Struvite precipitation in raw and co-digested swine slurries for nutrients recovery in batch reactors

2015 ◽  
Vol 71 (6) ◽  
pp. 892-897 ◽  
Author(s):  
Raffaele Taddeo ◽  
Raghida Lepistö
Keyword(s):  
Environmental Concern ◽  
Calcium Phosphates ◽  
Industrial Effluents ◽  
Organic Content ◽  
Batch Reactors ◽  
Ph Values ◽  
Batch Tests ◽  
Struvite Precipitation ◽  
Excessive Nutrients ◽  
Co Precipitation

The release of nitrogen (N) and phosphorus (P) from agro-industrial sources is a major environmental concern. Furthermore, the scarcity of mineable P and the growing demand for food worldwide necessitate that we find an alternative P source. This study applied struvite precipitation for N-P recovery to slurries with high levels of organics and ammonia to achieve environmental protection from excessive nutrients diffusion and to generate a sustainable P source. Batch tests were carried out on raw and co-digested swine slurries to study the feasibility of struvite precipitation and the effect of several parameters, including pH, reaction time, competing ions (Ca2+, K+), total solids (TS), and alkalinity. The batch assays with raw swine slurries showed high N-P removals (up to 80%), while the anaerobic liquor returned lower recovery efficiency due to the high solids and alkali content. Struvite crystallization was detected at pH values as low as 6, and the characteristics of the recovered struvite matched those of the theoretical. Slight co-precipitation of calcium–phosphates occurred and was dependent on the Ca2+/Mg2+ ratio rather than on varying pH values. Struvite precipitation was shown to be feasible in complex matrices as agro-industrial effluents, characterized by high NH4+, alkalinity, solids and organic content, and interfering ions such as Ca2+ and K+.

scholarly journals Influence of pH and Temperature on Struvite Purity and Recovery from Anaerobic Digestate

2021 ◽  
Vol 13 (19) ◽  
pp. 10730
Author(s):  
Carolina González-Morales ◽  
Belén Fernández ◽  
Francisco Molina ◽  
Darío Naranjo-Fernández ◽  
Adriana Matamoros-Veloza ◽  
...  
Keyword(s):  
Saturation Index ◽  
Anaerobic Sludge ◽  
Batch Reactors ◽  
Sludge Dewatering ◽  
Optimum Ph ◽  
Struvite Precipitation ◽  
Co Precipitation ◽  
Influence Of Ph ◽  
P Removal

The precipitation of struvite (MgNH4PO4.6H2O) from wastewater streams simultaneosuly recovers nitrogen (N) and phosphorus (P) for reuse as fertilisers. Struvite crystallisation is controlled by pH, saturation index, temperature and other ions in the solution (e.g., Ca2+, Mg2+ and CO32−). This work studies the effect of pH and temperature on phosphorus and nitrogen removal via struvite precipitation and the quality of the resulting precipitate product (i.e., crystal size, morphology and purity). Struvite was precipitated in batch reactors from the supernatant produced during anaerobic sludge dewatering at a wastewater treatment works, under controlled pH (8, 9 and 10) and temperature (25, 33 and 40 °C) conditions. The optimal P removal as struvite, reduction of the co-precipitation with Ca and the increase in particle size of the struvite precipitates were determined. The results showed that temperatures of 33 °C and 40 °C are not recommended for struvite precipitation—i.e., at 33 °C the purity is lower, and at 40 °C the ammonia losses are induced by volatilisation. At all pH-tests, the P removal efficiency was >93%, but the highest phosphate content and purity as struvite were obtained at a pH of 9.0. The optimum pH and temperature for the formation of large crystals (84 µm) and a high purity (>70%) of the struvite precipitates were 9 and 25 °C, respectively.

Effects of pH on enhanced biological phosphorus removal metabolisms

2002 ◽  
Vol 46 (4-5) ◽  
pp. 171-178 ◽  
Author(s):  
A.J. Schuler ◽  
D. Jenkins
Keyword(s):  
Phosphorus Removal ◽  
Ph Effects ◽  
Batch Reactors ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Ph Values ◽  
Acetate Uptake ◽  
Batch Tests ◽  
P Release ◽  
Biological Phosphorus

