Lignin and holocellulose from coir pith involved in trimethylamine (fishy odor) adsorption

Coir pith is a highly potential adsorbent for adsorbing trimethylamine(TMA). It harbors a higher adsorption capacity for TMA compared to commercial activated carbon(CAC). It was found that lignin and holocellulose extracted from coir pith played an important role in TMA adsorption. Lignin itself had the highest TMA adsorption capacity(269.01 mg/g)followed by holocellulose(75.43 mg/g), coir pith(14.3 mg/g) and CAC(10.26 mg/g),respectively. The pseudo-first-and second orders were applied to the kinetic data. For the adsorption of TMA by coir pith, the best fit was achieved by the pseudo-second order.Thermodynamic studies showed an endothermic and physico-chemical adsorption process between TMA and the coir pith. TMA desorption study suggested that only 14%–47% of TMA was desorbed with distilled water. In addition, Fourier transform-infrared(FT-IR) spectra showed that C–H bond(methyl group), C–O bond from phenolic alcohol and C–O bond from tertiary alcohol in lignin and holocellulose were involved in TMA adsorption. Coir pithbased filter showed high TMA adsorption efficiency(98%) and kept constant for more than48 days in a continuous system. Pilot scale experiment, coir pith beads filter could be succesfully applied as a packing material for TMA removal. Therefore, coir pith can be used as a promising packing material for TMA treatment at contaminated site.     

Enhancing mixed toluene and formaldehyde pollutant removal by Zamioculcas zamiifolia combined with Sansevieria trifasciata and its CO2 emission

Indoor air pollutants comprise both polar and non-polar volatile organic compounds (VOCs). Indoor potted plants are well known for their innate ability to improve indoor air quality (IAQ) by detoxification of indoor air pollutants. In this study, a combination of two different plant species comprising a C3 plant (Zamioculcas zamiifolia) and a crassulacean acid metabolism (CAM) plant (Sansevieria trifasciata) was used to remove polar and non-polar VOCs and minimize CO₂ emission from the chamber. Z. zamiifolia and S. trifasciata, when combined, were able to remove more than 95% of pollutants within 48 h and could do so for six consecutive pollutant’s exposure cycles. The CO₂ concentration was reduced from 410 down to 160 ppm inside the chamber. Our results showed that using plant growth medium rather than soil had a positive effect on decreasing CO₂. We also re-affirmed the role of formaldehyde dehydrogenase in the detoxification and metabolism of formaldehyde and that exposure of plants to pollutants enhances the activity of this enzyme in the shoots of both Z. zamiifolia and S. trifasciata. Overall, a mixed plant of Z. zamiifolia and S. trifasciata was more efficient at removing mixed pollutants and reducing CO₂ than individual plants.