Non-apatite Inorganic P Research Articles

Study on the fate of phosphorus, fluorine and chlorine in sludge during incineration

Sludge is often incinerated to achieve complete harmlessness and maximum capacity reduction, but the utilization of P (phosphorus) and the environmental pollution of F (fluorine) and Cl (chlorine) released from sludge incineration are usually ignored. In this paper, a series of experiments were employed to inquire into the conversion of various forms of P and the release of various forms of F and Cl after sludge incineration at different temperatures; the agriculture application prospect of P in sludge incineration ash and the environmental pollution caused by the release of F and Cl were discussed. The results show that P in sludge mainly exists as NAIP (non-apatite inorganic P) which biological effect was small. In the process of sludge incineration, InorgP (inorganic P) began to volatilize at 900 ℃, and the remaining P in sludge ash was 30.96 % at 1100 ℃. The forms of P in sludge incinerated at different temperatures varied considerably: a small amount of OrgP (organic P) in the sludge was converted into InorgP at 400 ℃; with the increase of incineration temperature, AP (apatite P) increased gradually, with 3.00 × 103–7.98 × 103 g/t in sludge ash at 700–1100 ℃. At 900 ℃, the content of AP in incineration ash was the highest, accounting for 58.98 % of Total P, which was the most suitable for slow-release phosphate fertilizer. At 600–1100 ℃, more Cl release, with a release rate of 50.61–92.70 %, among which the Cl for HCl (ClHCl) was 1.64 × 103–1.95 × 103 g/t at 700–1100 ℃. The F release rate was 1.52–37.39 %, among which the InorgF (inorganic F: mainly refers to F in HF and SiF4) was 1.13–27.91 g/t at 300–1100 ℃, the release amount of OrgF (organic F) was 1.59–1.86 g/t at 600–800 ℃. It can be seen that after incineration above 700 ℃, the sludge incineration ash may be used as a slow-release phosphate fertilizer, the release of Cl has greater environmental pollution and instrument corrosion than that of F, and the exhaust gas from sludge incineration cannot be discharged directly into the atmosphere.

Total phosphorus and phosphorus forms change in sediments along the Tone River

Phosphorus (P) is an essential element for the metabolism, growth, and development of living organisms, and it often limits primary production in freshwater ecosystems. During flood events, rivers can transport considerable amounts of particulate organic P (org-P) and inorganic P from the basin to the ocean. Understanding the transport mechanisms and changes in P distribution from upstream to downstream areas of rivers is crucial to estimate its flux to the ocean. However, the processes involved in P transformation and cycling among different forms in rivers are not well understood. To better understand P transformation and total P (TP) concentrations in river basins, this study examined various P forms in bottom sediments, river bank sediments, parent rock material, and soil samples along the Tone River, Japan. P forms such as org-P, Ca-bound phosphorus (apatite, Ca-P), P bound with iron oxides/hydroxides (Fe-P), bio unavailable non-apatite inorganic P (NAIP), and TP were analyzed. The results showed an increase in TP concentration in bottom and bank sediment samples along the course of the Tone River. This change in TP was mostly due to the increases in Fe-P and bioavailable org-P, while Ca-P and NAIP decreased toward the downstream area. Analysis of parent rock in three main mountain group areas (Mount Tanigawa, Mount Akagi, and Mount Tsukuba) showed their downstream impacts on TP and the distribution of P forms. Sediment grain size distribution analysis suggested that Fe-P and org-P fractions increased with decreasing sediment particle size, while Ca-P and NAIP were relatively evenly distributed among all grain sizes. The data revealed the transformation of P forms in sediments of the largest river in the Kanto region, Japan, which influence its flux to the Pacific Ocean. The results suggest that Fe-P and org-P may play a more significant role in P transport from river basins to the ocean than previously thought. The findings of this study can be useful for estimating P fluxes to the ocean and for the management of freshwater ecosystems.