Laboratory-scale sequencing batch reactors exhibiting enhanced biological phosphorus removal were analyzed for pH effects on anaerobic phosphorus (P) release, glycogen degradation, and acetate uptake. Samples with non-soluble P/total suspended solids values of either 0.13-0.14 mg/mg (HP) or 0.065-0.075 mg/mg (LP) were analyzed in anaerobic batch tests with excess acetate addition at pH values ranging from 5.2 to 9.5. A polyphosphate-accumulating metabolism (PAM) had a competitive advantage over a glycogen-accumulating metabolism (GAM) at pH > 7.0. Maximum acetate uptake rates by the HP and LP samples occurred at pH values 8.0 and 6.9, respectively. Anaerobic P release/acetate uptake increased with increasing pH at rates similar to previously reported values. Glycogen degradation/acetate uptake decreased with increasing pH above pH 7, which disagreed with previous reports that glycogen degradation/acetate increased or was unaffected by increasing pH. The results suggested that the acetate uptake mechanisms of GAM and PAM may be different.

scholarly journals Induction of a geochemical barrier for As, Fe and S immobilization in a sulfide substrate

2012 ◽  
Vol 36 (2) ◽  
pp. 671-679 ◽  
Author(s):  
Igor Rodrigues de Assis ◽  
Luiz Eduardo Dias ◽  
Emerson Silva Ribeiro Jr ◽  
Walter Antônio Pereira Abrahão ◽  
Jaime Wilson Vargas de Mello ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Environmental Concern ◽  
Experimental Period ◽  
Control Treatment ◽  
Geochemical Barrier ◽  
Acid Mine ◽  
Element Mobilization ◽  
Co Precipitation ◽  
The Impact

Acid mine drainage (AMD) is an environmental concern due to the risk of element mobilization, including toxic elements, and inclusion in the food chain. In this study, three cover layers were tested to minimize As, Fe and S mobilization from a substrate from former gold mining, containing pyrite and arsenopyrite. For this purpose, different layers (capillary break, sealant and cover layer) above the substrate and the induction of a geochemical barrier (GB) were used to provide suitable conditions for adsorption and co-precipitation of the mobilized As. Thirteen treatments were established to evaluate the leaching of As, Fe and S from a substrate in lysimeters. The pH, As, Fe, S, Na, and K concentrations and total volume of the leachates were determined. Mineralogical analyses were realized in the substrate at the end of the experimental period. Lowest amounts of As, Fe and S (average values of 5.47, 48.59 and 132.89 g/lysimeter) were leached in the treatments that received Na and K to induce GB formation. Mineralogical analyses indicated jarosite formation in the control treatment and in treatments that received Na and K salts. However, the jarosite amounts in these treatments were higher than in the control, suggesting that these salts accelerated the GB formation. High amounts of As, Fe and S (average values of 11.7, 103.94 and 201.13 g/lysimeter) were observed in the leachate from treatments without capillary break layer. The formation of geochemical barrier and the use of different layers over the sulfide substrate proved to be efficient techniques to decrease As, Fe and S mobilization and mitigate the impact of acid mine drainage.

scholarly journals Influence of pH on Structural, Morphological, Optical, Photocatalytic, and Antibacterial Properties of Yttrium Oxide Nanoparticles via Co-Precipitation Method

2021 ◽  
Author(s):  
Kiruthika Parangusan ◽  
Venkat Subramanium ◽  
Lakshmanaperumal Sundarabharathi ◽  
Karthik Kannan ◽  
Devi Radhika
Keyword(s):  
Yttrium Oxide ◽  
Antibacterial Properties ◽  
Blue Emission ◽  
Precipitation Method ◽  
Diffusion Method ◽  
Bandgap Energy ◽  
Oxide Nanoparticles ◽  
Ph Values ◽  
Co Precipitation ◽  
Yttrium Oxide Nanoparticles

Abstract Yttrium oxide nanoparticles with multiform morphologies have been synthesized by the co-precipitation method. The structure, morphology, functional groups, optical and photoluminescence properties were examined through X-ray diffraction (XRD), Scanning electron microscope (SEM), Fourier transform infrared spectrometer (FTIR), UV-Visible (UV-Vis), Photoluminescence spectra (PL). The XRD patterns obtained for the samples synthesized at various pH values confirmed the cubic structure of Y2O3. The patterns obtained on the samples at pH values of 8 and 9 appeared as have sharp peaks suggested, that the samples were well crystallized. From UV-vis spectra, it revealed that the bandgap energy exhibits a blue shift in the absorption edge for the samples with the increase of pH due to their changing morphologies and surface structures. In the PL spectra, the obtained Y2O3 samples demonstrate an intense and bright UV and blue emission under the excitation wavelength range of 250 nm. The photocatalytic degradation of the Y2O3 nanostructure was studied against the Methylene blue (MB) dye under sunlight irradiation. The results showed good recital under solar light irradiation. Further, the antimicrobial activities of Y2O3 nanostructure against foodborne pathogens (Staphylococcus aureus and Salmonella typhi) were examined by using the disc diffusion method. Moreover, the Y2O3 nanostructure was found to be biocompatible.

