K. Mielczarek

The Use of Reverse Osmosis in the Removal of PAHs from Municipal Landfill Leachate

Polycyclic aromatic hydrocarbons (PAHs) are relatively well-known organic pollutants and due to their carcinogenic and mutagenic properties their presence in the environment still attracts a lot of attention. According to literature reports and own research, PAHs presence in wastewaters is common. It was confirmed that PAHs are the components of municipal landfill leachate. Membrane techniques are one of the most interesting ways of removing PAHs from leachate. The purpose of this article is to monitor PAHs concentration changes during the membrane (reverse osmosis - RO) leachate treatment processes. In the first stage of testing leachates were filtrated on the sand bed (pre-filtration). After the pre-filtration they were directed to the membrane module for the main filtration. Sixteen PAHs listed by EPA were analyzed. The results with information on PAHs concentration in leachate samples were presented using HPLC with fluorescence detection (FLD). The changes in PAHs concentration were determined in leachate samples before and after pre-filtration as well as after RO. The decrease of PAHs concentration in the samples was observed after these processes. The total concentration of 16 PAHs in raw municipal landfill leachates amounted to 23.64–26.95 μg/L. The research confirmed the high efficiency in removal of PAHs while using a reverse osmosis (59–72%). Including the pre-filtration, the overall level of removed PAHs reached 81–86%. The average PAHs concentration after pre-filtration and RO was in the 4.46–4.99 μg/L range. The municipal landfill leachate with a high concentration of PAHs should be cleaned before it is discharged into the environment.

Comparison of the retention of selected PAHs from municipal landfill leachate by RO and UF processes

AbstractThe aim of the conducted research was to compare the changes in the retention of polycyclic aromatic hydrocarbons (PAHs) during membrane filtration (ultrafiltration—UF and reverse osmosis—RO). In the study, municipal landfill leachate was used. In the first stage of testing, leachates were filtrated on the sand bed (prefiltration). After prefiltration, they were directed to the membrane module for main filtration. The ultrafiltration process was carried out at the transmembrane pressure of 0.1–0.2 MPa. The membrane separation process was based on a capillary membrane type ZW-10. The transmembrane pressure of the reverse osmosis stood at 2 MPa and for this process one nylon membrane (ADF) was used. The prepared samples of the municipal landfill leachates were subjected to extraction with applying 2-propanol. Extracts were cleared on octadecyl C18 columns, and then concentrated in the nitrogen stream. High-performance liquid chromatography HPLC with fluorescence detection (model HPLC THERMO) was use...

Comparison of post-process coke wastewater treatment effectiveness in integrated and hybrid systems that combine coagulation, ultrafiltration, and reverse osmosis

The paper presents the results of a study whose target was to determine the effectiveness of coke wastewater, from the coking plant treatment using an integrated system combining volumetric coagulation and ultrafiltration, and a hybrid coagulation “in-line” with ultrafiltration. In both systems, the process of coagulation was carried out using sulfate(VI) iron(III). Coagulant doses varied in the range of 400 mg/dm3–100 mg/dm3. Low-pressure membrane filtration was performed on polysulfone membrane which was obtained from film-forming solution containing 16% weight content of polysulfone and 5 s. time of the solvent evaporation from the membrane surface. The wastewater, after the ultrafiltration process was cleaned thoroughly by means of the reverse osmosis method using the membrane of an American brand GE-Water type ADF. Leaning on the assumptions of the model relaxation, describing the changes in permeate flux during membrane filtration system carried out in non-stationary, an attempt to predict the size ...

Modeling performance of commercial membranes in the low-pressure filtration coking wastewater treatment based on mathematical filtration models

AbstractBased on the results achieved in the coking industry wastewater ultrafiltration treatment and the presumptions of relaxation mathematical model carried out in non-stationary system, and based on the assumptions of the model of hydraulic resistance to filtration, the changes in the volumetric permeate flux in the process of membrane filtration has been described. The research was conducted on the effectiveness of the treatment of wastewater from coke plant industry. Coking industry wastewater treatment was carried out with the use of American GE-Water ultrafiltration membranes. The process of ultrafiltration was performed at 23°C, using transmembrane pressure of around 0.4 MPa and linear wastewater flow rate of 2 m/s. For all the examined membranes, the transport characteristics corresponded to the relation between the volume flux of de-ionized water and transmembrane pressure of 0.2–0.8 MPa. The level of wastewater purification was defined for raw and cleaned wastewater indicators. None of the ult...