Trimethylamine (TMA) biofiltration and transformation in biofilters

Bioremoval of trimethylamine (TMA) in two three-stage biofilters packed with compost (A) and sludge (B), respectively, was investigated. Both biofilters were operated with an influent TMA concentration of 19.2-57.2mgm(-3) for 67 days. Results showed that all of the inlet TMA could be removed by both biofilters. However, removal efficiency and transformation of TMA in each section of both biofilters was different. In the Introduction section, TMA removal efficiency and maximum elimination capacity of the compost medium were greater than those of sludge medium under higher inlet TMA concentration. In comparison with biofilter A, considerably higher NH(3) concentrations in effluent of all three sections in biofilter B were observed after day 19. Although, NO(2)(-)-N concentration in each section of biofilter A was relatively lower, NO(3)(-)-N content in each section of biofilter A increased after day 26, especially in the Materials and method section which increased remarkably due to a lesser amount of TMA and higher ammonia oxidation and nitrification in compost medium. In contrast, neither NO(2)(-)-N nor NO(3)(-)-N were detected in either section of biofilter B at any time throughout the course of the experiment. The cumulative results indicated that compost is more favorable for the growth of TMA-degrading and nitrifying bacteria as compared to the sludge and could be a highly suitable packing material for biodegradation and transformation of TMA.     

Effect of different N fertilizer forms on antioxidant capacity and grain yield of rice growing under Cd stress

Cadmium contamination in soil has become a serious issue in sustainable agriculture production and food safety. A pot experiment was conducted to study the influence of four N fertilizer forms on grain yield, Cd concentration in plant tissues and oxidative stress under two Cd levels (0 and 100 mg Cd kg(-1)soil). The results showed that both N form and Cd stress affected grain yield, with urea-N and NH(4)(+)-N treatments having significantly higher grain yields, and Cd addition reducing yield. NO(3)(-)-N and NH(4)(+)-N treated plants had the highest and lowest Cd concentration in plant tissues, respectively. Urea-N and NH(4)(+)-N treatments had significantly higher N accumulation in plant tissues than other two N treatments. Cd addition caused a significant increase in leaf superoxide dismutase (SOD) and peroxidase (POD) activities for all N treatments, except for NO(3)(-)-N treatment, with urea-N and NH(4)(+)-N treated plants having more increase than organic-N treated ones. The results indicated that growth inhibition, yield reduction and Cd uptake of rice plants in response to Cd addition varied with the N fertilizer form.     

Selective inhibition of nitrite oxidation by chlorate dosing in aerobic granules

Partial nitrification was successfully achieved with addition of 5mM KClO(3) in the aerobic granules system. Batch tests demonstrated that KClO(3) selectively inhibited nitrite-oxidizing bacteria (NOB) but not ammonia-oxidizing bacteria (AOB). During stable partial nitrification, the influent pH was kept at 7.8-8.2, while the DO and temperature were not controlled in the SBR. When the NH(4)-N and COD levels were kept at 100mg/l and 400mg/l in the influent, the NH(4)-N and COD removal efficiencies reached 98.93% and 78.65%, respectively. The NO(2)-N accounted for 92.95% of the NO(χ)-N (NO(2)-N+NO(3)-N) in the effluent. Furthermore, about 90% of the chlorate was reduced to nontoxic chloride, thus it would not cause environmental problem. SEM showed that the main composition of the aerobic granules was bacilli and coccus bacteria. FISH analysis revealed that AOB became the dominant nitrifying bacteria, whereas NOB were detected only in low abundance. Chlorate could be used to control the development and maintenance of aerobic granules sludge for partial nitrification.     

Spatio-temporal dynamics of nutrients in the upper Han River basin, China

The upper Han River basin with an area of approximately 95,000 km(2), is the water source area of the Middle Route of China's South to North Water Transfer Project. Thus, water quality in the basin's river network is of great importance. Nutrients including dissolved inorganic nitrogen (DIN), NO(3)(-)-N, NH(4)(+)-N, and dissolved phosphorus (DP) were analyzed in 41 sites during the period of 2005-2006. Cluster analysis (CA), analysis of variance (ANOVA) and general linear models (GLM) were performed to explore their spatio-temporal variations in the basin. The results revealed that the DIN, NO(3)(-)-N and NH(4)(+)-N increased over the 2 year study period, and their concentrations in the wet season was higher than those in the dry season. The seasonal variation in nitrogen was strongly associated with seasonal pattern of precipitation and there was a negative relationship between DP concentration and river flow. Cluster analysis indicated high nutrient contents in the urban and agricultural production areas. The research will help articulate water resource management strategy for the interbasin water transfer project.     

