Impacts of separate rejection water treatment on the overall plant performance

2003 ◽  
Vol 48 (4) ◽  
pp. 139-146 ◽  
Author(s):  
B. Wett ◽  
J. Alex

A separate rejection water treatment appears as a high-tech unit process which might be recommendable only for specific cases of an upgrading of an existing wastewater treatment plant. It is not the issue of this paper to consider a specific separate treatment process itself but to investigate the influence of such a process on the overall plant performance. A plant-wide model has been applied as an innovative tool to evaluate effects of the implemented sidestream strategy on the mainstream treatment. The model has been developed in the SIMBA environment and combines acknowledged mathematical descriptions of the activated sludge process (ASM1) and the anaerobic mesophilic digestion (Siegrist model). The model's calibration and validation was based on data from 5 years of operating experience of a full-scale rejection water treatment. The impact on the total N-elimination efficiency is demonstrated by detailed nitrogen mass flow schemes including the interactions between the wastewater and the sludge lane. Additionally limiting conditions due to dynamic N-return loads are displayed by the model's state variables.

Filtration is a one of the most important and critical unit process followed worldwide which removes dirt particles from water. As the water quality standards are changing and becoming more stringent, the improvement in the performance of existing rapid sand filters is unavoidable. The use of filter conditioning to improve filter performance is a relatively recent development in drinking water treatment. Different advantages claimed by such use of filter aid includes lessening ripening period, superior turbidity removal and relatively stable filtrate quality. It also has limitations like reduction in filter run and comparatively higher back washing requirement. To assess the suitability of such method,under the existing conditions is of enormous importance.12 Current research explains the impact of filter media conditioning on the overall performance of conventional rapid sand filter. The study was carried out by installing a pilot plant at Ichalkaranji municipal water treatment plant. Different doses of alum as filter conditioner were tested and the comparison was made with the performance of conventional filter without filter aid. The parameters for evaluation were turbidity removal, filter run and backwash requirements. The dose of alum as filter conditioner was given as slug dose. The effect of zeta (ζ) potential change was observed to be one of the major reasons of the performance improvement, accelerating the surface removal since initial phase


1992 ◽  
Vol 26 (5-6) ◽  
pp. 1255-1264
Author(s):  
K. L. Martins

During treatment of groundwater, radon is often coincidentally removed by processes typically used to remove volatile organic compounds (VOCs)-for example, processes such as liquid-phase granular activated carbon (LGAC) adsorption and air stripping with vapor-phase carbon (VGAC). The removal of radon from drinking water is a positive benefit for the water user; however, the accumulation of radon on activated carbon may cause radiologic hazards for the water treatment plant operators and the spent carbon may be considered a low-level radioactive waste. To date, most literature on radon removal by water treatment processes was based on bench- or residential-scale systems. This paper addresses the impact of radon on municipal and industrial-scale applications. Available data have been used todevelop graphical methods of estimating the radioactivity exposure rates to facility operators and determine the fate of spent carbon. This paper will allow the reader to determine the potential for impact of radon on the system design and operation as follows.Estimate the percent removal of radon from water by LGAC adsorbers and packed tower air strippers. Also, a method to estimate the percent removal of radon by VGAC used for air stripper off-gas will be provided.Estimate if your local radon levels are such that the safety guidelines, suggested by USEPA (United States Environmental Protection Agency), of 25 mR/yr (0.1 mR/day) for radioactivity exposure may or may not be exceeded.Estimate the disposal requirements of the waste carbon for LGAC systems and VGAC for air stripper “Off-Gas” systems. Options for dealing with high radon levels are presented.


1996 ◽  
Vol 68 (7) ◽  
pp. 1179-1186 ◽  
Author(s):  
Stephen D. J. Booth ◽  
Daniel Urfer ◽  
Gerard Pereira ◽  
Karl J. Caber

2001 ◽  
Vol 2001 (5) ◽  
pp. 394-402 ◽  
Author(s):  
Astrid Huertas ◽  
Benoit Barbeau ◽  
Christian Desjardins ◽  
Gary A. Toranzos

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1965 ◽  
Author(s):  
Skoczko ◽  
Szatyłowicz

