Cyanobacterial organic matter (COM) positive feedback aggravates lake eutrophication by changing the phosphorus release characteristics of sediments.

Phosphorus is a key nutrient that causes eutrophication in lakes. Our investigation of 11 eutrophic lakes found that the concentrations of soluble reactive phosphorus (SRP) in the water column and EPC0 in sediments decreased with aggravated eutrophication. There was a significant negative correlation between the SRP concentrations and eutrophication parameters such as chlorophyll a (Chl-a), total phosphorus (TP) and algal biomass (P < 0.001). In addition, SRP concentrations were significantly affected by EPC0 (P < 0.001), while EPC0 was significantly affected by the content of cyanobacterial organic matter (COM) in sediments (P < 0.001). Based on these findings, we hypothesized that COM can alter the phosphorus release characteristics of sediments, including the phosphorus adsorption parameters of sediment (PAPS) and the phosphorus release rate of sediment (PRRS), thereby stabilizing SRP concentrations at lower levels and rapidly replenishing them when depleted by phytoplankton, which in turn benefits cyanobacteria due to their low SRP adaptation strategies. Simulation experiments were conducted to confirm this hypothesis by adding higher plant OM and COM to sediments. The results showed that all types of OM could significantly increase the maximum phosphorus adsorption capacity (Qmax), but only COM could reduce sediment EPC0 and promote PRRS (P < 0.001). Changes in these parameters (i.e., Qmax, EPC0, and PRRS) resulted in a larger SRP adsorption quantity and faster SRP release rate at low SRP concentrations. This promotes the competitive edge of cyanobacteria due to they have a higher affinity for phosphorus than other algae. As an important component of cyanobacteria, EPS can change the phosphorus release characteristics (i.e., PAPS and PRRS) by reducing sediment particle size and increasing sediment surface functional groups. This study revealed the positive feedback effect of COM accumulation in sediments on lake eutrophication from the perspective of phosphorus release characteristics of sediments, which provides a basic reference for the risk assessment of lake eutrophication.

Interactions between Phosphorus Enrichment and Nitrification Accelerate Relative Nitrogen Deficiency during Cyanobacterial Blooms in a Large Shallow Eutrophic Lake.

Regime shifts between nitrogen (N) and phosphorus (P) limitation, which trigger cyanobacterial succession, occur in shallow eutrophic lakes seasonally. However, the underlying mechanism is not yet fully illustrated. We provide a novel insight to address this from interactions between sediment P and nitrification through monthly field investigations including 204 samples and microcosm experiments in Lake Chaohu. Total N to P mass ratios (TN/TP) varied significantly across seasons especially during algal bloom in summer, with the average value being 26.1 in June and descending to 7.8 in September gradually, triggering dominant cyanobacterial succession from Microcystis to Dolichospermum. The regulation effect of sediment N/P on water column TN/TP was stronger in summer than in other seasons. Iron-bound P and alkaline phosphatase activity in sediment, rather than ammonium, contributed to the higher part of nitrification. Furthermore, our microcosm experiments confirmed that soluble active P and enzymatic hydrolysis of organic P, accumulating during algal bloom, fueled nitrifiers and nitrification in sediments. These processes promoted lake N removal and led to relative N deficiency in turn. Our results highlight that N and P cycles do not exist independently but rather interact with each other during lake eutrophication, supporting the dual N and P reduction program to mitigate eutrophication in shallow eutrophic lakes.

Internal phosphorus recycling promotes rich and complex dynamics in an algae-phosphorus model: Implications for eutrophication management.

