Removal of trace heavy metal contaminants from algae and the carrageenan contained therein

DETAILED DESCRIPTION What is claimed: 1.
A process for removing trace heavy metal contaminants from algae that contain a major amount of lambda-type carrageenan and from said carrageenan which comprises treating said algae with a water solution containing an effective amount of a soluble food grade potassium salt for removal of said trace heavy metal contaminants using a concentration of potassium ion in the solution which is below 1.
0 mole K.
sup.
+ /liter and at a temperature not in excess of about 10.
degree.
C.
such that there is no appreciable extraction of the lambda-type carrageenan from the algae.
2.
A process as claimed in claim 1 wherein the algae is selected from the genus Gigartina.
3.
A process as claimed in claim 1 wherein the algae are selected from the group consisting of Gigartina acicularis and Gigartina pistillata.
4.
A process as claimed in claim 1 wherein the soluble potassium salt is selected from the group consisting of potassium chloride, tripotassium orthophosphate, monohydrogen dipotassium orthophosphate, and tetrapotassium pyrophosphate.
5.
A process as claimed in claim 1 wherein the weight ratio of potassium solution to algae is greater than about 7:1.
6.
A process as claimed in claim 1 wherein the potassium salt is potassium chloride.
7.
A process as claimed in claim 1 wherein the algae are washed with the solution for a period of time ranging from about 10 minutes to 2 hours.
8.
A process as claimed in claim 1 wherein the contaminant which is removed is arsenic.
9.
A process as claimed in claim 1 wherein the algae is selected from the genus Iridaea.




Description:
TECHNICAL DESCRIPTION OF THE INVENTION Although treating of algae has been proposed using certain salt solutions, Marshall et al.
Investigations in Britain, "British Seaweeds and the Preparation of Agar" pp.
71-75 (1949) and U.
S.
Pat.
Nos.
3,176,003, 2,620,335 and 2,624,727, either to remove readily diffusible salts that are physically entrapped in algae, to selectively extract carrageenan from the algae or to treat algae containing predominant amounts of gel-forming, or kappa type, carrageenan, it has not been recognized that potassium salt containing solutions can be used under certain reaction conditions to materially reduce the level of trace heavy metal contaminants which are contained in algae having a major amount of lambda-type carrageenan therein without at the same time causing swelling of the algae and consequent extraction of the carrageenan from the algae