Removal of chemically hazardous p-hydroxybenzoic acid during total chlorine free bleaching process of Hevea Brasiliensis

The industrial usage of plant biomass, paper pulp manufacture, is increasing every day. In Malaysia, Rubber wood is the dominant raw material and the Soda-anthraquinone and total chlorine free bleaching processes lead the procedure of rubber wood paper pulp production. This paper aims to identify the structural modification in the pulp depending on the applied procedure. Fourier transform infrared (FTIR) spectrometry and HPLC have been applied to analyze rubberwood chip, soda-AQ and TCF pulp. The relationship between spectral characteristics and sample composition has been established, as well as the variation in the structural behavior after pulping and bleaching has been observed. FTIR spectra clearly show that after TCF the structure of the wood components is partially modified or removed. Along with FTIR data, the HPLC results confirmed the absence of chemically hazardous p-Hydroxybenzoic acid in the pulp samples, which finally results in the contamination of the river water streams. ► TCF pulp from Hevea Brasiliensis was prepared through NaOH-AQ and OZP bleaching. ► Variation in structural behavior after pulping and TCF bleaching observed by FTIR. ► HPLC and FTIR results confirmed the absence of hazardous phenolic compound. ► The removal of p-Hydroxybenzoic acid from TCF is taken place. ► Finally contaminating the fresh water systems.