Mobility of phosphate from waste water in calcareous sands of Rottnest Island (WA)

Soil Research ◽  
1993 ◽  
Vol 31 (3) ◽  
pp. 235 ◽  
Author(s):  
RG Gerritse
Keyword(s):  
Frontal Zone ◽  
Calcium Phosphates ◽  
Calcareous Soils ◽  
Effective Width ◽  
Infiltration Rates ◽  
Ph Values ◽  
Treated Sewage ◽  
Finite Concentration ◽  
Calcareous Sands ◽  
Sharp Front

Natural levels of inorganic phosphate in soils of Rottnest Island are quite high: about 300 mg/kg as P (or about 4 t of P per ha per meter depth of soil). In comparison, the production of phosphorus in wastewater from sewage, treated on Rottnest Island, amounts to approximately 2 t per year. The phosphate, occurring in the soil naturally, is mainly in mineral form and not very soluble. Solution concentrations in the soils are less than 0.001 mg/L P-PO4 (at pH values of 8.5-8.9). Conditions in the calcareous soils of Rottnest Island are favourable for precipitation of phosphate as calcium phosphates. Theoretically >>99% of phosphate in wastewater from treated sewage can be stored indefinitely as hydroxy-, fluoro- and chloro-apatites. In practice, however, application of wastewater to these soils will result in a (kinetically defined) finite concentration of phosphate to move through the soil slowly as a sharp front. The effective width of the frontal zone was taken to be equal to the longitudinal hydrodynamic dispersivity. Mobilities, relative to water, of fronts resulting from step increases of phosphate in soils were then calculated with an experimentally obtained, time-dependent, adsorption equation and the average residence time of phosphate in the frontal zone. Calculated mobilities were verified experimentally by leaching phosphate through small columns of soil at different concentrations of phosphate and rates of infiltration. For concentrations in wastewater between 10 and 15 mg/L P-PO4, mobilities of phosphate, relative to water, in soils of Rottnest Island are less than 2% for expected infiltration rates of wastewater between 0.5 and 1 cm/day.

scholarly journals Tryptic phosphopeptides from whole casein. II. Physicochemical properties related to the solubilization of calcium

1989 ◽  
Vol 56 (3) ◽  
pp. 335-341 ◽  
Author(s):  
Rafael Berrocal ◽  
Serge Chanton ◽  
Marcel A. Juillerat ◽  
Blaise Favillare ◽  
Jean-Claude Scherz ◽  
...  
Keyword(s):  
Binding Sites ◽  
Calcium Phosphates ◽  
Chemical Properties ◽  
Sodium Caseinate ◽  
Ph Values ◽  
Physico Chemical ◽  
Casein Phosphopeptides ◽  
Hydrolysis Of ◽  
Phosphate Solutions ◽  
Tryptic Hydrolysis

SummaryCasein phosphopeptides (GPP) were produced by tryptic hydrolysis of sodium caseinate and further purified by precipitation and chromatography on QAE-Sephadex A-25. Their physico-chemical properties were compared with the properties of an enzymically dephosphorylated equivalent preparation (DPP). Binding of Ca2+ to the peptides was measured using a Ca selective electrode and was found to increase with pH and to show 1/1 stoicheiometry Ca/Porg in CPP at pH 6·5 a.nd 7·6. Klotz plots indicated equivalent binding sites at these two pH values, but some heterogeneity was seen at pH 3·5. In contrast, DPP did not bind significant amounts of Ca2+.CPP effectively inhibited the formation of insoluble calcium phosphates at different Ca/P ratios. The effective CPP concentration was 10 mg/1 and complete stability of calcium phosphate solutions was obtained at about 100 mg/1. This stabilizing effect was dependent on the presence of organic P.

scholarly journals Elevated biogas production from the anaerobic co-digestion of farmhouse waste: Insight into the process performance and kinetics

