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Miscellaneous Water Treatment Methods I
Published in Subhash Verma, Varinder S. Kanwar, Siby John, Environmental Engineering, 2022
Subhash Verma, Varinder S. Kanwar, Siby John
The maximum limit of nitrates in drinking water is 45 mg/L. Excessive levels of nitrates are damaging to babies. In some groundwaters, nitrates can be excessive and need to be removed. One common method for nitrate removal is anion exchange, much like cation exchange in the case of iron and manganese. In anion exchange, selective nitrate resins are used. These resins are called selective because they are less selective for multivalent anions like sulphates. Sodium chloride or brine is used in the regeneration of both ordinary and selective resins. RCl+NO3−⇒NitrateremovalRNO3+Cl−
Petroleum Geochemical Survey
Published in Muhammad Abdul Quddus, Petroleum Science and Technology, 2021
Living organisms need nitrogen in substantial amounts to synthesize amino acids, proteins and other life compounds. More than 79% nitrogen is available in the atmosphere. The abundant atmospheric nitrogen cannot be utilized by organisms for their metabolism processes. Nitrogen is a non-reactive inert element. Therefore, nitrogen has to be ‘fixed’ into food or chemicals in such a way that it can be used by organisms or as fertilizer or as soil nutrients. Some bacteria living in plants can transform atmospheric nitrogen directly into ammonia. The ammonia is then transferred to amino acids. Proteins are made from amino acids. Protein is a constituent of all living organisms. Another type of bacteria convert the ammonium ion (NH4+) into nitrite ions (NO2)– and nitrate ions (NO3)–. Nitrate mineral in the soil becomes a nutrient for plant life. Nitrogen in the atmosphere is converted to oxides of nitrogen by lightning and solar radiation in the atmosphere. The nitrogen oxides are brought to the earth’s surface by rain drops, where they are converted to soluble nitrate minerals. Artificial fixation of nitrogen is carried out by interacting atmospheric nitrogen and hydrogen gas in the ratio of 1:3, to produce ammonia (NH3). Ammonia is used to manufacture urea and other nitrogen fertilizers needed in agriculture.
Soil Toxicology
Published in Lorris G. Cockerham, Barbara S. Shane, Basic Environmental Toxicology, 2019
K.C. Donnelly, Cathy S. Anderson, Gary C. Barbee, Donat J. Manek
Wastes applied to soils that are high in nitrogen should be analyzed to determine their form(s) of nitrogen. Nitrogen transformation or plant uptake, leaching, and volatilization can affect the various forms of nitrogen in soil. Nitrate is the form of nitrogen of major concern because of its high mobility in the soil and water. Also, microbes can convert nitrate to nitrite which can cause methemoglobinemia. The maximum allowable level of nitrate in drinking water is 10 ppm.
Pastoral agriculture, a significant driver of New Zealand’s economy, based on an introduced grassland ecology and technological advances
Published in Journal of the Royal Society of New Zealand, 2023
John R. Caradus, Stephen L. Goldson, Derrick J. Moot, Jacqueline S. Rowarth, Alan V. Stewart
Nitrate is a naturally occurring compound readily taken up by plants as their main source of nitrogen; it is the main nutrient that limits plant growth. Nitrate leaches from all agricultural systems, primarily from urine patches (Hoogendoorn et al. 2010) exacerbated by increases in soil pH when urea hydrolyses to ammonia which in turn increases transformation of NH4+ to NH3 (Curtin et al. 2020). Ammonia and nitrous oxide volatilisation also occurs from both urine patches and applied fertiliser which can result in losses of up to 40% of applied nitrogen (Sherlock et al. 2008). For a time, dicyandiamide (CDC) a nitrification inhibitor was applied to mitigate this effect (Di and Cameron 2002) but has been withdrawn due to residue contamination issues in milk (Welten et al. 2016).
Association between nitrate concentration in drinking water and rate of colorectal cancer: a case study in northwestern Iran
Published in International Journal of Environmental Health Research, 2022
Golnoosh Nasseri Maleki, Maryam Bayati Khatibi, Zhila Khamnian, Zahra Jalali, Saeed Dastgiri, Hossein Ghodrati Aroogh
The relationship between nitrate concentration of drinking water and rate of CRC has been the topic of several interdisciplinary studies over the years (DellaValle et al. 2014). According to WHO standards, the maximum permissible limit of nitrate concentration (NO3) in drinking water is 50 mg/L. However, adhering to this cutoff assures protection only against infantile methemoglobinemia and leaves individuals vulnerable to other adverse health outcomes associated with nitrate exposure. Continuous transformation of ingested nitrate into carcinogenic N-nitroso compounds, even in concentrations well below the 50 mg/L threshold, is believed to add to an individual’s risk of developing CRC via cumulative exposure (Taneja et al. 2017). Several adverse health outcomes have been also attributed to chronic exposure to low concentrations of water nitrate and have put the validity of the current WHO permissible cutoff in question (Parvizishad et al. 2017). In a study on the bottled water in Iran, the concentration of nitrate was reported to be in the range of 0.15–50.1 mg/L (mean 10.55 mg/L) with only one case exceeding the WHO standard cutoff (Alimohammadi et al. 2018). In another study on rural areas of Iran, water nitrate ranged from 6 to 35 mg/L (mean 16 mg/L) (Radfard et al. 2018).
Removal of antibiotics and nutrients by Vetiver grass (Chrysopogon zizanioides) from secondary wastewater effluent
Published in International Journal of Phytoremediation, 2020
Saumik Panja, Dibyendu Sarkar, Rupali Datta
Results obtained from this study indicate the feasibility of applying vetiver system to remove emerging and legacy contaminants from secondary wastewater effluent. Our previous studies have shown that vetiver grass successfully removed CIP and TTC from nutrient media. However, the wastewater matrix is more complex compared to nutrient media, and it was important to study the effectiveness of the vetiver technology in removing antibiotics and nutrients from wastewater effluents. Our results show that vetiver not only removed antibiotics but also removed nitrogen and phosphorus load from wastewater, making the wastewater effluent cleaner and safer for discharge. Vetiver grass exhibited competitive removal of antibiotics over nutrients, i.e., increasing antibiotic concentration lowered the removal rate of nutrients from secondary wastewater effluent. However, significant removal of both antibiotics and nutrients were observed in vetiver treatment within 30 days. Vetiver also removed TOC content which is anticipated to alleviate the physiological stress imposed by TTC and CIP. Both TTC and CIP are water-soluble organic compounds, and the reason behind vetiver’s antibiotic removal capacity might be attributed to nonselective organic uptake. On the other hand, nitrate and phosphate are essential nutrients for the physiological growth of plants. TTC is rapidly metabolized in vetiver tissue and induces phytotoxicity symptoms in vetiver (Panja et al.2019; Sengupta et al.2016). Although no visible stress symptoms were observed in CIP exposed vetiver grass, a corresponding decline in nutrient removal was observed.