Internal phosphorus recycling in lakes is an important nutrient source that promotes algal growth. Its persistence impedes the effort to improve water quality and thus poses a challenge to the management of eutrophication in lakes, especially in shallow lakes where the occurrence of internal phosphorus recycling is reportedly more common. This paper aims to provide crucial insights on the effects of internal phosphorus recycling on eutrophication dynamics for effective management of lake eutrophication. For this purpose, a mathematical model for lake eutrophication, comprising two compartments of algae and phosphorus, is first formulated for application to a eutrophic tropical lake named Tasik Harapan in Universiti Sains Malaysia. Numerical bifurcation analysis of the model is then performed to assess the combined influences of internal phosphorus recycling, algal mortality and external phosphorus loading on Tasik Harapan eutrophication dynamics. Specifically, co-dimension one bifurcation analysis of algal mortality rate is carried out by means of XPPAUT for various external phosphorus loading rates. The emergence of limit cycle for a certain range of algal mortality rate could be related to the hydra effect (i.e., algal concentration increases in response to greater algal mortality) and the paradox of enrichment (i.e., destabilization of algae in nutrient rich environment). To trace the locus of co-dimension one bifurcation, co-dimension two bifurcation analysis is performed by means of MatCont. The analysis demonstrated that the inclusion of the internal phosphorus recycling term induces rich and complex dynamics of the model. These dynamics include saddle-node bifurcation, cusp, Bogdanov-Takens bifurcation, Generalized Hopf bifurcation and limit point bifurcation of cycles. The results suggest that high internal phosphorus recycling rate promotes bistability and catastrophic shift in a shallow and tropical lake like Tasik Harapan. Hence, the key to effective management of eutrophication in shallow and tropical lakes is the control of internal phosphorus recycling.

Remote monitoring of total dissolved phosphorus in eutrophic Lake Taihu based on a novel algorithm: Implications for contributing factors and lake management.

Understanding the spatiotemporal dynamics of total dissolved phosphorus concentration (CTDP) and its regulatory factors is essential to improving our understanding of its impact on inland water eutrophication, but few studies have assessed this in eutrophic inland lakes due to a lack of suitable bio-optical algorithms allowing the use of remote sensing data. We developed a novel semi-analytical algorithm for this purpose and tested it in the eutrophic Lake Taihu, China. Our algorithm produced robust results with a mean absolute square percentage error of 29.65% and root mean square error of 9.54 µg/L. Meanwhile, the new algorithm demonstrates good portability to other waters with different optical properties and could be applied to various image data, including Moderate Resolution Imaging Spectroradiometer (MODIS), Medium Resolution Imaging Spectrometer (MERIS), and Ocean and Land Color Instrument (OLCI). Further analysis based on Geostationary Ocean Color Imager observations from 2011 to 2020 revealed a significant spatiotemporal heterogeneity of CTDP in Lake Taihu. Correlation analysis of the long-term trend between CTDP and driving factors demonstrated that air temperature is the dominant regulating factor in variations of CTDP. This study provides a novel algorithm allowing remote-sensing monitoring of CTDP in eutrophic lakes and can lead to new insights into the role of dissolved phosphorus in water eutrophication.

Decline in nitrogen concentrations of eutrophic Lake Dianchi associated with policy interventions during 2002-2018.

Excessive nutrient discharges have resulted in pervasive water pollution and aquatic eutrophication. China has made massive efforts to improve water quality since 2000. However, how long-term policy interventions govern external and internal fluxes as well as nitrogen (N) concentrations is not well known. Here we examined the historical N concentration change and its key drivers in eutrophic Lake Dianchi (southwest China) over the period 2002-2018, based on monthly observations of water quality and external N fluxes, local surveys of mitigation measures, and process-based model simulations of internal N fluxes. Our data indicated that N concentrations peaked at 3.0 mg L-1 in 2007-2010 but afterwards declined down to 1.2 mg L-1 in 2018. Compared with 2010, the decline in lake N concentrations was attributed to reduced riverine N inflow decreasing by 0.20 g N m-3 month-1 and the water-sediment exchange flux decreasing by 0.07 g N m-3 month-1 from 2010 to 2018. Adoptions of wastewater treatment, pollution interception, and transboundary water transfer dominated the changes in external and internal fluxes of N and thereby the decline of lake N concentrations. These findings underscore the priority of reducing external discharge for historical lake water quality improvement and the need of enhancing internal N removal for future lake ecosystem restoration.

