Effect of leachate loading rate and incubation period on the treatment efficiency by T. versicolor immobilized on foam cubes

Abstract

This study focuses on treatment of landfill leachate in column experiments by immobilized Trametes versicolor on polyurethane foam, collected from Nonthaburi landfill site, Thailand. In this study, glucose was used as a co-substrate. The effect of biomass growth on color removal was observed by immobilizing fungi on polyurethane foam. The same immobilized fungi were used for four cycles of 5 days each to find the reuse of fungi. Leachate was diluted to see the effect of organic loading on color removal. At optimum pH of 4 and in 20 days with 3 g/L of glucose, the fungi could decolorize 78 % and 63 % for 5-times dilution and concentrated leachate, respectively, using immobilized fungi after 4 days initial growth. Fungi could also reduce biological oxygen demand and chemical oxygen demand of 52 % and 42 % (with initial biological oxygen demand and chemical oxygen demand of 48,900 and 96,512 mg/L), respectively, with glucose 3 g/L in concentrate leachate and with 4 days initial immobilization of fungi on polyurethane foam. About 1-6% higher color removal was observed on day 20 with 15 days fungi immobilization initially as compared to 4 days immobilization. Higher removal efficiency was observed for the same leachate after dilution due to reduction in organic loading. Addition of co-substrate enhances significantly removal of color, biological oxygen demand and chemical oxygen demand. Chemical oxygen demand removal reached to 0.6 mg/mg of biomass with the co-substrate. Therefore, white rot fungi can be considered as potentially useful microorganisms in landfill leachate treatment.

Treatment of Landfill Leachate Using Ganoderma Australe Mycelia Immobilized on Ecomat

“…This finding is in accordance with the findings by Saetang and Babel that obtained higher COD removal compared to BOD in their study [17].…”

“…However, COD removal occurred at most of the cycles and diluted leachate demonstrated higher COD removal after each cycles compared to raw leachate. Similar results were found by Saetang and Babel who found that removal of BOD and COD was lower when the leachate was diluted 5 times compared to concentrated leachate [17].…”

“…Fungal mycelia require adaptation for the enzymes to act. [17]. However, COD removal occurred at most of the cycles and diluted leachate demonstrated higher COD removal after each cycles compared to raw leachate.…”

“…Previous study done on pellets (free cell) and immobilized cells of Trametes versicolor showed that removal efficiency of BOD 5 and COD in leachate was found to be higher in the case of immobilized fungi compared to free cell [17]. This is because immobilization of fungal cells could stably maintain the production of various enzymes at levels higher than achieved with pellet form.…”

Utilization of the White-rot Fungus, Trametes menziesiifor Landfill Leachate Treatment

“…These enzymes are able to oxidize a variety of high-priority aromatic pollutants such as polycyclic aromatic hydrocarbons, chloromatics and polyaromatic dyes (Kotterman et al 1996). Saetang and Babel (2009) have applied immobilized T. versicolor to treat landfill leachate in column experiments since the immobilization is expected to improve the mass transfer of oxygen and nutrients for fungal mycelia by providing a large attaching surface area. Besides that, Saetang and Babel (2010) stated that the advantages of using immobilized microorganism for pollutant degradation is due to their economically cheaper, easier to handle and the immobilized fungus is reusable for several batches.…”