Pretreatment Of Pharmaceutical Wastewater Research Articles

Treatment of pharmaceutical wastewater by a sequential KMnO4/CoFe2O4-mediated catalytic ozonation process

Pharmaceutical compounds, which are of utmost concern, have found their way into natural water bodies, causing numerous problems for both human health and ecosystems. In this study, an integrated system including potassium permanganate (PM) pre-oxidation, followed by a heterogeneous catalytic ozonation process (HCOP) using CoFe2O4 magnetic nanoparticles (CF MNPs), and an activated sludge-based biological treatment (BT) was employed for the first time to treat pharmaceutical wastewater (PWW). In this regard, the effluent from PM pre-oxidation process was used as a batch for the HCOP, and the effluent was used as a batch for the BT process. The results showed that PM pre-treatment of PWW (PM dose = 1264 mg/L and pH = 8.0) reduced the COD content of the PWW from 900 ± 50 to 443 ± 10 mg/L within 120 min of reaction time. The application of HCOP for further treatment of PWW dramatically enhanced COD and TOC removal compared with the single ozonation process (SOP). Under optimum conditions (pH = 10, O3 = 4.0 mg/L, and CF MNPs = 1000 mg/L), HCOP successfully reduced the COD and TOC contents of PWW by 37 % and 46.1 %, respectively, after 120 min of treatment. The consecutive combination of PM pre-treatment followed by HCOP exhibited good potential and reduced COD by over 69 %, resulting in a residual COD of less than 280 mg/L. A biodegradability ratio of over 81 % and residual COD of 54 mg/L for the PWW treated by the PM/HCOP/BT integrated system indicated that biodegradability was enhanced, and a high fraction of refractory organic compounds was effectively removed. In conclusion, the PM/HCOP/BT integrated system is an efficient, synergistic, and easy-to-operate technique for enhancing the biodegradability of PWW.

Treatment of real pharmaceutical wastewater using combined approach of Fenton applications and aerobic biological treatment

The pharmaceutical wastewater of different organic loads i.e. high (HSW) and low strength wastewater (LSW) were collected from the bulk pharmaceutical industry and subjected to different applications of Fenton’s treatment followed by subsequent biological treatment. For both the HSW and LSW, applications of Fenton such as, dark-Fenton (DF), solar driven photo-Fenton (PF) and electro-Fenton (EF) were utilized as pre-treatment technologies to improve the biodegradability and reduce the organic load of wastewater by combine oxidation and coagulation. The operational parameters like pH, hydrogen peroxide dosage and iron concentration were optimized in case of DF and PF processes, whereas in case of EF process, applied voltage and hydrogen peroxide dosage were optimized to make water biocompatible for subsequent biological degradation. The use of Fenton applications as a pre-treatment resulted in a significant enhancement in the BOD5/COD ratio validating the production of easily degradable metabolites or secondary products. Overall results indicated that among the utilized Fenton technologies, pre-treatment of pharmaceutical wastewater with PF lead to better COD and TOC removal efficiency with subsequent biological degradation when compared to DF and EF pre-treatment. Overall COD removal efficiency of the combined PF and biological treatment was around 84% for LSW and 82% for HSW. Conclusively, it can be established that combined Fenton applications as pretreatment technology and biological treatment is more effective approach in comparison to single stage oxidation either by Fenton or biological treatment. Cytotoxicity assessment revealed that complete detoxification of wastewaters were achieved indicating that hybrid treatment technology of Fenton’s and biological treatment did not exhibited any toxicity against the selected microbes.

English

A series of sodium bentonite and thiamine were used as raw materials to prepare a new adsorbent – thiamine-modified bentonite. The adsorbent was applied in the pretreatment of pharmaceutical wastewater. The optimum preparation conditions of thiamine-modified bentonite were studied. The experiments showed that the removals of COD (chemical oxygen demand) reached 47.98 % under optimal condition. The FTIR results indicated that bentonite has been modified by thiamine. The X-ray diffraction result showed that the inter planar distance of modified bentonite was increased by intercalating thiamine. From the analyses of the SEM photographs, it can be clearly observed that the bentonite, after thiamine insertion reaction, loses its foliated structure and exhibits a rougher surface. Among several isotherm equations, Langmuir and Freundlich adsorption isotherms were investigated. They were widely used to describe equilibrium data for water and wastewater treatment applications. Adsorption isotherms correlate well with the Langmuir isotherm model. Detailed isothermal and kinetic studies show that the modified bentonite removes organic pollutants from pharmaceutical wastewa ter by physical adsorption processes.

Pretreatment of Pharmaceutical Wastewater by Microelectrolysis of Iron and Fenton Reagent

The characteristics of raw pharmaceutical wastewater was as follows: CODCr30000~32000 mg/L, BOD54050~4360 mg/L, B/C: 0.12~0.14, Fe-C micro-electrolysis with Fenton reagent was adopted to pretreat this wastewater. Through static experiments analysis, optimal parameters of iron-carbon microelectrolysis Fenton pretreatment process are listed as follows: raw water pH, iron-carbon mass ratio (i.e. 2:3), the mass of iron-carbon (i.e. 500 g/L) and reaction time (i.e. 2 h). The optimal operation conditions (i.e. H2O2dosage is12 mg/L, pH is 3.5, reaction time is 80 min) of Fenton reagent oxidation were confirmed.

RO/NF membrane treatment of veterinary pharmaceutical wastewater: comparison of results obtained on a laboratory and a pilot scale

Emerging contaminants (ECs) are commonly derived from industrial wastewater, which is often a consequence of an inadequate treatment of the latter. Improperly pretreated pharmaceutical wastewater could cause difficulties in operations of wastewater treatment plants while incomplete elimination of ECs during the processing might result in their appearance in drinking water. This paper deals with membrane treatment of pharmaceutical wastewater on a laboratory and a pilot scale as well as with the removal of the following veterinary pharmaceuticals (VPs) (sulfamethoxazole, trimethoprim, ciprofloxacin, dexamethasone, and febantel). The pretreatment of pharmaceutical wastewater by means of coagulation and microfiltration (MF) prevented the irreversible fouling of the fine porous structure of the reverse osmosis (RO) and nanofiltration (NF) membranes which were used in the final stage of wastewater processing. The percentage of the removal of the selected VPs ranges from 94% to almost 100% in the case of NF and RO membranes in both scales. The recovery percentage concerning the pilot scale amounted to 88%. Membrane cleaning was successfully carried out in both scales. The differences in retention between laboratory and pilot tests are due to different raw wastewater quality and different recovery and hydrodynamic of the two systems. Fouling and concentration polarization were more pronounced in laboratory setup (frame-plate module) than in pilot unit (spiral module). The proposed integrated membrane treatment (coagulation, MF, NF, and RO) can be employed for treatment of wastewater originating from pharmaceutical factory. The obtained permeate can be safely discharged to sewer system or could be reused in manufacturing process.