Clean Technologies for Production of Valuable Fractions from Sardine Cooking Wastewaters: An Integrated Process of Flocculation and Reverse Osmosis

Abstract

The increase in environmental consciousness and stricter regulations has motivated industries to seek sustainable technologies that allow valorising wastewaters, contributing to the profitability of overall processes. Canning industry effluents, namely sardine cooking wastewater, have a high organic matter load, containing proteins and lipids. Their untreated discharge has a negative environmental impact and an economic cost. This work aims to design an integrated process that creates value with the costly sardine cooking wastewater effluent. The research strategy followed evaluates coagulation/flocculation technologies as pre-treatment of the sardine cooking wastewater followed by reverse osmosis. Two different added-value products were obtained: a solid fraction rich in proteins, lipids (above 20%), and aromas that might be used for feed/pet/aquaculture applications and, from the processing of the resultant aqueous stream by reverse osmosis, a natural flavouring additive, which can be applied in food/feed. Additionally, the permeate from reverse osmosis presents a much lower organic load than the original raw material, which may be reused in the overall process (e.g., as water for washings) or discharged at a lower cost, with environmental benefits and economic savings.

Recovery of Valuable Aromas from Sardine Cooking Wastewaters by Pervaporation with Fractionated Condensation: Matrix Effect and Model Validation

“…The total permeate fluxes obtained in the seafood model solution experiments using the same operating conditions were 889.84 g/m 2 .h and 731 g/m 2 .h with sardine cooking wastewaters. This lower value for the permeate flux was expected due to the total lipid (28.13 ± 2.84 g/100 g) and protein content (25.38 ± 1.95 mg/mL) of the sardine wastewater sample [ 10 ]. The presence of lipids and proteins in the feed medium might lead to interactions with aroma compounds present and also to some degree of fouling of the pervaporation membrane.…”

“…The experimental setup and analytical methods of study were the same as described in previous studies [ 7 , 10 ].…”

“…At the end of the trials, the membrane used was rinsed with a known amount of water at room temperature, and the content of lipids, proteins, and aromas present in this solution was characterised according to the methods described in Pereira et al [ 10 ].…”

The Potential of Acorn Extract Treatment on PUFAs Oxidative Stability: A Case Study on Fish Cooking Wastewater

“…Consequently, an increase in the market of dietary supplements and functional ingredients containing EPA and DHA has been reported [ 1 , 6 ]. The rising demand for fisheries’ production of food, nutraceuticals, pharmaceuticals, cosmetics, and other applications, coupled with pollution and environmental changes, has exerted significant pressure on marine ecosystems [ 6 , 9 ]. Therefore, finding alternative sources of PUFAs is a highly relevant topic.…”

“…Fish cooking wastewater represents a source of significant amounts of proteins and Ω-3 [ 4 , 12 ]. Valorizing these byproducts aligns with the principles of a circular economy approach and helps mitigate the technical, economic, and environmental issues associated with their elimination [ 9 , 10 , 12 , 13 ].…”