Dataset - Treatment of industrial textile wastewater by means of forward osmosis aiming to recover dyes and clean water

Summary

Dataset related to the publication "Treatment of industrial textile wastewater by means of forward osmosis aiming to recover dyes and clean water" published in Heliyon, https://doi.org/10.1016/j.heliyon.2024.e40742

Materials and Methods

Membrane plant

A forward osmosis plant was employed. It was equipped with 50 liters tank to contain the feed solution. Mass data were obtained with a Kern FKB 36K0.1 balance (Kern & Sohn, Germany) connected to a laptop for an automatic data recording. The HFFO2 hollow-fiber membrane (Aquaporin Inside®) was employed. the membrane plant was always operated with the membrane active layer facing the feed stream. After wetting the membrane module (lumen and shell sides) with deionized water for 30 minutes (in single-pass mode), the Jw and the Js of the pristine membrane was tested, employing deionized water as feed and 0.5 M NaCl as draw solution. The process was performed in single-pass mode, during 5 minutes. To that end, the flow rate was set at 60 L·h-1 and 25 L·h-1 (as recommended by the manufacturer) for the feed and draw streams, respectively. A transmembrane pressure of 0.2 bar (feed to draw) was applied. These conditions were also used to test Jw and Js after the treatment of the wastewater and after the membrane cleaning. When textile wastewaters were treated, 50 L of each effluent was employed. A solution of NaCl was used as the draw solution for the FO process.

Dyeing test

In order to study the possible adsorption of the dyes on the membrane surface, several flat sheet FO membranes prepared with the same active layer as the hollow-fiber HFFO2 membrane were dyed with the concentrated stream obtained during each FO experiment. To that end, the obtained concentrated stream was filtered employing a 40 μm cartridge filter (Merck, Germany). After the filtration, the flat sheet membranes were placed in petri dishes and they were covered with the concentrated streams obtained after treating the effluents from the cotton dyeing, diluted cotton dyeing, wool dying, end-of-pipe mixture 1, and end-of-pipe mixture 2. Contact times of 1 min, 5 min, 15 min, 30 min, 1 h, 5 h and 24 h were evaluated. After this time, the membranes were rinsed with distilled water and dried at room temperature to be compared.

Cleaning in place

To clean the membrane, an osmotic backwash was applied, employing a 0.7 M NaCl solution as feed, whereas reverse osmosis water was used as draw solution. The membrane was considered to be clean when 90% of the initial water flux was recovered.