Influence of alkalinity on the stabilization of municipal solid waste in anaerobic simulated bioreactor

Four simulated landfill anaerobic bioreactors were performed to investigate the influence of alkalinity on the anaerobic treatment of municipal solid waste (MSW). Leachate was recirculated in all the four reactors. One reactor was operated without alkalinization. The other three were operated under alkaline conditions. Na(2)CO(3), NaHCO(3) and NaOH were added to leachate in the second, third and fourth reactor, respectively. Experimental results showed that CO(3)(2-) and HCO(3)(-) addition had a more pronounced effect on MSW stabilization while the effect of addition of OH(-) was weak. The concentration of COD, BOD(5), total nitrogen (TN), ammonium nitrogen (NH(4)(+)-N) and nitrate nitrogen (NO(3)(-)-N), etc. in leachate significantly reduced in four reactors. The removal efficiencies were 90.56%, 92.21%, 92.74% and 90.29% for COD, 66.45%, 72.38%, 68.62% and 68.44% for NO(3)(-)-N, and 96.5%, 98.75%, 97.75% and 98% for NO(2)(-)-N in the control, Na(2)CO(3), NaHCO(3) and OH(-) added reactors, respectively. The final BOD(5)/COD was 0.262, 0.104, 0.124, and 0.143, and pH was 7.13, 7.28, 7.42, and 7.24 for control, Na(2)CO(3) added, NaHCO(3) added, and OH(-) added reactor, respectively. Therefore, alkalinity addition had positive effect on the stabilization of MSW.     

Photocatalytic decolorization of soluble dyes by a bis-ions coexistence system of NH4(+) and NO3(-) with high photoreduction ability

In this paper, we found that the acidic and basic dyes were easily decolorized by a bis-ions coexistence system of NH(4)(+) and NO(3)(-) under UV light irradiation. The coexistence of NH(4)(+) and NO(3)(-) is a necessary condition for the photocatalytic decolorization of soluble dyes. The photocatalytic decolorization of methyl orange (MO) and methylene blue (MB) follows the first order rate kinetics. The location of an absorption peak in the visible region is blue-shifted with the increase in the illumination time. It is proposed that the photocatalytic decolorization of soluble dyes in the bis-ions coexistence system of NH(4)(+) and NO(3)(-) is a photoreduction reaction, in which the ammonium nitrate acts as a photocatalyst. The chromophore of acidic and basic dyes reacts with hydrogen and then results in their rapid decolorization.     

Chemical denitrification of water by zero-valent magnesium powder

A laboratory-scale study was conducted in batch mode to investigate the feasibility of using zero-valent magnesium (Mg(0)), for removal of nitrate from aqueous solution. Reaction pH, dose of Mg(0), initial nitrate concentration and temperature were considered variable parameters during the study. Strong acidic condition enhanced nitrate reduction and in absence of external proton addition, reaction pH increased rapidly above ten and insignificant nitrate removal (7-16%) was achieved. At Mg(0):NO(3)(-)-N molar ratio of 5.8 and controlled reaction pH of 2, 84% denitrification efficiency was achieved (initial NO(3)(-)-N 50 mg/L) under ambient temperature and pressure and total nitrogen removal was 70% with 3.2% and 10% conversion of initial NO(3)(-)-N to NO(2)(-)-N and NH(4)(+)-N, respectively. The reaction was first order with respect to nitrate concentration. Nitrate removal rate decreased with solution pH and increased linearly with Mg(0) dose. Nitrate removal was coupled with 96-100% removal of dissolved oxygen and 85-90% generation of soluble Mg(2+) ion. An activation energy (E(a)) of nitrate reduction over the temperature range of 10-50 degrees C was observed as 17.7 kJ mol(-1).     

Sorption and biodegradation of tetracycline by nitrifying granules and the toxicity of tetracycline on granules

This paper examines the simultaneous sorption and biodegradation performance of tetracycline (TC) by the nitrifying granular sludge as well as the short-term exposure toxicity of TC. The removal of TC was characterized by a quick sorption and a slow process of biodegradation. The adsorption process fits pseudo-second-order kinetic model, with a complex mechanism of surface adsorption and intra-particle diffusion. Both temperature and mixed liquor suspended solid (MLSS) influenced TC sorption to the granules. TC biodegradation was enhanced with the increase of COD and NH(4)(+)-N concentrations, with except of the NH(4)(+)-N concentrations higher than 150 mg/L. With the ATU addition, TC degradation was weakened remarkably, indicating a synergistic effect of multiple microbes. Results of the short-term exposure (12h) effects showed that the respirometric activities of the microbes decreased greatly. The addition of TC also decreased the rate of NH(4)(+)-N utilization considerably, with the half saturation constant (K(s)) increasing from 297.7 to 347.2 mg/L.     

