Removal of nickel ions from synthetic wastewater by bulk liquid membrane

Heavy metals extraction and separation from industrial wastewater has becomes a majorconcern for both environmental and economic reasons. This paper describes a comparetive kinetic study ofthe removal and recovery of nickel ions from aqueous solutions by bulk liquid membrane (BLM) usingcoupled faciletated transport mechenisms and two carriers of diffarent chemical nature: tributyl phosphate(TBP) and di-2-ethylhexyl phosphoric acid (D2EHPA). Xylene oil was used as the liquid membrane phase.In addition, environmentall friendly materials such as vegetable oils (soybean oil) used as a suitablereplacement for the conventional organic solvents in this work. A comprahensive kinetic study was carriedout and effact of various parameters such as, pH of feed and stripping phase, initial concentration of metalions, concentration of extractant in the membrane phase and stirring speed were studied. The chelatingcharacteristics of EDTA was used as stripping agent as well as precipitating agent to enhance the transportefficiency of the nickel ions. The extraction and recovery efficiency were found as 80.89% and 87.80%respectively for nickel ions, At the optimum process conditions for transport of Ni(II) were found as follows:pH in the feed phase (4), pH in the stripping phase (8), initial concentration of nickel ions (120 ppm), carrierconcentration (12%) (v/v) TBP and stirring speed (125±10 rpm), respectively.

Removal of Acetaminophen Residues from Wastewater by Bulk Liquid Membrane Process

The removal of Anit-Inflammatory drugs, namely; Acetaminophen (ACTP), from wastewater by bulk liquid membrane (BLM) process using Aliquat 336 (QCl) as a carrier was investigated. The effects of several parameters on the extraction efficiency were studied in this research, such as the initial feed phase concentration (10-50) ppm of ACTP, stripping phase (NaCl) concentration (0.3,0.5,0.7 M), temperature (30-50oC), the volume ratio of feed phase to membrane phase (200-400ml/80ml), agitation speed of the feed phase (75-125 rpm), membrane stirring speed (0, 100, 150 rpm), carrier concentration (1, 5, 9 wt%), the pH of feed (2, 4, 6, 8, 10), and solvent type (CCl4 and n-Heptane). The study shows that high extraction efficiency for ACTP of about 97% was achieved by a bulk liquid membrane at 50 ppm initial concentration of feed; stirring speed of feed phase 130 rpm; stirring speed of membrane phase 100rpm; 0.5 M NaCl concentration; carrier concentration 1wt%; volume ratio of 200ml feed:80ml membrane; feed pH of ACTP is 6, and 50˚C. The transport kinetics was evaluated using a kinetic model with two consecutive first-order irreversible reactions. The kinetics of (ACTP) transport by bulk liquid membrane was investigated at the best experimental conditions. The activation energy values of the extraction and stripping processes were 1.733 and 1.826 kJ.mol−1. The activation energy confirms that the transport process from solutions is controlled by diffusion.

Liquid-liquid extraction and facilitated membrane transport of Pb2+ using a lipophilic acridono-crown ether as carrier

Studies on liquid-liquid extraction and bulk liquid membrane (BLM) technique-based metal ion separation by a previously published Pb2+-selective acridono-18-crown-6 ether selector molecule were performed. The effects of the stirring speed, the quality of apolar organic membrane, the counterions of Pb2+, the pH of the aqueous phase, the concentration of the source phase, the concentration of the carrier in the BLM and the temperature on the Pb2+-separation were investigated. Moreover, the effects of the competitive inhibition due to the presence of Ag+, Ca2+, Co2+, Cu2+, K+, Mg2+, Na+ and Zn2+ as competing ions in a multicomponent aqueous source phase of different ion-concentrations were also studied. After a proper dilution of the multicomponent aqueous source phase, excellent Pb2+-selectivity was achieved without a significant reduction in the efficiency compared to the liquid membrane transport of single-component systems. Based on the BLM-cell studies the applied selector molecule proved to be suitable for the development of liquid membrane-based Pb2+-selective separation methods, which can be greatly aided by the analysis of the effects on the separation and by the optimization of the parameters of the process discussed here.

Separation of indole-3-acetic acid from tryptophan by bulk liquid membrane

Background: Indole-3-acetic acid (IAA) is an important growth hormone for plants obtained by biosynthesis from tryptophan. Aim: In this paper was studied the competitive transport of two biologically active compounds, indole-3-acetic acid (IAA) and tryptophan (TRP) through a liquid membrane. Methods: The separation of the two compounds was obtained using a hybrid liquid membrane system having as a carrier trioctylphosphine oxide (TOPO). Results: The most important operational parameter of the system were studied, pH influence on the efficiency of the transport process in correlation with the speciation diagrams of the two compounds: TRP and IAA. The evaluation of the transport process was performed through calculating the composition of the phases at the end of the transport process and the organic substrate flow at the membranes exit. Conclusion: Due to the transport efficiency of over 90% in the case of IAA and the high selectivity at the transport between IAA and TRP, the procedure can be applied at the sample preparation containing these analytes.

Process Optimization Study of Pb(II) Removal by Bulk Liquid Membrane (BLM)

Box-Wilson experimental design method was employed to optimized lead ions removal efficiency by bulk liquid membrane (BLM) method. The optimization procedure was primarily based on four impartial relevant parameters: pH of feed phase (4-6), pH of stripping phase (9-11), carrier concentration TBP (5-10) %, and initial metal concentration (60-120 ppm). maximum recovery efficiency of lead ions is 83.852% was virtually done following thirty one-of-a-kind experimental runs, as exact through 24-Central Composite Design (CCD). The best values for the aforementioned four parameters, corresponding to the most restoration efficiency were: 5, 10, 7.5% (v/v), and 90 mg/l, respectively. The obtained experimental data had been utilized to strengthen a semi-empirical model, based on a second-degree polynomial, to predict recovery efficiency. The model was tested using ANOVA software (Design expert®) and found acceptable R-Squared were (0.9673). Yield responseurface and contour plots have been created using the developed model, which revealed the presence of high-recovery plateaus whose specs will be useful in controlling pilot or industrial scale future devices to ensure economic feasibility.