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Useful Wastes Produced by Lynas Chemical Plant

**This article was published in English and has no translation in Bahasa Melayu** 
**This article was published in NEW STRAITS TIMES on 24 September 2019.

By Dr J Shamshuddin

Professor Ahmad Ibrahim’s article published in The Star (September 2, 2019) caught my attention. He argued convincingly that the public must be better informed about the radiation levels taken place under natural condition, at work places and others. I agree fully with his notion on the matter.

His view is actually directed mainly towards the recent brouhaha related to the radiation levels and radioactivity brought about by Lynas chemical plant in Gebeng, Pahang that produces rare earth. People in the surrounding area are divided between believing the myth propagated by the opponents and the reality of the issue. For all intents and purposes, Lynas built to produce rare earth (highly needed in high end industries) is not a nuclear reactor. Whether we like or not, Lynas plant is here to stay in order to keep the economy of Malaysia or even the world going.

I want to say a bit about the problem with radiation and heavy metal pollution which has become a national issue of late. I spent time conducting research on a by-product of the chemical plant for agriculture (oil palm), which was the non-radioactive Neutralization Underflow (NUF) residue, aka Mg-Rich Synthetic Gypsum. During the course of my study, I often visited the state-of-the-arts Lynas plant in Gebeng and was completely informed of what was going on in the vicinity.

The production of rare earth involved many steps. Along the way, two contrasting by-products are produced. The process started with lanthanide ore coming from Mt Weld, Australia, containing rare earth. After a series of chemical processes, radioactive Water Leach purification (WLP) residue is produced. This is followed by the production of NUF residue.  

A team of researchers from UPM and UKM led by me have evaluated the benefit of applying NUF on land cropped to oil palm. We found that NUF contained high amounts of Mg, Ca and S, which are macronutrients. Mg and Ca are needed in large amounts to sustain oil palm growth, while S is required for producing the oil. The application of the by-product have positive impact on oil palm in terms of growth and/or production. NUF is able to replace kieserite as Mg source or even dolomitic limestone as Ca or Mg source. Besides, it increases soil pH.

In a glasshouse study conducted at UPM, Serdang, NUF application was found to have increased soil pH that reduced soil acidity, resulting in enhancing the growth oil palm seedlings. This study concluded that NUF not only was a good Mg and Ca fertilizer, but also an excellent soil amendment. Furthermore, NUF application in oil palm plantation does not pollute the surrounding environment – either soils or the waterways.

WLP, on the other hand, has low level of radioactivity, with value of about 6 Bq/g of thorium 232. Note that a Bq (Becquerel) is one atom decaying per second. The permissible radiation level in Malaysia right now is set at 1 Bq/g although across the world it has gone up to 10 Bq/g. In Australia, it is by law that the radioactivity of chemical plant residue has to be diluted by mixing with a suitable material (e.g. soil) before it can be put back on soil for whatever purpose in mind. The same thing can be done with the WLP produced by Lynas, but it has to be done with caution to ensure the sustainability of the process. Once done, the WLP can be turned into a useful by-product that can be used in agriculture or otherwise.

I believe that the WLP residue accumulated in high amount at Lynas chemical plant in Gebeng can be put to good use instead of storing it permanently at an approved facility in the country. For sure, it can be a source of P fertilizer as it contains 25-50% iron phosphate.

In terms of radioactivity, phosphate rocks used in agriculture in Malaysia (for rubber and oil palm cultivation) for decades have low level of naturally occurring radioactive material, with radiation level comparable to that of WLP. Thus, Star online reported on May 27, 2019 that the WLP produced by Lynas could be used as fertilizers and helped reduce the import of phosphate rocks.  This is translated into saving the hard-earned Malaysian foreign exchange.

In the spirit Malaysia BOLEH, we can turn the wastes produced by chemical plants in the country into useful materials that can be used to enhance our economic activities. Thus, NUF and WLP residues can be used as fertilizers in oil palm and/or rubber plantations. In so doing, fertilizer import is reduced, yet agricultural productivity is sustained for the benefit of its citizen.

 

Writer:

Dr J Shamshuddin
Research Fellow, UPM
Fellow, Academy of Sciences Malaysia

Date of Input: 23/10/2019 | Updated: 28/11/2019 | hairul_nizam

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