Nitritation and denitritation of ammonium-rich wastewater using fluidized-bed biofilm reactors

Fluidized-bed biofilm nitritation and denitritation reactors (FBBNR and FBBDR) were operated to eliminate the high concentrations of nitrogen by nitritation and denitritation process. The dissolved oxygen (DO) concentration was varied from 1.5 to 2.5 g/m(3) at the top of the reactor throughout the experiment. NH(4)-N conversion and NO(2)-N accumulation in the nitritation reactor effluent was over 90 and 65%, respectively. The average NH(4)-N removal efficiency was 99.2 and 90.1% at the NLR of 0.9 and 1.2 kg NH(4)-N/m(3)day, respectively. Increasing the NLR from 1.1 to 1.2 kg NH(4)-N/m(3)day decreased the NH(4)-N elimination approximately two-fold while NH(4)-N conversion to NO(2)-N differences were negligible. The NO(2)-N/NO(x)-N ratios corresponded to 0.74, 0.73, 0.72, and 0.69, respectively, indicating the occurrence of partial nitrification. An average free ammonia concentration in the FBBNR was high enough to inhibit nitrite oxidizers selectively, and it seems to be a determining factor for NO(2)-N accumulation in the process. In the FBBDR, the NO(x)-N (NO(2)-N+NO(3)-N) concentrations supplied were between 227 and 330 mg N/l (NLR was between 0.08 and 0.4 kg/m(3)day) and the influent flow was increased as long as the total nitrogen removal was close to 90%. The NO(2)-N and NO(3)-N concentrations in the effluent were 3.0 and 0.9 mg/l at 0.08 kg/m(3)day loading rate. About 98% removal of NO(x)-N was achieved at the lowest NLR in the FBBDR. The FBBDR exhibited high nitrogen removal up to the NLR of 0.25 kg/m(3)day. The NO(x)-N effluent concentration never exceeded 15 mg/l. The total nitrogen removal efficiency in the FBBRs was higher than 93% at 21+/-1 degrees C.     

Nitrogen removal in the bioreactor landfill system with intermittent aeration at the top of landfilled waste

High ammonia concentration of recycled landfill leachate makes it very difficult to treat. In this work, a vertical aerobic/anoxic/anaerobic lab-scale bioreactor landfill system, which was constructed by intermittent aeration at the top of landfilled waste, as a bioreactor for in situ nitrogen removal was investigated during waste stabilization. Intermittent aeration at the top of landfilled waste might stimulate the growth of nitrifying bacteria and denitrifying bacteria in the top and middle layers of waste. The nitrifying bacteria population for the landfill bioreactor with intermittent aeration system reached between 10(6) and 10(8) cells/dry g waste, although it decreased 2 orders of magnitude on day 30, due to the inhibitory effect of the acid environment and high organic matter in the landfilled waste. The denitrifying bacteria population increased by between 4 and 13 orders of magnitude compared with conventional anaerobic landfilled waste layers. Leachate NO(3)(-)-N concentration was very low in both two experimental landfill reactors. After 105 days operation, leachate NH(4)(+)-N and TN concentrations for the landfill reactor with intermittent aeration system dropped to 186 and 289 mg/l, respectively, while they were still kept above 1000 mg/l for the landfill reactor without intermittent aerobic system. In addition, there is an increase in the rate of waste stabilization as well as an increase of 12% in the total waste settlement for the landfill reactor with intermittent aeration system.     

Improving the performance of sequencing batch reactor (SBR) by the addition of zeolite powder

Two types of operation means "SBR reactor alone (control reactor)" and "adding zeolite powder into SBR reactor (test reactor)" were used to treat municipal wastewater. The test results revealed that zeolite powder addition could improve the activity of the activated sludge. It was investigated the specific oxygen utilization rate (SOUR) of the tested zeolite sludge were about double times that of the control activated sludge, and the nitrification rate and settling property of zeolite-activated sludge were both improved. Due to the combination of zeolite adsorption for NH(4)(+)-N and enhanced simultaneous nitrification and de-nitrification (SND), a higher nitrogen removal was observed in test reactor compared to the control reactor, and the addition of zeolite powder is helpful to inhabit sludge bulking. In addition, through long-term parallel shock load test, it was found that the zeolite powder addition could enhance the ability of activated sludge in resisting the shock load of organics and ammonium. Compared to the control activated sludge, zeolite powder added activated sludge could remove COD, NH(4)(+)-N, TN and TP significantly in a shorter cycle time. At the same operational time period, the test SBR could treat wastewater quantity 1.22 times that treated in control SBR.     