Implications of phosphorus partitioning at the suspended particle-water interface for lake eutrophication in China's largest freshwater lake, Poyang Lake.

Nutrient partition, especially for phosphorus (P), has been prominently changed that was caused by variation of river-lake relationship during the post-Three Gorges Reservoir and catchment alternations. Changes in proportion of total particulate phosphorus (TPP) and total dissolved phosphorus (TDP) might accelerate lake eutrophication, but limited attention has been paid to P partition over suspended particle (SP) levels. Data analysis showed that SP concentration presented a positive effect on TPP in wet season and soluble reactive phosphorus (SRP) in dry season, indicating seasonal physical and chemical variations. Based on this phenomenon, we proposed a hypothesis that the SP levels would affect TDP and TPP proportions by partition in aqueous-solid. It was found that using the parabola models to fit the sorption relationships of SRP and TDP (R2 > 0.6, p < 0.01), the maximum sorption capacity (Qmax) was 64.54 mg/kg and 60.52 mg/kg at 400 mg/L of SP level, respectively. In addition, the partition coefficients (KP) of TDP and SRP were logarithmically increased with SP levels, indicating that higher SP levels (>400 mg/L) would hinder the sorption process. Furthermore, enhancing turbulence lead to less sorption of SRP and TDP at high SP levels (>800 mg/L). The sorption of SRP and TDP related to the presence of Fe/Al oxy-hydroxides were enriched in the Fe/Al-P fraction (47% of TP). The findings of this study indicated that the low SP levels would increase P bioavailability for alga and is not conducive for lake eutrophication management.

Submerged macrophytes successfully restored a subtropical aquacultural lake by controlling its internal phosphorus loading.

Intensive aquaculture has largely changed the global phosphorus (P) flow and become one of the main reasons for the eutrophication of global aquatic ecosystem. Artificial planting submerged macrophytes has attracted enormous interest regarding the restoration of eutrophic lakes. However, few large-scale (>80 km2) studies have focused on the restoration of aquatic vegetation in the subtropical lakes, and the mechanism underlying the restrain of sediment P release by macrophytes remains unknown. In this study, field surveys and the diffusive gradients in thin films (DGT) technique were used to elucidate the effects of macrophytes on internal P loading control in a typical eutrophic aquacultural lake. Results showed that half of the P content in overlying water and sediments, particularly dissolved P in overlying water and calcium bound P (Ca-P) in sediment, were removed after restoration. Temperature, as well as dissolved oxygen (DO) and P concentration gradients near the sediment-water interface (SWI) jointly controlled the release of labile P from surface sediments. Submerged macrophytes can effectively inhibit the release of sediment P into the overlying water, which depended on DO concentration in the bottom water. Future restoration projects should focus on the temperature response of submerged macrophytes of different growth forms (especially canopy-forming species) to avoid undesirable restoration effects. Our results complement existing knowledge about submerged macrophytes repairing subtropical P-contaminated lakes and have positive significance for lake restoration by in situ phytoremediation.

Retention of nitrogen and phosphorus in Lake Chaohu, China: implications for eutrophication management.

