Removal of cadmium from scallop processing waste by washing with weak acid solution and utilization of useful constituents for organic fertilizer manufacturing

Abstract

Hepatopancreases were washed four times with 2% acetic acid solution. In both the washed hepatopancreases and the supernatant of the washing solution, the residual cadmium (Cd) concentration was in accordance with the required standard for organic fertilizers. Hepatopancreases do not naturally contain high levels of nitrogen, but they do contain several amino acids which are useful for cultivation, and these were retained during the washing process. Although the condensed precipitate of the washing solution contained a considerable amount of Cd, Cd elution levels at the time of final disposal met judgment standard for special management industrial waste as a result of kneading and immobilizing with chelating adsorbent for treatment of contaminated soil. The volume of the precipitate of the washing solution was one-fifth of the original hepatopancreas, and the solid waste was suitable for burial at a final disposal site without further treatment.

Growth, nutrient utilization, oxidative condition, and element composition of juvenile red sea bream Pagrus major fed with fermented soybean meal and scallop by-product blend as fishmeal replacement

“…The adductor muscle is the only edible part of the scallop, and the rest is treated as waste product [2]. The huge amounts of these by-products are usually disposed of according to the strict Japanese Government regulations for waste disposal [3]. This is often seen as a threat to the industry, as a considerable amount of money is spent on disposal of byproducts, even though they are nutrient-rich resources which have the potential to be utilized in aquafeed.…”

New Alternatives in Seafood Restructured Products

“…Heavy metals are distributed in diverse tissues (muscle, internal organs, fatty tissues, etc. ), but in most cases, the highest concentration of heavy metals is found in the hepatopancreas, probably because of its high Critical Reviews in Food Science and Nutrition 2016;56(2):237-248 metallothionein content (Pourang et al, 2004;Ren et al, 2008). In this regard, the higher levels of heavy metals in molluscan (Mediterranean mussel, Mytilys gallopronvincialis) than in fish (rainbow trout, Oncorhyncus mykiss) could be due to the fact that mussel metallothioneins are more reactive than fish proteins to metal binding (Vergani et al, 2005).…”

“…In this respect, Ren et al (2008) studied the removal of cadmium from scallop hepatopancreas by washing four times with a weak acid solution (2% acetic acid or citric acid) which produced a reduction in the cadmium level from approx. 39 ppm to <0.6 ppm.…”