Role of humic substances and alkaline in phosphorus release from sludge pre-treated by (alkali-) hydrothermal

The scarcity of phosphorus (P) resources makes the recovery of P urgent. Sludge is a secondary resource rich in P, and the release of P from it is a key step for recovery. Hydrothermal (HT) is currently a popular method for sludge pretreatment, and its combination with alkaline (alkali-hydrothermal, AHT) could reduce the energy consumption in treatment. This study tried to compare their P release profiles in treating activated sludge in which organic P (OP) and non-apatite inorganic P (NAIP) were co-existence. Apart from the OP release in cell lysis, P release from NAIP brought by the joint effect of OH− and humic substances (HS) formed in treatment was focused. The results showed that, compared to HT treatment, more P was released when OH− participated (AHT), and the peak P release was observed at 160 °C. Variation of P distribution in the treated sludge revealed that more P was released from NAIP in AHT than in HT. HS formed in treatments was extracted and characterized. The amount and the structure of the HS varied significantly with the treatment conditions, and there was a linear correlation ship between PO43−-P release and the humic acid (HA) amount in HS. Mechanism study indicated there was a synergism between HS and OH− in promoting PO43−-P release from NAIP. This study linked HS produced by sludge with P release, which provided a new perspective for subsequent P recovery from sludge.

Vertical distributions and risk assessment of phosphorus in core sediments from the Can Gio coastal district in southern Vietnam.

In this study, total phosphorus (P) and P released forms were measured in core sediments from the areas affected by human settlement and shrimp farming activities and the core zone of the Can Gio Biosphere Reserve, a coastal district in south Vietnam. Furthermore, ecological risk assessment and parameters controlling P release from sediments were investigated, including pH, major elements (Al-Ca-Mg-Fe), and fine fraction. The average total amount of P in the sediments varied from 287 to 669mg/kg, with significantly lower values being observed in the mangrove biosphere reserve area. According to the results of the correlation analysis, organic matter was the primary source of P in the sediments, but the majority of the P released was inorganic. Positive correlations were found between Fe and non-apatite inorganic P (NAIP) and apatite P (AP), as well as intercorrelations between P fractions (r = 0.40-0.79, p < 0.05), suggesting that Fe might be the controlling factor of P release in the investigated sediments. The rank orders of concentrations of P forms were significantly different between the areas. The range of P forms was AP (35-248mg/kg) > NAIP (63-201mg/kg) > LP (labile P) (4-25mg/kg) in the human settlement and aquaculture areas and NAIP (84-99mg/kg) > AP (20-38mg/kg) > LP (7-12mg/kg) in the mangrove biosphere reserve area. Risk assessment based on the total concentration of P and the availability of P from a single extraction suggested a relatively low risk of P from sediment as an internal load in the studied areas.

Phosphorus transformation during the carbonaceous skeleton assisted thermal hydrolysis of sludge

On the basis of the carbonaceous skeleton assisted thermal hydrolysis that we proposed to achieve efficient sludge dewatering, this work further explored phosphorus (P) transformation in the process. The results showed that during independent thermal hydrolysis in the temperature range of 120–240 °C, organic-P was first decomposed into soluble-P and particulate-P in liquid, and then combined with Ca, Fe, and Al to form more apatite-P (AP) and less non-apatite inorganic-P (NAIP). When the skeleton assisted the sludge thermal hydrolysis, the turning point of the hydrolysis temperature would reduce from 180 °C to 150 °C, at which the liquid-P began to decrease and the organic-P generally decomposed. Moreover, the increment in the content of AP halved while that of NAIP doubled compared to that in the process without the carbonaceous skeleton. These effects come from the exogenous components introduced by adding the skeleton, which were different from the sludge. Compared with the P-rich compound and metal elements that tend to bond with phosphate introduced by the skeleton, hemicellulose as a main organic component played a leading role in the different P transformations of AP and NAIP. The hemicellulose slightly increased the acidity of sludge products, thereby inhibiting AP production and promoting the production of recyclable NAIP. Overall, the carbonaceous skeleton assisted thermal hydrolysis was beneficial for P recovery with a very low filtrate loss rate.

Behavior of Phosphorus during Sewage Sludge Ozonation

ABSTRACT Since phosphorus (P) is a nonrenewable element essential for life, it is extremely important to understand its potential supply sources. This paper describes the behavior of P during the ozonation of waste activated sludge (WAS) as it is an important pool of P. Also, we investigated whether ozonation of WAS could be an effective method for both P recovery in solution and its bio- and plant-availability in solid residues based on the analysis by the Standards, Measurements, and Testing Program. The results showed that P was enriched in WAS at concentrations above 23 mg/g. Phosphorus transferred from the solid phase to the liquid phase, and the total P content in the liquid phase increased from 1.67 to 40.68 mg/L as the ozone dosage increased from 0 to 0.20 g O3/g MLSS. PO4 3–P was the main form of P in the liquid phase after ozonation, which is beneficial for P recovery. The P fraction analysis revealed that the released P mainly came from apatite P (AP) during ozonation. Additionally, P was more available in solid residues as the proportion of bio-available P (non-apatite inorganic P (NAIP) + organic P (OP)) improved from 73.6% in the raw WAS to 91.7% at an ozone dosage of 0.20 O3/g MLSS. In addition, the solid residues were suitable for plant availability at a moderate Fe/P ratio (0.91) after ozonation. Thus, ozonation is recommended as the preferable solution to achieve an advanced P supply in both the liquid phase and solid residues.

