An ultrasound/O3 and UV/O3 process for atrazine manufacturing wastewater treatment: a multiple scale experimental study

Abstract

An ultraviolet (UV) and ultrasound (US) enhanced ozonation method were developed to investigate their efficiency on the removal of atrazine and chemical oxygen demand (COD) in the authentic atrazine manufacturing wastewater. The bench-scale tests suggested a positive effect of UV and US on the degradation of atrazine within a limited energy range. The pilot-scale flow-through system was further tested by using response surface methodology. The results showed that O3 and its interaction with UV promoted the degradation of both COD and atrazine while its interaction with US inhibited the removal of COD but promoted the removal of atrazine. The optimal removal rate of atrazine (96.9%) was achieved in the condition of 6.86 W/L UV, 1.96 g/L·h O3 and 294 W/L US. Chloride ions hindered the atrazine degradation, but the generated free chlorine radicals were still able to react with atrazine. In terms of energy-effectiveness, the configuration of 14.7 W/L UV and 1.96 g/L·h O3 is the best option, which have the electrical energy per order of 181.6 kWh/m3 for atrazine and 0.13 kWh/g COD. These method and findings could be helpful in the development of energy-efficient advanced oxidation processes in treating wastewater with high salinity and COD loadings.

Degradation of Residual Herbicide Atrazine in Agri-Food and Washing Water

“…In addition, for abiotic water treatment processes, as shown in Section 2 and Section 3 of this article, many advanced oxidation processes (AOPs) have been involved in the degradation of atrazine in water. These AOPs can be used individually or in combination to improve efficiency such as US/UV [ 71 , 157 ], US/UV/O 3 [ 114 , 158 ], electrochemistry (EC)/O 3 [ 111 ], UV/H 2 O 2 [ 159 ], UV/US/PS [ 160 ], UV/MW [ 161 , 162 ], UV/Fenton [ 83 ], etc. Generally, AOPs rely on the in situ formation of reactive species [ 78 ], such as hydroxyl radical ( • OH) [ 163 ], sulfate radical (SO 4 •− ) [ 164 , 165 ], singlet oxygen ( 1 O 2 ) [ 132 ], superoxide radical anions (O 2 •− ) [ 37 ], hydrated electron (e aq − ) [ 78 ] and hydrogen radical (H • ) [ 78 ].…”