scholarly journals Struvite Phosphorus Recovery from Aerobically Digested Municipal Wastewater

2019 ◽  
Vol 11 (2) ◽  
pp. 376 ◽  
Author(s):  
John Hallas ◽  
Cheryl Mackowiak ◽  
Ann Wilkie ◽  
Willie Harris

Small, municipal wastewater treatment plants (WWTPs) that use aerobic digestion treat approximately 40% of the discharged wastewater in the USA, and yet they are an overlooked source of recoverable P. There are no known reports of small, aerobic WWTPs recovering P through struvite (MgNH4PO4·6H2O) precipitation for repurposing as a mineral fertilizer, even though some large WWTPs with anaerobic digestion are. Four small WWTPs in north Florida, USA, with treatment capacities from 371 to 2650 m3 wastewater d−1 and incoming P loads from 2 to 14 kg d−1 were investigated for their potential to produce struvite from digester filtrates. A chemical equilibrium model was used to predict the feasibility of struvite production and the results compared with actual WWTP filtrate measurements. Filtrates from aerobic digesters were able to form struvite if solution pH was increased by ≤1 pH unit. Depending on the WWTP, P recovery in filtrates through struvite precipitation ranged from 27–57% by mass at pH 8.5, via NaOH additions or air sparging. Increasing filtrate Mg concentrations improved P recovery up to 97%. Based upon these results, small WWTPs using aerobic digestion will be able to lower their P waste output through recovery as struvite fertilizer.

2021 ◽  
pp. 0734242X2110652
Author(s):  
Charlotte Nilsson ◽  
Viktor Sjöberg ◽  
Anna Grandin ◽  
Stefan Karlsson ◽  
Bert Allard ◽  
...  

Given the high efficiency in phosphorus removal at municipal wastewater treatment plants (MMWWTP), sewage sludge constitutes a promising resource for phosphorus (P) recovery. Sewage sludge is, however, a complex matrix and its direct use as fertiliser is limited by its content of metals/metalloids and organic pollutants. In order to increase its usability as a potential resource of P, there is a need for increased knowledge on phosphorus speciation in these matrices. The sludge composition is highly influenced by local conditions (i.e. wastewater composition and treatment method), and it is therefore important to study sludge from several MMWWTPs. In this study, three different protocols for sequential extraction were utilised to investigate the chemical speciation of phosphorus in sludge from three different MMWWTP sludges in Sweden, as well as in corresponding ashes following incineration. The results showed that the total amounts of phosphorus ranged from 26 to 32 mg g−1 sludge (dry weight), of which 79–94% was inorganically bound (IP). In the sludge, 21–30% of the IP was associated with calcium (Ca-P), which is the preferred species for fertiliser production. Following incineration, this fraction increased to 54–56%, mainly due to transformation of iron-associated phosphorus (Fe-P), while aluminium-associated species of phosphorus (Al-P) remained unaltered. The results from this study confirm that incineration is a suitable treatment for sewage sludge in terms of potential phosphorus recovery.


2011 ◽  
Vol 6 (1) ◽  
Author(s):  
A. Iborra-Clar ◽  
J.A. Mendoza-Roca ◽  
A. Bes-Pií ◽  
J.J. Morenilla-Martínez ◽  
I. Bernácer-Bonora ◽  
...  

Rainfall diminution in the last years has entailed water scarcity in plenty of European regions, especially in Mediterranean areas. As a consequence, regional water authorities have enhanced wastewater reclamation and reuse. Thus, the implementation of tertiary treatments has become of paramount importance in the municipal wastewater treatment plants (WWTP) of Valencian Region (Spain). Conventional tertiary treatments consist of a physico-chemical treatment of the secondary effluent followed by sand filtration and UV radiation. However, the addition of coagulants and flocculants sometimes does not contribute significantly in the final water quality. In this work, results of 20-months operation of three WWTP in Valencian Region with different tertiary treatments (two without chemicals addition and another with chemicals addition) are discussed. Besides, experiments with a 2 m3/h pilot plant located in the WWTP Quart-Benager in Valencia were performed in order to evaluate with the same secondary effluent the effect of the chemicals addition on the final water quality. Results showed that the addition of chemicals did not improve the final water quality significantly. These results were observed both comparing the three full scale plants and in the pilot plant operation.


2003 ◽  
Vol 3 (5-6) ◽  
pp. 321-327 ◽  
Author(s):  
M. Gallenkemper ◽  
T. Wintgens ◽  
T. Melin

Endocrine disrupting compounds can affect the hormone system in organisms. A wide range of endocrine disrupters were found in sewage and effluents of municipal wastewater treatment plants. Toxicological evaluations indicate that conventional wastewater treatment plants are not able to remove these substances sufficiently before disposing effluent into the environment. Membrane technology, which is proving to be an effective barrier to these substances, is the subject of this research. Nanofiltration provides high quality permeates in water and wastewater treatment. Eleven different nanofiltration membranes were tested in the laboratory set-up. The observed retention for nonylphenol (NP) and bisphenol A (BPA) ranged between 70% and 100%. The contact angle is an indicator for the hydrophobicity of a membrane, whose influence on the permeability and retention of NP was evident. The retention of BPA was found to be inversely proportional to the membrane permeability.


1982 ◽  
Vol 14 (1-2) ◽  
pp. 121-133
Author(s):  
C Forsberg ◽  
B Hawerman ◽  
B Hultman

Experience from advanced municipal wastewater treatment plants and recovery of polluted waters are described for the last ten years in Sweden. Except in municipalities with large recipients, the urban population is served by treatment plants with combined biological and chemical treatment. Most of these plants are post-precipitation plants. Several modified operational modes have been developed in order to improve the removal efficiencies of pollutants and to reduce the costs. Results are presented on the recovery of specially investigated lakes with a lowered supply of total phosphorus and organic matter.


Author(s):  
Giuseppe Campo ◽  
Alberto Cerutti ◽  
Claudio Lastella ◽  
Aldo Leo ◽  
Deborah Panepinto ◽  
...  

The management of sewage sludge originated from municipal wastewater treatment plants (WWTPs) is an urgent issue. In 2019, the local authority of the Piemonte region started a survey with the aim of collecting recent data concerning wastewater and sludge management in the WWTPs located in its own territory. The survey’s results revealed that 60% of the sludge (51,000 t, as dry substance, d.s.) produced by the local WWTPs was recovered or disposed of outside of the region, and a similar amount of sludge was recovered in agriculture directly or after composting. The increase in the costs to accommodate sewage sludge in recovery or disposal plants, followed to a recent Italian Sentence (27958/2017), and the more and more stringent requirements fixed by lots of European countries for the application of sludge in agriculture, are pushing the Piemonte region authority to re-organize its own network for sludge management, with solutions based onto proximity and diversification. Whether the provisions of the current German legislation are applied in the future also in Italy, approx. 90% of sewage sludge produced into the Piemonte region should be incinerated, with a subsequent step of phosphorous recovery. The new regional plan, according to the Regional Address Deed, should consider a diversification of sludge treatment and recovery practices. On this basis, a need for new plants for around 40,000 t d.s./y could be planned.


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