Figure 7. Variations of the residual hydrogen peroxide in the paper processing wastewater The oxidation process using only hydrogen peroxide also has good COD removal efficiencies. Fig. 8 shows the COD removal observed at different concentrations of hydrogen peroxide. Higher COD removal efficiencies are observed for higher concentrations of hydrogen peroxide applied. When 10,000 mg/1 hydrogen peroxide is used, the COD removal can reach 59%. Figure 8. Effect of hydrogen peroxide in the paper processing wastewater

ABSTRACT

I fo r th e th re e ty p e s o f w a s te w a te rs . F o r b o th F W an d PW , th e sp ec if ic C O D

rem o v a l d e c re a se s w ith in c re a s in g h y d ro g e n p e ro x id e c o n c e n tra tio n . T h e FW

h as h ig h e r sp ec if ic C O D rem o v a l e ff ic ie n c ie s th an PW . F o r e x a m p le , at 500

mg/1 h y d ro g e n p e ro x id e , th e sp ec ific C O D rem o v a l fo r PW is 0 .55 m g /m g

w h ic h is sm a lle r th a n th e sp ec ific C O D rem o v a l o f 1.2 m g /m g fo r th e FW . A t

10 ,000 mg/1 h y d ro g e n p e ro x id e , th e sp ec ific C O D re m o v a ls fo r th e P W and

th e F W are 0 .33 an d 0 .4 9 m g /m g , resp ec tiv e ly . A d d itio n a lly , th e sp ec if ic C O D

rem o v a l fo r th e m ix tu re is a lw ay s lo w e r th a t fo r th e FW and fo r th e PW ex cep t

w h en th e h y d ro g e n p e ro x id e c o n c e n tra tio n is m a in ta in ed at 10 ,000 mg/1. A t

th is h y d ro g e n p e ro x id e c o n c e n tra tio n , the sp ec ific C O D rem o v a l for the

m ix tu re ( 0 .3 9 m g /m g ) is s lig h tly h ig h e r th an th e sp ec ific C O D rem o v a l ( 0 .33

m g /m g ) fo r th e PW . B ased on th e re su lts sh o w n in T able I, th e sp ec ific C O D

rem o v a l fo r th e m ix tu re is co n s id e re d to be poor.