Chloride plant tolerance

Chloride. Chloride is known to significantly increase the rate of corrosion in acidic fluoride media. The level of chloride that can be tolerated in the HF process before corrosion hinders plant operation is quite low. 

Calcium is a macronutrient essential for all organisms. Chlorine is a micronutrient essential for higher (ie, seed) plants but not considered essential for mammals. Above certain levels chloride is toxic to plants and animals, thus when considering calcium chloride, potentially large concentrations of calcium ion can be tolerated, but at these concentrations the chloride ion becomes toxic. 

Bajaj, Y.P.S. Gupta, R.K. (1986). Different tolerance of callus cultures of Pennisetum americanum L. and P. purpureum Shum. to sodium chloride. Journal of Plant Physiology, 125, 491-5. 

Bhaskaran, S., Smith, R.H. Schertz, K.F. (1986). Progeny screening of sorghum plants regenerated from sodium chloride-selected callus for salt tolerance. Journal of Plant Physiology, 122, 205-10. 

Phytoextraction is mainly carried out by certain plants called hyperaccumulators, which absorb unusually large amounts of metals compared to other plants. A hyperaccumulator is a plant species capable of accumulating 100 times more metal than a common nonaccumulating plant. Therefore, a hyperaccumulator will concentrate more than 1000 mg/kg or 0.1% (dry weight) of Co, Cu, Cr, or Pb, or 10,000 mg/kg (1%) of Zn and Ni (dry matter).43-44 Similarly, halophytes are plants that can tolerate and, in many cases, accumulate large amounts of salt (typically sodium chloride but also Ca and Mg chlorides). Hyperaccumulators and halophytes may be selected and planted at a site based on the type of metals or salts present, the concentrations of these constituents, and other site conditions. 

The solubilized aluminium is the main toxic agent to plants in acidic soils, and acid tolerant (calcifuge) plants are usually also aluminium tolerant. The ECEC method determines the levels of AP+, H+, Ca + and Mg + extracted by 1 M potassium chloride and is described in Method 5.2. 

Tolerance of and/or dependence upon socEurn chloride can be an important consideration in the survival of plants and aquatic animals. This depends upon osmotic regulation rather than sodium specificity. 

Precautions Iodized table salt (NaCl) and rock salt made from calcium chloride (CaCI) are not reeommended. Older plants are more salt-tolerant than young ones, so wait a year after planting a new bed before applying salt. 

Worldwide more than 90% of the potassium-containing fertilizer used is potassium chloride. Potassium sulfate, potassium magnesium sulfate and potassium nitrate are, however, also used as fertilizers, in particular for plants which have a poor tolerance for chloride ions (e.g. tobacco, spinach, cucumbers etc.) or where magnesium-containing fertilizer is also required. 

C Critchley, 1C Baianu, Govindjee and FIS Gutowsky (1982) The role of chloride In Os evolution by thylakoids from salt tolerant higher plants. Biochim Biophys Acta 725 10-18... 

The monovalent anions F-, Cl-, Br-, and I- are the only oxidation states of the halogens in soils. Chloride is essential for plants in trace amounts and for animals in larger amounts. Although F is held to some degree in soils, as a group these ions are retained weakly and are in low amounts in well-drained soils.. Plants are much more tolerant of high Cl concentrations than of high concentrations of other micronutrient... 

Type 304 and 316 stainless steel are used in the high-pressure pipes and pipe fittings in RO plants. The 300 series SS are also sensitive to chlorides at a pH of 6.5—8 and at temperatures below 60°C. Type 316 SS tolerates chlorides up to 1000 ppm, but concentrations can reach 26,000 ppm in dry zones (for MgCl2), resulting in failure. In seawater RO desahnation plants, duplex (2205) or super-duplex (2507) steels are used instead of 316 SS. The compositions of these steels are detailed below [25] ... 

Depleted brine will be physically saturated with chlorine, and some chlorine wUl react to form hypochlorite (Section 7.5.9.1). This chlorine value represents an economic asset to be recovered and, particularly in the case of membrane cells, an intolerable contaminant in the brine treatment system. There are several approaches to this problem [208], and we cover these below. We divide them into methods aimed at recovery of the bulk of the chlorine in a useful form (primary dechlorination Section 7.5.9.2) and those whose purpose is to reduce the active chlorine to chloride and safeguard the environment or other parts of the process (secondary dechlorination Section 7.5.9.3). Some of the hypochlorite that forms in the anolyte will continue to react to form chlorate. This is a much less harmful impurity in the cells, and higher concentrations are tolerable. Many plants keep the chlorate concentration under control by natural or deliberate purges from the brine system (Section 7.5.7.2A). In others, it is necessary to reduce some of the chlorate ion to chloride in order to maintain control (Section 7.5.9.4). 

High salt concentration did not delay lipogenesis during ripening seeds but delay anthesis date and did not seem to decrease drastically total lipids content. This finding could be related to the salt tolerance of Cotton plant. However low sodium chloride concentration (3g/l) stimulated oil synthesis. Sodium chloride reduced the content of the major fatty acid (linoleic acid) of Cotton seeds as it did for the principal olive fatty acid (oleic acid) (Marzouk et al. 1986). 

We wish to design a reverse osmosis plant to prepare drinking water from water with too high a salt content to drink. If the maximum pressure we can afford is lOOpsig, what is the highest salt content in the water we can tolerate and still produce pure drinking water Assume that the salt is aU sodium chloride, that it is 100% ionized, and that it forms an ideal solution. 

---