Table 6: Equivalent value related to the cost of 3 h of ZnO photoirradiated reaction.

Equipment and reagents Quantity used (3 h)* Cost for the process (3 h) (US$)* Pump energy consumption (kW-h) 0.0287 0.008323*** Reagents H2SO4 + NaOH (g) 0.02 0.0008105** Total cost:   0.0164

*US$ 1,00 = R$ 1.71; Cotações UOL. **Quote N° 212712 from Labsynth Produtos of Laboratórios Ltda. ***1 kW-h = US$ 0.29; the third most expensive electricity in Brazil—Portal Business Brasil.