and multivariate statistical approaches.

This paper presented the characteristics of nitrogen and phosphorus pollution in Beijing surface water during the survey. A significant difference was found out in concentration distribution of various parameters of nitrogen and phosphorus. Most water bodies in five water systems were polluted by total nitrogen with the content even up to 120 mg/L which was higher than exceeded the fifth class standard of national surface water quality standard GB3838-2002 except for several segments of Chaobaihe and Yongdinghe. Ammonia and phosphorus showed a similar tendency of distribution with higher content in Daqinghe, Beiyunhe and Jiyunhe water systems, but with relatively low concentrations in Chaobaihe and Yongdinghe water systems. Meanwhile, nitrate was found at comparatively low content (mostly less than 10 mg/L) and could fit for corresponding water quality requirements. Totally, the water quality of Daqinghe, Jiyunhe and Beiyunhe river systems as well as the lower reaches of Yongdinghe and Chaobaihe was contaminated seriously with high content of total nitrogen and phosphorus. Through multivariate statistical approaches, it can be concluded that total nitrogen, ammonia and total phosphorus was highly correlated to chemical oxygen demand, biochemical oxygen demand, dissolved oxygen and electrical conductivity, which explained the same pollution source from anthropogenic activities.

China↗
PubMed2005

Evaluation of bipolar electrocoagulation applied to biofiltration for phosphorus removal.

To reduce the residual organic matter and phosphorus contained in secondary effluent, a biofiltration system combined with electrocoagulation using bipolar iron electrodes was evaluated as a supplementary treatment to existing small-community sewage treatment. Based on the results of batch tests, bipolar electrocoagulation (BEC) was found to be more effective on phosphorus removal than monopolar electrocoagulation (MEC) but energy consumption was less in monopolar electrocoagulation. Optimum conditions of BEC to treat the secondary effluent were current density 15 A/m2, electrode spacing 1 cm and pH < 8. The removals of COD(Cr) and phosphorus by biofiltration system without BEC were 69.1% and 9.6%, respectively. However, biofiltration system combined with BEC showed 76.6-83.7% and 70.7-93.0% removal for COD(Cr) and phosphorus respectively. Extraordinary increase in phosphorus could be achieved by introducing electrocoagulation to biofiltration, and BEC/biofiltration system was evaluated to be applicable to existing small-community sewage treatment plants as a supplementary process.

Biodegradation, Environmental↗
PubMed2005

Phosphorus removal from synthetic and municipal wastewater using spent alum sludge.

In the present study, phosphorus removal was studied using as coagulant spent alum sludge from a water treatment plant of EYDAP (Athens Water Supply and Sewerage Company) and compared to alum (Al2(SO4)3.18H2O), iron chloride (FeCl3.7H2O), iron sulfate (Fe2(S04).10H2O) and calcium hydroxide (Ca(OH)2) at a constant pH (equal to 6). The comparison was based on their efficiency to remove phosphorus in synthetic wastewater consisting of 10 mg/L P as potassium dihydrogen phosphate and 50 mg/L N as ammonium chloride, The experiments were carried out using a jar-test apparatus and the measurements were performed according to the Standard Methods for the Examination of Water and Wastewater. Pure alum, iron chloride and iron sulfate were much more efficient in phosphorus removal than the spent alum sludge but in the case of calcium hydroxide, phosphorus removal was very low in pH = 6. Specifically, orthophosphate were totally removed by alum using 15 mg/L as Al, by alum sludge using 75 mg/L as Al and by FeCl3.7H2O or Fe2(SO4).10H2O using 30 mg/L of Fe while in the case of calcium hydroxide P removal was actually zero. pH measurements showed that the uptake of phosphates is associated to the release of OH ions in the solution and that the end of P uptake is accompanied by the stabilization of pH. Finally this spent alum sludge was tested on municipal wastewater and proved to be effective as apart from phosphorus it was shown to remove turbidity and COD.

Alum Compounds↗
PubMed2006

[Expression characteristics of MtPAP1 and its exotic expression in Arabidopsis affecting organic phosphorus absorption of plants].

