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Wastewater treatment scheme according to the developed technological scheme with a hydrocyclone (designations in the text)
Source publication
Technologies associated with the use of a membrane bioreactor (MBR) is becoming one of the dynamically developing directions in the wastewater disposal system. However, a certain part of the used design of membrane units are exposed to mechanical contamination, which significantly impairs their performance. This is especially noticeable when workin...
Contexts in source publication
Context 1
... improved technological scheme for wastewater treatment using a membrane bioreactor ( Figure 1, innovative patent of the Republic of Kazakhstan No. 21444) includes bioreactor 1; sewage pump 2 equipped with a hydrocyclone 3. ...
Context 2
... tests of the hydrocyclone unit and the membrane module "Mikrodin" were carried out in summer at the site of the wastewater treatment plant in Nur -Sultan as part of the wastewater treatment process line (Figure 2). The prototype of the installation was manufactured according to the technological scheme (Fig. ...
Citations
... If it is necessary to clean the lifted liquid from various mechanical impurities or to take the water-ground mixture from the water source, additional water treatment devices are used, mainly in the form of hydrocyclones of various designs and operating modes [11][12][13][14][15][16][17]. This is due to the fact that hydrocyclones are characterized by their high performance and ability to efficiently clean water from mechanical impurities at a relatively small size and cost, with low resource costs for operation. ...
... As a comparative analysis of the operation of hydrocyclone water treatment plants shows, the working processes in hydrocyclones can be carried out both in the pressure field and in the vacuum field [11][12][13][14][15][16][17][18][19][20]45]. At the same time, the nature of the movement of a liquid with mechanical particles in a hydrocyclone and the parameters of hydrodynamic processes differ little from each other. ...
The intake of natural water or waste water from a depth exceeding the suction height of centrifugal pumps is mainly carried out due to additional water supply at the suction of the pump. However, this process becomes more complicated if it is necessary to purify water from mechanical impurities. The purpose of the presented work is to consider this issue based on the development and study of the parameters of an ejector water intake treatment plant equipped with a pressure-vacuum hydrocyclone. The main contribution of the ongoing research is the establishment of the technological parameters of the installation, and their features in the pressure-vacuum mode of operation, in contrast to the known pressure and vacuum hydrocyclones separately. In terms of methodology, the main parameters of the developed installation were established during the testing of its prototype on a specially built stand using well-known regulatory guidelines in the hydraulic research system. As a result of the study, the nature of the change in pressure inside a cylindrical–conical hydrocyclone, with established design dimensions and the patterns of formation of vacuum and pressure-vacuum modes depending on the initial parameters, was revealed. The data obtained to determine the effect of technological parameters of ejection and the characteristics of the supplied water with impurities on the operating mode of the hydrocyclone confirm the efficiency of water intake and purification. A rational mode of joint operation of the elements of a closed system is achieved at the maximum value of the installation efficiency and ensuring low specific energy consumption per 1 m3 of treated water.
... The first group includes insoluble solids, suspended and colloidal particles. The second group includes the compounds, the presence of which in water leads to the formation of solid inclusions (Kassymbekov et al. 2021, Sevostianov et al. 2021. It is possible to remove the substances belonging to the first group at the expense of mechanical methods, besides preliminary clarification of water on the filter leads to increase in productivity of a membrane (Polyakov et al. 2019). ...
... The first facility to implement the technology using hydrocyclones in continuous-flow configuration was Strass in Austria in 2012 in an oxidation ditch process, with over 25 installations in the past 9 years in various other formats of continuous-flow configurations, including continuousflow anaerobic-anoxic-oxic (A 2 O) configuration (Avila et al., 2021), anaerobic-oxic (AO) simultaneous nitrification/denitrification (SND) configuration (Regmi et al., 2019), modified Ludzack-Ettinger (MLE) configuration Partin, 2019) integrated fixed-film activated sludge (IFAS) four-stage Bardenpho configuration (Ford et al., 2016;Partin, 2019), and membrane bioreactors (Noguchi et al., 2018;Zhuzbay et al., 2021). Despite this large diversity of installations, a detailed morphological transition of hydrocyclone based densification is missing, and opportunities for its control are needed. ...
Full-scale demonstration of activated sludge conversion into a granule-floc hybrid process was implemented in Dijon (France) water resource recovery facility (WRRF). Biomass densification was achieved based on external gravimetric selection using hydrocyclones within continuous-flow Anaerobic-Anoxic-Oxic (A2O) biological nutrient removal (BNR) bioreactor. The goal was to optimize settleability of biological sludge by lowering and stabilizing Sludge Volume Index (SVI) to improve process robustness and resiliency. Process proved to stabilize operation and to uncouple the total solids residence time (SRT) between floc and granule morphologies. The densified biomass initially produced stable SVI < 100 mL/g for a period of 4 months and thereafter a steady state year-round SVI below 50 mL/g, including the winter period during which the control train SVI expansion >200 mL/g. The densified biomass successfully broke the vicious cycle of interannual bulking. Form and function interrelationship is proposed for the densified biomass (hybrid floc-granule). The concept of biological architecture is proposed as the purposeful control of granule and floc proportions, with a proposed ‘form factor’ ratio of 1:2 granule to floc, that produce a ‘SRT uncoupling function factor’ ratio of 4:1 granule to floc, further resulting in very stable settling and effluent functionalities.
Practitioner Points
• Controlling granule-floc proportions allows for Sludge Volume Index (SVI) operational adjustment, which further allows for increased clarified design accuracy.
• One-third aggregates dramatically improved settling characteristics: 20% and 35% of AGS ensures SVIs below 100 mL/g and 50 mL/g, respectively.
• Densified biomass enables new clarifier flux rates approach for engineering and operation practices:
• Doubling typical surface loading rates from 6.0-8.5 to 15-20 kg.m⁻².h⁻¹ and surface overflow rates from 0.6-0.8 to 1.5-2.4 m/h
• SRT uncoupling of 1:4 is achieved between floc and granule, enabling specific niche environment for fast and slow growing organisms.
The flow field of a hydrocyclone was investigated using both computational fluid dynamics (CFD) and particle image velocimetry (PIV). A refractive index matching method was employed to improve the precision of the PIV measurements. The CFD results are in good agreement with PIV measurements. Detailed analysis reveals significant axial asymmetry in the velocity components, with the radial velocity component exhibiting notable disparities. This observation is supported by quantitative data comparing different sections of the hydrocyclone. It is further found that the asymmetry might be mainly attributed to the secondary vortexes with the single inlet of the hydrocyclone. And the secondary vortexes, superimposed on the primary flow rather than existing on its own, spiral downwards from near the inlet towards the underflow orifice. It is hypothesized that specific boundary effects and pressure gradients play a pivotal role in the formation of secondary flows. This assumption is grounded on both theoretical considerations and empirical observations, suggesting that these factors significantly influence the flow dynamics within the hydrocyclone. The insights gained from our measurement methodology and enhanced understanding of secondary flows within hydrocyclones are not only poised to serve as valuable references for fellow researchers but also have the potential to inform the design and operational optimization of hydrocyclones for improved efficiency and performance.
