Rubber wastewater treatment using UV, ozone, and UV/ozone and its effluent potency for microalgae Spirulina platensis cultivation medium

Figures & data

Figure 1. A schematic of the laboratory-scale UV/ozone reactor.

Table 1. The composition of wastewater and nutrients

Wastewater Composition (%) (v/v)	NaHCO3 (mg L^−1)	Urea (mg L^−1)	TSP (mg L^−1)
0	4600	220	50
30	2300	110	25
50	2300	110	25
80	2300	110	25

Figure 2. The results of the three AOPs. a) COD reduction of rubber wastewater following b) the first-order and c) the second-order kinetics.

Table 2. Coefficient determination and kinetic rate constants of the COD reduction following the first- and the second-order kinetics

Treatment Method	First-order kinetics		Second-order kinetics
	R^2	k (s^−1)	R^2	k (L g^−1 s^−1)
UV	0.936	3 x 10^−4	0.927	2 x 10^−7
Ozone	0.959	1.2 x 10^−3	0.892	2 x 10^−6
UV/ozone	0.984	1.7 x 10^−3	0.865	7.4 x 10^−3

Figure 3. (a) COD, (b) Total-N, (c) Total-P, and (d) pH reduction of rubber wastewater, which was treated with different methods using various flow rates.

Figure 4. The growth of Spirulina platensis for 10 days of cultivation. In this study, 0, 30, 50, and 80% (v/v) of wastewater treated with UV/ozone was used as a growth medium.