Ptsa (pressure and thermal swing adsorption) method to remove trihalomethanes from drinking water

1997 ◽  
Vol 35 (7) ◽  
Keyword(s):  
Drinking Water ◽  
Adsorption Method ◽  
Thermal Swing Adsorption

PTSA (pressure and thermal swing adsorption) method to remove trihalomethanes from drinking water

1997 ◽  
Vol 35 (7) ◽  
pp. 243-250 ◽  
Author(s):  
Shigekazu Nakano ◽  
Tomoko Fukuhara ◽  
Masami Hiasa
Keyword(s):  
Drinking Water ◽  
Residual Chlorine ◽  
Remarkable Difference ◽  
Adsorption Method ◽  
Heating And Cooling ◽  
Point Of Use ◽  
Thermal Swing Adsorption ◽  
Long Time ◽  
Musty Odor ◽  
Vacuum Heating

It has been widely recognized that trihalomethanes (THMs) in drinking water pose a risk to human health. THMs can be removed to a certain extent by the conventional point-of-use (POU) unit which is composed of activated carbon (AC) and microfilter. But it's life on THMs is relatively shorter than on residual chlorine or musty odor. To extent the life of AC adsorber, pressure and thermal swing adsorption (PTSA) was applied by preferential regeneration of chloroform. PTSA was effective to remove THMs, especially chloroform. Adsorption isotherms of chloroform at 25 and 70°C showed a remarkable difference so that thermal swing was considered effective. Chloroform was also desorbed by reducing pressure. By vacuum heating at 70°C, chloroform was almost desorbed from AC and reversible adsorption was considered possible. A prototype of POU unit with PTSA was proposed. Regeneration mode would consist of dewatering, vacuum heating and cooling (backwashing). The unit was maintained in bacteriostatic condition and could be used for a long time without changing an AC cartridge.

Removal of Fluoride from Drinking Water by Gel Composite of Metal Ion and Humic Acid Adsorbent

2013 ◽  
Vol 726-731 ◽  
pp. 695-699
Author(s):  
Li Hong ◽  
Si Xiang Wang ◽  
Yong Liu ◽  
Yue Chun Zhang
Keyword(s):  
Drinking Water ◽  
Humic Acid ◽  
Contact Time ◽  
Metal Ion ◽  
Fluoride Removal ◽  
Batch Adsorption ◽  
Solution Ph ◽  
Adsorption Method ◽  
Sem Images ◽  
Fluoride Adsorption

Humic acid adsorbent modified with metal ions was prepared by gel polymerization and named gel composite of metal ion and humic acid, which abbreviated GCMH to uptake fluoride from drinking water. The samples were measured by X-ray diffraction (XRD) patterns and scanning electron microscope (SEM) images. Fluoride adsorption onto the synthesized samples was investigated by batch adsorption method. In previous works, detailed studies were carried out to investigate the effect of contact time, adsorbent dose, initial solution pH, temperatures and co-existing anions. The maximum fluoride removal was obtained at pH7. Presence of HCO3− adversely affected the adsorption of fluoride. The optimum absorption conditions were at the dose of 10g/L, temperature of water of 55°Cand contact time of 6hs.

Effect of pH on Four Defluoridation Adsorbents under Natural High Fluoride Groundwater

2014 ◽  
Vol 643 ◽  
pp. 335-341
Author(s):  
Lian Xiang Li ◽  
Di Xu ◽  
Xian Jun Cheng ◽  
Rui Gang Sun ◽  
Xiao Qin Li
Keyword(s):  
Drinking Water ◽  
Field Performance ◽  
Activated Alumina ◽  
Adsorption Method ◽  
Adsorption Effect ◽  
Application Systems ◽  
High Fluoride ◽  
Actual Field ◽  
Ph Range ◽  
Filed Application

Appropriate drinking water defluoridation technology is urgently needed in china, which has a wide fluoride-rich area. The adsorption defluoridation method in the industrial high fluoride wastewater treatment is generally considered to be efficient and economic. However, the practical application of the method is not ideal in obtaining drinking water defluoridation. Four representative adsorbents activated alumina, activated zeolite, hydroxyapatite and hydrous zirconium oxide have been tested in terms of defluoridation efficiency under natural high fluoride groundwater and compared to clarify existing problems of adsorption methods. Results show that pH significantly affected adsorption efficiency. The adsorbents have low adsorption capacity under natural high fluoride groundwater and can achieve good adsorption effect under acidic conditions. However, in adjusting the water to the appropriate pH range, the adsorption method loses its advantages of convenience and affordability. Therefore, any adsorbent should be tested with actual field waters before designing filed application systems. Further research is also warranted in evaluating the field performance and the economic acceptance of the proposed method.

