The research in this article aimed to present the possibilities of wastewater treatment coming from the confectionery plant in the nanofiltration (NF) process and the use of photooxidation to mitigate membrane fouling. The process was carried out initially in a dead-end flow system, where the most favorable membrane was selected. Next, the purification efficiency and blocking intensity of this membrane in the system were compared with cross flow. The next research involved the use of a photolytic oxidation process to pretreat sugar wastewater. UV radiation was emitted by a medium pressure mercury UV lamp model TQ 150 V. The effectiveness of the process was also evaluated based on the degree of pollutant load removal. The evaluation of the efficiency of a treatment process was based on the change of wastewater quality indicators before and after the membrane process. The following parameters were controlled: color, COD (chemical oxygen demand), TOC (total organic carbon), absorbance of UV254, nitrate, phosphate, ammonium, conductivity, and pH. During the course of pressure filtration, the following properties of the membrane were determined: the dependence of the volumetric flux of the permeate on the process duration, the permeability of the membrane, as well as the contact angle of the membranes. It was found that the use of UV reduced the phenomenon of fouling of nanofiltration membranes. The value of the permeate volumetric flow after the hour of running the process increased by 17%. However, no impact of UV on the efficiency of wastewater treatment was found. However, the NF process provided the required quality of treated wastewater that can be reused in industrial applications. The NF process resulted in a total decrease in absorbance, 99% TOC removal, and 98% color removal.For the wastewater treatment in a closed cycle, mainly physicochemical methods are used, such as chemical precipitation, sorption, and membrane filtration. More expensive, more modern technology of wastewater treatment, such as nanofiltration or reverse osmosis, allows more effective purification. The advantage of these methods is that, after the treatment process in the wastewater, there are no semi-finished products of pollutants decomposition and additional chemicals [4,5].The main advantages of membrane processes are low power demand, small device constructions, high flexibility in terms of installation efficiency and effectiveness, the ability to incorporate membrane modules into existing systems of wastewater treatment equipment, removing a whole pollutants range, and not only changing them into forms of occurrence, effective removal of pathogenic microorganisms, effective removal of organic fouling, and obtaining water of better quality than specified in the requirements [5]. However, as is well known, these processes are accompanied by the inherent phenomena contributing to the reduction of the membrane performance owing to the increase of filtration system resistance. They include the fouling phenomenon. There are many studies r...
Abstract:The aim of presented study which was associated with modification of the various work cycle phases duration in the membrane bioreactor, was to reduce the concentration of phosphate phosphorus during the leachate co-treatment with dairy wastewater. The experimental set-up was comprised of the membrane bioreactor equipped with the immersed membrane module installed inside the reactor chamber, and the equalization tank. During the co-treatment experiment performance the excessive activated sludge was constantly removed from the membrane bioreactor in order to keep its concentration at 3.5 g/dm 3 . The load of the sludge with the contaminants was equal to 0.06 g COD/g d.m. d. The concentration of oxygen was equal to 3 mg/dm 3 . The share of the leachates in the co-treated mixture was equal to 10% vol. The membrane bioreactor worked as the sequential biological reactor, in two cycles per day. Duration of each phase was equal as follows: filling -10 min -with concurrent mixing phase lasting for 4 h, aeration phase -1 h, sedimentation -30 min and removal from purified wastewater -30 min. After 4 weeks under these conditions, the modification of the sequential membrane bioreactor's work cycle was made. The duration of particular phases was shortened and two phases of denitrification and nitrification were introduced. Work cycle phases were modified as follows: filling -10 min -with concurrent mixing phase lasting for 3 h, aeration phase -4 h, mixing phase -1 h, aeration phase -3 h, sedimentation -30 min and removal from purified wastewater -30 min. Based on research, it was found that the change in membrane bioreactors' work cycle affects the effectiveness of treated mixture. It was found that the applied modification of phases of the cycle of the MSBR did not affect the concentration of organic compounds and the no significant changes in the concentration of ammonium and nitrate nitrogen in the effluent from the bioreactor were observed, however, the total nitrogen removal efficiency increased by 50%. Alteration of MSBR reactor particular phases duration caused reduction of concentration of P-PO4 3 from 4.7 to 2.9 mg/dm 3 .
