EFFECTIVENESS OF TEA RESIDUE TO REDUCE HEAVY METAL CONTENTS FROM INDUSTRIAL WASTE WATER

An experiment was conducted to investigate the physicochemical characteristics of industrial effluents and to find out the effectiveness of tea residues (TR) for managing heavy metal pollution. Industrial waste water samples and tea residues (waste part of tea) were used as experimental objects. The industrial waste water were collected and analyzed for metal contents. After that tea residues were used in different combination (treatments) for checking the efficacy of metal removal from waste water. The adsorption of heavy metals on tea residues was studied by batch technique with the help of AA-7000 spectrophotometer. There were ten treatments namely: T0 denotes raw water (untreated water), T1: 2g TR (tea residue) at 1 day after treated (dat), T2: 2g TR at 7th dat, T3: 2g TR at 15th dat, T4: 5g TR at 1 dat, T5: 5g TR at 7th dat, T6: 5g TR at 15th dat, T7: 10g TR at 1 dat, T8: 10g TR at 7th dat, T9: 10g TR at 15th dat. Water samples were collected in four sampling sites of four different industries located at Mymensingh city of Bangladesh. The physicochemical parameters like color, odor, pH (7.6-8.64), TDS (180-533ppm), EC (425-1692us) and the concentration of Zn (1.861, 2.802, 3.618ppm), Cr (3.966, 2.036, 1.589ppm), Pb (6.351, 1.076, 2.789ppm) were reported. The pH and TDS were within the standard level but the EC were found much higher one sample. The concentration of heavy metals like Pb, Cr and Zn of S1, S2, S3 were higher but only S4 cannot find any toxic or traces elements. Results revealed that T8 and T9 showed the highest Zn removal rate than other treatments, where T1 treatments showed lower rate. The highest removal rate of Pb concentration showed at T9 and T6 treatments and lowest removal rate at T7 treatments for all three samples. The concentration of Cr showed higher removal rate at T9 treatments for S1 sample, T8 for S2 and T6 for S3 sample but all three samples were not so effective at T1 treatments. The results may conclude that using of tea residue may very helpful to minimize the metal pollution level for sound environment.