Nutrient retention is an important process in lake nutrient cycling of lakes and can mitigate lake eutrophication. However, little is known about temporal lake nutrient retention efficiency and it varies due to changes in hydrological, ecological, and nutrient inputs to lake waters. Quantitative information about seasonal lake N and P retention is critical for developing strategies to reduce eutrophication in lake systems. This study investigated TN and TP retention efficiencies and retention masses using water and mass balance calculations, and statistically analyzed the seasonal variability of nutrient retention in Lake Chaohu, China, from 2014 to 2018. Lake Chaohu experienced large amounts of external loads inputs (23.2 g N m-2 year-1 and 1.3 g P m-2 year-1), and approximately 58% TN and 48% TP were retained annually. The lake acted more as a sink for N than for P. The mean annual TP retention efficiency decreased (P < 0.05) over the study period, indicating that TP retention capacity was gradually exceeded. Seasonal variability of TN and TP retention efficiency was high and ranged from - 18.7 to 144.1% and from - 58.8 to 170.7%, respectively, over the five study years. The internal P loads over the study period were equivalent to roughly 9% of the total external loads. The annual nutrient retention efficiency of TN and TP increased with hydraulic residence time, while water temperature was an essential factor for the contrasting seasonal variation patterns of TN and TP retention efficiencies.

Sediment internal nutrient loading in the most polluted area of a shallow eutrophic lake (Lake Chaohu, China) and its contribution to lake eutrophication.

It is well known that sediment internal loading can worsen lake water quality for many years even if effective measures have been taken to control external loading. In this study, a 12-month field study was carried out to reveal the relationship between sediment phosphorus (P) and nitrogen (N) forms as well as their fluxes across sediment-water interface from the most polluted area of Lake Chaohu, a large shallow eutrophication lake in China. The possible contribution of mobile fraction of P and N to lake eutrophication is also analyzed. The results indicate that the content of total P and N and their forms in water and sediment were rather dynamic during the year-long field investigation. Low concentrations of P and N from sediment and overlying water were observed in the winter but increased sharply in summer. The phosphate and ammonium fluxes showed evident seasonal variation, and higher fluxes can be observed in warmer seasons especially during the period of algal bloom with high sedimentation. The reduction of ferric iron and degradation of organic matter could be responsible for the increased P flux from sediment in algal bloom seasons, which is consistent with the seasonal variation of P forms in sediment. A comparison of the mole ratio of P flux:N flux to both the P:N mole ratio in sediments and the Redfield ratio was used to further distinguish the dominant sediment P forms' release during seasonal variation. Moreover, the anoxic condition and enhanced microbial activity in warmer seasons contribute a lot to the ammonium release from sediment. Consequently, the nutrient fluxes seasonally influence their corresponding nutrient concentrations in the overlying water. The results of this study indicate that sediment internal loading plays an important role in the eutrophication of Lake Chaohu.

Assessment of lake eutrophication using a novel multidimensional similarity cloud model.

Lake eutrophication is characterized by a variety of indicators, including nitrogen and phosphorus concentrations, chemical oxygen demand, chlorophyll levels, and water transparency. In this study, a multidimensional similarity cloud model (MSCM) is combined with a random weighting method to reduce the impacts of random errors in eutrophication monitoring data and the fuzziness of lake eutrophication definitions on the consistency and reliability of lake eutrophication evaluations. Measured samples are assigned to lake eutrophication levels based on the cosine of the angle between the cloud digital characteristics vectors of each sample and those of each eutrophication grade. To field test this method, the eutrophication level of Nansi Lake in Shandong Province was evaluated based on monitoring data collected in 2009-2016. Results demonstrate that, in 2009 and in 2011-2015, the upper lake of Nansi Lake exhibited moderate eutrophication while the lower lake exhibited mild eutrophication. In 2010, 2016, elevated concentrations of total nitrogen and total phosphorus led to an increase in the eutrophication level of the lower lake, matching that of the upper lake. Based on the results of these field tests, we conclude that the MSCM presented in this study provides a more flexible and effective method for evaluating lake eutrophication data than the existing multidimensional normal cloud model.

Dredging project caused short-term positive effects on lake ecosystem health: A five-year follow-up study at the integrated lake ecosystem level.

