Removal of Chromium from Industrial Wastewater by Adsorption using Coffee Husk

Fresh water  is vital to human life and economic well-being, and   societies  extract   vast  quantities  of  water   from  rivers,  lakes, wetlands,  and  underground aquifers  but  most of  these freshwater sources   are    polluted   by   different   chemicals   discharged   from industries. Our need for fresh water  has long caused us to overlook equally  vital  benefits  of  water  that  remains  in  streams to  sustain healthy  freshwater  habitats.  Heavy   metals  are   discharged  from different  industries  into  freshwaters  and  are  easily  absorbed by fish and   other   aquatic  organisms.  Small  concentrations  can   be   toxic because heavy  metals  undergo bioconcentration.  Chromium  is  an essential element that  is required in small amounts for carbohydrate metabolism, but  becomes toxic at  higher concentrations. The  most bioavailable  and   therefore  most  toxic  form  of  chromium  is  the hexavalent Cr (VI) ion. It is well recognized as an element of environmental and  public health concern. The  objective of this study was to examine  the  potential  of coffee  husk in  removing  chromium from   polluted   water.   In   this  study,  the   adsorption  potential   of activated carbon for the removal of Cr (VI) ions from industrial wastewater has  been  investigated.  The  adsorption  of  hexavalent chromium  from  aqueous solution  by  coffee  husk activated  carbon prepared by chemical method  and  its application to real wastewater was studied.  The  extent  of adsorption  was studied  as a  function  of PH, contact time, adsorbent dose, and  initial adsorbed concentration. Optimum  results  were  found  to be  60  minutes,  80 mg/l,  2, 3g/l  and 200rpm   for  time  contact, initial  concentration,  PH,  adsorbent dose and    stirring   speed   respectively   at   the    optimal   condition   the adsorption of hexavalent chromium was found to be 98.19%.