A new membrane-based method was applied to investigate the performance of three phosphorus-free antiscalants of different chemical structures to prevent calcium carbonate scale. Apart from a polyacrylate homopolymer, two copolymers were studied, one of it also being free of nitrogen. The results show that an inhibition of CaCO₃ scale on reverse osmosis (RO) membranes is possible with phosphorus-free antiscalants. The individual performance strongly depends on the chemical structure of the polycarboxylate. A specially adapted copolymer clearly outperforms the polyacrylate homopolymer in case of severe scaling conditions. The average residence time of the water in the test plant is approximately 1 h, compared to around less than a minute in a full-scale RO plant. So the operating conditions in the test plant make it more difficult for an AS to inhibit scaling compared to a full-scale RO plant. By energy-dispersive X-ray fluorescence (EDXRF), the scaling layer thickness can be estimated. The SEM images and the 3D images from CLSM showed that the water quality and the applied antiscalant have a great influence on the scaling layer morphology. The effective blocking of the membrane does not only depend on the amount of precipitated CaCO₃ but there is also a great influence of the scaling layer structure. With a normal scaling potential of the water, the scaling layer consists of calcite, and at higher LSI values of the feed water, there was also aragonite found on the membrane. From the three antiscalants AA/AMPS shows, as it was expected, the lowest performance as calcium carbonate scale inhibitor, because it is designed predominantly as a disperser and as stabilizer for calcium phosphate. PAA proved to be an efficient inhibitor for hardness at standard applications. For the application in waters with high scaling potential, AA/EA is very suitable, because this inhibitor is able to serve as a good stabilizer for hardness and at the same time as a disperser. A combination of different polymers enables special solutions for high requirements.

In this work, supported cellulose acetate (CA) mixed matrix membranes (MMMs) were prepared and studied concerning their gas separation behaviors. The dispersion of carbon nanotube fillers were studied as a factor of polymer and filler concentrations using the mixing methods of the rotor–stator system (RS) and the three-roll-mill system (TRM). Compared to the dispersion quality achieved by RS, samples prepared using the TRM seem to have slightly bigger, but fewer and more homogenously distributed, agglomerates. The green γ-butyrolactone (GBL) was chosen as a polyimide (PI) polymer-solvent, whereas diacetone alcohol (DAA) was used for preparing the CA solutions. The coating of the thin CA separation layer was applied using a spin coater. For coating on the PP carriers, a short parameter study was conducted regarding the plasma treatment to affect the wettability, the coating speed, and the volume of dispersion that was applied to the carrier. As predicted by the parameter study, the amount of dispersion that remained on the carriers decreased with an increasing rotational speed during the spin coating process. The dry separation layer thickness was varied between about 1.4 and 4.7 μm. Electrically conductive additives in a non-conductive matrix showed a steeply increasing electrical conductivity after passing the so-called percolation threshold. This was used to evaluate the agglomeration behavior in suspension and in the applied layer. Gas permeation tests were performed using a constant volume apparatus at feed pressures of 5, 10, and 15 bar. The highest calculated CO₂/N₂ selectivity (ideal), 21, was achieved for the CA membrane and corresponded to a CO₂ permeability of 49.6 Barrer.

Water shortage and a rising water demand are prevalent issues on the political agenda worldwide. Available water resources must not only be provided to ensure a domestic and drinking water supply for a steadily increasing population but also for the growing industrial and agricultural sectors. This work outlines how the use of the innovative vacuum multi‐effect membrane distillation contributes to improve the water management efficiency in the following key industry sectors: desalination, drinking water and beverage industry, pharmaceutical, agro and chemical as well as oil and gas industry.

Pelleted biomass has a low, uniform moisture content and can be handled and stored cheaply and safely. Pellets can be made of industrial waste, food waste, agricultural residues, energy crops, and virgin lumber. Despite their many desirable attributes, they cannot compete with fossil fuel sources because the process of densifying the biomass and the price of the raw materials make pellet production costly. Leaves collected from street sweeping are generally discarded in landfills, but they can potentially be valorized as a biofuel if they are pelleted. However, the lignin content in leaves is not high enough to ensure the physical stability of the pellets, so they break easily during storage and transportation. In this study, the use of eucalyptus kraft lignin as an additive in tree-leaf pellet production was studied. Results showed that when 2% lignin is added the abrasion resistance can be increased to an acceptable value. Pellets with added lignin fulfilled all requirements of European standards for certification except for ash content. However, as the raw material has no cost, this method can add value or contribute to financing continued sweeping and is an example of a circular economy scenario.