Sediment dredging is a controversial technology for lake eutrophication control. A lengthy and holistic assessment is important to understand the effects of a dredging project on a lake ecosystem. In this study, a dredging project was followed for 5 years. To understand the variations of lake ecosystems before, during and after the project, water quality, phytoplankton, zooplankton and benthic animal biomass were monitored; Four subindicators, including eco-exergy (Ex), structural eco-exergy (Exst), buffer capacity of total phosphorus for phytoplankton (ß(TP)(phyto)) and trophic level index (TLI) were calculated and developed to an integrated ecosystem health indicator (EHI). The monitoring results showed that the dredging project caused many short-term positive effects such as decreased total nitrogen, total phosphorus, permanganate index and phytoplankton biomass throughout the entire lake water, increased Secchi disk depth in the whole lake and increased benthonic animal biomass in the nondredged regions. However, these positive effects disappeared overtime. Water chemistry and biomass returned to the initial state before dredging. EHI showed that the dredging project caused negative effects on the lake health in the dredged region at first. Subsequently, the health status of the entire lake, including the dredged and nondredged regions, improved until 1-2 years after the project finished. Because of the lack of other timely ecological restoration measures, the lake gradually returned to its initial health status. However, the health status in the dredged regions was only slightly better than before dredging and often worse than that of the nondredged regions. Our study suggested that dredging projects may only cause short-term positive effects on lake ecosystem health. The external interception and dredging ratio were important. A dredging project should be combined with other ecological lake restoration measures when the project has caused positive effects in a lake.

Spatial distribution of sediment nitrogen and phosphorus in Lake Taihu from a hydrodynamics-induced transport perspective.

Hydrodynamics play an important role in sediment nutrient dynamics in large shallow eutrophic lakes. In this study, the spatial patterns of sediment nitrogen and phosphorus in Lake Taihu were compared from a hydrodynamics-induced transport perspective based on high-resolution investigation of sediment, field observations, numerical simulations and long-term ecological data analysis. The results showed that sediments were primarily distributed in the west and southeast portions of the lake. Additionally, the total nitrogen (TN) and phosphorus (TP) stored in the active sediments was 166,329 t and 67,112.4 t, respectively. The sediment TN content was 319.4-3123.8 mg kg-1, with high content areas being primarily located in the Zhushan, Meiliang and East Taihu bays. The external nitrogen-containing nutrients in the overlying water, which is mostly dissolved nitrogen, can be horizontally transported by lake currents to the water areas with high biomass levels and weak vertical hydrodynamic disturbance where sediment nitrogen enrichment primarily occurs via bio-deposition. The sediment TP content ranged between 382.6 and 1314.1 mg kg-1, and the high content areas were primarily distributed near the inflowing river mouths. Sediment phosphorus enrichment primarily occurred via physical and chemical deposition. Surface waves caused vertical phosphorus transport from sediments to the overlying water but had a limited effect on its spatial distribution. Although the horizontal transport of phosphorus was found to be weaker than that of nitrogen, short-distance vertical transport of sediment phosphorus may relieve nutrient limitations, leading to maintenance of cyanobacterial blooms found in Lake Taihu.

Enhancement of sediment phosphorus release during a tunnel construction across an urban lake (Lake Donghu, China).