Distribution characteristics of phosphorus-containing substances in a long running aerobic granular sludge-membrane bioreactor with no sludge discharge

This work aimed at revealing the distribution characteristics of phosphorus (P) containing substances in an aerobic granular sludge-membrane bioreactor (AGS-MBR). During the long running period (180 days) with no sludge discharge, AGS was successfully cultivated on day 20, and the system performed well in removing organic pollutants and total nitrogen (TN). However, the removal of total P (TP) showed a fluctuant tendency, and P was found to distribute in all the phases of the system. In the intracellular phase, it occupied the largest ratio all through the period. In AGS, inorganic P (IP) was measured to be about 74.4–77.8% of TP, with non-apatite IP (NAIP) composing 57.5–69.6%, while in organic P (OP), the ratio of monoester and diester phosphate was in the range of 19–26.9% and 12–13.5%, respectively. The presence of highly releasable and bioavailable P (NAIP + OP) in AGS implied that it might be a potential P resource for utilization.

Distribution and transformation of phosphorus-containing substances in a combined oxidation ditch-membrane bioreactor

This work aimed at revealing the distribution and transformation of phosphorus (P) -containing substances in a combined oxidation ditch (OD)-membrane bioreactor (MBR). During the operation, it was found that P mainly occurred in microbial cells, followed by extracellular phase and the least in aqueous phase. The primary P fraction in the bioreactor was inorganic phosphorus (IP), in which non-apatite inorganic P (NAIP) accounted for the major ratio, comprising 57–73% of IP. The values of P uptake and release rate attained a low value after operating for 40 days with no sludge discharged. The relative proportion of Poly-P identified by 31P NMR declined obviously after long-term operation without discharging sludge, revealing lower bioactivity of PAOs in the OD-MBR. In terms of maintaining a stable P-removal efficiency, an MBR should discharge excess sludge at a suitable time point by comprehensively considering the relative values of PUR&PRR, and the proportion of Poly-P.

Enhancing phosphorus release from waste activated sludge by combining high-voltage pulsed discharge pretreatment with anaerobic fermentation

Abstract The effect of high-voltage pulsed discharge (HVPD) pretreatment on waste activated sludge (WAS) for phosphorus (P) release enhancement via anaerobic fermentation (AF) was studied. Batch tests were performed to investigate the P release via HVPD pretreatment and AF. The P release could be enhanced by a 26.7% soluble ortho-P [SOP(L)] concentration increase via HVPD + AF compared with the control sample (AF of WAS without pretreatment). The HVPD and AF contributed 42.2% and 57.8% to the total SOP(L) increase, respectively. The P speciation analyzed using the Standards, Measurements, and Testing extraction protocol indicates that the decrease of non-apatite inorganic P (NAIP) in the solid phase is consistent with the increase of SOP(L) in the liquid phase and the release of poly-P from WAS could be enhanced due to the destruction of sludge flocs by HVPD. In addition, removal rates of 23.8% of total suspended solids (TSS) and 34.3% of volatile suspended solids (VSS) were calculated for the HVPD-pretreated solid phase, which suggests that the soluble organics production and WAS reduction were also enhanced via HVPD + AF. The results reveal that HVPD pretreatment is a promising method for the recovery of P from WAS and WAS reduction.

Clarification of phosphorus fractions and phosphorus release enhancement mechanism related to pH during waste activated sludge treatment

This study aimed to clarify phosphorus (P) fractions in waste activated sludge (WAS) and explore release performance and enhancement mechanism of different P species related to pH. Results showed that inorganic P (IP) was the major P fraction in raw sludge (87.86% of total solid P), and non-apatite inorganic P (NAIP), the most labile P forms, occupied 81.30% of IP, suggesting that WAS could be selected as potential substitution of phosphate rock. The optimized acid and alkaline conditions were pH=4 and pH=12 for molybdate reactive P accumulation, increased by 311.20mg/L and 479.18mg/L compared to raw sludge, which were 3.80 and 5.84 times higher than that of control, respectively. The mechanism study demonstrated that high pH promoted NAIP release, and apatite P was sensitive to low pH. Moreover, the releasable and recoverable P depended on both fractions of different P species in sludge and pH adjustment for sludge treatment.