The MtPAP1 encodes 465 amino acids (Fig.1). The transcript of MtPAP1 was detected mainly in leaf under high-phosphate conditions (Fig.2). While under low-phosphate condition, the transcript level was low in leaves and very high in roots, with the strongest hybridization signal detected in roots (Fig.2). Chimeric MtPAP1 binary vector was constructed and the transcript levels of MtPAP1 in roots of transgenic T(3) Arabidopsis lines were analyzed (Fig.3). Under the condition in which phytate was the sole source of phosphorus, transgenic Arabidopsis plants over-expressing MtPAP1 showed acid phosphatase activities in root apoplast increasing markedly than that of the control plant (Fig.4). The results of analysis of organic phosphorus degradation in liquid culture by HPLC indicated that the APase secreted by the transgenic plants could quickly degrade the phytate (Fig.5). Significant increase in biomass production, Pi and total phosphorus content of plants achieved in the transgenic lines when phytate, an organic phosphorus compound, was supplied as the sole source of phosphorus (Fig.6,7).

Amino Acid Sequence↗
PubMed1991

Breast-milk calcium and phosphorus concentrations of mothers in rural Zaire.

The breast-milk calcium and phosphorus concentrations of 12 mothers living in a poor, rural area of Zaïre have been measured serially over 18 months of lactation. Calcium concentrations remained steady for the first 3-4 months and then decreased by approximately 27%. Phosphorus concentrations decreased by an average of 16% during the first 6 months and then reached a low plateau. The calcium:phosphorus ratio decreased from 1.7 in early lactation to 1.3 after 15 months. A wide range of mineral concentrations was observed between individuals in Zaïre and the differences between mothers were maintained throughout lactation. No influence of maternal nutritional status, age or parity on breast-milk mineral concentrations was observed. Comparison of the results of this study with published data from Britain and The Gambia obtained in the same laboratory demonstrated that breast-milk calcium concentrations in Zaïre resembled Gambian values in being significantly lower than those in Britain by 15%-20%. In contrast, breast-milk phosphorus concentrations in Zaïre were similar to those in Britain and were lower than those in The Gambia. This pattern of mineral composition resulted in Ca:P ratios in Zaïre that were intermediate in value between those of British and Gambian breast-milk. More information is required about the factors which determine calcium and phosphorus secretion into breast-milk.

Calcium↗
PubMed1990

Effect of clonidine on serum inorganic phosphorus in patients with essential arterial hypertension.

The decrease in arterial blood pressure in patients with essential arterial hypertension treated with clonidine is associated, in 88.9% of cases, with a rise in serum inorganic phosphorus. The increase of inorganic phosphorus in the serum of patients with hypophosphataemia, during clonidine therapy, is higher (P less than 0.001) than in hypertensive patients with normal values of serum phosphorus (P less than 0.01). This effect is more significant in overweight hypertensive patients (P less than 0.0005) than in normal weight hypertensives (P less than 0.02). No correlation was noted between the rise of serum inorganic phosphorus and the decrease in systolic and diastolic arterial blood pressure. The rise of serum phosphorus concentration in hypertensive patients is attributed to inhibition of insulin release and enhancement of growth-hormone secretion induced by clonidine.

Blood Pressure↗
PubMed1989

Nutritive utilization of phosphorus in the rat: influence of intestinal resection and dietary medium chain triglycerides and vitamin D3.

The effects of intestinal resection and diet on the digestive and metabolic utilization of phosphorus were studied in adult rats from which 50% of the distal small intestine had been removed and in sham-operated controls. Metabolic parameters were measured both 1 and 3 months after surgery. The loss of half of the distal small intestine led to a decline in digestive utilization of phosphorus 1 month after surgery as reflected in bone mineral content. Digestive efficiency had improved by 3 months after surgery. One month's feeding with a diet in which fat was provided as equal parts of medium chain triglycerides, sunflower seed oil and olive oil instead of 100% olive oil enhanced phosphorus absorption and retention, although this improvement was less evident after 3 months. The negative effects of distal small intestine resection on the nutritive utilization of phosphorus were not only palliated but significantly enhanced by supplementing the diet with vitamin D3 at a rate of 0.08 mg/100 g diet. This dose is within physiological limits, and favors phosphorus deposition in bone tissue.

