Ong Soon An
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Ong Soon An
Official Name
Ong, Soon An
Alternative Name
Ong, Soon An
Ong, S. A.
Soon An, Ong
Soon-An, Ong
ONG, Soon An
Ong, Soon an
Soon-An, Ong
Main Affiliation
Scopus Author ID
57201387782
Researcher ID
B-9255-2012

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  • Publication
    Adsorption and toxicity of heavy metals on activated sludge
    ( 2010)
    Ong Soon An
    ;
    Eiichi Toorisaka
    ;
    Makoto Hirata
    ;
    Tadashi Hano
    The adsorption of Cu, Cd, Ni, Zn, and Cr from synthetic solutions on powdered activated carbon (PAC), activated sludge, and dried sludge were investigated under laboratory conditions to assess its ability to remove heavy metals. The adsorption efficiency increased rapidly within the first 30 min and then slowed down as it approached a steady state after 5 h of contact time. The results showed that activated sludge and PAC had a higher adsorption capacity than dried sludge. However, PAC showed a better adsorption capacity for Cu, Zn, and Ni than activated sludge. The maximum adsorption capacity, as quantified by the Langmuir parameter Q for activated sludge was 44, 30, 24, 23, and 18 mg/g for Cu, Ni, Cd, Cr, and Zn, respectively. In the case of dried sludge, the respective values of Q were 20, 13, 11, 3, and 10 mg/g. The acute toxicity of these five heavy metals to the activated sludge microorganisms was determined on the basis of the reduction in the specific oxygen uptake rate (SOUR). The results obtained from the SOUR measurements indicated a decreasing toxicity scale, Cu > Cd > Ni ' Cr > Zn on activated sludge microorganisms.
  • Publication
    Photocatalytic degradation of sugarcane vinasse using ZnO photocatalyst: operating parameters, kinetic studies, phytotoxicity assessments, and reusability
    ( 2021)
    Kee Wei Chin
    ;
    Wong Yee Shian
    ;
    Ong Soon An
    ;
    Nabilah Aminah Lutpi
    ;
    Sam Sung Ting
    ;
    Audrey Chai Yee Chieh
    ;
    Kim-Mun Eng
    Photocatalytic degradation performance is highly related to optimized operating parameters such as initial concentration, pH value, and catalyst dosage. In this study, the impact of various parameters on the photocatalytic degradation of anaerobi‑ cally digested vinasse (AnVE) has been determined through decolourization and chemical oxygen demand (COD) reduction efciency using zinc oxide (ZnO) photocatalyst. In this context, the application of photocatalytic degradation in treating sugarcane vinasse using ZnO is yet to be explored. The COD reduction efciency and decolourization achieved 83.40% and 99.29%, respectively, under the conditions of 250 mg/L initial COD concentration, pH 10, and 2.0 g/L catalyst dosage. The phytotoxicity assessment was also conducted to determine the toxicity of AnVE before and after treatment using mung bean (Vigna radiata). The reduction of root length and the weight of mung bean indicated that the sugarcane vinasse contains enormous amounts of organic substances that afect the plant's growth. The toxicity reduction in the AnVE solution can be proved by UV–Vis absorption spectra. Furthermore, the catalyst recovery achieved 93% in the reusability test. However, the COD reduction efciency and decolourization were reduced every cycle. It was due to the depletion of the active sites in the catalyst with the adsorption of organic molecules. Thus, it can be concluded that the photocatalytic degradation in the treatment of AnVE was efective in organic degradation, decolorization, toxicity reduction and can be reused after the recovery process.