PH dependent phosphorus release from waste activated sludge: contributions of phosphorus speciation

For phosphorus (P) recovery from waste activated sludge (WAS), the most important step is to release P into the solution, which is greatly dependent on the pH of the solution. The contributions of different P speciation to P release amount from WAS as well as P release kinetics were investigated at different pHs, with the Standards Measurements and Testing (SMT) protocol being used for P fractions tests. The results showed that the total P in the solid (TP(s)) release percentages were 36.2% and 12.4% at pH=2.0 and pH=11.0, respectively. P speciation and fractions study made clear that the released P comes mainly from dissolving of inorganic P (IP) under acid condition, but from non-apatite inorganic P (NAIP) and organic P (OP) under alkaline condition. Simulation study using Visual MINTEQ indicated that the P release amount came from the experimental results is unanimous.

Identification of inorganic and organic species of phosphorus and its bio-availability in nitrifying aerobic granular sludge

Phosphorus (P) recovery from sewage sludge is necessary for a sustainable development of the environment and thus the society due to gradual depletion of non-renewable P resources. Aerobic granular sludge is a promising biotechnology for wastewater treatment, which could achieve P-rich granules during simultaneous nitrification and denitrification processes. This study aimed to disclose the changes in inorganic and organic P species and their correlation with P mobility and bio-availability in aerobic granules. Two identical square reactors were used to cultivate aerobic granules, which were operated for 120 days with influent ammonia nitrogen (NH4–N) of 100 mg/L before day 60 and then increased to 200 mg/L during the subsequent 60 days (chemical oxygen demand (COD) was kept constant at 600 mg/L). The aerobic granules exhibited excellent COD removal and nitrification efficiency. Results showed that inorganic P (IP) was about 61.4–67.7% of total P (TP) and non-apatite inorganic P (NAIP) occupied 61.9–70.2% of IP in the granules. The enrichment amount of NAIP and apatite P (AP) in the granules had strongly positive relationship with the contents of metal ions, i.e. Fe and Ca, respectively accumulated in the granules. X-ray diffraction (XRD) analysis and solution index calculation demonstrated that hydroxyapatite (Ca5(PO4)3(OH)) and iron phosphate (Fe7(PO4)6) were the major P minerals in the granules. Organic P (OP) content maintained around 7.5 mg per gram of biomass in the aerobic granules during the 120 days' operation. Monoester phosphate (21.8% of TP in extract), diester phosphate (1.8%) and phosphonate (0.1%) were identified as OP species by Phosphorus-31 nuclear magnetic resonance (31P NMR). The proportion of NAIP + OP to TP was about 80% in the granules, implying high potentially mobile and bio-available P was stored in the nitrifying aerobic granules. The present results provide a new insight into the characteristics of P species in aerobic granules, which could be helpful for developing P removal and recovery techniques through biological wastewater treatment.

Phosphorus distribution and fractionation during weathering of amphibolites and gneisses in different climatic setups of the Kaveri river catchment, India

Phosphorus distribution and fractionation during weathering of rocks are seminal to its availability to the life system. Here, the P fractionation pattern is reported in weathering profiles of two different rock types i.e. amphibolites and granitic gneisses, subjected to semi-arid and humid climatic conditions in the catchment of the Kaveri river, southern India, known for its fertile flood plain and delta. Weathering profiles developed on the two rock types were analysed for evaluating the intensity of chemical weathering using major ion geochemistry and for accompanying P fractionation. The Chemical Index of Alteration (CIA) and the mineralogy of different zones of the weathering profiles show that profiles under humid climatic conditions are more weathered than those under semi-arid conditions. It was also found that P, present dominantly as the apatite inorganic P (AIP) fraction in the bedrocks was converted into non-apatite inorganic P (NAIP) and organic P (OP), both of which increase with progressive weathering. The two major rock types show a very similar pattern of P fractionation during weathering which is similar to those observed in soil chronosequences. However, the transfer of P from AIP to OP and NAIP is near total in both rock types under humid conditions of weathering. Under semi-arid conditions, a part of AIP was also available in the most weathered zone. Thus the lithology of the bedrock has little, and climate a dominant, control on P fractionation during rock weathering. It was also observed that there is a net loss of total P during the weathering associated fractionation that could be attributed to the incorporation into biologically available forms and their subsequent removal to the fertile floodplains and delta in an undisturbed riverscape.

