Nutrient removal and value added product formation from wastes via struvite precipitation (STRUVITE)

Demirer, Goksel Niyazi
The major goal of the proposed research is the investigation of the applicability of struvite precipitation technique (SPT) separately or coupled with in an anaerobic digester for recovering nutrients from the anaerobic digestion process (ADP) residues. Optimising SPT will not only improve the performance of ADP which is the most commonly used process for disposing many agro-industrial wastes, in terms of reduced the nutrient (nitrogen and phosphorus) loads discharged to natural aquatic environments, but also lead production of a value-added product in the form of struvite fertilizer. Nutrient recovery from sewage sludge and other organic solid wastes in the form struvite has become the focus of many research studies because of limited phosphorus (P) rock reserves, which are mainly exploited for the production of fertilizers, in the world. There are many additional benefits of recovering nutrients during the anaerobic digestion of the organics by fixing N and P as follows; • controlling struvite formation within the digester may prevent the undesired accumulation of struvite, which causes problems in the hydraulic works, • enrichment of the anaerobic sludge produced in huge amounts in terms of N and P and improvement of its fertilizer quality, • avoiding the nutrient removal requirement of the effluent from anaerobic digesters, which contains usually higher concentrations of N and P than discharge limits, • making the digestion process more self sustainable in terms of avoiding different pretreatment techniques for N and P, • more widespread use of anaerobic biotechnology due to better performance in terms of nitrogen and phosphorus, • reduced oxygen demand in the receiving water bodies, • reduced eutrophication risks in the lakes, etc.


Anaerobic acidification of sugar-beet processing wastes: Effect of operational parameters
Alkaya, Emrah; Demirer, Göksel Niyazi (Elsevier BV, 2011-01-01)
The objective of this study was to maximize the hydrolysis and acidification of sugar-beet processing wastewater and beet pulp for volatile fatty acid (VFA) production through acidogenic anaerobic metabolism. Experiments were conducted to determine the optimum operational conditions (HRT, waste-mixing ratio and pH) for effective acidification in daily-fed, continuously mixed anaerobic reactors. For this purpose, reactors were operated at 35 +/- 1 degrees C with different combinations of HRT (2-4 days), wast...
Anaerobic mesophilic co-digestion of sugar-beet processing wastewater and beet-pulp in batch reactors
Alkaya, Emrah; Demirer, Göksel Niyazi (2011-03-01)
In this study, biochemical methane potential (BMP) assay was conducted to investigate the effect of waste mixing and F/M ratio on the co-digestion of wastewater and beet-pulp, in addition to the digestion of the wastes separately. In the studied F/M range (0.51–2.56 g COD/g VSS), observed treatment efficiencies (63.7–87.3% COD removal and 69.6–89.3% VS reduction) were indications of high biodegradability for both wastewater and beet-pulp, which decreased with increasing F/M. It was evident that the extent o...
Metabolic flux analysis for serine alkaline protease fermentation by Bacillus licheniformis in a defined medium: Effects of the oxygen transfer rate
Çalık, Pınar; Ozdamar, TH (1999-07-01)
The metabolic fluxes through the central carbon pathways in the bioprocess for serine alkaline protease (SAP) production by Bacillus licheniformis were calculated by the metabolic flux-based stoichiometric model based on the proposed metabolic network that contains 102 metabolites and 133 reaction fluxes using the time profiles of citrate, dry cell, organic acids, amino acids, and SAP as the constraints. The model was solved by minimizing the SAP accumulation rate in the cell, The effects of the oxygen-tran...
Carbon sources affect metabolic capacities of Bacillus species for the production of industrial enzymes: theoretical analyses for serine and neutral proteases and alpha-amylase
Çalık, Pınar (Elsevier BV, 2001-07-01)
The metabolic fluxes through the central carbon pathways were calculated for the genus Bacillus separately for the enzymes serine alkaline protease (SAP), neutral protease (NP) and alpha -amylase (AMY) on five carbon sources that have different reduction degrees (gamma), to determine the theoretical ultimate limits of the production capacities of Bacillus species and to predict the selective substrate for the media design. Glucose (gamma = 4.0), acetate (gamma = 4.0), and the TCA cycle organic-acids succina...
POLAT, H; Selçuk, Nevin; SOYUPAK, S (1993-01-01)
Data for semicontinuous anaerobic digestion of sunflower heads were obtained in fermentors of 11 of effective volume, maintained at 55-degrees-C Experiments were carried out with a 2% sunflower head-water mixture for hydraulic retention times of 15, 10, and 8 days. Biogas quantities and compositions were measured each day until steady state was achieved. The steady state was achieved after three times of each hydraulic retention time (HRT). Gas productions of 0.180 m3/ with 62% CH4, 0.280 m3/m3.di...
Citation Formats
G. N. Demirer, “Nutrient removal and value added product formation from wastes via struvite precipitation (STRUVITE),” 2011. Accessed: 00, 2020. [Online]. Available: