Coffee Waste as Novel Bio-Adsorbent: Detoxification of Nickel from Contaminated Soil and Coriandrum Sativum

According to the recent surveys, the air and soil pollution levels have risen from the toxic metals due to accumulation of these metals in soil and plants. These concerns have become one of the basic problems of agricultural products, which lead to food contamination. In recent years, the use of low-cost bio-adsorption has been considered which is mainly due to agricultural waste. It is worth mentioning that coffee consumption is over eleven billion tons per year around the world. Coffee bean waste (canephorat, Arabica) is solid and insoluble in water, which is why it is racked up and compiled in nature. Packed potting soil purchased from Tehran market. Meanwhile in 45 vases the Coffee waste (from 0% to 5%) dry weight percentage were mixed by soil, due to observing the effect of Coffee waste as adsorbent and in defined times: 1, 10, 20, 30, 40 days in the study. ICP-MS. Ion concentration was addressed in three replicates determined the Nickel (Ni) contents in aerial parts of vegetable in treated and untreated samples. The soil, leaves of vegetable was digested by wet method according the standard protocol (AOAC). Mean values were calculated using Analysis of Variance, (ANOVA) and adsorption capacity varied by considering the effects of assorted parameters like contact time, initial concentrations, and adsorbent dose. It was acknowledged by the results that coffee bean waste (CBW) has more potential to adsorb Ni during the first days of the study (p < 0.001) and adsorption capacity was diversified by considering the effects of various parameters like contact time, initial concentrations, pH, and absorbent dose. Coffee bean waste could acquire high level of Nickel in a short time and the uptake rate by edible vegetable plant is significantly afflicted by their concentrations in the contaminated soil (p< 0.05). A contact time of 30 days by %3 corianders was resulted to be optimum.