Faculty Publications
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Item Enhancing the Dewatering Ability of Sludge by Locally Available Biomass(Springer Nature, 2023) Chopade, G.; Devatha, C.P.In this study, the effect of modified coconut shell biochar is analyzed for its efficacy achievable in sludge dewatering properties. Initially the coconut shell biochar is modified at different molar concentrations of FeCl3, i.e., 1, 2, and up to 5 mol/L, and it is analyzed with different dosages at 0.1, 0.2, and up to 0.4 (g/g of dry solids (DS)) for the improvement in capillary suction time (CST) (s), moisture content reduction (%), filterability (min), and settleability (SV30%) of the sludge. It is found that there is significant decrease in each of these parameters. The optimization study is carried out to optimize the process of sludge conditioning, considering independent regression parameters as dosage (g/g of DS), molarity (M), mixing time (min), and response taken as moisture content (%), the optimum values for the dosage, molarity, mixing time is found to be 0.4 (g/g of DS), 2.5 M and 24.72 min, respectively, with optimized moisture content value of 78% was achieved. Hence, the modified coconut shell biochar can be used as a potential candidate to increase the dewatering ability of the sludge. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023.Item Experimental investigation on sludge dewatering using granulated blast furnace slag as skeleton material(Springer, 2020) Rashmi, R.H.; Devatha, C.P.The highly compressible nature of sludge and the presence of colloidal particles cause difficulties in sludge dewatering. Reducing the moisture content in secondary sludge is a key factor in reducing the capital costs, operational costs, and transportation costs in wastewater management. This investigation concerned the combined utilization of quicklime and granulated blast furnace slag (GBFS) to improve sludge dewatering. The experimental work included the initial characterization of the sludge and granulated blast furnace slag and evaluation of the dewatering ability of the treated sludge (CST, moisture content, turbidity, zeta potential, and heavy metal and biopolymer contents). Optimization using the Box-Behnken design (BBD) was carried out with various operational parameters, and the best performance was found to be at a pH of 10.2, a dose of 0.34 g/g DS, and a contact time of 14 min. A characterization study was carried out by scanning electron microscopy (SEM) in conjunction with EDS, X-ray diffractometry (XRD), and Fourier transform infrared spectroscopy (FTIR) to confirm the structural features (dense), elemental composition, and the presence of different functional groups. Hence, this study concluded that the use of quicklime with granulated blast furnace slag is suitable for conditioning during sludge dewatering. [Figure not available: see fulltext.]. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.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