The aim of the study was the assessment of corrosivity and aggressiveness for boiler feed water. The negative effects of water corrosivity and aggressiveness may include silting up of the steel water supply system and the destruction of boiler equipment touched or washed by such water. They may cause the whole industrial production system to fail or be destroyed. That is why it was important to reach a high water purification level, including the calculation of water aggressiveness and corrosivity indicators. The carried out test showed that the simple system used before the modernization of the industrial water treatment plant is not sufficient to reach clean and stable water. The authors proposed modernization, including additional processes to improve boiler water quality, and designed new devices for water treatment. As a result of the new idea, groundwater taken as raw water was treated in individual and complex processes, such as pre-aeration, filtration, ion exchange (cation and anion exchange resigns), extra aeration, and extra degassing. The conducted research included chemical analyses of raw and treated water. In the conducted studies, the indirect method of water aggressiveness and corrosivity assessment was applied using mathematical calculation of the Langelier Saturation Index (LSI), the Ryznar Stability Index (RI), the Larson–Skold Index (LI), and the Singley Index (SI). The results proved that the new proposed processes for the boiler feed water treatment station allow reaching a high water quality and low level of water aggressiveness and corrosion.


2002 ◽  
Vol 45 (3) ◽  
pp. 229-237 ◽  
Author(s):  
T. Frehmann ◽  
A. Niemann ◽  
P. Ustohal ◽  
W.F. Geiger

Four individual mathematical submodels simulating different subsystems of urban drainage were intercoupled to an integral model. The submodels (for surface runoff, flow in sewer system, wastewater treatment plant and receiving water) were calibrated on the basis of field data measured in an existing urban catchment investigation. Three different strategies for controlling the discharge in the sewer network were defined and implemented in the integral model. The impact of these control measures was quantified by representative immission state-parameters of the receiving water. The results reveal that the effect of a control measure may be ambivalent, depending on the referred component of a complex drainage system. Furthermore, it is demonstrated that the drainage system in the catchment investigation can be considerably optimised towards environmental protection and operation efficiency if an appropriate real time control on the integral scale is applied.


Opflow ◽  
2019 ◽  
Vol 45 (11) ◽  
pp. 24-27
Author(s):  
Nathan J. Boyle ◽  
Paul G. Biscardi ◽  
Dawn M. Guendert ◽  
Carl W. Spangenberg

2018 ◽  
Vol 7 (4.35) ◽  
pp. 639
Author(s):  
HA Mohiyaden ◽  
LM Sidek ◽  
G Hayder ◽  
MN Noh

The quality of Klang river water is deteriorating dramatically since it is in urban places every day and become one of the major problems.  Therefore, the Malaysian government had initiated one river cleaning project named River of Life (ROL) project. This project is for rehabilitating and restoring the Klang river. A series of river water treatment plant (RWTP)s have been operated in Klang river catchment since 2014. Six RWTPs station has been monitored up to eight stations until presents. Eight parameters consisting of physio-chemical types and biological types have been recorded. RWTP effluent discharges are targeted to achieve Malaysia Interim National Water Quality Standard (INWQS) under Class II B. Since previous RWTP performance only emphasized on local river pollutants and certain conditions, this paper will investigate the effectiveness of full-scale RWTP unit process for river condition. Water quality assessment are involved which are consist of effluent water quality monitoring and pollutant removal efficiency. Most of the major pollutants able to be reduced by more than 50% reduction. Although BOD and AN still not able to achieve standard range gazetted by INWQS Class IIB, there is an improvement of river water quality at Klang River by using IFAS technology adopted in the RWTP system.


2019 ◽  
Vol 19 (7) ◽  
pp. 2098-2106
Author(s):  
Chelsea W. Neil ◽  
Yingying Zhao ◽  
Amy Zhao ◽  
Jill Neal ◽  
Maria Meyer ◽  
...  

Abstract Source water quality can significantly impact the efficacy of water treatment unit processes and the formation of chlorinated and brominated trihalomethanes (THMs). Current water treatment plant performance models may not accurately capture how source water quality variations, such as organic matter variability, can impact treatment unit processes. To investigate these impacts, a field study was conducted wherein water samples were collected along the treatment train for 72 hours during a storm event. Systematic sampling and detailed analyses of water quality parameters, including non-purgeable organic carbon (NPOC), UV absorbance, and THM concentrations, as well as chlorine spiking experiments, reveal how the THM formation potential changes in response to treatment unit processes. Results show that the NPOC remaining after treatment has an increased reactivity towards forming THMs, and that brominated THMs form more readily than chlorinated counterparts in a competitive reaction. Thus both the reactivity and quantity of THM precursors must be considered to maintain compliance with drinking water standards, a finding that should be incorporated into the development of model-assisted treatment operation and optimization. Advanced granular activated carbon (GAC) treatment beyond conventional coagulation–flocculation–sedimentation processes may also be necessary to remove the surge loading of THM-formation precursors during a storm event.


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