Wyniki wyszukiwania - Biblioteka Nauki

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Chemiczne czyszczenie membran nanofiltracyjnych stosowanych do regeneracji chromowych ścieków garbarskich

100%

Kowalik-Klimczak A. , Religa P. , Gierycz P.

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tom Nr 4

261--262

PL

Podczas badań określono skuteczność czyszczenia membran NF za pomocą pojedynczych kąpieli myjących takich jak: kwas solny, wodorotlenek sodu, a także w zintegrowanym systemie dwustopniowego czyszczenia za pomocą kwasu solnego i wodorotlenku sodu. Jedynie zastosowanie dwustopniowego mycia membran NF umożliwia przywrócenie początkowych ich właściwości.

EN

The effectiveness of NF membranes’ cleaning by hydrochloric acid or sodium hydroxide baths and also in the integrated system of two-stage cleaning by hydrochloric acid and sodium hydroxide was analyzed in the paper. Only the two-stage cleaning of NF membranes enabled one to restore their initial properties.

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The permeability of the nanofiltration membranes using for chromium concentration in the model solutions

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Kaźmierczak B. , Religa P. , Gierycz P. , Wojtkowska M.

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tom no. 2

79--85

EN

In the paper, the permeability of polymer nanofiltration membranes was analysed. The studies were carried out for the model wastewater chromium (III) solutions at pH 4. The model wastewater chromium (III) solutions were included different concentrations of NaCl, Na2SO4, and CrCl3 . It was found that on the membrane permeability is influenced by their morphology and electrostatic properties, regardless of the composition of the feed. The negative charge of the DL membrane was limited by the polarization of the membrane and the osmotic effect. This had a beneficial effect on the permeability of the DL membrane. It positively influenced the permeability of the membrane. For the HL membrane, it does not have a surface charge under the process conditions, and the electrostatic effect is not observed. The formation of the polarization layer and the osmotic effect is limited only to a small extent by the Donnan effect. Thus, a significantly higher permeability drop for the separated salt of solutions was observed for the HL membrane, despite its looser structure. In the case of the CK membrane, it increased the polarization of the membrane, because, under the process conditions, the membrane was positively charged. This caused a reduction in membrane permeability, practically excluding its use as a nanofiltration membrane for concentrating chromium in salt solutions. The presence of small amounts of chromium in the solution containing a fixed concentration of chlorides and sulphates resulted in a slight increase in the permeability of the DL membrane to the solutions of the salts themselves. In the case of the HL membrane, this relationship was not observed. In the case of both membranes, an increase in chromium concentration caused a constant, slow decrease in permeability.

PL

W pracy przeanalizowano przepuszczalność polimerowych membran nanofiltracyjnych. Badania przeprowadzono dla modelowych roztworów ścieków chromowych o pH 4, zawierających różne stężenia NaCl, Na2SO4 oraz CrCl3 . Stwierdzono, że bez względu na skład nadawy, przepuszczalność membran zależy od ich morfologii oraz właściwości elektrostatycznych. Ujemny, w warunkach procesu, ładunek membrany DL ograniczał polaryzację membrany oraz efekt osmotyczny, co korzystnie wpływało na jej przepuszczalność. W przypadku membrany HL, w warunkach procesu nie posiada ona ładunku powierzchniowego, więc nie obserwuje się efektu elektrostatycznego. Powstawanie warstwy polaryzacyjnej i efektu osmotycznego tylko w nieznacznym stopniu jest niwelowane przez efekt Donnana. Zatem w przypadku membrany HL, mimo jej otwartej struktury, obserwowano znacznie wyższy spadek przepuszczalności dla separowanych roztworów soli. W przypadku dodatnio naładowanej w warunkach procesu membrany CK występowało zwiększenie polaryzacji membrany oraz obniżenie jej przepuszczalności. Praktycznie wykluczające użycie membrany CK jako membrany nanofiltracyjnej do zatężania chromu w roztworach soli. Obecność niewielkich ilości chromu w mieszaninie zawierającej ustalone stężenie chlorków i siarczanów powodowała nieznaczny wzrost przepuszczalności membrany DL w stosunku do roztworów samych soli. W przypadku membrany HL takiej zależności nie obserwowano. W przypadku obu membran wzrost stężenia chromu powodował stały, powolny spadek przepuszczalności.

3

Evaluation of contaminants removal by a nanofiltration membrane modified with polymer-ion nanoparticles

100%

Seif V. , Peyman H. , Roshanfekr H. , Azizi S. , Madiba I. G. , Sibali L. L.

Environment Protection Engineering

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2023

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tom Vol. 49, nr 2

75--102

EN

Iron nanoparticles coated with ionic choline-chloride liquid were used to improve the hydrophilicity and flow rate through the polyethersulfone (PES) membrane. Choline chloride as a modifier was used to obtain the highest water flux by increasing the hydrophilicity of the PES membrane. Changes in membrane structure and morphology were analyzed using FTIR, contact angle, porosity measurement, BET, TGA, DSC, and SEM images. Membrane clogging was measured in the presence of BSA. To evaluate the removal efficiency, Acid Orange 7 dye was used. Suitable removal conditions were obtained by Design-Expert software using a CCD model at optimum pH 6.7 and temperature of 33.9 °C by the DOE method (removal of 97.6%). Iron/choline chloride nanocomposite increased the PES membrane's hydrophilicity and fluid flow rate. Also, the membrane modified by iron/choline chloride nanocomposite removed the sample contaminant from the fluid environment under optimal conditions.

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Experimental Study of Produced Water Treatment Using Activated Carbon with Aluminum Oxide Nanoparticles, Nanofiltration and Reverse Osmosis Membranes

100%

Hussein M. Y. , Al-Naemi A. N. A. , AlJaberi F. Y.

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2023

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tom Vol. 24, nr 5

78--87

EN

This work inspected the produced water discharged from the Amara oil field in (Misan-Iraq) to improve the quality of water before reuse and reinjection or disposal. The process of treatment included a pretreatment step using activated carbon and post-treatment using flat polymeric nanofiltration membrane (NF) (1.0 nm) and reverse osmosis membrane (RO) (0.3 nm), respectively. Therefore, activated carbon without aluminum oxide (Al2O3) nanoparticles and with (Al2O3) nanoparticles (20 nm) was used to examine the removal efficiency of the total organic compound (TOC). The height of the fixed bed of activated carbon and its diameter were 35 cm and 2.5 cm, respectively. The volumetric flow rates of the produced water flowing through the activated carbon column were taken as (25, 20, 15, 10 and 5)×10-4 m3/h respectively, at transmembrane pressure (TMP) of 1.0 bar, pH equals 6, and the temperature of 25 °C. The TOC removal efficiencies attained using activated carbon without Al2O3 nanoparticles were (52, 64, 77, 83 and 87%), respectively, and (65, 72.7, 83.4, 92.5 and 95.2%) with the use of Al2O3 nanoparticles, respectively. Produced water effluent from the activated carbon column was treated by flat NF and RO membranes to reduce the total dissolved solids (TDS). The cross-flow rates through NF and RO membranes were 0.1 and 0.25 m3/h, TMP (1–12 bar) and 60 bar, respectively. The removal efficiency of TDS was enhanced up to 40% and 99.67%, respectively. In addition, the TOC removal efficiency was 100% in the effluent of the RO membrane.