TY - JOUR
T1 - Wastewater treatment with starch-based coagulants for nutrient recovery purposes : Testing on lab and pilot scales
AU - Righetto, Ilaria
AU - Al-Juboori, Raed A.
AU - Kaljunen, Juho Uzkurt
AU - Mikola, Anna
PY - 2021/4/15
Y1 - 2021/4/15
N2 - The interest in using natural coagulants for wastewater treatment has increased in recent years due to the environmental and health problems associated with the use of traditional coagulants. In this study, starch-based coagulants were tested to treat reject water produced by the dewatering of mesophilic digester sludge at the Viikinmäki wastewater treatment plant (WWTP) in Finland. The goal of this treatment is to prepare the stream for the nitrogen recovery process with membrane contactor technology. Screening tests showed that PrimePHASE 3545 was the best coagulant, and the effective dosage and pH ranges were 10–20 ml/l of the 25% diluted starch and 8–10 pH values, respectively. The process was optimized using Response Surface Methodology (RSM). The best dosage and pH combination generated by RSM was 14.1 ml/l and 9.1, respectively. In these conditions, TN, TP, TOC, SS and VSS removal percentages were 18 ± 0.57%, 80 ± 0.99%, 28 ± 1.19%, 90 ± 3.37%, and 89 ± 2.35%, respectively. However, NH3-N concentration increased by 20 ± 1.7%, mainly due to pH increase. These results held true when tested on a pilot scale at Viikinmäki WWTP in a continuous process. The sludge produced with natural coagulant was found to be of a better quality compared to that of conventional coagulants.
AB - The interest in using natural coagulants for wastewater treatment has increased in recent years due to the environmental and health problems associated with the use of traditional coagulants. In this study, starch-based coagulants were tested to treat reject water produced by the dewatering of mesophilic digester sludge at the Viikinmäki wastewater treatment plant (WWTP) in Finland. The goal of this treatment is to prepare the stream for the nitrogen recovery process with membrane contactor technology. Screening tests showed that PrimePHASE 3545 was the best coagulant, and the effective dosage and pH ranges were 10–20 ml/l of the 25% diluted starch and 8–10 pH values, respectively. The process was optimized using Response Surface Methodology (RSM). The best dosage and pH combination generated by RSM was 14.1 ml/l and 9.1, respectively. In these conditions, TN, TP, TOC, SS and VSS removal percentages were 18 ± 0.57%, 80 ± 0.99%, 28 ± 1.19%, 90 ± 3.37%, and 89 ± 2.35%, respectively. However, NH3-N concentration increased by 20 ± 1.7%, mainly due to pH increase. These results held true when tested on a pilot scale at Viikinmäki WWTP in a continuous process. The sludge produced with natural coagulant was found to be of a better quality compared to that of conventional coagulants.
KW - Membrane contactor
KW - Natural coagulants
KW - Nutrient recovery
KW - Pilot scale
KW - Starch
KW - Wastewater
UR - http://www.scopus.com/inward/record.url?scp=85100256930&partnerID=8YFLogxK
U2 - 10.1016/j.jenvman.2021.112021
DO - 10.1016/j.jenvman.2021.112021
M3 - Article
AN - SCOPUS:85100256930
VL - 284
JO - Journal of Environmental Management
JF - Journal of Environmental Management
SN - 0301-4797
M1 - 112021
ER -