Low-Temperature Direct Contact Membrane Distillation for the Treatment of Aqueous Solutions Containing Urea

Abstract

Research activities on the application of direct contact membrane distillation (DCMD) for processing at low temperature (up to 50 °C) solutions containing urea were presented and discussed. Feeds were urine (also in mixture) and human plasma ultrafiltrate. Moreover, as a case study, the performance of membrane modules of different sizes and features was investigated for reaching the productivities needed in the treatment of the human plasma ultrafiltrate. In particular, two modules were equipped with the same type of capillaries, but differed in terms of membrane area, while the third module contained a different type of membranes and presented a membrane area in between those of the two previous modules. The three modules were compared, at a parity of operating temperatures and streams velocity, in terms of transmembrane flux, permeate production and size, underlining the directions to follow for a real implementation of the technique.

Modification of PET Ion-Track Membranes by Silica Nanoparticles for Direct Contact Membrane Distillation of Salt Solutions

“…Despite some limitations, the most studied type is DCMD due to its simplicity and availability [3,[9][10][11][12][13][14]. DCMD can be successfully used to purify water from salts [15][16][17][18][19], heavy metals [20][21][22], dyes [23,24], radioactive wastes [25][26][27][28], acid solutions [29], urea [30], mining, and industrial wastewater [31,32].…”

The Role of Electrospun Nanomaterials in the Future of Energy and Environment

“…Membrane distillation has been considered as a promising alternative technology in desalination of seawater, treatment of concentrated hypersaline brines [ 211 ], wastewater treatments, separation of nonvolatile compounds from fluids and concentration of solutions such as urea recovery from urea synthesis plants [ 212 , 213 ]. Membrane distillation is a cost-effective procedure compared to other pressure-driven membrane technologies in view of working at low pressures and low temperature ranges that can be harnessed from solar energy, geothermal resources, or industrial waste heat.…”

“…The vapor phase condenses in the cold distillate side or on the surface of a cold plate (air-gap membrane distillation) (Figure 20). Membrane distillation has been considered as a promising alternative technology in desalination of seawater, treatment of concentrated hypersaline brines [211], wastewater treatments, separation of nonvolatile compounds from fluids and concentration of Membrane distillation has been considered as a promising alternative technology in desalination of seawater, treatment of concentrated hypersaline brines [211], wastewater treatments, separation of nonvolatile compounds from fluids and concentration of solutions such as urea recovery from urea synthesis plants [212,213]. Membrane distillation is a cost-effective procedure compared to other pressure-driven membrane technologies in view of working at low pressures and low temperature ranges that can be harnessed from solar energy, geothermal resources, or industrial waste heat.…”

Long-Term Treatment of Highly Saline Brine in a Direct Contact Membrane Distillation (DCMD) Pilot Unit Using Polyethylene Membranes

“…Membrane Distillation (MD) technologies, either used alone or in combination with other innovative separation processes, are better alternative options that are designed for complete salt removal. This is because: (i) membrane distillation desalinates thermal brine and generates a permeate that is suitable for immediate reuse [4], and (ii) RO technologies may mostly be used in cases where the salinity of brine is minimized to levels close to that of seawater [5].…”