scholarly journals Treatment Method Assessment of the Impact on the Corrosivity and Aggressiveness for the Boiler Feed Water

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.

2012 ◽  
Vol 7 (2) ◽  
Author(s):  
Christopher C. Boyd ◽  
Steven J. Duranceau

A pilot test program was conducted to evaluate methods for maintaining the productivity of a hollow fiber ultrafiltration membrane operating at constant flux values of 49.2 and 62.3 gallons/ft2-day. The ultrafiltration pilot filtered settled water from a conventional surface water treatment plant in Florida. The testing assessed the impact of different chemical maintenance protocols on UF membrane performance. Seasonal variations in water quality necessitated changes in the type and combination of cleaning agents used to maintain membrane performance. Sodium hypochlorite, citric acid and sodium hydroxide were used during pilot testing as the fouling characteristics of the water changed with time. Pilot results were used to develop alternative chemically enhanced backwash strategies that varied with seasonally-impacted changes in feed water quality. Citric acid, with a target pH of <3, was found to be effective in August and September; whereas, a combination of citric acid and high pH sodium hydroxide chemically enhanced backwashes successfully maintained performance between November, 2010 and May, 2011.


2015 ◽  
Vol 46 (4) ◽  
pp. 291-335 ◽  
Author(s):  
M. Pivokonsky ◽  
J. Naceradska ◽  
I. Kopecka ◽  
M. Baresova ◽  
B. Jefferson ◽  
...  

2016 ◽  
Vol 11 (3) ◽  
pp. 621-633
Author(s):  
J. Nathoo ◽  
E. Hong Gay ◽  
N. Hussain

The feed water quality associated with mine water treatment is typically characterised by a dynamic variability resulting from the fact that the final feed water to the water treatment plant (WTP) can be an amalgamation of water streams emanating from a number of sources. Consequently, the ability to deal with the dynamic nature of the feed water quality towards successful and sustainable mine water treatment goes beyond a proactive approach and requires a systemic, predictive approach. This paper discusses the development of an unsteady state mass balance model on a surface dam located on a coal mine towards predicting the dynamic fluctuations in total dam volume and its total dissolved solids (TDS) concentration in the feed water to a NuWater 20 MLD mobile WTP, comprising chemical conditioning, ultrafiltration and reverse osmosis (RO). The unsteady state mass balance, incorporated water entering the dam via the opencast pits, underground compartments, seasonal rainfall and the RO brine return. Water leaving the dam comprised the feed water to the WTP, partial brine treatment, surface evaporation and seepage. Validation of the model using actual data over an 8-month period showed excellent results. The model showed that without water treatment, the dam would overflow in 218 days. Although the dam's volume could be sustained at the ideal volume by treating 14.2 MLD, its TDS would exceed the maximum environmental limit in 197 days. Consequently, the combination of a 13.2 MLD WTP with a 1 MLD brine treatment plant provided the optimal water treatment strategy to sustainably maintain the dam's TDS concentration and volume within acceptable limits over the 5-year investigation period. This paper demonstrates the importance of using a predictive methodology for forecasting feed water characteristics and as an early warning system for most water treatment systems that are subjected to dynamic conditions.


2014 ◽  
Vol 9 (3) ◽  
pp. 386-391 ◽  
Author(s):  
M. N. Dammo ◽  
A. Y. Sangodoyin

Water quality and supply are central to the socio-economic development of any nation. Scarcity of potable water results in the construction of dams and water treatment plants. Unfortunately, provision of potable water through improvement and treatment may prove to be difficult because of the socio-economic activities around a dam. This study is aimed at assessing the socio-economic activities around the Alau Dam Maiduguri, and how they affect the quality of raw water supply to Maiduguri Water Treatment Plant. The data was generated through the administration of questionnaires, and by interview and water quality analysis of dam and irrigation sites. The samples were subjected to physical, chemical and biological analysis to assess the impact of socio economic activities on the dam water, and its suitabilityfor drinking and agricultural uses. Findings reveal pollution with high concentration of nitrate (260–230 mg-NO3/l), phosphate (22–28 mg/l) and Escherichia coli (13–24 n/100 mg). This arose from improper sanitary management, inadequate public education on irrigation,indiscriminate waste disposaland some farming practices. Regular monitoring of socio-economic activities around the dam, and doing away with unhealthy waste disposal practices are recommended to safeguard the raw water supply to the treatment plant.


2015 ◽  
Vol 737 ◽  
pp. 285-288
Author(s):  
Yu Yun Fu ◽  
Jin Duo Shi

EDI water treatment technology currently in power plant boiler feed water preparation systems more and more common. The main reason is due to the EDI water treatment technology has obvious advantages in terms of environmental protection. However, during operation to ensure that the equipment is running well and boiler water effluent quality to meet the requirements, but also the factors affecting the operation of enough attention. Through the analysis of the actual operation characteristics of EDI case of water treatment technology and application notes were simply described.


2011 ◽  
Vol 374-377 ◽  
pp. 1021-1024
Author(s):  
Xian Qiu Zhang ◽  
Jing Feng Xu ◽  
Ming Xia Du ◽  
Yong Zhang

A boiler-water treatment device main composed of solar energy heater and reverse osmosis was designed Experiments on permeation flow and water quality as functions of temperature caused by solar energy were conducted. The experimental results showed that when the operation pressure was kept at 0.9MPa, permeation flow could increase 35.5%, from 6.5L/min to 8.8L/min if the feed water temperature increased from 18°C to 38°C by solar energy; and the produced water could totally meet Chinese water quality standard for middle or low pressure steam-boiler. On the other hand, if the permeation flow was kept at 8 L/min, the operation pressure would drop by 32.2%, from 1.18MPa to 0.78MPa. Based on these experimental results, economic and environmental analysis on a case of 10m3/h boiler-water treatment device by reverse osmosis employing solar energy were conducted, the results shows great significance for energy saving and environmental pollutants cut. All this showed this new RO system with pre-heating the feed water by solar energy could be widely applied in boiler-water treatment.


2004 ◽  
Vol 4 (5-6) ◽  
pp. 271-276
Author(s):  
D. Codiasse ◽  
Ch. Caudron ◽  
I. Baudin ◽  
M. Chouhou ◽  
C. Campos

Many water treatment plants are currently facing the challenge of removing both turbidity and organic matter at a reasonable cost. This double objective often requires high coagulant doses, resulting in high operating costs due to the increase in both reagents use and sludge production. An attractive approach to reducing operating costs while maintaining the finished water quality is to add the coagulant in a double step sequence, which is referred to as double step coagulation. In this article, bench-scale experiments were conducted to assess the impact of a double step addition of coagulant on both turbidity and organic matter removal in clarification processes. The results showed that coagulant dose required for a given turbidity target can be significantly reduced. For example, for a final turbidity of 1 NTU, the coagulant dose can be reduced by 20% with respect to the Coagulant Reference Dose (CRD), which represents 200,000 Euros per year without any additional investment on infrastructure. Following these bench scale demonstrative tests, the double step coagulation strategy was adopted at full scale by the Sidi Said Maachou Water Treatment Plant in Morocco. Operated by the Société des Eaux de l'Oum Er-rbia, this plant treats 200,000 m3/day to supply the city of Casablanca. The double step coagulation was implemented to achieve a double objective: turbidity and organic matter removal at the lowest chemical cost.


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