Assessment of Untreated Coffee Wastes for the Removal of Chromium (VI) from Aqueous Medium

Table 5

Cost estimation of SCGs.

Step no.	Step	Cost ($)/kg SCGs
1	SCGs collection	0.00
2	Distilled water washing (2 L/kg of SCGs)	0.33
3	Drying at 105°C (0.055 k Wh × time × $0.25/kWh)	0.32
4	Sieving (0.5 kWh × sieving time × $0.25/kWh)	0.18
5	Cost of SCGs adsorbent (summation of step 1–4)	0.83
6	General expenses (10% of no. 5)	0.08
7	Total cost of SCGs adsorbent (No.5 + No.6)	0.91