Introduction
Conventionally, inert media such as plastic, ceramic or zeolite are conventionally used for wastewater biofiltration. However, these media need activation by microorganisms, and differentiate essentially based on their surface/mass ratio since biofiltration entirely occurs at the surface biofilm. The use of biodegradable media may enhance the sustainability of the system, while avoiding generation of decomposition-related pollutants. In this respect, d ue to their surface extension, peculiar microbiota and structural resistance, aquatic mosses appear to be very good (and innovative) supports for biofilters.
Materials and Methods
In this study, we evaluated aquatic moss mats as alternative mats for the biofiltration of aquaculture or aquaponic effluents. Two moss species [1] , Taxiphyllum barbieri and Leptodictyum riparium, were obtained in semi-axenic form (Green Greener srl Policoro, Italy) and tested for their contribution on N metabolism, by evaluating i) TAN, NO2 and NO3 , ii) competition with hydroponic cultivation by comparative application, and iii) microbiota association by 16S rRNA metabarcoding . A direct comparison with a classic biofilter was performed in a complete RAS populated with Apulian naturalized [2 ] Nile tilapia (Oreochromis niloticus) obtained from Azienda Ittica Agricola Residence San Nazario srls (Lesina, Foggia, Italy).
Results
Due to their extraordinary surface extension, mosses performed very well in N metabolization without preliminary activation. C ompetition with plants grown in a hydroponic culture configuration was not significant, which may have positive aspects. Mosses microbiota was peculiar and did not favor parasites or pathogens. Therefore, for their structural resistance, aquatic mosses appeared a very good support for biofilters demonstrating equivalence in real conditions with inert media. However, the quantity of mosses required can be several times less than any competing media.
Conclusions
Aquatic moss biomasses showed to be valuable and efficient biofilter media applicable to aquaculture, hydroponics and aquaponics.
Literature
[1] Anglana C, Barozzi F, Capaci P, Migoni D, Rojas M, Fanizzi FP, Di Sansebastiano GP (2024) Characterization of three species of aquatic mosses in axenic culture for biomonitoring and biotechnological applications. Aquatic Botany 193:103762. doi : 10.1016/j.aquabot.2024.103762.
[2] Scordella G, Lumare F, Conides A, Papaconstantinou C (2003) First o ccurrence o f t he t ilapia Oreochromis niloticus niloticus (Linnaeus, 1758) i n Lesina Lagoon (Eastern Italian Coast). Mediterranean Marine Science 4:41. doi : 10.12681/mms.239.
Supported by Fish RISE project PON 2014/20 (project ID number: ARS01_01053) funded by MIUR: Ministry of Education and Merit and By HORIZON-CL6-2022-FARM2FORK-01-05: AWARE (AQUAPONICS FROM WASTEWATER RECLAMATION) Project Number: 101084245