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Water Treatment
Published in Carl Bozzuto, Boiler Operator's Handbook, 2021
The new conductivity meters provide a reading directly in ppm of total dissolved solids (TDS). Older meters gave the reading in “mho’s” for conductance. Conductivity is measured in micromho, where a mho is “ohm,” the label for resistance to electricity, spelled backwards. That required a table lookup to match the corresponding TDS level. It is a lot easier to have a meter that is simply labeled with values for TDS. TDS is a measure of the amount of solid material that is dissolved in the water. Those solids include what the water managed to dissolve as it hungaround as droplets in a cloud, including gases from the atmosphere and fine particles of dust, what it picked up as a raindrop falling from that cloud, from the dirt and rocks it ran over going down the stream or river or as it trickled down through the earth to the well, and everything it managed to get from the piping until it entered the boiler plant, plus the chemicals that were added to it. TDS is measured in ppm. Steam boiler water should have the highest value of TDS and condensate the lowest, with makeup and boiler feed water falling in between. It is a value that is useful in determining percentage makeup and condensate as well as providing values for blowdown control (described later).
Water Treatment and Purification
Published in P.K. Tewari, Advanced Water Technologies, 2020
Total dissolved solids (TDS) is the sum of all dissolved chemicals present in water. Most TDS (about 99%) in natural water is contributed by six major ions: calcium, magnesium, sodium, bicarbonate, chloride and sulphate. The balance of TDS is contributed by a number of contaminants like iron, manganese, potassium, ammonia, nitrite, nitrate, fluoride, phosphate and trace metals. There are several kinds of inorganic contaminants. Some of the important ones which affect health adversely are chromium, mercury, arsenic and selenium. Organic contaminants that contaminate drinking water are chemicals such as pesticides.
Legal Aspects of Wastewater Reclamation and Reuse
Published in Donald R. Rowe, Isam Mohammed Abdel-Magid, Handbook of Wastewater Reclamation and Reuse, 2020
Donald R. Rowe, Isam Mohammed Abdel-Magid
The factors that affect the quality of municipal wastewater effluent include36Type of treatment system.Quality of water supply (primarily the effects of TDS).Water usage.Impact of any industrial waste discharges.Infiltration into collection system.
An overview on water quality, pollution sources, and associated ecological and human health concerns of the lake water of megacity: a case study on Dhaka city lakes in Bangladesh
Published in Urban Water Journal, 2023
Minhaz Uddin, Tapos Kormoker, Md. Abu Bakar Siddique, Md Masum Billah, Md Rokonuzzaman, Abdullah Al Ragib, Ram Proshad, Md. Yeamin Hossain, Md. Kamrul Haque, Khalid A. Ibrahim, Abubakr M. Idris
pH values affect biological and chemical reactions, and it is one of the most traditional measuring parameters for most water worldwide. The pH value of lake water was slightly acidic to alkaline (6.63 to 7.90) with a maximum value of 7.90 in Crescent Lake (Table 3). The highest EC value was reported on Gulshan Lake followed by Ramna Lake which exceeded the permissible limit for drinking and industrial uses. The total dissolved solids (TDS) include inorganic salts and a small measure of dissolved organic matter. TDS less than 600 mg/L is suitable for drinking water; but if the concentration level exceeds 1000 mg/L, the water becomes unpalatable (WHO 2011). Most of the Dhaka city lakes found less TDS under the recommended limit for drinking and industrial purposes except the Gulshan Lake (Table 3). Banani Lake was found with a high alkalinity value (261.3 mg/L) which exceeded the tolerable limit whereas the rest of the studied lakes were reported with less alkalinity under the guideline values. DO values recorded in all lakes indicates aquatic lives are under serious threat due to less oxygen in the water body than the standard limit (6.0 mg/L for drinking and 4.5–8.0 mg/L for industrial purposes). The maximum BOD value was found in Gulshan Lake (74.13 mg/L) and only the COD (chemical oxygen demand) value (32.7 mg/L) was recorded in Dhanmondi Lake. Table S2 represents the ranges of some water quality parameters and their impacts on aquatic organisms.
Application of molasses as draw solution in forward osmosis desalination for fertigation purposes
Published in Environmental Technology, 2021
Bizhan Bagheri, Ayoub Karimi-Jashni, Mohammad Mahdi Zerafat
The final volumes of DS and FS were recorded, solutions samples were collected and their osmotic pressures were measured at the end of each experiment. The volume changes of DS due to continuous dilution were recorded and used to calculate the membrane water flux as a key FO performance parameter. Also, EC variations of DIW as FS were measured to assess RSF. The TDS of solutions were measured using a portable TDS and EC metre (Hach HQ40D). A modular compact rheometer (MRC-302, Anton Paar, Austria) was used to measure the viscosity of molasses. Two 10–100 LPH flowmeters (LMZ-15ZT, Tianjin U- ideal Instrument, China) are used to measure the FS and DS recirculation flow rates and velocities. Effect of CDS on water flux was investigated at various cross-flow velocities using DIW feed.
Evaluation of drinking and irrigation suitability of groundwater with special emphasizing the health risk posed by nitrate contamination using nitrate pollution index (NPI) and human health risk assessment (HHRA)
Published in Human and Ecological Risk Assessment: An International Journal, 2020
Balamurugan Panneerselvam, Shankar Karuppannan, Kirubakaran Muniraj
The statistical analysis of the groundwater in the study area is presented in Table 4. The pH ranges from 7.46 to 9.05, with a mean of 8.29. Figure 5a shows that the spatial distribution of hydrogen ions in the study area, 365.39 km2, is permissible, and 21.40 km2 is not allowable. A higher value of pH was recorded in the nine sample locations in the study area. The presence of the calcareous and Charnockite nature of aquifers in the study area is a major reason for the elevated pH (Kumar and Balamurugan 2018). EC of the sample varies from 371 to 5011 μS/cm with a mean of 1464.49 μS/cm. As per WHO standards, 261.31 km2 area are permissible and 125.46 km2 area are not permissible for domestic uses (Figure 5b). About 23 sample locations exceed the allowable level in the study area. Besides, Handa (1969) classification is presented in Table 5. It shows that 19.43% of the sample location is a doubtful condition for both drinking and irrigation uses. TDS is a measure of total organic and inorganic dissolved salts in water. In the present study, the 6.43 km2 area is most desirable, 356.08 km2 area is maximum permissible, and 23.39 km2 is not allowable for drinking uses (Figure 5c). TH was recorded between 117 and 1117 mg/L, with an average of 376.21 mg/L. The spatial analysis revealed that 343.50 km2 area is maximum allowable, and 43.24 km2 area is not permissible. The elevated value of TH was recorded in the domestic waste dump site of the study area (Figure 5d).