Author/Authors :
Hatamoto، M نويسنده Department of Environmental System Engineering , , Nagai، H نويسنده Department of Civil and Environmental Engineering , , Sato، S نويسنده Department of Environmental System Engineering , , Takahashi، M نويسنده Department of Environmental System Engineering , , Kawakami، S نويسنده Department of Environmental System Engineering , , Choeisai، P.K نويسنده Department of Environmental Engineering , , Syutsubo، S نويسنده Center for Regional Environmental Research , , Ohashi، A نويسنده Department of Social and Environmental Engineering , , Yamaguchi، T نويسنده Department of Environmental System Engineering ,
Abstract :
A newly developed natural rubber deproteinization process produces deproteinized natural
rubber (DPNR) wastewater as an intermediate product containing a high concentration of sodium dodecyl
sulfate (SDS) and rubber. In this study, a novel process to recover the residual rubber and energy as methane
from DPNR wastewater was developed. As a pretreatment, SDS and residual rubber in DPNR wastewater
were coagulated and recovered by addition of CaCl2 at Ca2+/SDS and Ca2+/rubber mass ratios of 0.070 and
0.055, respectively. The remaining organic matter in the pre-treated DPNR wastewater was converted to
methane by using a mesophilic up-flow anaerobic sludge bed (UASB) reactor. The UASB reactor with the
diluted pre-treated DPNR wastewater showed a total chemical oxygen demand (COD) removal efficiency of
92 ± 2% at a maximum loading rate of 6.8 ± 1.8 kgCOD·m-3·d-1 at a hydraulic retention time (HRT) of 12 h.
Under the condition of effluent recirculation with raw pre-treated DPNR wastewater, the UASB reactor
showed a total COD removal efficiency of 84 ± 8% at the maximum loading rate of 6.4 ± 1.7 kgCOD·m-3·d-1 at
HRT of 39 h. The results suggest that the newly developed resource recovery process for DPNR wastewater
could be a promising treatment system.
