Haloacetic Acids Formation Potential of Tropical Peat Water DOM Fractions and Its Correlation with Spectral Parameters

Tropical peat water dissolved organic matter (DOM) fractions spectral parameters correlate with the formation of carcinogenic disinfection by-products (DBPs), haloacetic acids (HAAs). Peat water DOM has been fractionated using Superlite DAX-8, Amberlite XAD-4, and Amberlite IRA-958 resins to separate hydrophobic acid (HPOA), transphilic (TPH), hydrophilic-charged (HPIC), and hydrophilic-neutral (HPIN). The formation potential of HAA was determined using the total concentration of 5 HAAs (HAA5). The DOM characteristic was determined using dissolved organic carbon (DOC) and ultraviolet-visible (UV-Vis) absorbance was evaluated at 200-700 nm. The HPOA fraction dominates the DOM of tropical peat water with a 40% DOC concentration when the HPIC fraction was the slighter. The spectral absorbance ratios (E-4/E-6 and A(253)/A(203)) and spectral slopes (S206-213, S251-280, S281-295, and S->295) have a strong positive correlation with HAA5 formation potential (HAA5FP). Similarly, the absorbance ratio A(210)/A(254) and spectral slopes S200-205 are strongly correlated to HAA5FP, but in a negative direction. In contrast, the E-2/E-3 and A(280)/A(350) spectral ratio, and spectral slopes (S214-227, and S228-250), has a weaker correlation with HAA5FP. The E-2/E-3 and A(280)/A(350) ratios and S251-280 S200-205 spectral slope show a strong relationship with the brominated HAA5FP (B-HAA5FP). The spectral parameters of DOM fractions can be used as surrogate parameters of HAA5FP of peat water.

Automated summary

The spectral parameters of DOM fractions in tropical peat water are correlated with the formation of carcinogenic disinfection by-products (DBPs) and haloacetic acids (HAAs), with the hydrophobic acid (HPOA) fraction dominating the DOM composition. UV-Vis absorbance parameters show a strong positive correlation with HAA formation potential (HAA5FP), while A(210)/A(254) and S200-205 parameters are negatively correlated with HAA5FP.