Strategies to improve membrane performance in wastewater treatment

The wastewater generated as a result of car washes is considered a new source of water. However, recovered water must meet the required quality criteria for reuse. For this purpose, the ultrafiltration (UF) process can be successfully used. The main aim of the present work was to investigate the influence of the membrane’s molecular weight cut-off (MWCO) on the UF performance in terms of the fouling phenomenon and retention degree of car wash wastewater. Moreover, for a better understanding of the fouling mechanisms, Hermia’s model was used. The experimental studies were conducted with the use of two polyethersulfone (PES) membranes (MWCO of 10 kDa and 100 kDa). It has been noted that the used membranes provided a high-quality permeate and excellent turbidity removal, up to 99%. Moreover, it has been noted that the MWCO membrane has a significant impact on the fouling mechanism. Generally, a much greater intensity of fouling for the membrane with MWCO of 100 kDa was observed. Results obtained in the present study showed that both real wastewaters and the clean solutions used for washing cars cause the fouling phenomenon. It has been proven that rinsing the membranes with water is not sufficient to recover the initial membrane’s performance. Hence, periodic chemical cleaning of the membranes was required. Fitting the experimental data to Hermia’s model allowed us to indicate that membranes with MWCO of 100 kDa are more prone to intermediate blocking. To sum up, the findings suggest that for the UF of the car wash wastewater, the use of membranes with MWCO equal to 10 kDa is recommended.

Section: Introductionmentioning

confidence: 99%

The Application of Polyethersulfone Ultrafiltration Membranes for Separation of Car Wash Wastewaters: Experiments and Modelling

Tomczak

Gryta

2023

“…This is why the use of membranes is recommended in the Best Available Technologies (BAT) manual for wastewater treatment [ 3 ]. The development of membrane techniques and, consequently, the increasing use of membranes is due to the development of new membrane materials that are adapted to specific processes requirements [ 4 ]. The fact that membrane techniques remain not only within the sphere of application of researchers is confirmed by an increasing, but still low, number of literature reports indicating research also using real industrial wastes on a pilot scale.…”

Section: Introductionmentioning

confidence: 99%

Recovery of Metals from Wastewater—State-of-the-Art Solutions with the Support of Membrane Technology

Staszak

Wieszczycka

2023

This paper discusses the most important research trends in the recovery of metals from industrial wastewater using membrane techniques in recent years. Particular attention is paid to the preparation of new membranes with the required filtration and separation properties. At the same time, possible future applications are highlighted. The aspects discussed are divided into metals in order to clearly and comprehensibly list the most optimal solutions depending on the composition of the wastewater and the possibility of recovering valuable components (metalloids, heavy metals, and platinum group metals). It is shown that it is possible to effectively remove metals from industrial wastewater by appropriate membrane preparation (up to ~100%), including the incorporation of functional groups, nanoparticles on the membrane surface. However, it is also worth noting the development of hybrid techniques, in which membrane techniques are one of the elements of an effective purification procedure.

“…The use of reverse osmosis membrane technology for the purification of natural and waste water has been carried out over the past 40 years [ 1 , 2 , 3 , 4 , 5 , 6 ]. In recent years, interest has increased in nanofiltration as a method for preparing drinking water from surface water sources [ 1 , 2 ], due to the high efficiency of retention by these membranes of organic substances that form water color [ 7 , 8 , 9 , 10 ].…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, the high color and high water oxidation that is attributed to halogenocarbons and other volatile organics can be successfully solved using nanofiltration membranes [ 1 , 2 , 3 , 4 ]. Application of nanofiltration membranes does not require the use of sorption materials that require high operational costs [ 5 ]. This is confirmed by long successful experience of a number of large-scale nanofiltration facilities [ 1 , 2 ].…”

Section: Introductionmentioning

confidence: 99%

Production of Drinking Water with Membranes with Simultaneous Utilization of Concentrate and Reject Effluent after Sludge Dewatering

Первов

Spitsov

2023

A new technology is described that enables us to completely exclude liquid discharges during production of drinking water from surface sources. The proposed described technological scheme separates the natural water into a stream of purified drinking water and dewatered sludge. The sludge moisture has a value of 80 percent. The experimental program is described to treat the natural water with nanofiltration membranes and to produce a drinking-quality water with recovery value of 0.99 and higher. Concentrate of membrane plant is mixed with the wet sludge and the reject effluent after sludge dewatering is again treated by reverse osmosis membranes and returned back to the sludge thickening tank. Results of experiments to treat reject water after sludge dewatering are presented. The use of nanofiltration membranes provides reduction in the Total Dissolved Solids content (TDS), aluminum, color and oxidation to meet drinking water standards. Experimental plots are presented that can be used to select membrane characteristics and to predict product water chemical composition at each stage of the membrane treatment scheme. Concentrate of membrane treatment plant is mixed with the wet sludge in the thickening tank. The sludge, after the thickening tank, is dewatered using either filter-press or centrifugal equipment. The reject (or fugate), after sludge dewatering, is treated by membrane facility to separate it into deionized water stream and concentrate stream. The deionized water can be mixed with the feed water or drinking water and the concentrate stream is returned back to the thickening tank. Thus, the salt balance is maintained in the thickening tank, whereby all dissolved salts and impurities that are rejected by membranes are collected in the thickening tank, and then are withdrawn together with the dewatered sludge. Based on the results of experimental data processing, balance diagrams of the sludge dehydration process with waste water purification at the membrane plant and with the addition of the membrane plant concentrate to the sludge thickener are presented, according to which all contaminants removed by the membranes are removed together with the sludge.