Photocatalytic Degradation of Pesticides in Natural Water: Effect of Hydrogen Peroxide

Table 4

Characterization of samples of surface wáter fortified with pesticides in photocatalytic treatments.

Initial sample
Physical-chemical parameters
pH	8.0	Colour (PCU)	0
Conductivity (μS cm^−1)	508	Dissolved oxygen (mg L^−1)	9.9
Turbidity (NTU)	69	Hardness (mg CaCO3 L^−1)	108
Suspended solids (mg L^−1)	27	NH4^+ concentration (mg L^−1)	0.15
Phosphorous (mg L^−1)	0.8	CN^- concentration (mg L^−1)	0.002
DOC (mg C L^−1)	22	Toxicity (% inhibition)	33.6
Chlorine demand (mg Cl2 L^−1)		6.0
Anion concentrations in solution (mg L^−1)
Fluorides	0.1	Nitrates	10.8
Chlorides	63.8	Phosphates	<0.2
Sulphates		98
Sample after treatment TiO2/radiation
Physical-chemical parameters
pH	8.0	Colour (PCU)	0
Conductivity (μS cm^−1)	589	Dissolved oxygen (mg L^−1)	6.2
Turbidity (NTU)	54	Hardness (mg CaCO3 L^−1)	109
Suspended solids (mg L^−1)	7	NH4^+ concentration (mg L^−1)	0.15
Phosphorous (mg L^−1)	0.4	CN^- concentration (mg L^−1)	0.0015
DOC (mg C L^−1)	14	Toxicity (% inhibition)	18.9
H2O2 concentration (mg L^−1)	5	Chlorine demand (mg Cl2 L^−1)	1.0
Anion concentrations in solution (mg L^−1)
Fluorides	<0.1	Nitrates	11.6
Chlorides	66.4	Phosphates	<0.2
Sulphates		101.0
Sample after treatment TiO2/H2O2/radiation
Physical-chemical parameters
pH	8.0	Colour (PCU)	0
Conductivity (μS cm^−1)	625	Dissolved oxygen (mg L^−1)	9.8
Turbidity (NTU)	56	Hardness (mg CaCO3 L^−1)	95
Suspended solids (mg L^−1)	5	NH4^+ concentration (mg L^−1)	0.15
Phosphorous (mg L^−1)	0.2	CN^- concentration (mg L^−1)	0.001
DOC (mg C L^−1)	22	Toxicity (% inhibition)	43.3
H2O2 concentration (mg L^−1)	0.5	Chlorine demand (mg Cl2 L^−1)	55.6
Anion concentrations in solution (mg L^−1)
Fluorides	<0.1	Nitrates	11.4
Chlorides	65.0	Phosphates	<0.2
Sulphates		99.2