Table 2 Comparison of different wastewater treatment techniques.
Related Figures (16)
Common characteristics of tannery wastewater. Table 1 Fig. 1. Schematic representation of modified MBR set up for TWW Treatment (Giacobbo et al., 2014) Application of modified MBR in TWW treatment. Table 3 Application of Anaerobic MBR (AnMBR) for TWW Table 4 Fig. 2. Variation in (a) COD and (b) NH3-N removals as functions of backflow ratio and salinity (Madan et al., 2022). Table 5 Application of moving bed biofilm bioreactor (MBBR) in TWW. and 90 + 10 mg-COD,, Ly Though, it was noticed that at rates of approximately transmembrane pressure (TMP) of 1.02 kPa/day and cake layer thickness of 1.2 mm/day, both increased during TWW. It is indicated that the cake layer thickness was between 47.8 and 51.5 mm. Furthermore, various inorganic components of the residue cake were analyzed by using an Inductively Coupled Plasma-Optical Emission Spectrometer (ICPOES), and the study reported that Al, Cr, Mg and Ca were prevalent (weight percentage rate 72:13:4:10). Fig. 3. Schematic representation of OMBR for TWW (Luo et al., 2016) The MBBR method is a robust, efficient, and self-driven recognized technology for wastewater treatment (Yu et al., 2019). This method is widely used to treat wastewater originating from slaughterhouses, paper and pulp industries, phenol industries, dairies, refineries, poultry pro- cessing, pharmaceuticals, potable water, and aquaculture. The MBBRs can powerfully be applied under extreme volumetric loading conditions extending from 25 to 30 kg COD/m°d. The significant benefits of MBBR compared to other biofilm processes include its suppleness with manner to the preference of carrier filling and reactor shape along with a min- imum surface area of 200-250 cm?m° and at carrier filling of 30-70 %. The optimal gross nitrogen, total phosphorus, BOD, and COD removal accuracy of in TWW were found to be 99, 99, 96 and 97 % at HRT of 2-6 h. The concentration of the biomass was found to be between 6900 and 7200 mgL~’ which clung on bio-carriers surface with improved activeness of biofilm (Hosseini and Borghei, 2005). This constant pro- cess ensures the advantages of MBBR, including ease of operation, flexibility, strong resistance against loading impact and a smaller carbon footprint. The MBBR process also significantly efficiently processes wastewater discharged during household and industrial operations with a lower carbon footprint. The MBBR ensures superior efficiency with the lowest operational cost. It can be mixed with other cutting-edge tech- nologies, i.e., oxidation ponds, microbial fuel cells, and AS for TWW treatment, to achieve higher removal efficiency. In future, integrating IFAS with higher rate of MBBRs along with high STR and low HRT can be used to improve the efficiency (Hosseini and Borghei, 2005). An innovative operating design of anoxic-aerobic MBBR (AMOMOX process) was demonstrated through an experiment to enable instanta- neous sludge production minimization, pollutant reduction, and nitro- gen reduction (Deng et al., 2016). The AMOMOX experiment saw significant fluctuation in method parameters when the feed operation switched from synthetic wastewater to tannery influent. The tight adherence to operating techniques significantly eliminated sCOD, TCOD, total nitrogen and ammonia nitrogen up to 94.8, 93.5, 88.7, and 95.2 %, respectively. The feeding of filamentous bacteria and the deliberate encouragement of cell lysis efficiently maintained sludge yield limitation. In this case, the sludge produced (Yobs) was reduced to 0.51 gVSS/ gCOD, resulting in an estimated sludge reduction of 46.8 % to a parallel-run traditional AS treatment. The AMOMOX process experimental accomplished instantaneous sludge reduction, pollution, and nitrogen removal from synthetic to actual TWW. The AMOMOX Application of Osmotic membrane bioreactor (OMBBR) in TWW treatment. Table 6 microfiltration) or can be used not only for producing energy (i.e., electricity and biogas) but also can able to recover nutrient-water and solute recovery (Hou et al., 2017). For instance, OMBRs integrated with bio electrochemical system (BES)-can yield electric energy through the contact between EAB on organic compounds and the anode in the wastewater (Yang et al., 2018). Furthermore, BES-based OMBRs can recover reverse-fluxed solutes by bringing electricity generation benefits a BES (Aslam et al., 2018). experiment produced excellent treated effluent quality, with 93 % TCOD, 88 % TN removal and 95 % ammonia nitrogen, corresponding to a feed OLR of 1.56-2.02 gCOD/Ld. The findings demonstrated that the AMOMOXxX system’s engagement of food scarcity-driven cryptic and cell-lysis growing resulted in profitable sludge reduction (around 46.8 %) compared to the i-CAS reactor. An integrated correlation model was developed because the trial sludge yield agreed with the stated SRT correlation. Fig. 4. Schematic representation of Hybrid MBR (Radmehr et al., 2022) Application of Hybrid MBR for TWW treatment. Table 7 focused on lab-scale applications, with only a small fraction exploring full-scale implementations. Encouragingly, promising bioreactor-based treatment technologies for up-scaling TWW treatment has received considerable attention from researchers and scientists. Addressing the imbalance in research efforts is essential, as scientists from developed countries have conducted most studies. At the same time, the impor- tance of TWW treatment is greater in developing countries where the TWW treatment is more crucial to greening the leather processing eco- friendly and sustainable.
