The　removal　of　Cd　(II)　ions　by　rice　husk　biochar　as　adsorbent　was　evaluated　through　batch　study.　Activated　biochar　was　prepared　using　the　physicochemical　activation　method.　Preparation　was　consisting　of　pre-impregnation　of　NaOH　and　nitrogen　(N-2)　pyrolysis.　The　Influence　of　preparation　parameters　which　were　chemical　impregnation　(NaOH:　RH),　pyrolysis　temperature,　and　pyrolysis　time　on　biochar　yield,　cadmium　removal　rate,　and　adsorption　capacity　on　cadmium　ions　was　investigated.　A　quadratic　model　for　correlating　biochar　preparation　variables　with　biochar　production,　cadmium　removal　rate,　and　adsorption　capability　was　built　according　to　central　composite　design　(CCD).　The　experimental　results　revealed　that　pyrolysis　temperature　and　heating　time　are　important　factors　that　affect　the　yield　of　biochar　and　positively　affect　Cadmium＇s　removal　rate　and　adsorption　capacity.　The　impregnation　ratio　positively　impacted　Cadmium　removal　and　adsorption　capacity,　and　it　did　not　affect　biochar　yield.　The　optimal　biochar　was　obtained　using　458　degrees　C　temperature,　120　min　reaction　time,　and　3　NaOH　impregnation　ratio,　resulting　in　34.5%　of　biochar　yield,　72%　of　cadmium　removal,　and　17.8　mg/g　of　adsorption　capacity　on　Cadmium.　(C)　2021　THE　AUTHORS.　Published　by　Elsevier　BV　on　behalf　of　Faculty　of　Engineering,　Ain　Shams　University.