scholarly journals FEATURES OF WATER TREATMENT FOR BOILER ROOMS

2021 ◽  
Vol 43 (4) ◽  
pp. 17-24
Author(s):  
A. A. Dolinsky ◽  
O. M. Obodovych ◽  
V.V. Sydorenko ◽  
A.Y. Lymar
Keyword(s):  
Water Treatment ◽  
Dissolved Oxygen ◽  
Negative Impact ◽  
Salt Content ◽  
Cation Exchange Resin ◽  
Hot Water ◽  
Feed Water ◽  
Resource Saving ◽  
Steam Boilers ◽  
Total Salt Content

Thousands of medium and low steam boilers and hot water boilers operate in the country's industry, municipal energy and agriculture. Their reliable operation is largely determined by the maintenance of a rational water-chemical regime. The main problems of source water are the presence of dissolved oxygen, iron ions, salts of calcium, and magnesium. The aim of the work is to analyze the existing technologies and equipment for water treatment for different types of boilers. Determination of physicochemical parameters and requirements for source and prepared water. Presentation of new multi-purpose energy-efficient and resource-saving water treatment equipment. The article considers the negative impact of dissolved iron, hardness salts, dissolved gases present in the feed water on the operation of boiler equipment. The main requirements for feed water in terms of hardness, the content of dissolved oxygen, and oils for steam and hot water boilers are given. The mechanism of scale formation is given. The main existing methods of feed water treatment are considered, namely softening on Na-cation exchange resin, liming, softening, and reduction of total salt content on reverse osmosis units, softening, and reduction of total salt content by the sequential passage of water through H, OH-ion exchange filters. A multi-purpose aeration-oxidation setup of rotor type (AORT) is presented, which implements the method of discrete-pulse energy input, on which it is possible to carry out operations to remove iron, manganese, hardness salts, increase pH and degassing from water.

Diagnosis for Water and Steam Quality Problem in Taishan Ultra-Supercritical Power Plant

2014 ◽  
Vol 1044-1045 ◽  
pp. 291-294
Author(s):  
Mao Dong Li ◽  
Chen Lin Dai ◽  
Jun Ming Zhao ◽  
Yu Hui Du ◽  
Lin Yang ◽  
...  
Keyword(s):  
Water Treatment ◽  
Power Plant ◽  
Dissolved Oxygen ◽  
Working Condition ◽  
Iron Deposit ◽  
Feed Water ◽  
Steam Quality ◽  
Control Effect ◽  
Boiler Water ◽  
Quality Problem

Water and steam quality during operation must be strictly controlled for ultra-supercritical unit. Changes of indicators in water and steam are supervised, water and steam quality and working condition of boiler water, as well as supervision of water and steam quality are reviewed in this paper. Risks of corrosion and scaling in Taishan power plant is assessed. As a result, control effect of TOC is remarkable in Taishan power plant, content of Cl- and SO42- can satisfy the control standard, that is , risk of corrosion and scaling is low. Dissolved oxygen is significantly exceeded in the condensate polishing desalination device , and there has risk of iron deposit. To convert the feed water treatment from AVT(All Volatile Treatment) to OT(Oxygenated Treatment) can solve the problems above .

scholarly journals Progress in Research and Application of Nanofiltration (NF) Technology for Brackish Water Treatment

Membranes ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 662
Author(s):  
Jiayu Tian ◽  
Xingrui Zhao ◽  
Shanshan Gao ◽  
Xiaoying Wang ◽  
Ruijun Zhang
Keyword(s):  
Water Treatment ◽  
Brackish Water ◽  
Membrane Fouling ◽  
Control Strategies ◽  
Salt Content ◽  
Operating Conditions ◽  
Size Exclusion ◽  
Membrane Properties ◽  
Future Research ◽  
Feed Water

Brackish water is a potential fresh water resource with lower salt content than seawater. Desalination of brackish water is an important option to alleviate the prevalent water crisis around the world. As a membrane technology ranging between UF and RO, NF can achieve the partial desalination via size exclusion and charge exclusion. So, it has been widely concerned and applied in treatment of brackish water during the past several decades. Hereon, an overview of the progress in research on and application of NF technology for brackish water treatment is provided. On the basis of expounding the features of brackish water, the factors affecting NF efficiency, including the feed water characteristics, operating conditions and NF membrane properties, are analyzed. For the ubiquitous membrane fouling problem, three preventive fouling control strategies including feed water pretreatment, optimization of operating conditions and selection of anti-fouling membranes are summarized. In addition, membrane cleaning methods for restoring the fouled membrane are discussed. Furthermore, the combined utilization of NF with other membrane technologies is reviewed. Finally, future research prospects are proposed to deal with the current existing problems. Lessons gained from this review are expected to promote the sustainable development of brackish water treatment with NF technology.

