Photo -Chemical Degradation of 2, 4- Dichlorophenoxyacetic acid (2, 4-D) in the Effluent

Background: 2, 4-dichlorophenoxy acetic acid (2, 4-d) is well known as inexpensive herbicides but it can give rise to undesirable pollution. the objective of this investigation was to describe a photo-chemical system for degradation of 2, 4-d.methods: a designed photolytic cell system was used in this study with a 150w or 400w uv lamp. a set of experiments was carried out at ph 1.5, 2.5, 3.5 and 4.5 to investigate the effect of ph on the degradation rate of 2, 4-d. the samples were collected and analyzed by uv spectrophotometer, and hplc.results: with a 150 wuv- source, the percentage degradation of 2, 4 -d after one hour was 3% while 60% of destruction was achieved using a 400w. the percentage degradation of 2, 4-d was 19% and 99.9% after 8 hours with a 150 w or 400 w uv lamp, respectively. the complete degradation of 2, 4-d was achievable with addition of hydrogen peroxide after 120 and 15 min using 150 w and 400 w uv lamp, respectively. conclusion: this investigation finding shows that 2, 4-d is degradable in acidic ph of 2.5 or 3.5. in addition, 2, 4-d degradation can be achieved in wastewater by uv light and depends on intensity of lamp or present of h2o2 oxidant.