KAJIAN ADSORPSI Zn(II) DENGAN MENGGUNAKAN LIMBAH JERUK (Citrus nobilis var. microcarpa) TERSAPONIFIKASI BENTUK Na DAN Ca

The utilization of orange (citrus nobilis var. microcarpa) waste for the adsorption of Zn(II) has been examined in this study. The orange waste was modified through saponification using NaOH and Ca(OH)2 to form saponified orange waste of Na (SOW-Na) and saponified orange waste of Ca (SOW-Ca). The synthesis of SOW-Na and SOW-Ca was done by adding respectively the solutions of NaOH and Ca(OH)2 to the orange waste to achieve the solution medium pH 10, 10.5, 11, 11.5, 12 and 12.5. Characterization of SOW-Na and SOW-Ca was carried out using Fourier Transform Infrared Spectrophotometry (FTIR). The result showed that the highest ion exchange capacity of SOW-Na was achieved at pH 12.5, i.e. 1.53 mol/Kg, while SOW-Ca was at pH 11.5, i.e. 2.39 mol/Kg. Adsorption of Zn(II) on both SOW-Na and SOW-Ca was optimum at medium pH 6 and it followed pseudo second order with adsorption rate constant were 1.02·10-3 mM-1·min-1 and 2.40·10-3 mM-1·min-1, respectively. Adsorption of Zn(II) on both adsorbent fitted well to Langmuir isotherm with capacity 45.94 mg/g for SOW-Na and 41.06 mg/g for SOW-Ca. By using biner solution Zn(II) � Pb(II), the abilities of SOW-Na and SOW-Ca in adsorbing Zn(II) decreased significantly, while in biner solution Zn(II) � Cd(II) the abilities of the both adsorbents in adsorbing Zn(II) were affected insignificantly

SINTESIS MCM-41 DAN NH2-MCM-41 SEBAGAI ADSORBEN Hg(II) DALAM MEDIUM AIR

Synthesis of MCM-41 and NH2-MCM-41 as adsorbents of Hg(II) in aqueous solution had been done. MCM-41 was synthesized through hydrothermal process used Na2SiO3 solution and cethyltrimethylammonium bromide (CTAB) adjusted at pH = 10 by using 1 M H2SO4 solution. NH2-MCM-41 was made by refluxing a mixture of MCM-41 and (3-aminopropyl)trimethoxysilane (APTMS) in toluene at temperature of 60 oC for 12 h. The solid products were characterized by infrared spectrofotometry (FTIR), X-ray diffraction (XRD), Tranmission Electron Microscope (TEM), and N2 physisorption method using a gas sorption analyzer based on the BET equation. The synthesized MCM-41 and NH2-MCM-41 were applied as adsorbents of Hg(II) in aqueous solution at various pH, contact time, and concentration of Hg (II). Characterization of solid products by using FTIR spectroscopy showed the existence of Si-OH and Si�O�Si groups in both MCM-41 and NH2-MCM-41 structure. Observed aminopropyl groups in NH2-MCM-41 spectra indicated that the enchoring process was successful. Both the XRD pattern and TEM image displays consistency results that MCM-41 and NH2-MCM-41 had an ordered hexagonal pore structure. Results of N2 physisorption analysis showed that after anchoring process, the size of BET surface area, pore diameter, and total pore volume were decreases. The adsorption study of Hg (II) on solid MCM-41 and NH2-MCM-41 showed the maximum adsorption occurs at pH = 4. The adsorption kinetics study of Hg (II) using MCM-41 coincide well the first order kinetic with value of k1 1.73 x 10-3 minute-1, while adsorption of Hg(II) using NH2-MCM-41 coincide well the second order kinetic with value of k2 3.97 x 10-5 (g/mol.minute). NH2-MCM-41 possesed greater adsorption capacities, i.e. 63,29 mg/g (3,16 x 10-4 mol/g) than MCM-41, i.e. 14,21 mg/g (7,09 x 10-5 mol/g), it means that modification of MCM-41 to NH2-MCM-41 was proved to increase the adsorption capacity for Hg(II)

SINTESIS KARBOKSIMETIL SELULOSA (CMC) - ASAM HUMAT DAN APLIKASINYA SEBAGAI PEMBENAH TANAH PADA PERTUMBUHAN TANAMAN CABAI (Capsicum annum L)

Humic acid (HA) has been immobilized through cross linking in carboxymethyl cellulose (CMC) using crosslink agent of N,N methylenbisacrilamide and its application as planting media mixture of Capsicum annum. L. Humic acid was extracted from peat soil of Rawa Pening, while CMC was synthesized from cellulose isolated from bagasse. Humic acid from the peat soil of Rawa Pening was extracted by soaking in 0.1 M NaOH solution (ratio of soil and NaOH, 1:10 (b/v)) and followed by acidication using HCl solution to pH@1. Cellulose as raw material for CMC was isolated by refluxing the bagasse at 100oC for 3 hours in 100 mL NaOH solution in various concentrations (5.0 %. 7.5 %, 10.0 % and 15.0 % (w/v)). Cellulose as residue was purified by bleaching method using 5% (v/v) NaOCl solution. The synthesis of CMC was done by reacting the isolated cellulose with sodium chloroacetic (SCA) at 70oC. The immobilization of HA on CMC was carried out through cross linking of AH on CMC obtained from the reaction of 5 g cellulose and 2 g SCA in water medium at temperature 70oC by using MBA. The results of the characterization with FTIR indicated that there was similarity between the spectra of technical cellulose (Sigma) and those of cellulose obtained from process of extraction using 5% (w/v) NaOH. The water absorption ability test showed that CMC obtained from the reaction of 5 g cellulose and 2 g SCA possessed the highest absorption of water, i.e. as much as 80.15 mL/g. FTIR spectra indicated that COOH group has already been released from its interaction with impurities after one step purification using the mixture of HCl and HF solution. Humic acid capability to absorb water was not as good as CMC. Indication of the presence of cross linking among CMC, MBA, and HA could be found in the FTIR spectra, i.e. by the decreasing of absorption intensity at 3300-2900 cm-1 for O-H stretching. Capability to absorb water was the highest for the immobilization product of CMC and HA at weight ratio 5:1, i.e. as much 14.39 mL/g. Cation exchangable capacity (CEC) test indicated that the increase of HA portion could increase the CEC of CMC-HA. The use of the immobilization product of AH on CMC in planting media of chili was able to minimize the need of fertilizer to 50%