scholarly journals Properly Recycled Perlite Saves Money, Does Not Reduce Greenhouse Tomato Yield, and Can Be Reused for Many Years

2005 ◽  
Vol 15 (2) ◽  
pp. 342-345 ◽  
Author(s):  
H.Y. Hanna
Keyword(s):  
Negative Impact ◽  
Salt Content ◽  
Hot Water ◽  
Optimum Level ◽  
Marketable Yield ◽  
Greenhouse Tomato ◽  
Tomato Yield ◽  
The Media ◽  
Reduced Salt ◽  
The Cost

A study was conducted to determine if raising tomatoes (Lycopersicon esculentum) in cleaned and disinfected used perlite would be more economical than new perlite and have no negative impact on yield. Cleaning and disinfecting used perlite for recycling saved 56% of the cost to replace the media and reduced salt content to the optimum level recommended for raising container grown plants. Disinfecting used perlite with hot water raised media temperatures above limits necessary to kill several fungi and nematodes. Tomatoes planted in recycled perlite produced greater marketable yield and heavier fruit than those planted in new perlite. Season and year of planting also have significant effects on yield. Used perlite can be cleaned and disinfected as needed and recycled for many years because it is not organic in nature and physically and chemically stable.

scholarly journals Reducing Time and Expense to Recycle Perlite for Repeat Use in Greenhouse Tomato Operations

2010 ◽  
Vol 20 (4) ◽  
pp. 746-750 ◽  
Author(s):  
Hanna Y. Hanna
Keyword(s):  
Water Treatment ◽  
Negative Impact ◽  
Minimum Cost ◽  
Fruit Weight ◽  
Hot Water ◽  
Hot Water Treatment ◽  
Marketable Yield ◽  
Tomato Yield ◽  
Electric Drill ◽  
Weight Pruning

Planting greenhouse tomatoes (Solanum lycopersicum) in the same perlite more than once without reconditioning to restore medium loose structure, desalination to remove excess salt, and disinfection to guard against pest contamination is risky, and replacing the perlite to produce every new crop is costly. Reconditioning and treating perlite with hot water at a minimum cost provides a favorable solution for both problems and saves natural resources. A study was conducted in a 30 × 96-ft greenhouse in Spring 2007, 2008, and 2009 (January–July) to evaluate three methods for perlite recycling cost, desalination efficiency, and effects on tomato yield at three or four fruit per cluster. Each recycling method consisted of two components: the reconditioning action and the hot water treatment. The three recycling methods included no stir/sift then disinfect, stir then disinfect, and sift then disinfect. Perlite recycled with the no stir/sift then disinfect method was not reconditioned before the hot water treatment. Instead, it was agitated with a nozzle mounted on a pressure washer wand during the hot water treatment. Perlite recycled with the stir then disinfect method was reconditioned first with an auger mounted on an electric drill and then treated with hot water. Perlite recycled with the sift then disinfect method was reconditioned first by sifting the perlite with a homemade apparatus and was then treated with hot water. Recycling perlite with the no stir/sift then disinfect method reduced labor input by 49% and 81% compared with the stir then disinfect and the sift then disinfect methods, respectively. The no stir/sift then disinfect method reduced recycling cost by 22% and 50% compared with the other two methods, respectively. Perlite that was not reconditioned (no stir/sift) had higher nitrate-nitrogen (NO3-N) before hot water treatment than the stirred perlite and equal NO3-N to the sifted perlite. Hot water treatment significantly reduced medium electrical conductivity, NO3-N, potassium, and sodium. Tomatoes grown in perlite recycled with any of the three methods produced similar marketable and cull yields and fruit weight. Pruning fruit to three per cluster increased marketable yield, fruit weight, and reduced cull yield. There was no significant recycling method × cluster pruning interaction for yield components, indicating that all recycling methods had similar effects on tomato yield at three or four fruit per cluster. We conclude that the no stir/sift then disinfect method is less time consuming, more economical, and has no negative impact on yield. Tomatoes grown with three fruit per cluster in perlite recycled with any of the three methods produced greater marketable yield, less cull yield, and heavier fruit than tomatoes grown with four fruit per cluster.

scholarly journals STUDY OF WATER ECONOMIZERS OF STEAM BOILERS AND DEVELOPMENT OF MEASURES FOR EXTENDING THEIR OPERATION

2021 ◽  
Vol 2 (37) ◽  
pp. 64-67
Author(s):  
O. Glushchenko ◽  
I. Sapytsky
Keyword(s):  
Negative Impact ◽  
Combustion Products ◽  
Thermal Calculation ◽  
Feed Water ◽  
Steam Boiler ◽  
Boiler Unit ◽  
Excess Air ◽  
Steam Boilers ◽  
Heat Perception ◽  
Main Components

