Maintaining low nitrate concentrations in aquaponic systems is crucial for improving water quality and maximizing the growth efficiency of fish and vegetables.Downflow hanging sponge(DHS)and upflow sludge blanket(USB)...Maintaining low nitrate concentrations in aquaponic systems is crucial for improving water quality and maximizing the growth efficiency of fish and vegetables.Downflow hanging sponge(DHS)and upflow sludge blanket(USB)reactors have shown potential for wastewater treatment,but their use in aquaponic systems is relatively underexplored,particularly for overall performance and efficiency.In this study,a DHS reactor was coupled with a denitrifying USB reactor in an aquaponic system comprising Nile tilapia(Oreochromis niloticus)and kale(Brassica oleracea L.var.acephala DC).The USB reactor achieved a nitrate removal rate of 80.8%±20.5%.The specific growth rate of tilapia was 6.11%per day from day 16 to day 30.On day 45,kale growth achieved stem lengths of(4.1±1.2)cm,root lengths of(12.2±6.0)cm,and leaf counts of(6.3±2.0)leaves per plant.Changes in the microbial communities within the reactors positively contributed to denitrification,resulting in a nitrogen utilization efficiency of 88.3%.The DHS–USB aquaponic system effectively maintained optimal water quality and stable parameters(pH,dissolved oxygen,and temperature).It regulated ammonia levels well and achieved 80.8%±20.5%removal rates for nitrite and nitrate after day 10.Microbial analysis highlighted significant shifts in the microbial communities within the DHS and USB reactors,underscoring their critical roles in nitrification and denitrification.Therefore,the DHS–USB aquatic system has the potential to improve agricultural production efficiency and promote sustainable development.展开更多
This study examined the application of co-benefit-type wastewater treatment technology in the fish-processing industry. Given that there was a dearth of information on fish-processing industrial wastewater in Indonesi...This study examined the application of co-benefit-type wastewater treatment technology in the fish-processing industry. Given that there was a dearth of information on fish-processing industrial wastewater in Indonesia, site surveys were conducted. For the entire fish-processing industry throughout the country, the dissemination rate of wastewater treatment facilities was less than 50%. Using a co-benefit approach, a real-scale swim-bed technology (SBT) and a system combining an anaerobic baffled reactor (ABR) with SBT (ABR–SBT) were installed in a fishmeal processing factory in Bali, Indonesia, and the wastewater system process performance was evaluated. In a business-as-usual scenario, the estimated chemical oxygen demand load and greenhouse gas (GHG) emissions from wastewater from the Indonesian fish-processing industry were 33 000 tons per year and 220 000 tons of equivalent CO_(2) per year, respectively. On the other hand, the GHG emissions in the co-benefit scenarios of the SBT system and ABR–SBT system were 98 149 and 26 720 tons per year, respectively. Therefore, introducing co-benefit-type wastewater treatment to Indonesia’s fish-processing industry would significantly reduce pollution loads and GHG emissions.展开更多
基金supported by the Japan Science and Technology Agency(Grant No.JPMJPF2211).
文摘Maintaining low nitrate concentrations in aquaponic systems is crucial for improving water quality and maximizing the growth efficiency of fish and vegetables.Downflow hanging sponge(DHS)and upflow sludge blanket(USB)reactors have shown potential for wastewater treatment,but their use in aquaponic systems is relatively underexplored,particularly for overall performance and efficiency.In this study,a DHS reactor was coupled with a denitrifying USB reactor in an aquaponic system comprising Nile tilapia(Oreochromis niloticus)and kale(Brassica oleracea L.var.acephala DC).The USB reactor achieved a nitrate removal rate of 80.8%±20.5%.The specific growth rate of tilapia was 6.11%per day from day 16 to day 30.On day 45,kale growth achieved stem lengths of(4.1±1.2)cm,root lengths of(12.2±6.0)cm,and leaf counts of(6.3±2.0)leaves per plant.Changes in the microbial communities within the reactors positively contributed to denitrification,resulting in a nitrogen utilization efficiency of 88.3%.The DHS–USB aquaponic system effectively maintained optimal water quality and stable parameters(pH,dissolved oxygen,and temperature).It regulated ammonia levels well and achieved 80.8%±20.5%removal rates for nitrite and nitrate after day 10.Microbial analysis highlighted significant shifts in the microbial communities within the DHS and USB reactors,underscoring their critical roles in nitrification and denitrification.Therefore,the DHS–USB aquatic system has the potential to improve agricultural production efficiency and promote sustainable development.
文摘This study examined the application of co-benefit-type wastewater treatment technology in the fish-processing industry. Given that there was a dearth of information on fish-processing industrial wastewater in Indonesia, site surveys were conducted. For the entire fish-processing industry throughout the country, the dissemination rate of wastewater treatment facilities was less than 50%. Using a co-benefit approach, a real-scale swim-bed technology (SBT) and a system combining an anaerobic baffled reactor (ABR) with SBT (ABR–SBT) were installed in a fishmeal processing factory in Bali, Indonesia, and the wastewater system process performance was evaluated. In a business-as-usual scenario, the estimated chemical oxygen demand load and greenhouse gas (GHG) emissions from wastewater from the Indonesian fish-processing industry were 33 000 tons per year and 220 000 tons of equivalent CO_(2) per year, respectively. On the other hand, the GHG emissions in the co-benefit scenarios of the SBT system and ABR–SBT system were 98 149 and 26 720 tons per year, respectively. Therefore, introducing co-benefit-type wastewater treatment to Indonesia’s fish-processing industry would significantly reduce pollution loads and GHG emissions.
