Pukyong National University

"The waste oyster shells can be recycled as coastal purification materials."
Woo Hee-eun of Pukyong National University received the thesis award from Korean Society of Coastal and Ocean Engineers

The research results that can use industrial waste oyster shell as a purification material for coastal pollution attract public attention.

This is the ‘Investigation of changes in the permeability and benthic environment of coastal polluted sediment properties caused by pertaining of plastic oyster shells (Kim Gyeong-Hui, adviser)’, which Woo Hee-eun, department of Ocean Engineering, Pukyong National University (2 years, Ph.D. See picture), who recently received from the Korean Society of Coastal and Ocean Engineers (Chairman Kang Beom-gu), received an award at the academic conference.

Woo received the attention of researchers by presenting this paper at the 2019 Joint academic conference with Korea Institute of Ocean Science & Technology (KIOST) held at the Jeju International Convention Center last year by the Korean Society of Coastal and the Korean Society for Marine Environment and Energy (Kosmee).

In this paper, Woo proposed a method of using oyster shells as heat-treating pollutants as a method of increasing water permeability (water drainage) by heat treatment. The essence of this paper is that the application of heat-treated oyster shells to contaminated coastal sediments makes it easier for contaminants to escape into the ocean.

Woo conducted experiments to measure the water permeability by placing pieces of oyster shells heat-treated at 350 degrees Celsius and 600 degrees Celsius, along with sediments taken from the coast, into each experimental equipment.

As a result of the experiment, the permeability increased up to 65 % and 89 % respectively, when the oyster shell pieces heat-treated at 350 degrees Celsius and 600 degrees Celsius were added to the sediments than when nothing was added to the sediments.

As a result of analyzing the nutrients in the sediment after the permeability measurement experiment, the concentration of phosphate and calcium decreased by 80-90 %.

"There have been studies on heat treatment at a high temperature of 700 degrees Celsius to 1200 degrees Celsius for recycling oyster shells, but there was a limit to the economic efficiency due to the high heat treatment cost," she said and added, "This study confirmed the possibility of using oyster shells heat-treated at relatively low temperatures to secure economic efficiency." <Pukyong Today>