Landfill leachate treatment with a novel process: anaerobic ammonium oxidation (Anammox) combined with soil infiltration system

A novel combined process was proposed to treat municipal landfill leachate with high concentrations of ammonium and organics. This process consisted of a partial nitritation reactor (PNR), an anaerobic ammonium oxidation (Anammox) reactor (AR) and two underground soil infiltration systems (USIS-1 and USIS-2). Based on the optimum operating conditions obtained from batch tests of individual unit, the combined process was continuously operated on a bench scale for 166 days. Partial nitritation was performed in a fixed bio-film reactor (PNR, working volume=12 L). Ammonium nitrogen-loading rate (Nv) and DO were combined to monitor partial nitritation, and at T=30+/-1 degrees C, Nv=0.27-1.2 kg/(m3.d), DO=0.8-2.3 mg/L, the ratios of nitrite nitrogen (NO2--N) to ammonium nitrogen (NH4+-N) were successfully kept close to 1.0-1.3 in the effluent. Nitrate nitrogen (NO3--N) less than 43 mg/L was observed. The effluent of PNR was ideally suited as influent of AR. Sixty-nine percent CODcr from the raw leachate was degraded in the PNR. Anammox was carried out in a fixed bio-film reactor (AR, working volume=36 L). At T=30+/-1 degrees C, Nv=0.06-0.11 kg/(m3.d), about 60% NH4+-N and 64% NO2--N in the influent of AR were simultaneously removed. Inhibition of high-strength NO2--N (up to 1011 mg/L) should be responsible for the low removal rate of nitrogen. About 35% aquatic humic substance (AHS) was degraded in the AR. With the same working volume (200 L), USIS-1 and USIS-2 were alternately performed to treat the effluent from AR at one cycle of about 30 days. At hydraulic loading rate (HLR)=0.02-0.04 m3/m3.d, pollutant loading rates (PLR)=NH4+-N相似文献   

Nitrate removal by Thiobacillus denitrificans immobilized on poly(vinyl alcohol) carriers

Nitrate contamination is becoming a widespread environmental problem, and autotrophic denitrification with Thiobacillus denitrificans is a promising process considering efficiency, cost and maintenance. The denitrification efficiencies of T. denitrificans were compared in batch reactors between free cells and cells immobilized on polyvinyl alcohol (PVA) carriers made with thrice freezing/thawing and boric acid methods. The results indicated that the free cell reactor of T. denitrificans added with 10% (v/v) of PVA carrier made by thrice freezing/thawing (PVA-TFT) exhibited faster in S(2)O(3)(2-)-S consumption, SO(4)(2-) generation, and NO(3)(-)-N denitrification, with corresponding values being 165 mg (S(2)O(3)(2-)-S)/L.d, 491 mg (SO(4)(2-))/Ld, and 44 mg (NO(3)(-)-N)/Ld, which were increased by 50%, 61%, and 57% respectively compared to the control reactor with only free cells. Inhibition of denitrification by accumulated SO(4)(2-) in PVA-TFT reactor appeared at the concentration of approximately 6000 mg (SO(4)(2-))/L, and 75% of NO(3)(-)-N removal efficiency was achieved after 12d operation under the condition of initial 700 mg/L NO(3)(-)-N concentration.     

Effect of amended soil and hydraulic load on enhanced biological nitrogen removal in lab-scale SWIS

