scholarly journals Digestate: A New Nutrient Source - Review

Biogas ◽  
10.5772/31355 ◽  
2012 ◽  
Author(s):  
Marianna Makdi ◽  
Attila Tomcsik ◽  
Viktria Orosz
Keyword(s):  
1997 ◽  
Vol 35 (2-3) ◽  
pp. 131-138 ◽  
Author(s):  
Pirjo-Riitta Rantala ◽  
Hannu Wirola

The aim of the study was to determine if solid, slightly soluble compounds can be used as nutrient source in activated sludge treatment plants instead of liquid phosphoric acid. Four different solid materials were tested in lab-scale solubility tests to find compounds which are least soluble. Two materials were chosen for further studies: apatite and raw phosphate. The use of apatite and raw phosphate as nutrient source was studied in lab-scale activated sludge reactors along with a control reactor where phosphorus was added in liquid form. The phosphorus dosage, measured as elementary phosphorus, was the same for all three reactors. The reactors were fed with pre-clarified chemi-thermomechanical pulp mill (CTMP) wastewater. There were no significant differences in the reductions of organic matter between the three reactors. The mean effluent concentration of total phosphorus was 3 mg P/l in the control reactor and less than 1 mg P/1 in the other two reactors. The soluble phosphorus concentration was more than 2 mg P/l in the control reactor and less than 0.5 mg P/l in the other two. Apatite was an even better nutrient source than raw phosphate. Further lab-scale tests were conducted using two different grain sizes of apatite. No significant differences were found between the studied grain sizes (<0.074 mm and 0.074 mm-0.125 mm). Apatite was then used in full-scale at a CTMP-mill two different times. The experiments showed that the mean concentrations of phosphorus can be reduced radically by using apatite as a nutrient source instead of liquid phosphorus. Solid phosphorus compounds are a viable alternative to reduce the phosphorus load from forest industry wastewater treatment plants.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Christopher R. Horne ◽  
Hariprasad Venugopal ◽  
Santosh Panjikar ◽  
David M. Wood ◽  
Amy Henrickson ◽  
...  

AbstractBacteria respond to environmental changes by inducing transcription of some genes and repressing others. Sialic acids, which coat human cell surfaces, are a nutrient source for pathogenic and commensal bacteria. The Escherichia coli GntR-type transcriptional repressor, NanR, regulates sialic acid metabolism, but the mechanism is unclear. Here, we demonstrate that three NanR dimers bind a (GGTATA)3-repeat operator cooperatively and with high affinity. Single-particle cryo-electron microscopy structures reveal the DNA-binding domain is reorganized to engage DNA, while three dimers assemble in close proximity across the (GGTATA)3-repeat operator. Such an interaction allows cooperative protein-protein interactions between NanR dimers via their N-terminal extensions. The effector, N-acetylneuraminate, binds NanR and attenuates the NanR-DNA interaction. The crystal structure of NanR in complex with N-acetylneuraminate reveals a domain rearrangement upon N-acetylneuraminate binding to lock NanR in a conformation that weakens DNA binding. Our data provide a molecular basis for the regulation of bacterial sialic acid metabolism.


Author(s):  
Kabali Vijai Anand ◽  
Munuswamy Reshma ◽  
Malaichamy Kannan ◽  
Sekaran Muthamil Selvan ◽  
Sumit Chaturvedi ◽  
...  

2020 ◽  
Author(s):  
Pham Viet Huy Huynh

Abstract There are currently eight types of wastewater-fed aquaculture (WFA) systems in Ho Chi Minh City: seed production, fish-livestock, fish-water mimosa, fish-lotus, rice-fish, fish-only, water spinach, and fish-water spinach. Some utilize wastewater efficiently as a nutrient source, while some others have to control carefully the intake of wastewater. WFA has attracted farmers on their own initiative. Although it provides a living for a significant number of urban farmers and plays important roles in farmers' livelihoods, it is now under threat from the process of economic development of the city. The impacts of urbanization on former WFA sites in inner city zone of district 6 and district 8 where it is disappearing rapidly indicate what is likely to happen to current WFA sites in the city. Urbanization has also created livelihood uncertainties for farmers. The attraction of high prices of land and the impacts of urbanization projects are the main constraints, resulting in the decline in WFA areas. Pollution from uncontrolled and dispersed industrialization is another threat for WFA.


2006 ◽  
Vol 35 (1) ◽  
pp. 172-182 ◽  
Author(s):  
Jason G. Warren ◽  
Steven B. Phillips ◽  
Greg L. Mullins ◽  
Dale Keahey ◽  
Chad J. Penn

1976 ◽  
Vol 42 (4) ◽  
pp. 871-875 ◽  
Author(s):  
Richard C. Wahlstrom ◽  
George W. Libal
Keyword(s):  

1980 ◽  
Vol 49 (2) ◽  
pp. 506-512 ◽  
Author(s):  
W.S. Broecker ◽  
J.R. Toggweiler ◽  
T. Takahashi

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