Journal of critical reviews 1410 Journal of Critical Reviews ISSN- 2394-5125 Vol 7, Issue 8, 2020 PALM FROND BIOCHAR FOR SLUDGE GRANULATION IN AEROBIC GRANULAR SLUDGE SYSTEM Hasnida Harun *a , Nur Aifaa Truna a , Nor Hazren Abdul Hamid a , Norshuhaila Mohamed Sunar a , Nuramidah Hamidon a , Roslinda Ali a , Mimi Suliza Muhamad a , Faridahanim Ahmad b a Sustainable Environmental Technology Focus Group, Advanced Technology Centre, Department of Civil Engineering Technology, Faculty of Engineering Technology, UniversitiTun Hussein Onn Malaysia, Pagoh Education Hub, 84600, Johor, Malaysia b Department Structure and Materials, School of Civil Engineering, Faculty of Engineering, UniversitiTeknologi Malaysia, 81310 Skudai, Johor, Malaysia Email: * a hasnidah@uthm.edu.my Received: 20.05.2020 Revised: 17.06.2020 Accepted: 06.07.2020 Abstract This work investigated the role of biochar derived from palm frond addition in an aerobic granular sludge system to improve the granulation of sludge. The effect of biochar dosage was analysed based on the granules size and chemical oxygen demand (COD) removal performance. At the same time, the system performances including sludge volume index (SVI 30), mixed liquor suspended solid (MLSS) and mixed liquor volatile suspended solid (MLVSS) for 50 days were studied. Three identical of 2 L reactors which operated based on sequencing batch reactors (SBR) system were used in this study named R1, R2 and R3. Difference dosage of biochar was added into R2 and R3 which is 4g and 8g, respectively while, R1 as a control system with no biochar added. The existence of biochar improved the granulation process as aerobic granule size of 0.95- 1.49 mm with clear boundary was observed at 14 days of system operation. The biochar supplemented in the reactors act as a core for microorganism to accumulate and enhanced the granulation of sludge. After the granulation, R3 shows a good settling characteristic compared to R1 and R2, with an SVI of 50 mL/g SS at the end of system operation. The reactors performed steadily with COD removal efficiencies of 85%, 90% and 96% in R1, R2 and R3, respectively at initial COD concentration of 500 mg/L and 24 h of SBR cycle. The dosage of biochar had a positive impact on granulation and reactor performances even at the short duration of system operation. Keywords--Aerobic granular sludge, palm frond biochar, SBR, dosage, wastewater treatment © 2020 by Advance Scientific Research. This is an open-access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) DOI: http://dx.doi.org/10.31838/jcr.07.08.283 INTRODUCTION Aerobic granular sludge has become a promising wastewater treatment technology due to its unique features of excellent settleability, high biomass retention and high resistance against a wide range of organic loading and environmental conditions. In addition, theaerobic granules exhibited a compact microbial structure, good settling capability and high biomass retention, which classified them as a versatile wastewater treatment system. Dense and compact aerobic granular sludge structure contributes to a good settling ability which allows high biomass retention in reactor for the degradation process of organic matter which it is the main factors for the granulation field received attention by many researchers in the wastewater treatment.Aerobic granulation has been mainly successful developed in sequencing batch reactors(SBR)which had been widely extended the usage of lab scale SBRs operated with a simple operation into a higher leveloperation which equipped with a control and automation system to optimize the SBR performances (Lemaireet al., 2008). Therefore, numerous studies had been done focused on understanding ofmechanisms (Li et al., 2020), factors and optimizing the reactor operating conditions in promoting aerobic granulation (de Sousa Rollemberget al., 2020). Recently, researchershave focused on improvement study in the accelerating granulation process of aerobic granular sludge in SBR as this technology is limited by the drawback of the long start-up period of reactor. Liang et al., (2017) demonstrated a novel granulation strategy by introducing magnetic nanoparticles in an aerobic granular system which successfully improved the time of theaggregation process. Meanwhile, the used of rice husk biocharin aerobic granular sludge system reported by Zhang et al., (2017) and Ghaniet al., (2019), which had successfully developed a compact structure of aerobic granules at 60 days of cultivation in pyridine wastewater. The biochars act as a nucleus that enhancing the aerobic granulation process by facilitated the growth of microorganisms due to its coarse and irregular surface and characteristic adsorption property (Li et al., 2011). Thenucleus or cores,which located in the centre of aerobic granules is important in reinforcing the granular structure (Zhang et al., 2017). Thus, the existence of the supported material in the aerobic granulation system is significant inorder to improve the granulation time and maintain the granule stability. Although the application of biochar as a nucleus of aerobic granular sludge, especially biochar derived from feedstock such as rice husk, rice bran and walnut shell which was studied by Ming et al., (2020) had been investigated, they have different properties in physical and chemical which driven unique influence on theformation and performances of aerobic granules (Kambo and Dutta, 2015). Therefore, an effect of palm frond biochar in aerobic granular sludge system was explored in this study. METHODOLOGY Preparation of synthetic wastewater The synthetic wastewater contained phenol (0.2 g/mL), NH4Cl (0.20 g/mL), MgSO4.7H2O (0.13 g/mL), K2HPO4 (1.65 g/mL), KH2PO4 (1.35 g/mL) and for an optimal microbial growth, 10mL of micronutrients was added in each reactor. Micronutrient consists of H3BO3 (0.05 g/mL), ZnCl2 (0.05 g/mL), CuCl2 (0.03 g/mL), MnSO4.H2O (0.05 g/mL), (NH4)Mo7O24.4H2O(0.05 g/mL), AlCl3 (0.05 g/mL), CoCl2.6H2O (0.05 g/mL) and NiCl2(0.05 g/mL).