A New Method for the Selective Removal of Cadmium and Zinc Ions from Aqueous Solution by Modified Clinoptilolite

Abstract

Natural and modified clinoptilolite were used to remove zinc and cadmium ions from aqueous solution. The raw material was characterized by XRD and XRF analysis. Clinoptilolite was modified with benzyldimethyltetradecylammonium chloride (BDTA) to increase the adsorption of neothorin [2-(2-arsenophenylazo)chromotropic acid disodium salt, C 10 H 11 AsN 2 Na 2 O 11 S 2 ]. All experiments were undertaken using a continuous method. The ultimate goal of these studies was the selective removal of trace amounts of Cd(II) and Zn(II) ions from aqueous solution using a modified form of clinoptilolite.The results obtained showed that Cd(II) and Zn(II) ions were adsorbed quantitatively onto modified clinoptilolite over the respective pH ranges of 4.0-5.4 and 3.3-4.5. The influence on the adsorption process of various parameters such as the ionic concentration, the flow rate, the particle size, the pH value and the presence of other cations was studied to obtain the optimum conditions. Although clinoptilolite and its surfactant-modified form were not capable of the selective adsorption of the cations studied, on the basis of the results obtained it was possible to selectively remove Zn(II) and Cd(II) ions from aqueous solution by modified clinoptilolite using a two-step process, i.e. initial treatment with BDTA followed by treatment with neothorin.

Kinetics of adsorption of metal ions on inorganic materials: A review

“…However, many of the studies were without application of any kinetic models and were based on just showing the variation in adsorption capacity with time and usually to establish the time taken to arrive at equilibrium. A cross-section of such works that considered adsorption on various inorganic solids without dealing with any of the kinetic aspects is given below: Cu(II) on Ca-kaolinite [64], Cd(II), Cu(II) and Pb(II) on diatomite and Mn-diatomite [65], Ca(II) on hydroxy-Al pillared montmorillonite [66], Cd(II), Cr(III), Cu(II), Ni(II), Pb(II) and Zn(II) on kaolinite and illite [67], Cu(II) on sewage sludge ash [68], Ni on illite [69], Cd(II), Cr(III), Cu(II), Mn(II), Ni(II), Pb(II) and Zn(II) on Na-montmorillonite [70], As(V) on calcined synthetic hydrotalcite and calcined natural boehmite [71], Cd(II) and Zn(II) on apatite [72], Co(II), Cu(II), Mn(II) and Zn(II) on natural zeolite [73], Cu(II), Pb(II) and Zn(II) on natural zeolite [74], As(V) on bimetal oxide [75], Cd(II) and Pb(II) on amine-modified zeolite [76], As(III) and As(V) on TiO 2 [77], Cd(II) and Zn(II) on modified clinoptilolite [78], Co(II) and Zn(II) on treated bentonite [79], Cu(II) on clinoptilolite [80], Cu(II), Co(II) and Zn(II) on natural bentonite [81], Cr(III) on zeolite [82], Cr(VI) on surfactant-modified zeolite [83], Co(II) and Ni(II) on ion exchange resins [84], Hg(II) on natural and modified montmorillonite (treated with pyridine, dimethyl sulfoxide and 3-aminopropyltriethoxysilane) [85], Cd(II), Cr(III) and Mn(II) on natural sepiolite [86], Cu(II) on Serbian zeolite, clay and diatomite [87], Cu(II) on bentonite-polyacrylamide composites [88], etc.…”

Physiological and Biochemical Responses of Ulva prolifera and Ulva linza to Cadmium Stress

“…It has been classified as group (I) a human carcinogen by the International Agency for Research on Cancer (IARC) [7]. Cadmium toxicity may be characterized by a variety of syndromes and effects, including renal dysfunction, hypertension, hepatic injury, lung damage, and teratogenic effects [8]. To remove Cd pollutants, various treatment technologies, such as precipitation, ion exchange, adsorption, and biosorption, have been employed [9].…”

Biosorption of Pb(II) and Cd(II) from aqueous solution using green alga (Ulva lactuca) biomass

“…As a consequence, lead contamination is due to effluents of these industries, and also vehicular traffic and the mixing of roadside run-offs [4]. On the other hand, cadmium toxicity may be observed by a variety of syndromes and effects including renal dysfunction, hypertension, hepatic injury, lung damage and teratogenic effects [5]. Numerous processes such as ion exchange, precipitation, phytoextraction, ultrafiltration, reverse * Corresponding author.…”