بررسی کارایی پوسته تخم مرغ به عنوان جاذب طبیعی در حذف رنگ راکتیو قرمز198 از محلولهای آبی

Background: dye compounds is one of the most critical contaminant for natural ecosystems. the aim of this study were to determine the primary concentrations of reactive red 198 dye (rr 198), adsorbent dosage and ph influences for the adsorption of rr 198 onto chicken’s eggshell (es) as an adsorbent. methods: the target adsorbent was prepared in laboratory conditions and pulverized by astm standard sieves. surface characteristics and measurement of the adsorbent surface area was carried out with scanning electronic microscope (sem) and via n2 gas adsorption with brunauer-emmett-teller isotherm. the maximum absorption wave length of this dye (?max) was determined by spectrophotometer (optima sp-3000 plus).results: analysis of absorption spectra showed that the ?max of rr198 is 518 nm. the results show the calcium components are the main constituent of es with 1.2 m2/g. elevation of the es dose (2 to3 g) lead to increasing of dye removal from 80% to 92%. the results show that elevation of ph from 4 to 10 would lead to increasing of rr 198 adsorption from 44% to 64% but increasing of preliminary dye concentration would lead to decreasing of dye adsorption from 72% to 23%. the kinetic studies revealed that the adsorption of rr 198 is rapid and complying with second-order kinetic (r2= 0.995) which the kinetic constant is 0.0004min-1. conclusion: eggshell is a cheap adsorbent that can be used for the removal of dye components from alkaline solutions.