China
Africa
Explore chapters and articles related to this topic
Advanced Biotechnological Approaches towards Treatment and Recycling of Wastewater from Pharmaceutical Industry
Published in Gunjan Mukherjee, Sunny Dhiman, Waste Management, 2023
Aditya Amrut Pawar, Nomvano Mketo, Nilesh S. Waghl, Jaya Lakkakulal
Aerobic treatment technology has been used for treating wastewater effluents of various sources like wine, oil, food processing, dairy industry and municipal wastewater (Petruccioli et al. 2002, Vijayaraghavan et al. 2007, Malladi and Ingham 1993, Li and Zhang 2002, Witzig et al. 2002). Aeration is one of the most important elements of the aerobic treatment system of wastewater, because it supplies the required amount of dissolved oxygen to microorganisms, which are aerobic in nature for degradation of organic wastes (Khan and Mostafa 2011). However, transfer of oxygen in wastewater is affected by the characteristics of the biomass and design of aeration system. There are three parameters which characterize biomass during aeration: particle size, viscosity, and particle concentration (Germain and Stephenson 2005). To amplify the aerobic biochemical reaction, the oxygen supply rate into microbes must be rapid with limited oxygen. Therefore, a highly structured oxygen supplier and a sturdy system to treat wastewater are a requirement for an effective treatment (Mondal et al. 2017). Various configurations of aerobic treatment systems for treating industrial based pharmaceutical wastewater have been depicted in Table 2.
Miscellaneous Water Treatment Methods II
Published in Subhash Verma, Varinder S. Kanwar, Siby John, Environmental Engineering, 2022
Subhash Verma, Varinder S. Kanwar, Siby John
Aeration can be achieved by passing diffused air into water or cascading water through the air. A process called air stripping does both. In chemical oxidation, aeration may help prepare the water for treatment, thus reducing chemical dosages required for oxidation.
Advanced or Tertiary Treatment
Published in David H.F. Liu, Béla G. Lipták, Wastewater Treatment, 2020
Don E. Burns, George J. Crits, Donald Dahlstrom, Stacy L. Daniels, Bernardo Rico-Ortega, Chakra J. Santhanam, E. Stuart Savage, Frank P. Sebastian, Gerald L. Shell, Paul L. Stavenger
Conventional secondary treatment usually involves an extensive aeration step, mixing wastewater with a bacterial seed. The use of pure oxygen makes the aeration steps more efficient by providing an oxygen-rich environment for the entire process.
Estimation and comparison of gabion weir oxygen mass transfer by ensemble learnings of bagging, boosting, and stacking algorithms
Published in ISH Journal of Hydraulic Engineering, 2023
KM Luxmi, N. K Tiwari, S Ranjan
Aeration is the process of oxygen mass transfer from the atmosphere to water. The eddy generated by the porous weir will improve the oxygen mass transfer efficiency by creating a good number and bigger shapes of bubbles. The datasets were collected, and a physical test was accomplished on the gabion weir for the plunging jet. Ensemble learnings of bagging, boosting, and stacking were powerful machine learning paradigms that controlled a group of various individual learners to accomplish better-estimating potential than that could be realized by any base learner. Four ensemble learnings of bagging (R.F., DRF), boosting (GBM), stacking (S.E.), and empirical relations of LVR and NLVR were both generated in the present study, along with existing relations of Luxmi et al. (2022). Srinivas & Tiwari (2022a, 2022b) were used to simulate the oxygen mass transfer efficiency (OMTE20) of the gabion weirs with five inputs of discharge per unit width (q), gabion particle mean size (D50), gabion particle porosity (n), gabion height (P), and drop height (H). Two performance metrics viz. R2, RMSE, and graphical performance assessors, including scatter plots, predictive model fitting curves, relative error curves, Taylor diagrams, and violin error trees, were applied to assess the proposed model’s simulation accuracy in the training and testing stages.
Study of air–water interface generator as oxygen transfer enhancer in diffused aeration system
Published in Environmental Technology, 2022
Passaworn Warunyuwong, Tsuyoshi Imai
In the wastewater treatment process, aeration is a key process to provide oxygen and liquid circulation. Oxygen is supplied to wastewater by dispersing air bubbles through submerged diffusers. This conventional means of aeration can transfer gaseous oxygen through dispersed bubble and free water surface [1–6]. A large proportion of oxygen typically transfers through dispersed bubbles, however, a large area of free water surface in the aeration tank also has significant contribution [4]. From literatures [1–4,6], mass transfer from free water surface was from 11 to 70 percent (%) of the total mass transfer. Therefore, it comes to a concept of the oxygen transfer enhancement by increasing the contact area between air and water from the water surface transfer. There are many research studies focusing on water surface transfer improvement in diffused aeration system [7–11]. There is evidence reporting that their proposed apparatus called liquid-film-forming apparatus could enhance the overall oxygen transfer efficiency from 11 to 37 % depending on water depth, water surface area, water volume, air flow rate, and diffuser type (also referred as generated bubble size). In this study, our proposed apparatus called an air–water interface generator, which is originally designed from mentioned studies, was tested aiming for oxygen transfer improvement from surface transfer by increasing the contact area between air and water along the depth of the aeration tank.
Improvement of oxygen transfer by increasing contact area between gas and liquid using air–water interface generator
Published in Environmental Technology, 2021
Passaworn Warunyuwong, Tsuyoshi Imai
Aeration is a crucial process in wastewater treatment. Its principal role is to supply the oxygen needed for all aerobic treatment processes. In the activated sludge process, aeration also ensures water circulation to distribute dissolved oxygen concentration uniformly and strips excess gases produced by the biological degradation processes such as CO2. Water in a conventional diffused aeration tank generally contacts oxygen in the gas phase via two means. One is the oxygen transfer by dispersed bubbles in the water. A free, turbulent bubble plume ascends from bubble distributor to the water surface by buoyant forces and disperses in bulk water. The second is the free water surface transfer. Oxygen transfers from the atmosphere via the air–water interface situated on the open water surface due to turbulence induced by bubble-plume motion and water circulation. Although a large proportion of oxygen is typically absorbed from dispersed bubbles, the oxygen transfer on the air–water interface from the atmosphere in the aeration tank having a sizeable free surface area should not be neglected [1].