Nanofiltration for the treatment of coke plant ammoniacal wastewaters

Abstract

This work addresses the treatment by nanofiltration (NF) of solutions containing NaCN and NH(4)Cl at various pH values. The NF experiments are carried out in a Lab-Unit equipped with NF-270 membranes for model solutions that are surrogates of industrial ammoniacal wastewaters generated in the coke-making processes. The applied pressure is 30 bar. The main objective is the separation of the compounds NaCN and NH(4)Cl and the optimization of this separation as a function of the pH. Membrane performance is highly dependent on solution composition and characteristics, namely on the pH. In fact, the rejection coefficients for the binary model solution containing sodium cyanide are always higher than the rejections coefficients for the ammonium chloride model solution. For ternary solutions (cyanide/ammonium/water) it was observed that for pH values lower than 9 the rejection coefficients to ammonium are well above the ones observed for the cyanides, but for pH values higher than 9.5 there is a drastic decrease in the ammonium rejection coefficients with the increase of the pH. These results take into account the changes that occur in solution, namely, the solute species that are predominant, with the increase of the pH. The fluxes of the model solutions decreased with increased pH.

The Effect of pH on Atenolol/Nanofiltration Membranes Affinity

“…However, there are several factors that affect its performance, and it is important to highlight that this membrane technology, in addition to being governed by physical mechanisms, it is also influenced by electrostatic interactions that, for example, can be caused and/or altered by varying the pH of the incoming wastewater [ 24 ]. Furthermore, solute/membrane interactions can also be described by the solution-diffusion model, where a B parameter is used to quantify the affinity of a given solute for the membrane [ 25 ]. In this context, the aim of this study is to evaluate the influence of pH on the removal of the Atenolol by nanofiltration process, as well as its influence on the affinity of the solute for the membrane through the determination of the B parameter.…”

On the Purification of Agro-Industrial Wastewater by Membrane Technologies: The Case of Olive Mill Effluents

“…On the other hand, RO membranes permit complying with the most stringent regulations for public health and environment protection. Both types of membranes are already applied in the management of industrial eluents of very diferent sectors, such as stainless steel [40], energy cogeneration [41], nuclear power [42], textile and tannery [43][44][45][46][47], coking [48,49], carwash [50], pulp and paper [34,51], pharmaceutical [52], and agro-food industries, such as dairy [13], tomato [12], and olive oil [5][6][7][8][9][10]24], among others. However, again, the problem of fouling is always present in the treatment of any kind of eluent by NF and RO membranes.…”

The use of polymeric and ceramic ultrafiltration in biologically treated coke oven wastewater polishing

“…Korzenowski et al [10] applied NF process to fractionate cyanides/ammonium solutions -NF-270 membrane performance was found to be highly dependent on pH of the solution, as well as on its composition. In the ternary solutions, for pH values lower than 9, the rejection of ammonium chloride was 75% and sodium cyanide was 45%.…”