International Journal of Chemical Science 13 International Journal of Chemical Science Online ISSN: 2523-2843, Print ISSN: 2523-6075; Impact Factor: RJIF 5.22 Received: 07-11-2018; Accepted: 09-12-2018 www.chemicaljournals.com Volume 3; Issue 1; January 2019; Page No. 13-18 Adsorption of nickel ions from leachate on groundnut shell activated carbon Shilpa P Kodolikar 1* , Veena R Doss 2 1 Department of Chemical Engineering, MIT World Peace University, Pune, Maharashtra, India 2 Department of Engineering Sciences, Sinhgad College of Engineering, Pune, Maharashtra, India Abstract It has been widely recognized that heavy metal removal by activated carbon adsorption is due to the surface complex formation between the metal ions and the acidic surface functional groups. The present study focuses to investigate the possibility of the utilization of activated carbon prepared from groundnut shell as a low cost adsorbent material for the adsorption of heavy metal present in the leachate. Batch experiments were conducted to determine the effect of contact time, pH, adsorbent dosage, speed of agitation, temperature. Experimental data was evaluated to find out kinetic characteristics of the adsorption process. The isothermal data was well described by the Freundlich and D-R adsorption model with a fit (R 2 = 0.964). The maximum % removal of Nickel ions was observed to be 95% at pH =10 with speed of agitation = 500 rpm and 25ºC temperature. Keywords: activated carbon, groundnut shell, GSAC (groundnut shell activated carbon), leachate treatment 1. Introduction Pollution load of the environment is increasing due to global rise in population and our quest to lead comfortable life resulting in explosive growth of industrial and agricultural activities. Environmental contamination with metal ions represents a potential threat to human, animals and plants. Metal ions which many of them are soluble in aqueous solution become more available for living system and accumulate in the environment are of vital concern. Nickel is released into the environment in a large number of processes such as electroplating and steel manufacturing. In general, to be removed from wastewater, the metal must be precipitated or otherwise attached to an insoluble form through ion-exchange or adsorption [1] . For the present study groundnut shell activated carbon (GSAC) is used for adsorption method for removing Nickel metal from leachate. 2. Materials and Methods 2.1 Preparation of adsorbent Activated carbon from groundnut shell was prepared by treating it with potassium hydroxide. Initially the material was washed thoroughly with water to remove earthy matter and dried at 110 ºC. The dried material was then subjected to 1 N KOH 150ml for 10 min. This material was then washed with dilute HCl to make sample neutral. It was then carbonized at 500 ºC for 25 min in muffle furnace. Finally the material was ground in an agate mortar and then sieved to 16 mesh size. Various optimization conditions during lower and higher carbonization conditions were obtained for the preparation of adsorbent based on percentage yield and adsorption efficiency [2-17] . 2.2 Properties of adsorbent Physical characteristics of GSAC were estimated in terms of particle size, apparent density, surface area and surface functional groups. [See Table 1 and Table 2]. Table 1: Proximate analysis S. No. Parameter Values 1 Moisture 9 2 Ash 8.2 3 Volatile matter 11.4 4 Fixed carbon 71.4 Table 2: Physical and adsorptive characteristics of activated carbon S. No. Parameter Values 1 Apparent density(g/cm 3 ) 0.23 2 Iodine value 1114 3 Methylene number 238 4 Surface area(m 2 /g) 364.023 Moisture, ash and volatile matter was determined by heating 1gm of GSAC at 100 ºC, 800 ºC and 900 ºC respectively to constant weight. The difference in weight was calculated and expressed in percentage [18] . 2.3 Batch Adsorption Experiment The batch sorption studies were carried out by shaking series of bottle containing different amount of adsorbent and leachate sample. The leachate sample containing different dosages of activated carbon were shaken for six hours to determine the effect of speed of agitation, loading, temperature and pH. Both SEM and FTIR analysis were carried out on activated carbon prepared from groundnut shell to find out modification in the morphology and functional group. In order to obtain adsorption capacity, the amount of ions adsorbed per mass of carbon was evaluated using following expression.   = (  −  )   (1) Where C o and C e are concentration of Nickel before and after interaction with the activated carbon, Q e is the adsorption