Tunnel construction in watershed area of urban lakes would accelerate eutrophication by inputting nutrients into them, while mechanisms underlying the internal phosphorus cycling as affected by construction events are scarcely studied. Focusing on two main pathways of phosphorus releasing from sediment (enzymatic mineralization and anaerobic desorption), spatial and temporal variations in phosphorus fractionation, and activities of extracellular enzymes (alkaline phosphatase, ß-1,4-glucosidase, leucine aminopeptidase, dehydrogenase, lipase) in sediment were examined, together with relevant parameters in interstitial and surface waters in a Chinese urban lake (Lake Donghu) where a subaqueous tunnel was constructed across it from October 2013 to July 2014. Higher alkaline phosphatase activity (APA) indicated phosphorus deficiency for phytoplankton, as illustrated by a significantly negative relationship between APA and concentration of dissolved total phosphorus (DTP). Noticeably, in the construction area, APAs in both sediment and surface water were significantly lower than those in other relevant basins, suggesting a phosphorus supply from some sources in this area. In parallel, its sediment gave the significantly lower iron-bound phosphorus (Fe(OOH)∼P) content, coupled with significantly higher ratio of iron (II) to total iron content (Fe(2+)/TFe) and dehydrogenase activities (DHA). Contrastingly, difference in the activities of sediment hydrolases was not significant between the construction area and other basins studied. Thus, in the construction area, subsidy of bioavailable phosphorus from sediment to surface water was attributable to the anaerobic desorption of Fe(OOH)∼P rather than enzymatic mineralization. Finally, there existed a significantly positive relationship between chlorophyll a concentration in surface water and Fe(OOH)∼P content in sediment. In short, construction activities within lakes may interrupt cycling patterns of phosphorus across sediment-water interface by enhancing release of redox-sensitive phosphate, and thereby facilitating phytoplankton growth in water column.

Influence of sediment resuspension on the efficacy of geoengineering materials in the control of internal phosphorous loading from shallow eutrophic lakes.

Modified clay-based solid-phase phosphorous (P) sorbents are increasingly used as lake geoengineering materials for lake eutrophication control. However, some still dispute the feasibility of using these materials to control internal P loading from shallow eutrophic lakes. The lack of information about P behavior while undergoing frequent sediment resuspension greatly inhibits the modified minerals' use. In this study, a sediment resuspension generating system was used to simulate the effect of both moderate winds (5.1 m/s) and strong winds (8.7 m/s) on the stability of sediment treated by two geoengineering materials, Phoslock® (a lanthanum modified bentonite) and thermally-treated calcium-rich attapulgite. This study also presents an analysis of the P dynamics across the sediment-water interface of two shallow eutrophic lakes. In addition, the effect of wind velocity on P forms and P supply from the treated sediment were studied using chemical extraction and diffusive gradients in thin films (DGT) technique, respectively. Results showed that adding geoengineering materials can enhance the stability of surface sediment and reduce the erosion depth caused by wind accordingly. All treatments can effectively reduce soluble reactive phosphorus (SRP) concentration in overlying water when sediment is capped with thermally-treated calcium-rich attapulgite, which performs better than sediment mixed with modified attapulgite but not as well as sediment treated with Phoslock®. However, their efficiency decreased with the increase in occurrences of sediment resuspension. The addition of the selected geoengineering materials effectively reduced the P fluxes across sediment-water interface and lowered P supply ability from the treated sediment during sediment resuspension. The reduction of mobile P and enhancement of calcium bound P and residual P fraction in the treated sediment was beneficial to the long-term lake internal P loading management. All of the results indicated that the studied geoengineering materials are suitable for application in shallow eutrophic lakes with frequent sediment resuspension activity.

Reduction of sediment internal P-loading from eutrophic lakes using thermally modified calcium-rich attapulgite-based thin-layer cap.

We conducted a laboratory evaluation of a low-cost P-capping agent-700°C-heated natural calcium-rich attapulgite (NCAP700)-in terms of its ability to reduce internal P-loading in lake sediments. Batch studies indicated that NCAP700 could effectively reduce sediment mobile P (P mobile) in various types of lake sediment, and the dosage equation required to immobilize P mobile was developed accordingly. The equation was then applied to a laboratory incubation study on intact sediment cores. The results indicated that the NCAP700-based thin-layer cap can enhance the redox potential (Eh), pH and dissolved oxygen (DO) in surface sediment. However, this enhancing effect was decreased with increasing time. P fluxes and the concentration of P in overlying water and pore water from sediment could be effectively inhibited under anaerobic conditions. P fractionation analysis indicated that 34.5% of P mobile was bound in the upper 2 cm sediment layer during a 40-day remediation period, but this only exerted a minor influence on the P mobile in the 2-4 cm sediment layer. P immobilization by NCAP700 was mainly achieved through transformation of P mobile to stable Ca-P. These results indicate that NCAP700 can be used for lake eutrophication control by means of thin-layer capping.