Animals↗
PubMedDate not supplied

[Dynamics and mechanism of mineral metabolic disorders in excessive phosphorus content in the diet].

Keeping rats on a ration with a 1:3 proportion of calcium and phosphorus for 2 weeks results in hyperprosphatemia, hypocalcemia and renal calcinosis with uremia. When putting these animals on a food ration with the calcium and phosphorus ratio of 1:1 the concentration of these elements in the blood quickly returns back to normal, while renal calcinosis continues for the whole period of observation (7 months). The growing animals are more sensitive to a phosphorus excess than are the adult ones. An excessive consumption of phosphorus leads to its increased excretion with the urine with concurrent diminution of the calcium excretion. The blood and urine pH then experiences no change, whereas the ability of the turned inside out segments of the small intestine to absorb calcium as against the concentration gradient (active transport) in vitro not only does not diminish, but initially even goes up. It is suggested that the excess phosphorus content in the food ration tends to directly derange absorption of calcium in the intestines, this resulting in the development of hypocalciemia, hyperparathyroidism and calcinosis of the viscera and tissues.

Age Factors↗
PubMed1988

Accuracy of methods estimating calcium and phosphorus intake in daily diets.

Three different methods of estimating calcium and phosphorus content were compared with the chemical analysis of 20 daily diets taken from general hospital and cafeteria menus, individual food records, and menus designed for research. Comparisons of chemical analyses with estimated values showed an insignificant trend toward underestimation of calcium content; all methods significantly underestimated phosphorus content. On the average, estimates of phosphorus content deviated from actual by approximately 250 mg/day. Diets with a greater proportion of processed, convenience, or restaurant foods deviated by more than 350 mg/day. Our findings suggest that estimates of calcium intake calculated from available food composition tables are within an acceptable range of error; however, phosphorus intake is significantly underestimated by 15% to 25% of the actual level. For accurate calculation of phosphorus content, nutrient composition sources must be updated to reflect present industrial use of phosphate-containing additives.

Calcium, Dietary↗
PubMed1987

Effect of low calcium and low phosphorus diets on duodenal and ileal absorption of phosphate in chick.

The duodenal and ileal absorption of 32P was studied by an in vivo method in control chicks and in chicks fed for 2 weeks a diet deficient in calcium or phosphorus. The results showed a highly significant increase in duodenal and ileal phosphate absorption in chicks fed a low calcium diet and a smaller, though also significant increase in duodenal but not ileal phosphate absorption in chicks fed a low phosphorus diet. The adaptation phenomenon concerning intestinal phosphorus absorption is presumably due in part to a compensatory increase in 1,25-dihydroxy-vitamin D3 in both deficient diets. However, much higher renal l-hydroxylase activity was found in chicks fed the low calcium diet than in chicks fed the low phosphorus diet. The results indicate that duodenal and ileal absorption of phosphate is a vitamin D mediated process, but the adaptation to a low phosphorus diet tends to be less efficient than that to a low calcium diet, especially in the ileum.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
PubMed1985

Phosphorus fractions of crayfish haemolymph, serum and haemocyanin.

Different amounts of haemolymph proteins participate in clot formation in Astacus leptodactylus and Orconectes limosus (20% and 10%, respectively), although in both species the content of proteins in haemolymph is similar. In both species the content of total phosphorus in the clot was similar (0.33-0.49%, w/w) but it was about 6 times lower in serum of O. limosus than in serum of A. leptodactylus (2.2 and 14.8 mg/100 ml, respectively). An even greater difference in phosphorus content was found in the protein precipitated from serum. In both species lipid phosphorus was predominant (77% of total haemolymph phosphorus in A. leptodactylus and 52% in O. limosus). Phospholipids were found mainly in serum. Only traces of phosphorus (0.005%) and small amounts of fatty acids were found in purified haemocyanin preparations.

Animals↗