Enriched Co-Treatment of Pharmaceutical and Acidic Metal-Containing Wastewater with Nano Zero-Valent Iron

Abstract

Among traditional hazardous waste sources, pharmaceutical-containing wastewater and acidic mine drainage need treatment to preserve the expected water supply quality. A nano zero-valent iron (nZVI)-enriched treatment of these two streams is evaluated for simultaneous removal of various heavy metal ions, organic pollutants, sulfates, the efficiency of the treatment system, and separation of reaction products in the fluidized-bed reactor. The reactor packed with silica sand was inoculated with sludge from an anaerobic digester, then 1–3 g/L of nZVI slurry added to cotreat a hospital feed and acid mine wastewater at 5:2 v/v. The biotreatment process is monitored through an oxidation–reduction potential (Eh) for 90 days. The removal pathway for the nZVI used co-precipitation, sorption, and reduction. The removal load for Zn and Mn was approximately 198 mg Zn/g Fe and 207 mg Mn/g Fe, correspondingly; achieving sulfate (removal efficiency of 94% and organic matter i.e., chemical oxygen demand (COD), biological oxygen demand (BOD), dissolved organic carbon (DOC), total dissolved nitrogen (TDN) reduced significantly, but ibuprofen and naproxen achieved 31% and 27% removal, respectively. This enriched cotreatment system exhibited a high reducing condition in the reactor, as confirmed by Eh; hence, the nZVI was dosed only a few times in biotreatment duration, demonstrating a cost-effective system.

Sulfidogenic fluidized-bed bioreactor kinetics for co-treatment of hospital wastewater and acid mine drainage

“…After that, the cell was left for five minutes to finish the reaction. After the time-lapse, the DR3900 was reset by inserting a blank sample cell into the cell holder, and then the prepared sample was introduced into the cell holder to read the results [19] .…”

Efficient Catalytic Degradation of Azo Dyes from Textile Wastewater by Nano and Micro Amorphous Alloys

“…Zero-valent metals [40][41][42][43] have been used in the degradation of dye contaminants for water purification. Among them, zerovalent iron (ZVI) or crystalline elemental iron which can be in the form of microsized or nanosized powders, exhibits superior features at highly efficient dye removal due to their effective reducing agent properties, low-cost production, and simple operation techniques.…”