A novel treatment process for dairy wastewater with chitosan produced from shrimp-shell waste

Abstract

Recovery of proteins and fats from dairy wastewater has two advantages: the recovery process results in a pretreatment of wastewater prior to discharge to municipal sewers; and the recovered sludge can be used as a food additive. Carboxy Methyl Cellulose (CMC) is commonly used for the treatment of dairy wastewater after reducing the wastewater to pH 4.2. A novel application of a non-toxic cationic biopolymer – chitosan – is evaluated as a substitute for CMC. The results indicate that chitosan can achieve results similar to the CMC process even at pH as high as 5.3. Thus, the novel method can save up to 50 % of pH-adjusting chemicals requires for both for acidification and neutralisation. The process sludge contains valuable components which have been evaluated and found to be suitable as a food additive. A stable demand for chitosan is also expected to solve the existing shrimp-shell waste disposal problems along the west and north Norwegian coasts. The process is found to be both environmentally and economically attractive for all partners.

Use of chitosan for the removal of metal ion contaminants and proteins from water

“…Some of these form the basis of chemical processes for industrial production of chitosan from crab, shrimp, lobster or crawfish, which are the richest sources of chitin (in general 20-30% on dry basis) as well as being the only chitinous matter presently available in quantities sufficient to support a commercial chitin/chitosan industry (Johnson and Peniston, 1982;Omum, 1992;Selmer-Olsen, 1996). Crustacean shell waste consists mainly of protein (30-40%), minerals (30-50%) and chitin (30-40%).…”

“…Reclamation of proteins yields not only economically valuable products, but also the pretreatment off ood industry wastewater which is becoming a common requirement prior to discharge to the municiple sewer systems (Selmer-Olsen et al, 1996). The most widely researched application for chitosan is perhaps its use as a coagulant for suspended matter in food processing wastes.…”

“…Chitosan also has many other useful features, including hydrophilicity, biocompatibility, biodegradability, antibacterial property, and a remarkable affinity for many proteins (Bassi et al, 2000). Reclamation of proteins yields not only economically valuable products, but also the pretreatment of food, industrial wastewater which is becoming a common requirement prior to discharge to the municipal sewer systems (Selmer-Olsen et al, 1996). Chitosan, with its partial positive charge, can be used for coagulation and recovery of proteinaceous materials present in such food processing operation (Knorr, 1991).…”

Production and characterization of thick, thin and ultra-thin chitosan/PEO films

“…Due to the presence of amino and hydroxyl groups, chitosan exhibits multiple functionality including antimicrobial activity (Tsai & Su, 1999) and metal binding (Gamage & Shahidi, 2007). Many attempts have been conducted to develop functional materials from chitosan, such as films, sutures, beads, and hydrogels, and to apply them in the wound healing (Muzzarelli, 2009), drug delivery (Jin & Song, 2006;Kean & Thanou, 2010), metal removal (Selmer-Olsen et al, 1996), and antimicrobial food packaging (Ye, Neetoo, & Chen, 2008).…”

Contribuição ao estudo da reação de desacetilação de quitina: estudos da desacetilação assistida por ultra-som de alta potência

“…A biomassa pode ser empregada como fonte de energia e como matéria-prima, sendo que o seu aproveitamento pode contribuir para reduzir a quantidade de resíduos descartados no meio ambiente, além de abrir a possibilidade de substituição parcial dos combustíveis fósseis por uma fonte alternativa de energia, abundante e renovável 1 Quitina e quitosana são termos amplamente empregados, embora nenhum deles represente uma estrutura química única. De forma geral, a proposta mais aceita é que este polissacarídeo não seja encontrado na natureza como uma substância pura, uma vez que a quitina ocorre associada a outras substâncias, como proteínas, sais de cálcio, pigmentos e lipídeos 13,14 . De fato, quitina pura foi identificada, até agora, apenas em algas diatomáceas…”