2019 ◽  
Vol 37 (12) ◽  
pp. 1240-1249 ◽  
Author(s):  
Spyridon Achinas ◽  
Gerrit Jan Willem Euverink
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Ternary Mixtures ◽  
Batch Reactors ◽  
Process Performance ◽  
Mixing Ratios ◽  
Batch Tests ◽  
Biogas Plants ◽  
The Impact ◽  
Insight Into

The biodegradable portion of solid waste generated in farmhouses can be treated for energy recovery with small portable biogas plants. This action can be done across the Netherlands and all around the planet. This study aims to appraise the performance of anaerobic digestion of different wastes (cow manure, food waste and garden waste) obtained from a regional farmhouse. Batch reactors were established under mesophilic conditions in order to investigate the impact of ternary mixtures on the anaerobic digestion process performance. Different mixing ratios were set in the batch tests. The upshots from the experiments connoted that ternary digestion with cow manure:food waste:garden waste mixing ratio of 40:50:10 yielded higher biogas amount. The kinetics’ results showed quite good congruence with the experimental study. The results from the kinetic analysis appeared to be in line with the experimental one.

scholarly journals Involute the reactivity of persulfate with zero-valent iron for enhanced removal of arsenic (V) in aspect involvement of Fe2+ or Fe3+

2019 ◽  
Vol 80 (6) ◽  
pp. 1031-1041
Author(s):  
Yue Wang ◽  
Tianying Chang ◽  
Zhengchao Zhang ◽  
Kaijie Pei ◽  
Jie Fu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Sewage Treatment ◽  
Industrial Effluents ◽  
Ferrous Ions ◽  
Metals Removal ◽  
Wide Range ◽  
Pseudo Second Order ◽  
Timely Fashion ◽  
Co Precipitation ◽  
Removal Of Arsenic

Abstract Being a fundamental issue regarding sewage treatment, heavy metals removal from industrial effluents has been subject to intense scrutiny in both the academic and practical worlds. The removal of pentavalent arsenic (As(V)), one of the most poisonous pollutants, was investigated using a sodium persulfate and iron powder system activated by ferrous ions (Fe2+-ZVI-PS). As(V) could be effectively removed by an Fe2+-ZVI-PS system in a timely fashion (minute scale) with high removal rates (more than 90.0%) over a wide range of pH (1–9) and concentration (20–100 mg/L). The removal of As(V) by the Fe2+-ZVI-PS system integrated favorably with the pseudo-second-order reaction kinetics. Researches on X-ray photoelectron spectroscopy (XPS) demonstrated that the Fe2+-ZVI-PS system enables the removal of As(V) through the process of co-precipitation and adsorption. Our findings thus emphasized that the Fe2+-ZVI-PS system should be an effective trigger to purifying arsenic from the environment. Our results indicated that the Fe2+-ZVI-PS system could be an effective candidate for remediation of arsenic in the environment.

Comparison of malachite green adsorption by two yeast strains using Raman microspectroscopy

2019 ◽  
Vol 366 (13) ◽  
Author(s):  
Jinghua Liu ◽  
Dongchen Zha ◽  
Xinyi Chen ◽  
Yin Wang ◽  
Zihang Wang ◽  
...  
Keyword(s):  
Malachite Green ◽  
Dye Removal ◽  
Environmental Concern ◽  
Health Hazard ◽  
Industrial Effluents ◽  
Raman Microspectroscopy ◽  
Operational Conditions ◽  
Yeast Strains ◽  
Batch Biosorption

ABSTRACT Malachite green (MG), as a triarylmethane compound, poses a health hazard and causes considerable environmental concern. In this work, batch biosorption experiments were conducted under different operational conditions such as pH, contact time and adsorption dose to assess the optimal parameters of MG dye removal by yeast biomass from aqueous solutions. Then, the conventional biochemical assay was used to evaluate MG removal efficiency (75.18 and 95.85%) by Saccharomyces cerevisiae and Candida utilis. In addition, Fourier-transform infrared spectroscopy in combination with Raman microspectroscopy was employed to scrutinize the differences of dye removal between two types of yeast strains. This study demonstrates that Raman microspectroscopy may serve as a useful and powerful tool to quantitatively measure the content of MG dye on yeast cell surfaces in situ, and even offer an alternative new technique to seek potentially proper adsorbents for the removal of toxic dyes from industrial effluents.

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