To characterize the effect of amended soil on nitrogen removal in subsurface wastewater infiltration system (SWIS), culture, grass carbon, and zeolite were mixed to produce microbial inoculums, and then the optimal microbial inoculums, nutrient substance, cinder, and original soil were mixed to produce the soils through bioaugmentation. Results indicate that the microbial inoculums (culture+50% grass carbon+50% zeolite) and the amended soil (12.5% microbial inoculums+25% nutrient substrate+12.5% cinder+50% original soil) have the optimal biogenic stimulating properties, and the adsorption capacity of the amended soil are 1.216 mg-Pg(-1) and 0.495 mg-Ng(-1). The laboratory soil column experiment indicates that the efficient mode of nitrogen removal in lab-scale SWIS is adsorption-nitrification-denitrification and the nitrification/denitrification can be enhanced by the application of the amended soil. On average, the SWIS filled with amended soil converts 85% of ammonia nitrogen (NH(4)(+)-N) to NO(x)(-)-N and removes 49.8-60.6% of total nitrogen (TN), while the system filled with original soil removes 80% of NH(4)(+)-N and 31.3-43.2% of TN at 4-8 cm day(-1). Two systems are overloads at 10 cm day(-1). It is concluded that the microbial activities and nitrogen removal efficiencies are improved in SWIS after bioaugmentation.     

Magnetic gamma-Fe(2)O(3) nanoparticles coated with poly-l-cysteine for chelation of As(III), Cu(II), Cd(II), Ni(II), Pb(II) and Zn(II)

An anaerobic attached-growth bioreactor (AAGBR) of 3.52 L was operated for 510 days to treat sulfide-laden organic wastewater where nitrate and nitrite were introduced as electron acceptors. When the influent sulfide was kept at 200mg S(2-)-S/L and organic carbon was increased from 20 to 33.6 mg C/L, and the hydraulic retention time decreased from 41.4 to 2.67 h, the removal rates of sulfide and organic carbon reached 99.9% and 91.8% at the loading rates of 1800 mg S(2-)-S/(Ld) and 302.4 mg C/(Ld), respectively. Simultaneously, the introduced electron acceptors of nitrate and nitrite were, respectively, removed by 99.9% and 99.9% at the loading rates of 472.5 mg NO(3)(-)-N/(Ld) and 180 mg NO(2)(-)-N/(Ld). Inside the AAGBR, both autotrophic and heterotrophic denitrification processes were noted to take place. When the influent organic carbon was increased from 20 to 33.6 mg C/L, the nitrate and nitrite consumed for heterotrophic denitrification accounted for 27.3% and 48.5%, respectively. This simultaneous autotrophic and heterotrophic desulfurization-denitrification process has provided a demonstration of the possibility to eliminate sulfide and organic carbon with the presence of nitrate and nitrite.     

Advanced treatment of liquid swine manure using physico-chemical treatment

In this study, liquid swine manure was treated by physico-chemical treatment, including coagulation, flocculation, and sedimentation followed by an oxidation step as a polishing treatment at a bench-scale level. A superabsorbent polymer (SAP) and a mineral and salt formulation able to generate molecular iodine were used as coagulant and oxidant agents, respectively. The results indicated that SAP at a concentration of 1.25 g/L was able to reduce 32% of the initial total suspended solids (TSS) in experiments using supernatant at its natural pH. Following the SAP application, 82% of initial ammonia (NH(3)), 78% of initial total organic carbon (TOC), and 93% of the total coliforms were reduced using 40 mg/L of free iodine. In experiments performed with diluted supernatant (five-fold dilution), it was found that SAP at a concentration of 0.5 g/L was capable of reducing 80% of the initial TSS in experiments at pH 11. A leaching study was conducted to assess the safety of sludge disposal. From the leaching tests using non-diluted supernatant, it was found that 24% of the chloride (Cl(-)) and 50% of the phosphate (PO(4)(3-)) ions retained in the sludge leached to the ultrapure water after 48 h. Potential contamination due to leaching of NH(3), nitrite (NO(2)(-)) and nitrate (NO(3)(-)) was found to be statistically insignificant.     

Tertiary treatment of textile wastewater with combined media biological aerated filter (CMBAF) at different hydraulic loadings and dissolved oxygen concentrations

An up-flow biological aerated filter packed with two layers media was employed for tertiary treatment of textile wastewater secondary effluent. Under steady state conditions, good performance of the reactor was achieved and the average COD, NH(4)(+)-N and total nitrogen (TN) in the effluent were 31, 2 and 8mg/L, respectively. For a fixed dissolved oxygen (DO) concentration, an increase of hydraulic loading resulted in a decrease in substrate removal. With the increase of hydraulic loadings from 0.13 to 0.78m(3)/(m(2)h), the removal efficiencies of COD, NH(4)(+)-N and TN all decreased, which dropped from 52 to 38%, from 90 to 68% and from 45 to 33%, respectively. In addition, the results also confirmed that the increase of COD and NH(4)(+)-N removal efficiencies resulted from the increase of DO concentrations, but this variation trend was not observed for TN removal. With the increase of DO concentrations from 2.4 to 6.1mg/L, the removal efficiencies of COD and NH(4)(+)-N were 39-53% and 64-88%, whenas TN removal efficiencies increased from 39 to 42% and then dropped to 35%.     

