CONCLUSION
In this study, a resource recovery process for
DPNR wastewater (an intermediate product of a newly
developed natural rubber deproteinization process) was
developed. The residual rubber in the DPNR wastewater
was recovered by addition of CaCl2
in a Ca2+ to SDS
mass ratio of 0.07 and VS wastewater concentration of
0.055. The remaining P-DPNR wastewater was
effectively treated using a mesophilic UASB reactor at
HRT of 39 h and recirculation ratio of 2 over a period of
100 days. Under these conditions, a total COD removal
efficiency of 84% and a total BOD removal efficiency
of 91% were achieved at a loading rate of 6.4 kgCOD·m-
3
·d-1; methane recovery was 1.47 Nm3
/m3
/d. Thus, the
newly developed resource recovery process is suitable
for the DPNR wastewater treatment.