The operation of the economizer of the P-50 boiler unit, as well as the conditions of its operation have been studied. The economizer is one of the main components of the boiler unit. It works in very difficult conditions. The quality of the feed water supplied to the drum depends on the operation of the economizer. The thermal calculation of steam boiler type P-50 using different values ​​of feed water temperatures at the inlet to the economizer and different coefficients of excess air in the furnace, identified and analyzed factors that negatively affect the operation of the water economizer to conduct a detailed analysis and development of recommendations to improve the operation of the steam boiler as a whole and separately economizing heating surfaces. As a result of the calculations, the dependences of the heat perception of the economizer on the temperature of the feed water at the inlet to the economizer and the dependence of the excess air on the total volume of combustion products are obtained. The paper considers in detail the possible causes of failure of economizers and factors that have a negative impact on the condition of the metal pipes; proposed recommendations that will increase the service life of economizers until the next repair campaign.

Titration of sulphates and lead using lead ion selective electrode

1981 ◽  
Vol 46 (2) ◽  
pp. 368-376 ◽  
Author(s):  
Josef Veselý
Keyword(s):  
Ionic Strength ◽  
Electrode Surface ◽  
Salt Content ◽  
Ion Selective Electrode ◽  
Lead Ion ◽  
Selective Electrode ◽  
Limit Of Determination ◽  
Total Salt Content ◽  
Automatic Titration

Titration of sulphates with lead perchlorate employing lead ion selective electrode indication was studied using additions of various organic solvents at different pH' and ionic strength values. As the optimum emerged systems with 60-70% 1,4-dioxane, pH' 5.3-5.6. After dehydration with sodium hydroxide, dioxane must be freed from the electrode surface-oxidizing impurities by their reduction with sodium metal and subsequent distillation. The method was applied to determination of sulphates in mountain spring waters. Units of ppm can be determined; the limit of determination, however, depends considerably on the content of dioxane, total salt content in the sample, and speed of the semi-automatic titration. Lead can be determined with EDTA in concentrations down to c(Pb2+) = 5 . 10-6 mol l-1.

scholarly journals Evaluating polymer interplay after hot water pretreatment to investigate maize stem internode recalcitrance

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Amandine Leroy ◽  
Xavier Falourd ◽  
Loïc Foucat ◽  
Valérie Méchin ◽  
Fabienne Guillon ◽  
...  
Keyword(s):  
Cell Wall ◽  
Negative Impact ◽  
Lignin Content ◽  
Structural Features ◽  
Hot Water ◽  
Condensed State ◽  
Structural Factors ◽  
Water Pretreatment ◽  
Hot Water Pretreatment ◽  
The Impact

Abstract Background Biomass recalcitrance is governed by various molecular and structural factors but the interplay between these multiscale factors remains unclear. In this study, hot water pretreatment (HWP) was applied to maize stem internodes to highlight the impact of the ultrastructure of the polymers and their interactions on the accessibility and recalcitrance of the lignocellulosic biomass. The impact of HWP was analysed at different scales, from the polymer ultrastructure or water mobility to the cell wall organisation by combining complementary compositional, spectral and NMR analyses. Results HWP increased the kinetics and yield of saccharification. Chemical characterisation showed that HWP altered cell wall composition with a loss of hemicelluloses (up to 45% in the 40-min HWP) and of ferulic acid cross-linking associated with lignin enrichment. The lignin structure was also altered (up to 35% reduction in β–O–4 bonds), associated with slight depolymerisation/repolymerisation depending on the length of treatment. The increase in $${T}_{1\rho }^{H}$$ T 1 ρ H , $${T}_{HH}$$ T HH and specific surface area (SSA) showed that the cellulose environment was looser after pretreatment. These changes were linked to the increased accessibility of more constrained water to the cellulose in the 5–15 nm pore size range. Conclusion The loss of hemicelluloses and changes in polymer structural features caused by HWP led to reorganisation of the lignocellulose matrix. These modifications increased the SSA and redistributed the water thereby increasing the accessibility of cellulases and enhancing hydrolysis. Interestingly, lignin content did not have a negative impact on enzymatic hydrolysis but a higher lignin condensed state appeared to promote saccharification. The environment and organisation of lignin is thus more important than its concentration in explaining cellulose accessibility. Elucidating the interactions between polymers is the key to understanding LB recalcitrance and to identifying the best severity conditions to optimise HWP in sustainable biorefineries.

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