A B S T R A C TThe investigations were focused on the determination of the most favorable amount of leachates treated along with a synthetic sewage in a membrane bioreactor. The leachates percentage share was changed over a range of 3-40 vol%. COD and BOD 5 of the leachates varied from 3,000 to 3,500 mg/dm 3 and from 170 to 280 mg/dm 3 respectively. The leachates were characterized by a high concentration of ammonia nitrogen (over 1,000 mg/dm 3 ) and low BOD 5 /COD ratio (0.06 in average), which indicated their negligible susceptibility to biodegradation.The concentration of activated sludge in the membrane bioreactor was maintained within 3.5-4.0 g/dm 3 , the sludge load with contaminants reached the level of 0.1 gCOD/g DM d while the oxygen concentration in the aeration tank was 4.0 mgO 2 /dm 3 . The system operated in a 12-h cycle. The degree of impurities removal was assessed analyzing changes in the following indicators: COD, BOD5, TOC, N-NO À 3 , N-NH þ 4 , P tot . The results revealed that the volume of leachates in the treated mixture of sewage should not exceed 10 vol%. All the tests showed a decrease in COD and BOD 5 of around 90%. The only indicator which exceeded the permissible value was nitrate nitrogen. Thus, the leachates purified by activated sludge were additionally treated by reverse osmosis.
The aim of the study was to determine the effectiveness of leachates from municipal landfill co-treatment with the dairy wastewater in an aerobic membrane bioreactor. It was working in MSBR (sequential membrane bioreactor) systems twice daily and was equipped with the immersed membrane module installed inside what enabled its back-washing performance. The system was working. The concentration of activated sludge in the membrane bioreactor was equal to 4.0 g/dm3. However, the sludge load was at the level of 0.06 g COD/(g d.m. · d). The oxygen concentration was at the level of 3.0 g O2/m3. The share of leachate was varied in a range of 5 to 15 % vol. The evaluation of the effectiveness of the treatment process was based on the change of parameters characterizing the crude sewage and treated sewage. All analysis was carried out according to standards. Following parameters were determined: COD, BOD5, TOC and concentrations of phosphate phosphorus, total nitrogen and ammonium nitrogen. Chemical analysis is often not enough to define the degree of wastewater treatment. It was used toxicological research to determine the effect on the environment. Toxicity of wastewaters was measured using biotests with Vibrio fischeri and Daphnia magna. The results revealed that the volume of leachate in the treated mixture should not exceed 10 % vol. The following conclusion can be drawn from the present research - co-treated wastewater was not toxic. Landfill co-treatment with the dairy wastewater impacts on the effectiveness of biological wastewater treatment. Leachate includes substances which have low susceptibility to biodegradation; on the other hand, dairy wastewaters provide a lot of organic compounds, which can help to treat them.
Due to the high risk of exposure to various contaminants in drinking water, pitcher filtration is rapidly growing in popularity worldwide as a cheap and easy method to remove pollutants from drinking water. On the other hand, an evaluation of the real-time performance of pitchers is not possible for usual consumers. This study presents the performance of pitcher filtration in the removal of copper, chlorine, and chloroform from tap drinking water. Pitchers were packed with Aquaphor cartridges JS500, A5, and B25. Experiments were performed with model solutions, which were prepared from hard drinking water (7.5 mval/L, pH=7) spiked with copper, hypochlorite sodium, and chloroform. It was found that pitcher filtration is a very effective method for the removal of pollutants such as heavy metals, chlorine, and disinfectants byproducts. The concentration of copper, chlorine, and chloroform in filtrates did not exceed the maximum admissible values. Cartridges JS500, A5, and B25 reduced chlorine at a comparable level – almost 100%. During the whole experimental period, removal of chloroform was slightly better for JS500 (100%) and A5 (100%) cartridges than for B25 (91.4–97.7%).
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