Valorization of the treatment of antibiotic and organic contents generated from an in-situ-RAS-like shrimp farming pond by using graphene-quantum-dots deposited graphitic carbon nitride photocatalysts.

In this study, we investigated the possibility of a photocatalytic system that uses graphene-quantum-dot (GQD)-deposited graphitic carbon nitride (g-C3N4) to treat tetracycline (TC) and other organic compounds generated from an in-situ-recirculatory-aquaculture-system (RAS)-like shrimp farming pond. GQDs were successfully deposited on the exfoliated g-C3N4 base through a hydrothermal treatment. The results showed that the incorporation of GQDs into the g-C3N4 enhanced its porosity without aggregating its mesoporous structure. The GQDs-deposited g-C3N4 photocatalysts revealed sheet-like structures with nanopores on their surface that facilitate photocatalysis. More than 90% of the TC was removed by the photocatalysts under UV-LED irradiation. Low loadings of GQDs over g-C3N4 resulted in a faster and more effective photocatalysis of TC, mainly driven by.O2- radicals. The photocatalysts were also applicable in the degradation of organic compounds with 27% of the total organic compounds (TOC) being removed from the wastewater of a RAS-like shrimp farming pond.

Recycling of aquaculture wastewater and sediment for sustainable corn and water spinach production.

This study develops a method to reuse aquaculture wastewater and sediment from a catfish pond in order to increase agricultural productivity and protect the environment. Material flow analysis (MFA) is a central concept of this study that involves collecting catfish pond wastewater (CPW) and reusing it to irrigate five water spinach (Ipomoea aquatic) ponds before discharging it into a river. Typically, catfish pond sediment (CPS) was collected and composted to produce organic fertilizer for cornfields. The results revealed that pollutant removal efficiency of wastewater from CPW (by using water spinach) were total organic carbon (TOC) = 38.78%, nitrogen (N) = 27.07%, phosphorous (P) = 58.42%, and potassium (K) = 28.64%. By adding 20 tons of CPS compost per hectare of the cornfield, the corn yield boosted 15% compared to the control field. In addition, the water spinach grew and developed well in the medium of wastewater from the fish pond. Altogether, the results illustrate that catfish pond wastewater and sediment can act as organic fertilizers for crops meanwhile reduce environmental pollution from its reuse.