Eco-friendly
composite catalyst and ultrasound removes pollutants from water
National Research Council of Science
& Technology
The research team of Dr. Jae-woo
Choi and Dr. Kyung-won Jung of the Korea Institute of Science and Technology's
(KIST, president: Byung-gwon Lee) Water Cycle Research Center announced that it
has developed a wastewater treatment process that uses a common agricultural
byproduct to effectively remove pollutants and environmental hormones, which
are known to be endocrine disruptors.
The sewage and wastewater that are
inevitably produced at any industrial worksite often contain large quantities
of pollutants and environmental hormones (endocrine disruptors).
Because environmental hormones do not break down easily, they can have a significant negative effect on not only the environment but also the human body. To prevent this, a means of removing environmental hormones is required.
Because environmental hormones do not break down easily, they can have a significant negative effect on not only the environment but also the human body. To prevent this, a means of removing environmental hormones is required.
The performance of the catalyst that
is currently being used to process sewage and wastewater drops significantly
with time. Because high efficiency is difficult to achieve given the
conditions, the biggest disadvantage of the existing process is the high cost
involved.
Furthermore, the research done thus far has mostly focused on the development of single-substance catalysts and the enhancement of their performance. Little research has been done on the development of eco-friendly nanocomposite catalysts that are capable of removing environmental hormones from sewage and wastewater.
Furthermore, the research done thus far has mostly focused on the development of single-substance catalysts and the enhancement of their performance. Little research has been done on the development of eco-friendly nanocomposite catalysts that are capable of removing environmental hormones from sewage and wastewater.
The KIST research team, led by Dr. Jae-woo Choi and Dr. Kyung-won Jung, utilized biochar, which is eco-friendly and made from agricultural byproducts, to develop a wastewater treatment process that effectively removes pollutants and environmental hormones.
The team used rice hulls, which are discarded during rice harvesting, to create a biochar** that is both eco-friendly and economical. The surface of the biochar was coated with nano-sized manganese dioxide to create a nanocomposite. The high efficiency and low cost of the biochar-nanocomposite catalyst is based on the combination of the advantages of the biochar and manganese dioxide.
The KIST team used the hydrothermal
method, which is a type of mineral synthesis that uses high heat and pressure,
when synthesizing the nanocomposite in order to create a catalyst that is
highly active, easily replicable, and stable.
It was confirmed that giving the catalyst a three-dimensional stratified structure resulted in the high effectiveness of the advanced oxidation process (AOP), due to the large surface area created.
It was confirmed that giving the catalyst a three-dimensional stratified structure resulted in the high effectiveness of the advanced oxidation process (AOP), due to the large surface area created.
When used under the same conditions
in which the existing catalyst can remove only 80 percent of Bisphenol A (BPA),
an environmental hormone, the catalyst developed by the KIST team removed over
95 percent in less than one hour.
In particular, when combined with ultrasound (20kHz), it was confirmed that all traces of BPA were completely removed in less than 20 minutes. Even after many repeated tests, the BPA removal rate remained consistently at around 93 percent.
In particular, when combined with ultrasound (20kHz), it was confirmed that all traces of BPA were completely removed in less than 20 minutes. Even after many repeated tests, the BPA removal rate remained consistently at around 93 percent.
Dr. Kyung-won Jung of KIST's Water
Cycle Research Center said, "The catalyst developed through this study
makes use of a common agricultural byproduct. Therefore, we expect that
additional research on alternative substances will lead to the development of
catalysts derived from various types of organic waste biomass."
Dr. Jae-woo Choi, also of KIST's Water Cycle Research Center, said, "We have high hopes that future studies aimed at achieving process optimization and increasing removal rates will allow for the development an environmental hormone removal system that is both eco-friendly and low-cost."
Dr. Jae-woo Choi, also of KIST's Water Cycle Research Center, said, "We have high hopes that future studies aimed at achieving process optimization and increasing removal rates will allow for the development an environmental hormone removal system that is both eco-friendly and low-cost."
**Biochar: a term that collectively
refers to substances that can be created through the thermal decomposition of
diverse types of biomass or wood under oxygen-limited conditions