Modeling bioavailable phosphorus via other phosphorus fractions in sediment cores from Jiulongkou Lake, China

Bioavailable phosphorus (BAP) plays an important role in phosphorus (P) release from lake and river sediments, as well as serves as an indicator for the potential P-release risk in sediment. Developing a feasible model which could predict BAP via other P fractions is needed for the lakes and reservoirs without regular BAP monitoring. The algal available P (AAP), NaHCO3 extractable P (Olsen-P), water soluble P (WSP) and readily desorption P (RDP) are four fractions of BAP. The vertical and spatial distributions of BAP fractions of three sediment cores from Jiulongkou Lake were analyzed. In addition, the P fractions, including total P (TP), organic P (OP), inorganic P (IP), non-apatite inorganic P (NAIP), and apatite P (AP) were measured to develop a model for predicting BAP. The model for each BAP fraction was developed based on datasets from Jiulongkou Lake and validated by the datasets collected from Wujin and Wugong Lake. The results showed that all of the four BAP fractions decreased with depth, along the direction of contaminant transport. Their rank order was AAP > Olsen-P > WSP > RDP in all samples. The concentration of BAP was affected by the anthropogenic input and aquatic macrophyte growth. Each of the four BAP fractions could be simulated by different P fractions: both AAP and Olsen-P were expressed by NAIP and OP, WSP had a significant relationship with OP, and RDP had significant relationship with IP. NAIP and OP were the major sources of the BAP fraction. The simulated results in two other lakes further illustrated that this model could be used to successfully predict the BAP concentrations in lakes in the study area, and holds promise for predicting the BAP levels in other lakes and reservoirs as well.

만경강과 동진강 주요 지점 하천토사 중 형태별 인의 함량

Sediments of Mankyung and Dongjin river were examined on the physico-chemical properties and phosphorus fractionations. The content of total-P in sediment of Mankyung river ranged from 290.1 to 405.4 mg/kg (average = 363.4 mg/kg), while that in sediment of Dongjin river ranged from 304.1 to 431.7 mg/kg (average = 353.6 mg/kg). In both rivers, the total-P was highest in June to September. It is presumed that surficial sediment in arable land flowed into the rivers with rainfall-runoff. Phosphorus fractionations in Mankyung and Dongjin river were apatite-P 52.1% and 42.7%, residual-P 27.3% and 34.2%, nonapatite inorganic-P 18.1% and 22.5%, and adsorbed-P 0.6% and 0.6%, respectively. Adsorbed-P in sediment was the most scarcity fraction. It thus appears that adsorbed phosphorus was not effected in aquatic ecosystem. But nonapatite inorganic-P would be highly released under changes of redox condition and pH in aquatic ecosystem.

Modern and historic accumulation rates of phosphorus in Lake Okeechobee, Florida

Phosphorus accumulation rates in depositional zone sediments of Lake Okeechobee were determined in 11 mud-zone cores and two peat-zone cores dated by 210Pb. Although difficulties were encountered in interpreting 210Pb data from some sites, reliable dating of sediments from the mud zone of this shallow lake is possible. Sediment accumulation rates in this zone have increased during the present century by an average of about twofold, and accumulation of organic sediments in the lake during pre-settlement times apparently was much slower than during the past century. Concentrations of all forms of sedimentary P but especially nonapatite inorganic-P and organic-P also have increased since pre-settlement times and especially since about 1940. Annual P accumulation rates in the lake's sediments have increased about fourfold during the 1900s, with most of the increase occurring in the past 40–50 years. The recent accumulation rate of sedimentary P (past ~ 10 years) agrees within a factor of 1.5 with the net retention of P in the lake calculated from published input-output mass balances.

Using carbon isotopes of bulk sedimentary organic matter to reconstruct the history of nutrient loading and eutrophication in Lake Erie

Lacustrine productivity in Lake Erie was reconstructed using measurements of V3C of sedimented organic C (S13C,,,) and non-apatite inorganic P (NAIP) in three cores. Inferred changes in lacustrine productivity were related to historic changes in phosphorus loading. P loading increased slowly after forest clearance and early settlement in the late 18OOs, then increased exponentially from the late 1940s to early 197Os, and finally decreased after the mid- 1970s in response to management practices implemented to improve water quality. Similarly, the sediment accumulation rate of NAIP increased rapidly during the 1940s and 195Os, peaked during the late 1960s and early 197Os, and then decreased after the mid-1970s. The signal of 613C,, normalized to account for the historic 1.4o/oo depletion in V3C of atmospheric CO, mirrors that for accumulation of NAIP in sediments. Our results show that paleoproductivity peaked in the lower Great Lakes during the mid- 1970s but has since declined as a result of P abatement programs. Inferred trends for NAIP and 613C Orgc are those predicted in P-limited lacustrine systems and demonstrate that the carbon isotopic ratio of organic C can be used as a proxy for paleoproductivity in large, deep lakes.

