Blend of natural coagulants as a sustainable solution for challenges of pollution from aquaculture wastewater

Abstract

Dependency on sea food has increased owing to its nutrition as well as being complete food. As the production of seafood is enhanced through aquaculture, wastewater release has also improved. The composition of wastewater from aquaculture production has been a concern as it has oil and grease, organic content, etc., which makes its treatment challenging. The present study aims at treating aquaculture wastewater using two natural coagulants—chitin and seeds of Moringa oleifera. The efficiency of the natural coagulants was compared against inorganic chemical coagulant ferric chloride. A blended coagulant with two natural coagulants seeds of Moringa oleifera and chitin was also tested. Jar test apparatus was used in the current experiments, and four coagulant doses were tested against 3 pH ranges, from 6 to 8. The study results showed that the coagulants showed a 30–50% reduction in various physicochemical parameters. Further, the most promising result was obtained with the blended coagulants (di-blend) with 70–81% removal of total nitrogen and total phosphorus and the highest reduction of chloride with 95%. The Fourier-transform infrared spectroscopy showed functionalized groups responsible for coagulation, and X-ray powder diffraction analysis of the blended coagulant indicated the crystallinity and amorphous nature of the compounds. Scanning electron microscope analysis presented a firm and dense structure indicating adsorption of impurities onto the coagulant. Thus, it is evident that natural coagulants can be the solution for the challenges of aquaculture wastewater and specifically the di-blend used in the present is ascertained to be a promising solution.

Turbidity Removal Performance of Selected Natural Coagulants for Water Treatment in Colombian Rural Areas

“…In this context, natural coagulants represent a viable, nature-based solution for water treatment. Derived from natural sources like plants, they are readily accessible, cost-effective, simple to apply, biodegradable, non-toxic, environmentally friendly, efficient, and result in lower sludge volumes [9]. This makes them particularly suitable for rural areas, where economical and eco-sensitive water treatment methods are essential.…”

Protein and Long-Chain n-3 Polyunsaturated Fatty Acids Recovered from Herring Brines upon Flocculation and Flotation─A Case Study

“…Using chemical treatments followed by DAF, these authors reported on up to 97% removal of the poultry wastewater COD. In the study of Karnena, Konni, Dwarapureddi, and Saritha, 9 depuration of fish processing water using coagulation/flocculation alone provided 92% COD reduction using a combination of Tanfloc, FeCl 3 , and Zetag.…”

“…Using chemical treatments followed by DAF, these authors reported on up to 97% removal of the poultry wastewater COD. In the study of Karnena, Konni, Dwarapureddi, and Saritha, 9 depuration of fish processing water using coagulation/flocculation alone provided 92% COD reduction using a combination of Tanfloc, FeCl 3 , and Zetag. Although the mentioned studies were successful in wastewater depuration, the use of nonfood-grade chemicals limited the application of the recovered sludge to feedstock for biogas production purposes.…”

Integration of Copperas and <i>Moringa oleifera</i> Seeds as Hybrid Coagulant for Turbidity and Ammonia Removal from Aquaculture Wastewater

“…It has been demonstrated that a natural coagulant like Moringa oleifera (MO) can be utilized to treat effluent from aquaculture mainly to remove ammoniacal nitrogen, phosphorus, and turbidity [18][19][20]. Treatment sequence of wastewater using MO seeds by coagulationflocculation to sedimentation-filtration showed maximum turbidity and elimination of suspended materials.…”