Recycling "waste" nutrients back into RAS and FTS marine aquaculture facilities from the perspective of the circular economy.

The feasibility of use microalgae biotechnology to improve water quality together with the production of biomass to replace fish meal or fish oil in two marine fish farms with different production systems were studied. The samples were taken from a flow-through system (FTS) and a recirculating aquaculture system (RAS) with sea bass cultures of 300 g and 120 g, respectively. The most suitable stream for microalgae cultivation was that from RAS as the concentration of N in the microalgae reactor influent should be ≥8 mg TN L to operate at the same hydraulic retention time than the solids retention time, independently of the productivity of the reactor.

Sources and trends of artificial sweeteners in coastal waters in the bay of Cadiz (NE Atlantic).

This is the first comprehensive study on the input, occurrence, and distribution of artificial sweeteners (ASs) in coastal wastewater treatment plants (WWTPs) and their receiving coastal waters. Acesulfame (ACE), aspartame (ASP), cyclamate (CYC), saccharine (SAC), and sucralose (SUC) were monitored for 6 months in Cadiz Bay (SW Spain). ASP was always detected at <0.

Removal of pharmaceuticals in urban wastewater: High rate algae pond (HRAP) based technologies as an alternative to activated sludge based processes.

Microalgae biotechnology is a promising tool for many applications, including the elimination of nutrients and other contaminants from wastewater. In this work, we measured the removal efficiency of two wastewater treatment processes: an activated-sludge based conventional process and another based on microalgae biotechnology using high-rate algae ponds (HRAPs). The latter was tested using two different configurations.