Characteristics of suspended sediment in the upper rhone river, switzerland, including the particulate forms of phosphorus

AbstractSix stations along the Upper Rhone River above Lake Geneva were sampled by continuous flow centrifuge for recovery of suspended sediment. The samples were taken four times, once in 1982 and three times in 1983. In addition the mouth of the river was sampled in a like manner every two weeks during 1982 until August 1983. Samples were analysed for the major elements SiO2, Al2O3, K2O, MgO, Na2O, CaO, and Fe2O3; for trace elements, Zn, Cu, Ni, Mn, and Cr; for Org. C and Kjeldahl N; and the forms of phosphorus bound as Organic P (OP), Apatite P (AP), and Non Apatite Inorganic P (NAIP). The major elements and trace metals confirmed that there is virtually no change in the major geochemical characteristics of the suspended solids in the Rhone, spatially or temporally, indicating that this river is a well‐mixed sedimentary system. AP also remained consistent in concentration throughout the year. Sediment recovered during the winter low flow, low turbidity period has been designated SED 1 whereas sediment from the high flow, high turbidity summer condition of the river has been designated SED 2. Org C, OP, and NAIP show a dramatic decrease in concentration from SED 1 to SED 2. The decline is ascribed to dilution of a relatively constant supply of organic matter and phosphorus derived mainly from point source sewage treatment plants to the Rhone. This results in variable partitioning of the OP/NAIP and Org C under the different turbidity condition in the river between winter and summer. This interpretation is confirmed by a low and consistent C‐N ratio which except for March remains below 10. Higher values in March may be indicative of soil erosion during spring melt in the agricultural lands of the Rhone Valley. The estimated proportion of particulate bio‐available phosphorus is 14 per cent for SED 1 and 7 per cent for SED 2. These low values would suggest that there would be no observable direct effect on the primary production of the receiving waters of Lake Geneva, which would thus respond only to the cumulative loading of phosphorus from the Rhone River.

Inorganic Contaminants in Suspended Solids from Hamilton Harbour

Concentrations of heavy metals and phosphorus were measured in suspended solids collected from Hamilton Harbour in the spring and late summer of 1986. Forms of iron were determined using Mossbauer spectroscopy and related to the concentrations of heavy metals and phosphorus. Two iron forms, wustite and hematite, originating from anthropogenic activities were identified in addition to naturally occurring Fe 2+ from chlorite and clays and Fe 3+ from amorphous iron oxides. The highest metal concentrations are found in deep water and in areas adjacent to outfalls. The concentrations of wustite and hematite are correlated with the concentrations of heavy metals, particularly Zn and Pb. Heavy metals in suspended solids exceed guidelines for open water disposal of dredged sediments. Annual loadings of heavy metals to the sediments, calculated from the heavy metal concentrations in suspended solids, are ∼477 × 10 3 kg Fe, 16 × 10 3 kg Zn, 3 × 10 3 kg Pb, 958 kg Cu, 469 kg Ni, and 56 kg Cd. Phosphorus concentrations in suspended solids are high and range between 3,100 mg kg −1 and 7,300 mg kg −1. Higher than average non-apatite inorganic P (NAI-P) concentrations in solids are observed in samples taken from the vicinity of municipal discharges. Manganese and iron were released from bottom sediments during summer anoxia in the hypolimnion of the deep water; however, no phosphorus release was observed. The results indicate that wustite and hematite are good tracers of industrial pollution and their distribution is of importance in determining the particle dynamics in Hamilton Harbour.

Suspended sediment phosphorus composition in tributaries of the Okanagan lakes, B.C.

The phosphorus composition of suspended sediments transported during snowmelt to the Okanagan lakes averaged 62% apatite P, 16% non-apatite inorganic P (NAIP), and 22% organic P. Based on the average NAIP content, less than 16% of these P inputs were available for algal growth in the lakes. The content of NAIP in some stream suspended sediments was much higher than average, however. Management of the suspended sediment inputs to reduce P loadings will be most effective if applied to those tributaries contributing the most NAIP.