Lake eutrophication and its implications for organic carbon sequestration in Europe.

The eutrophication of lowland lakes in Europe by excess nitrogen (N) and phosphorus (P) is severe because of the long history of land-cover change and agricultural intensification. The ecological and socio-economic effects of eutrophication are well understood but its effect on organic carbon (OC) sequestration by lakes and its change overtime has not been determined. Here, we compile data from ~90 culturally impacted European lakes [~60% are eutrophic, Total P (TP) >30 µg P l(-1) ] and determine the extent to which OC burial rates have increased over the past 100-150 years. The average focussing corrected, OC accumulation rate (C ARFC ) for the period 1950-1990 was ~60 g C m(-2) yr(-1) , and for lakes with >100 µg TP l(-1) the average was ~100 g C m(-2) yr(-1) . The ratio of post-1950 to 1900-1950 C AR is low (~1.5) indicating that C accumulation rates have been high throughout the 20th century. Compared to background estimates of OC burial (~5-10 g C m(-2) yr(-1) ), contemporary rates have increased by at least four to fivefold. The statistical relationship between C ARFC and TP derived from this study (r(2) = 0.5) can be used to estimate OC burial at sites lacking estimates of sediment C-burial. The implications of eutrophication, diagenesis, lake morphometry and sediment focussing as controls of OC burial rates are considered. A conservative interpretation of the results of the this study suggests that lowland European meso- to eutrophic lakes with >30 µg TP l(-1) had OC burial rates in excess of 50 g C m(-2) yr(-1) over the past century, indicating that previous estimates of regional lake OC burial have seriously underestimated their contribution to European carbon sequestration. Enhanced OC burial by lakes is one positive side-effect of the otherwise negative impact of the anthropogenic disruption of nutrient cycles.

Batch investigations on P immobilization from wastewaters and sediment using natural calcium rich sepiolite as a reactive material.

Phosphorus from wastewaters and sediment flux to surface water represents a major source of lake eutrophication. Active filtration and in situ capping (which refers to placement of a covering or cap over an in-situ deposit of contaminated sediment) are widely used as a means to immobilize phosphorus from wastewaters and sediment, to mitigate lake eutrophication. There is, however, a need to develop more efficient means of immobilizing phosphorus through the development of binding agents. In this study, natural calcium-rich sepiolite (NCSP) was calcined at a range of temperatures, to enhance its phosphorus removal capacity. Batch studies showed that the 900 °C calcinated NCSP (NCSP900) exhibited excellent sorption performance, attaining a phosphorus removal efficiency of 80.0%-99.9% in the range of 0.05 mg/L-800 mg/L phosphorus concentrations with a dosage of 20 g/L. The material displayed rapid sorption rate (maximum amount of 99.9% of phosphate removal with 5 min) and could lower the very high phosphate concentration (200 mg/L) to less than 0.1 mg/L after 4 h adsorption. It was also noted that factors such as pH, competing anions (except [Formula: see text] ) and humic acid, had no effect on phosphorus removal capacity. The sediment immobilization experiment indicated that NCSP900 had the capacity to transform reactive phosphorus into inert-phosphorus and significantly reduce the amount of algal-bioavailable phosphorus. The excellent phosphorus binding performance of NCSP900 was mainly due to the improvement of point of zero charge (pHPZC) as well as the transformation of the inert-calcium of NCSP to active free CaO during calcination. Phosphorus speciation indicated that phosphorus was mainly captured by relatively stable calcium-bound phosphorus (Ca-P) precipitation, which can account for 80.1% of the total phosphorus. This study showed that NCSP900 could be used as an efficient binding agent for the sequestration of phosphorus from wastewaters and sediment.