Simultaneous removal of phenol, ammonium and thiocyanate from coke wastewater by aerobic biodegradation

A laboratory-scale activated sludge plant composed of a 20 L volume aerobic reactor followed by a 12 L volume settling tank and operating at 35 degrees C was used to study the biodegradation of coke wastewater. The concentrations of ammonium nitrogen (NH(4)(+) -N), phenols, chemical oxygen demand (COD) and thiocyanate (SCN(-)) in the wastewater ranged between 504 and 2,340, 110 and 350, 807 and 3,275 and 185 and 370 mg/L, respectively. The study was undertaken with and without the addition of bicarbonate. The addition of this inorganic carbon source was necessary to favour nitrification, as the alkalinity of the wastewater was very low. Maximum removal efficiencies of 75%, 98% and 90% were obtained for COD, phenols and thyocianates, respectively, without the addition of bicarbonate. The concentration of ammonia increased in the effluent due to both the formation of NH(4)(+) as a result of SCN(-) biodegradation and to organic nitrogen oxidation. A maximum nitrification efficiency of 71% was achieved when bicarbonate was added, the removals of COD and phenols being almost similar to those obtained in the absence of nitrification. Batch experiments were performed to study the influence of pH and alkalinity on the biodegradation of phenols and thiocyanate.     

Effect of carbon dioxide and bicarbonate as inorganic carbon sources on growth and adaptation of autohydrogenotrophic denitrifying bacteria

Acclimation of autohydrogenotrophic denitrifying bacteria using inorganic carbon source (CO(2) and bicarbonate) and hydrogen gas as electron donor was performed in this study. In this regard, activated sludge was used as the seed source and sequencing batch reactor (SBR) technique was applied for accomplishing the acclimatization. Three distinct strategies in feeding of carbon sources were applied: (I) continuous sparging of CO(2), (II) bicarbonate plus continuous sparging of CO(2), and (III) only bicarbonate. The pH-reducing nature of CO(2) showed an unfavorable impact on denitrification rate; however bicarbonate resulted in a buffered environment in the mixed liquor and provided a suitable mean to maintain the pH in the desirable range of 7-8.2. As a result, bicarbonate as the only carbon source showed a faster adaptation, while carbon dioxide as the only carbon source as well as a complementary carbon source added to bicarbonate resulted in longer acclimation period. Adapted hydrogenotrophic denitrifying bacteria, using bicarbonate and hydrogen gas in the aforementioned pH range, caused denitrification at a rate of 13.33 mg NO(3)(-)-N/g MLVSS/h for degrading 20 and 30 mg NO(3)(-)-N/L and 9.09 mg NO(3)(-)-N/g MLVSS/h for degrading 50mg NO(3)(-)-N/L.     

Simultaneous uptake of ammonium and phosphate ions by compounds prepared from paper sludge ash

Al-containing CaO-SiO(2)-H(2)O phases were prepared by hydrothermal treatment of mixtures of paper sludge ash (PSA) with various silica and calcia sources and their properties were determined with particular reference to the simultaneous uptake of ammonium and phosphate ions, which are implicated in the eutrophication of lakes and ponds. After examination of various silica and calcia sources, Ca(OH)(2) and SiO(2) sol were selected as the most appropriate starting materials. Dry milling was found to be superior to wet milling in avoiding contamination from the milling media during mixing. Nine samples with three different Ca/Si ratios and Al(2)O(3) contents were prepared with various mass ratios of Ca(OH)(2), PSA and SiO(2). The chemical compositions of the hydrothermal products of these mixtures moved towards the tieline of CaSiO(3)-PSA, with respect to the starting compositions. The major phase formed in all samples was poorly crystalline C-S-H(I), with hydroxysodalite also formed in the Al-containing mixtures. All the products showed a capacity for the simultaneous uptake of ammonium and phosphate ions. The saturated sorption capacities calculated from the Langmuir equation ranged from 0.9 to 2.4mmol/g for the ammonium ion and from 3.3 to 5.2mmol/g for the phosphate ion. Since the sorption capacities for both ions increased with increasing Ca contents of the product, substitution of Ca(2+) for NH(4)(+) and the formation of calcium phosphate phases such as apatite and brushite by precipitation are thought to be the main sorption mechanisms.