This paper describes the investigations on the possibilities of treatment of wastewater generated in an industrial laundry with application of a combined biological-photooxidation- membrane system aimed at water recycle and reuse. The two treatment schemes were compared: 1) scheme A consisting of a treatment in a moving bed biological reactor (MBBR) followed by microfiltration (MF) and nanofiltration (NF), and 2) scheme B comprising MBBR followed by oxidation by photolysis enhanced with in situ generated O₃ (UV/O₃) after which MF and NF were applied. The removal efficiency in MBBR reached 95–97% for the biochemical oxygen demand; 90–93% for the chemical oxygen demand and 89–99% for an anionic and a nonionic surfactants. The application of UV/O₃ system allowed to decrease the content of the total organic carbon by 68% after 36 h of operation with a mineralization rate of 0.36 mg/L·h. Due to UV/O₃ pretreatment, a significant mitigation of membrane fouling in the case of both MF and NF processes was achieved. The MF permeate flux in the system B was over two times higher compared to that in the system A. Based on the obtained results it was concluded that the laundry wastewater pretreated in the MBBR-UV/O₃-MF-NF system could be recycled to any stage of the laundry process.

Large laboratory scale biological treatment test of industrial real wastewater, generated in industrial big laundry, has been conducted in the period of May 2016–August 2016. The research aimed at selection of laundry wastewater treatment technology included tests of two-stage Moving Bed Bio Reactor (MBBR), with two reactors filled with carriers Kaldnes K5 (specific area – 800 m2/m3), have been realized in aerobic condition. Operating on site, in the laundry, reactors have been fed real wastewater from laundry retention tank. To the laundry wastewater, contained mainly surfactants and impurities originating from washed fabrics, a solution of urea to supplement nitrogen content and a solution of acid to correct pH have been added. Daily flow of raw wastewater Qd was equal to 0.6–0.8 m3/d. The values of determined wastewater quality indicators showed that substantial decrease of pollutants content have been reached: BOD5 by 94.7–98.1%, COD by 86.9–93.5%, the sum of anionic and nonionic surfactants by 98.7–99.8%. The quality of the purified wastewater, after star-up period, meets the legal requirements regarding the standards for wastewater discharged to the environment.

Laboratory tests were conducted simulating the process of polluting stormwater with fuels and afterwards treating this sewage in the separator of oil derivative substances. The diesel oil - ON and the pure biofuel - BIO 100, available on the market, were the subject of the tests. Depending on the kind of fuel, the differences in the concentration of oil derivative substances in the “treated” sewage were in the range of several hundred percent. Such big differences show the necessity for examination whether the assumptions accepted while designing separators will also be correct in the case of treating stormwater polluted with contemporary fuels available on the market, includuing biofuels