Combined chemical treatment of pharmaceutical effluents from medical ointment production.
Three wastewater samples from a pharmaceutical plant formulating medical ointments were subjected to lab-scale treatment by a Fenton-like system in combination with lime coagulation. All samples were plant pre-treated by adsorption/flocculation/filtration processes with utilization of bentonite, but the quality of effluents did not comply with the regulations for wastewater discharged to local sewerage. The optimization of Fenton-like oxidation demonstrated the highest process efficacy at H(2)O(2)/COD weight ratio of 2:1, H(2)O(2)/Fe(2+) molar ratio of 10:1 and 2h of treatment time. The fast pH decrease to acidic values approximately 3 during first min of oxidation for all effluents suggested that pH adjustment was unnecessary. Combination of Fe(III) precipitation and lime coagulation proved feasible to improve considerably COD and residual iron concentration reduction in pharmaceutical effluents. Additionally, considerable BOD(7) reduction and BOD(7)/COD ratio improvement of pharmaceutical wastewater samples was achieved by combined treatment. The application of Fenton-like oxidation with subsequent iron (III)/lime coagulation did not only enhance the quality of pharmaceutical effluents with different chemical characteristics and help to meet the requirements for wastewater discharged to sewage, but also improve the biodegradability of pharmaceutical effluents.
Kulik
Niina
N
Department of Chemical Engineering, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, Estonia. niina.kulik@ttu.ee
Trapido
Marina
M
Goi
Anna
A
Veressinina
Yelena
Y
Munter
Rein
R
D000327:Adsorption; D001546:Bentonite / Q000737:chemistry; D017610:Calcium Compounds / Q000737:chemistry; D005374:Filtration; D005427:Flocculation; D006861:Hydrogen Peroxide / Q000737:chemistry; D007220:Industrial Waste; D007501:Iron / Q000737:chemistry; D009824:Ointments; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*
D017610:Calcium Compounds; D007220:Industrial Waste; D009824:Ointments; D010087:Oxides; D004364:Pharmaceutical Preparations; D012722:Sewage; D001546:Bentonite; D006861:Hydrogen Peroxide; C016538:lime; D007501:Iron