In this work, the TG/DTA behavior of decabromodiphenyl ether (BDE-209) at nitrogen and air atmosphere by using a thermogravimetric analyzer was investigated. The results showed that both of TG and DTG curves at nitrogen atmosphere are very similarly with that at air atmosphere. About 75 wt% and 25 wt% of total mass loss were observed at the temperature range of about 300-430 °C and about 430-580°C, respectively. It is indicated that the mass loss of BDE-209 during the thermal treamtnet is mainly caused by the evaporation and thermal decomposition.

Currently, environmental contamination by polybrominated diphenyl ethers (PBDEs) in the world is of important concern and requires the effective remediation technologies. The degradation of decabromodiphenyl ether (BDE-209) in the supercritical n-hexane by zerovalent iron was studied in this work. The results showed that BDE-209 can be rapidly reduced into nona-, octa-, hepta-and lower brominated polybrominated diphenyl ethers (PBDEs) under the supercritical reaction conditions. Among n-hexane, methanol, tetrahydrofuran and mixed n-hexane+ tetrahydrofuran solvents, the conversion of BDE-209 in tetrahydrofuran was the highest. BDE-209 conversion increased with increased reaction temperature and pressure. Under the reaction condition: temperature: 523K; pressure: 3.2Mpa; reaction time: 10min; reaction system: 200ml 50mg BDE-209/L n-hexane; atmosphere: N2and catalyst load: 2g/L, the conversion of BDE-209 was as high as 88.9%.

The effectiveness of combined coagulation and Fenton oxidation to pharmaceutical plant wastewater was investigated under different operational conditions such as pH, dosage, coagulants and ratio of Fe2+to H2O2. Among the nonionic polyacrylamide, cationic polyacrylamide, anionic polyacrylamide, polyaluminum chloride and polymeric ferric sulfate, anionic polyacrylamide showed the best efficiency of coagulation for the pharmaceutical plant wastewater. The results also showed that after the combined coagulation and Fenton oxidation treatment, the COD and color were reduced by 69.9% and 78.9%, respectively. The BOD5/ COD ratio increased from 0.09 in initial to 0.22 after treatment. The wastewater of outlet was easier for the sequent biological process.