Method for simultaneously extracting iodine and fucoidin from salted kelp blanching wastewater

Abstract

The invention provides a method for simultaneously extracting iodine and fucoidin from salted kelp blanching wastewater, belonging to the technical field of environment protection and chemical industry. The method particularly comprises the following steps of: (1) cooling kelp blanching wastewater; (2) degrading nitrate nitrogen and nitrite nitrogen by inherent microbes in kelp blanching wastewater; (3) adding caustic soda into denitrified kelp blanching wastewater, so that the fucoidin is basified, flocculated, and layered in a floating way, filtering, and drying to obtain a fucoidin crude product; (4) pumping the fucoidin-removed kelp blanching wastewater into an acidification tank, adding oxidant, so that iodide ions in solution can be completely oxidized into iodine, and enriching iodine by ion exchange resin; (5) dissolving iodine absorbed in the resin by NA2SO3 solution; and (6) oxidizing iodide ions in desorption solution into the iodine by KClO3 oxidant, crystallizing, separating out, centrifuging, and filtering to obtain crude iodine. According to the method, iodine and fucoidin can be extracted, and the multipurpose utilization rate can be improved, so that the resources waste and the environment pollution can be avoided.

Description

technical field [0001] The invention belongs to the technical fields of environmental protection and chemical industry, and in particular relates to a method for simultaneously extracting iodine and fucoidan from blanching waste water of saline kelp. Background technique [0002] Salted kelp processing is an important processing method in kelp breeding production areas in my country, mainly concentrated in Rongcheng, Shandong, Dalian, Liaoning, and Lianjiang, Fujian. According to statistics, in 2010, the output of kelp culture in my country reached 884,000 tons (in terms of dry weight), and the annual output of algae processed products reached 946,000 tons, of which the annual output of salted kelp was 420,000 tons, and the annual output value exceeded 1.2 billion yuan. Fresh kelp is briefly blanched in hot water at 80-90°C, then cooled, drained, mixed with salt and dehydrated to obtain salted kelp. The blanching kelp processing lines all over the kelp breeding area produce...

AI Technical Summary

Problems solved by technology

If the air blowing method is used to extract iodine, the pH of the blanching water should be adjusted to 0.5~3.0 first. Fucoidan cannot be extracted under strong acidic conditions, and it will be discharged directly as waste, resulting in a serious waste of resources. Therefore, it is urgent to bleach kelp. Recycling of fucoidan in scalding wastewater