The　high　colority　and　difficulty　of　decolorization　are　the　most　important　tasks　on　printing　and　dyeing　wastewater.　This　study　investigates　the　ability　of　diatomite　earth&carbon　(DE&C)　as　an　adsorbent　to　removal　crystal　violet　(CV)　from　aqueous　solutions.　Fourier　transform　infrared　spectroscopy　results　indicate　the　importance　of　functional　groups　during　the　adsorption　of　CV.　The　obtained　N-2　adsorption-desorption　isotherm　values　accord　with　well　IUPAC　type　II.　Our　calculations　determined　a　surface　area　of　73.15　m(2)　g(-1)　for　DE&C　and　an　average　pore　diameter　of　10.56　nm.　Equilibrium　data　of　the　adsorption　process　fitted　very　well　to　the　Langmuir　model　(R-2＞0.99).　The　results　of　kinetics　study　showed　that　the　pseudo-second-order　model　fitted　to　the　experimental　data　well.　The　thermodynamic　parameters　were　also　evaluated.　Delta　H　degrees　＜0,　Delta　S　degrees　＞0　and　Delta　G　degrees　＜0　demonstrated　that　the　adsorption　process　was　spontaneous　and　exothermic　for　dye.　Furthermore　the　positive　value　of　Delta　S　degrees　reflected　good　affinity　of　the　CV　dye.