1.Adopting H_2SO_4 to regulate the pH value, when pH = 2, 91. 5% CrO_4~2- transformed to Cr_2O_7~2-Treating 1000 kg wastewater could produce 93 kg Na_2Cr_2O_7 crystal, the gross profit is about 726 Yuan RMB per ton production. Hence, considerable economic benefits could be achieved.
