POTENTIAL OF REUSED PALM OIL MILL EFFLUENT (POME) USING PALM OIL MILL SLUDGE (POMS) ADSORBENT IN MINERAL REMOVAL FOR BOILER FEED WATER

• Main Author: Dwiana Inema, Dinda
• Format: Theses
• Language: Indonesia
• Subjects: Teknik saniter dan perkotaan; teknik perlindungan lingkungan
• Online Access: https://digilib.itb.ac.id/gdl/view/81625
• Institution: Institut Teknologi Bandung

Crude Palm oil is the largest industrial sector in Indonesia with exports of around 22.67 million tons by 2022. In 1 ton of Palm Fruit Bunch (FFB) requires 1 m3 of clean water in the production process. The liquid waste generated from palm oil production is equivalent to 0.6- 0.8 m3 per 1 m3 of clean water used. In other words, the palm oil industry is classified as an industry that is not energy efficient and has the potential to pollute the environment. In general, liquid waste known as Palm Oil Mill Effluent (POME) is processed using an anaerobic-aerobic process which leaves sludge known as Palm Oil Mill Sludge (POMS). Both types of waste still have functional value if processed properly, one of which is making POME as raw material for recycled water for boiler units. Treated POME contains dissolved magnesium and calcium of 81.84 mgl/ and 54.85 mg/l, respectively, which can trigger scale formation on boiler equipment. However, POME requires additional treatment to remove the high Mg2+ and Ca2+ content that can potentially cause scaling in the boiler unit. POMS was activated using 4 M KOH compound and thermally using pyrolysis at 700 oC with 1.2 L/min nitrogen gas injection for 1 hour. Adsorption testing using SBAC was conducted at 25 ± 1 oC, pH 7.12, and 1000 rpm rotating speed. Hard water obtained from mixing 3 grams of MgCl2 salt and 1.67 grams of CaCl2 in 1000 ml of distilled water will produce hard water with a concentration of 103-105 mg/l. The optimum condition was obtained at a contact time of 45 minutes with an adsorbent dose of 1.8 grams with a rotating speed of 1000 rpm at a temperature of 25 ± 1 oC and pH 7.12. The removal efficiencies for SBAC in removing calcium and magnesium were 78.89% and 73.33% respectively with adsorption capacity of 4.39 mg/g for calcium removal and 1.09 mg/g for magnesium removal. The FTIR test found hydroxyl (O-H) and carboxyl (-COOH) groups on the surface of SBAC that can attract magnesium ions and calcium ions to the surface. Based on SEM-EDS testing, it was found that the pore size detected at maximum magnification was 0.5-1 micron with an asymmetrical and rough porous surface shape. While the EDS test showed that the surface of SBAC which originally contained 1.04% magnesium and 1.94% calcium increased after undergoing the adsorption process by 4.31% for Mg and 6.91% for Ca which indicated that magnesium ions and calcium ions were successfully absorbed in the pores of the microporous SBAC surface. Sludge Based Activated Carbon (SBAC) is characterized by an iodine number of 821 mg/g with moisture content, ash content, volatile content, and fixed carbon of 11.5%, 23.63%, 15.37%, and 62.96%, respectively. PSA test results showed that the pore size of SBAC was classified as microporous, measuring 1.7 nm with a Langmuir isoterm model pattern and pseudo second order adsorption kinetics. Existing application of SBAC to PT X POME decreased the removal efficiency by 51.41% for Ca2+ ions and 60.20% for Mg2+ ions. When SBAC is compared with CAC, it can be seen that SBAC has better sorption ability than CAC in sorbing magnesium ions and calcium ions. The production of SBAC experienced a mass shrinkage of 58.38% so that in applying SBAC as an adsorbent requires further study related to the cost of production and maintenance of SBAC. The production cost required in preparing Palm Oil Mill (PKS) WWTP sludge into SBAC is Rp 1,193,827.43 with a regeneration period of SBAC 3 times