KAJIAN ADSORPSI Pb(II) DENGAN ADSORBEN LIMBAH JERUK TERSAPONIFIKASI Ca(OH)2 DAN NaOH

Adsorption of Pb(II) on the adsorbent of orange (Citrus nobilis var. Microcarpa) waste modified by saponification has been studied. Saponification was done by using Ca(OH)2 solution to form saponified orange waste of Ca (SOW-Ca) and by using NaOH solution to form saponified orange waste of Na (SOW-Na). Saponification was carried out at pH 10, 10.5, 11, 11.5, 12 and 12.5. The SOW-Ca dan SOW-Na were characterized by using Fourier Transform Infrared Spectroscopy (FTIR) and were determined their ion exchange capacities through netralization titration using HCl solution. The results showed that the highest ion exchange capacity of SOW-Ca was achieved at pH 11.5, i.e. 2,39 mol/kg, while that SOW-Na was at pH 11.5, i.e. 1,53 mol/kg. Adsorption of Pb(II) on both SOW-Ca and SOW-Na was optimum at medium pH 5 and it followed pseudo second order with adsorption rate constants were 4,88 x 10-2 and 2,71 x 10-2 mM-1 min-1, respectively. Adsorption of Pb(II) on both adsorbent fitted well to Langmuir isotherm with capacity 195,84 mg/g for SOW-Ca and 164,58 mg/g for SOW-Na. By using biner solution Pb(II)- Zn(II), the abilities of SOW-Ca and SOW-Na in adsorbing Pb(II) increased significantly, while in biner solution Pb(II)-Cd(II) the abilities of both adsorbents in adsorbing Pb(II) were affected insignificantly

KAJIAN ADSORPSI Cr(VI) OLEH ABU LAYANG AMPAS TEBU TERAKTIVASI H2O2

Study on the adsorption of Cr(VI) on H2O2 activated bagasse fly ash has been conducted. The study was directed to reveal the effect of activation on the enhancement of pore size and surface area as well as the effect of pH, initial weight of bagasse fly ash and initial concentration of Cr(VI). The study was initiated by washing bagasse fly ash with aquadest and then followed by activation using H2O2 at various concentrations. Characterization was performed using spectroscopy infrared to elucidate the existence of functional groups, and by using surface area analysis to quantifity surface area and pore radius. The concentration of Cr(VI) in solution was analyzed by using spectroscopy UV-Vis at λmax 540 nm after complexation of Cr(VI) with diphenilcarbazide. Result showed that the activation of bagasse fly ash with H2O2 2 M was able to enhance the surface area from 44,39 m2/g to 46,60 m2/g, volume of total pore from 0,046 mL/g to 0,054 mL/g, and average pore radius from 19,60 � to 24,36 �. Adsorption of Cr(VI) on bagasse fly ash was optimum at pH 1,5 with adsorption capacity 0,991 mol/g which was slightly higher than that of adsorption capacity of unactivated bagasse fly ash, i.e. 0,989 mol/g

PEMANFAATAN PEKTIN-Na SEBAGAI ADSORBEN Cd(II) DALAM LARUTAN

The utilization of pectin-Na as adsorbent has been studied for Cd(II). The adsorbent has been obtained by the saponification of pectin�s orange waste of Citrus sinensis (L.) Osbeck with NaOH for 24 hours at 70o C. The pectin-Na was characterized by infra red spectrophotometer (FTIR), it has been studied also the effect of adsorption parameters (pH, time, and concentration of Cd(II)) on the adsorption of Cd(II) on pectin-Na, and the adsorption selectivity of pectin-Na for Cd(II) with the presence of Pb(II) or Zn(II). Adsorption of Cd(II) was done in batch mode as a function of pH, contact time, and variation of concentration of Cd(II). The effect of Pb(II) or Zn(II) on the adsorption of Cd(II) was also studied. Adsorption was performed with initial concentration of Cd(II) 100 mg L-1 and the solution pH range from 2 to 9. The adsorbed Cd(II) was calculated by subtracting the concentration of Cd(II) left in the solution after adsorption to the initial concentration. The concentration of Cd(II) was determined using atomic absorption spectroscopy. The results showed the characterization of pectin-Na with FTIR was observed by the lowering of C=O peak in ester at 1743,65 cm-1 which originally existed in pectin. It is an indication the presence of exchange of CH3+ with Na+. Adsorption of Cd(II) on pectin-Na was optimum at pH 7 and followed pseudo second order adsorption kinetics with adsorption rate constant 3.68 g mmol-1 min-1. The adsorption capacity was 0.20 mmol g-1 but the adsorption was still inselective with the presence of Pb(II) or Zn(II)