Faculty Publications
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Item Dewatering performance of sludge using coconut shell biochar modified with ferric chloride (Sludge dewatering using bio-waste)(Springer Science and Business Media Deutschland GmbH, 2022) Rashmi, H.R.; Devatha, C.P.Coconut shell is a bio-waste, and its availability is high to waste in the coastal region of Karnataka, India. The present study focused on using coconut shell biochar modified with ferric chloride to enhance the sludge dewaterability, and it is evaluated experimentally (Capillary suction time, moisture content, settleability, zeta potential, heavy metals, and phosphate). Further, scanning electron microscopy, Fourier transformation infrared spectroscopy, and X-ray diffraction characterization were carried out to identify the structure's change. A significant reduction in capillary suction time (56 s) and the moisture content (96.5%) of the dewatered sludge cake was obtained. Sludge dewatering using coconut shell biochar modified with ferric chloride was optimized by a Box Behnken method with three main factors including dosage, rapid mixing time, and slow mixing time. Optimum capillary suction time (55.6 s) was achieved at coconut shell biochar modified with ferric chloride dosage (41% dry solids), rapid mixing time (10 min), and slow mixing time (19 min). The significant structural change in sludge particles was confirmed through characterization studies. During the dewatering process, the removal of heavy metal (cadmium, chromium, lead, and nickel) and phosphate (50.6%) was evident. Hence attempt of coconut shell biochar modified with ferric chloride as a skeleton material is an economical and promising option for sludge dewatering. © 2021, Islamic Azad University (IAU).Item Experimental investigation on sludge conditioning and dewatering using an agricultural biomass coupled with resource recovery(Academic Press, 2024) Chopade, G.; Devatha, C.P.In this study, the effect of modified areca husk fibre biochar (MAFB-AlCl3) on dairy sludge conditioning and dewatering along with raw and modified coconut shell biochar (MCSB-FeCl3) was investigated. Further, MgO impregnated biochars of areca husk fibre and coconut shells was carried out to evaluate the performance on phosphate recovery from the diary sludge. The enhancement in sludge dewatering with MAFB-AlCl3 were evaluated experimentally and significant reduction of capillary suction time (CST) (51.6 %), moisture content (18%), zeta potential (1.3 mV) and increased settleability (32.7%) were observed. The sludge conditioning parameters namely dosage (% of dry solids (DS)), rapid mixing time (RMT), slow mixing time (SMT) were optimized by response surface methodology for the modified biochars. Optimum CST (31.51 s) was obtained at dosage (50 % of DS), RMT (9.89 min) and SMT (17.23 min). Results of batch study for phosphate recovery by MgO impregnated biochars (MgB) was found to be 96.6 % and 100 % by MgB of areca husk fibre (MgAFB) and coconut shells (MgCSB) respectively. The morphological characteristics and elemental distribution using field emission scanning electron microscopy (FE-SEM) & energy dispersive X-ray spectroscopy (EDS) reveals the structural change in the sludge particles for the modified biochars as well as for sludge. Hence MAFB-AlCl3, MgAFB and MgCSB is proved to be suitable and an effective candidate for sludge conditioning and dewatering coupled with phosphate recovery in handling the diary sludge. © 2024 Elsevier Ltd