Does the combination of biochar and clinoptilolite enhance nutrient recovery from the liquid fraction of biogas digestate?
Concentrating nutrients on biochar and clinoptilolite and subsequently using the nutrient-enriched sorbents as a fertiliser could be an alternative way to manage nutrients in digestate. In this study, we investigated the use of biochar and clinoptilolite columns in removing ammonium, potassium, orthophosphate and dissolved organic carbon (DOC) from the liquid fraction of digestate. Our objectives were to investigate the effect of the initial loading ratio between liquid and biochar on nutrient removal, and to investigate the effect of combining biochar with clinoptilolite on nutrient and DOC removal efficiency. Increasing the initial loading ratios increased nutrient concentrations on biochar to 8.61 mg NH4-N g-1, 1.95 mg PO4-P g-1and 13.01 mg DOC g-1, but resulted in decreasing removal efficiencies. The combination of biochar and clinoptilolite resulted in improved ammonium, potassium and DOC removal efficiencies compared to biochar alone, but did not significantly change PO4-P removal efficiencies. Removal efficiencies with combined sorbents were up to 67% for ammonium, 58% for DOC and 58% for potassium. Clinoptilolite showed higher removal efficiencies compared to biochar alone, and combining clinoptilolite with biochar improved only total P removal efficiency. Concentrating nutrients with clinoptilolite and biochar may be an option when both sorbents are available at low cost.
a Department of Plant and Environmental Sciences, Faculty of Science , University of Copenhagen , Frederiksberg C , Denmark.|b Alterra , Wageningen , The Netherlands.|c Department of Soil Quality , Wageningen University , Wageningen , The Netherlands.
Nazlı Pelin
NP
Kocatürk-Schumacher
b Alterra , Wageningen , The Netherlands.
Kor
K
Zwart
a Department of Plant and Environmental Sciences, Faculty of Science , University of Copenhagen , Frederiksberg C , Denmark.
Sander
S
Bruun
c Department of Soil Quality , Wageningen University , Wageningen , The Netherlands.
Lijbert
L
Brussaard
a Department of Plant and Environmental Sciences, Faculty of Science , University of Copenhagen , Frederiksberg C , Denmark.
Lars Stoumann
LS
Jensen
D000327:Adsorption; D064751:Ammonium Compounds / Q000737:chemistry; D056804:Biofuels; D002244:Carbon / Q000737:chemistry; D002606:Charcoal / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry; D011188:Potassium / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods; D014866:Waste Products; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D014934:Wood; D017641:Zeolites / Q000737:chemistry*
D064751:Ammonium Compounds; D056804:Biofuels; D010710:Phosphates; D014866:Waste Products; D014874:Water Pollutants, Chemical; C540010:biochar; C083175:clinoptilolite; D017641:Zeolites; D002606:Charcoal; D002244:Carbon; D011188:Potassium
Biochar; clinoptilolite; liquid fraction of digestate; nutrient recovery; sorption