scholarly journals Comparison of Water Defluoridation Using Different Techniques

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Abdolmajid Fadaei
Keyword(s):  
Drinking Water ◽  
Subsurface Water ◽  
Fluoride Removal ◽  
Adsorption Method ◽  
Physical Technique ◽  
Commercial Scale ◽  
Adsorption Capacities ◽  
The World ◽  
Removal Efficiencies ◽  
Human Use

Fluoride pollution in subsurface water is a significant problem for different nations across the world because of the intake of excessive fluoride caused by the drinking of the contaminated subsurface. Water pollution by flouride can be attributed to the natural and human-made agents. Increased levels of fluoride in drinking water may result in the irretrievable demineralization of bone and tooth tissues, a situation called fluorosis, and other disorders. There has long been a need for fluoride removal from drinking water to make it safe for human use. Among the various fluoride removal methods, adsorption is the method most popularly used due to its cheap cost, ease of utilization, and being a scalable and simple physical technique. According to the findings of this study, the highest concentration of fluoride (0.1–15.0 mg/L) was found in Sweden and the lowest (0.03–1.14 mg/L) in Italy. We collected the values of adsorption capacities and fluoride removal efficiencies of various types of adsorbents from valuable released data accessible in the literature and exhibited tables. There is still a need to find the actual possibility of using biosorbents and adsorbents on a commercial scale and to define the reusability of adsorbents to decrease price and the waste generated from the adsorption method. This article reviews the currently available methods and approaches to fluoride removal of water.

Experimental Study of Adsorption Treatment of the Arsenic-Containing Rural Drinking Groundwater

2013 ◽  
Vol 295-298 ◽  
pp. 1129-1134
Author(s):  
Jing Liu ◽  
Hua Yang ◽  
Yan Zuo ◽  
Zhi Min Ren ◽  
De Jun Bian
Keyword(s):  
Experimental Study ◽  
Drinking Water ◽  
Room Temperature ◽  
Arsenic Removal ◽  
Ph Value ◽  
Adsorption Method ◽  
Adsorption Time ◽  
Ph Values ◽  
Adsorption Treatment ◽  
Removal Of Arsenic

The arsenic-containing rural drinking groundwater was treated by adsorption method in the paper. It was studied that the varieties and dosages of adsorbents, pH value and adsorption time have an effect on removal of arsenic. The experimental results indicated that the rate of arsenic removal is able to reach 91.39% at room temperature and under the condition of neutral pH values, 2.0 g of zeolite as adsorbent and 1 h of adsorption time. The content of arsenic in the treated drinking groundwater can be up to the current national hygiene standards of rural drinking water (<0.05mg /L).

Habitat Association of Klebsiella Species

1985 ◽  
Vol 6 (2) ◽  
pp. 52-58 ◽  
Author(s):  
Susan T. Bagley
Keyword(s):  
Drinking Water ◽  
Gastrointestinal Tract ◽  
Surface Waters ◽  
Industrial Effluents ◽  
Opportunistic Pathogen ◽  
Habitat Associations ◽  
Habitat Association ◽  
Klebsiella Species ◽  
Almost All ◽  
Polluted Waters

AbstractThe genus Klebsiella is seemingly ubiquitous in terms of its habitat associations. Klebsiella is a common opportunistic pathogen for humans and other animals, as well as being resident or transient flora (particularly in the gastrointestinal tract). Other habitats include sewage, drinking water, soils, surface waters, industrial effluents, and vegetation. Until recently, almost all these Klebsiella have been identified as one species, ie, K. pneumoniae. However, phenotypic and genotypic studies have shown that “K. pneumoniae” actually consists of at least four species, all with distinct characteristics and habitats. General habitat associations of Klebsiella species are as follows: K. pneumoniae—humans, animals, sewage, and polluted waters and soils; K. oxytoca—frequent association with most habitats; K. terrigena— unpolluted surface waters and soils, drinking water, and vegetation; K. planticola—sewage, polluted surface waters, soils, and vegetation; and K. ozaenae/K. rhinoscleromatis—infrequently detected (primarily with humans).

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