Purification

Industrial whey dewatering via membrane processes remains challenging due to the rapid increase in viscosity, strong fouling tendencies from proteins and minerals, and the steep rise in osmotic pressure during concentration. These effects restrict operating windows and complicate energy-efficient process control. This study addresses the application of forward osmosis (FO) technology for industrial-scale dewatering of sweet whey using an Aquaporin Inside^® HFFO14 module. Various feed- and draw-side cross flow velocities (0.0397 to 0.0524 m s⁻¹ and 0.0127 to 0.0190 m s⁻¹, respectively) and draw solution (DS) osmotic pressures of 20 bar and 60 bar were investigated using a production-scale prototype plant. Sweet whey had an initial osmotic pressure of 7 bar and an electrical conductivity of 5.7 mS cm⁻¹. DS pressures of 20 bar and 60 bar resulted in a total recovery of 50% and over 80%, respectively. Water flux rates initially ranged from 10.1 to 11.6 L m⁻² h⁻¹ (LMH) and ceased at 3.3 LMH. Specific energy demand ranged from 0.15 to 1.1 kWh m⁻³. These findings support the feasibility of industrial-scale FO technology and underscore the potential of FO as an energy-efficient, sustainable solution for the dairy industry. However, frequent rinsing and cleaning routines are crucial to maintain membrane performance.

Despite significant progress in renewable energy development, nitrogen oxides (NO_x) remain a persistent air pollutant [...]

Although various special materials have been studied for their potential for phosphorus removal in constructed wetlands, varying methodologies make direct comparisons of adsorption capacities observed in laboratory experiments difficult. This paper aims to establish a methodology for determining the optimal ratio of phosphate to material mass for different materials and for achieving the necessary contact time for adsorption isotherms. To minimise the number of experiments required, pretests over 24 h should be repeated to determine the phosphate-specific ratios until they show around 60% of the initial concentration. The tested materials included lava sand and expanded sand (ExS), which showed saturating kinetics curves after 24 to 48 h. However, aggregates containing calcium silicate hydrate (CSH) phases (autoclaved aerated concrete AAC, sand–lime brick SLB, and hydrothermal granules HTG) did not show saturating curves, complicating contact time determination. Consequently, adsorption velocity is proposed to identify the phase with the lowest adsorption rate, which is then used as the contact time in adsorption isotherm experiments. Using this method, adsorption times of 48 h were observed for HTG and SLB, while that for AAC was 24 h. This methodology is intended as an initial approach to establish a common basis for researchers investigating novel materials and make the results comparable.