Treatment of winery wastewater with aerated cells mobile system

Abstract

Winery wastewater poses a serious environmental problem, especially for small wineries whose yearly wastewater production and/or financial resources may not be sufficient to warrant advanced treatment plants. We constructed an integrated mobile system comprised of a coago-flocculation module using nanocomposites to reduce TSS, and two series of aerated cells to reduce COD, N, polyphenols, and P concentrations so effluents could be discharged into a municipal wastewater treatment plant or under special conditions, recycled for irrigation. Each series consists of four portable containers (1.5m3) filled with volcanic tuff of a decreasing progressive particle-size structure and equipped with a forced-air apparatus to keep a minimum soluble oxygen level of 1.5mgL−1. The key feature of the aerated cells is constant air transfer through the substrate which greatly increases treatment capacity. The entire system was mounted on two flat lorry beds equipped with a special hook for easy transportation. We tested the system during two consecutive vintage seasons in 2013 and 2014. The nanocomposite module reduced the TSS by more than 95% while the aerated cells decreased the COD concentration to less than 700mgL−1 at the discharge point (90–95% removal efficiency), which meets the stringent requirement for release to a municipal wastewater treatment plant. TP concentrations were reduced from a mean of 42mgL−1 in the first cells to 2.2mgL−1 in the outlet of the system with an overall reduction efficiency of 95%. The maximum COD loading rate was 8.66kgm3 d−1, a remarkably high rate considering the minimal operating area. The aerated cells are susceptible to clogging, but we solved this problem with a ‘hoist-sack solution’ and/or treatment with a H2O2 solution that can be implemented easily without majorly impeding normal operation.