Table 1. Physicochemical properties of dairy wastewater reported in the literature and some disposal standards

S/N	pH	TDS (ppt)	BOD (mg/L)	COD (mg/L)	SS (mg/L)	Ref.
1	7.4	-	1,710	2,520	1,020	Passeggi et al. (2009)
2	6±0.69	1.28±0.25	355±78.99	982±67.57	-	Wang et al. (2005)
3	6.8±0.64	1.2±0.25	320±26.76	954±86.18	-	Wang et al. (2005)
4	7–8	1.300	1,040	2,100	1,200	Khan (2017)
5	6.4	2.180	1,445±30	4,410±60	1,660±60	Suman et al. (2017)
6	4–12		300–1,400	650–3,000	250–2,700	Cecconet et al. (2018)
7	9.8	1.222	650	1448	-	Ashekuzzaman et al. (2019)
Arab	6.7–9.1	-	1,941±864	3,383±1,345	-	Flayyih and Ali (2022)
Central Pollution Control Board	6.5–8.5	-	100	-	150
World Bank	6–9	-	50	250	10	Flayyih and Ali (2022)
Turkey	6–9	-	-	160	30	Flayyih and Ali (2022)
Iraq	6–9.5	-	<40	<45	60	Flayyih and Ali (2022)

The standards were extracted from Flayyih and Ali (2022).
TDS, total dissolved solids; BOD, biological oxygen demand; COD, chemical oxygen demand; SS, suspended solids.