Humic acid

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  • Soil Characterisation Essay

    Gastric bioaccessibility of Cd and Pb were generally observed to be much higher than those of As because under acidic gastric condition (pH = 1.2 – 1.5), the soil surfaces would be more positively charged than at ambient soil pH, which may inhibit Cd and Pb but enhance As sorption on soil. Furthermore, Cd and Pb were under direct competition with H+ at solid-solution interface and the high H+ activity under gastric conditions would displace Cd and Pb. By contrast, As binds to mineral surfaces via ligand exchange and the dissolution of mineral surfaces is likely to be a more significant process in gastro-induced desorption. Dissolution of As from oxide surfaces would be incomplete (low As gastric bioaccessibility) within the time frame of acid extraction (Cornell and Schwertmann, 2003) whilst significant metal-H+ replacement would occur rapidly (high Cd and Pb gastric bioaccessibility). When comparing bioaccessibility of Cd and Pb, bioaccessibility of Pb in gastric phase was lower than that of Cd. Especially in MGA soils, nearly half of the Pb was not bioaccessible while Cd remained highly soluble. Previous study indicates that Pb was retained in soils stronger than Cd which may be attributed to its greater hydrolysis constant, higher atomic weight and ionic radius, and larger Misono softness value over Cd (Shaheen, 2009). These parameters favoured Pb to more readily undergo inner-sphere surface sorption and complexation than Cd.…

    Words: 843 - Pages: 4
  • Synthesis Of Pb Film

    zeolite-like structure is well known as the prototype of a number of polynuclear transition-metal hexacyanometalates with the formula, Fe4Ⅲ[FeⅡ(CN)6]3 [1,2]. It exhibits electrochemical [3–5], electrochromic [6–8], photophysical [9,10], and magnetic properties [11,12]. In particular, the electrocatalytic property among these special properties enables the potential analytical application of electrochemical sensor using the PB-modified electrode [13,14]. The reduced form of PB is prussian white…

    Words: 768 - Pages: 4
  • Effect Of Dissolving Alka Seltzer In Different Liquids

    mixture is made up of only one uniform. The ingredients of an Alka-Seltzer pill consist of 324mg of aspirin, 1625mg of sodium hydrogen carbonate, 965mg of citric acid anhydrous, dimeticone, calcium silicate, docusate sodium, sodium benzoate sodium saccharin, natural and artificial lemon flavor, natural and artificial lime flavor. Each Alka-Seltzer pill has 445mg of sodium and once an Alka-Seltzer is dissolved in water, it turns into bicarbonate which reacts with the hydrogen from the citric acid…

    Words: 874 - Pages: 4
  • Pool Pump Functions

    You already know your pool has a pump, but do you really know what that pump actually does? You might be surprised! What Exactly Does a Pool Pump Do? Your pool pump is the heart of your pool and without it, it would die...so to speak. Just like a human heart, your pool's heart (the pump) only has one thing it has to do which is pump water. However, that one thing serves several very important functions, such as: • Pulls the water from your pool through the skimmers and drains. • Then it…

    Words: 776 - Pages: 4
  • Differences Between Salts And Molecules

    Salts and molecules have similar characteristics, and many differences whether we can tell by first looks or not. Testing these two only supports the differences, and many structural functions cause these differences. Since salts are ionically bonded, they have different properties and functions compared to the covalent bonded molecules. Salts have a ionic bond, and we can confirm due to their electronegativity. As you move from left to right on the periodic table you would notice that…

    Words: 1094 - Pages: 5
  • Cyanoethoxy Research Paper

    suitable N-protecting group for nucleosides (Sikehi et al., 2006 and reference theirin). A solvent-free reaction utilizing a simple low-energy ball mill apparatus was reported to convert the amino groups of nucleosides S.36, adenosine, 2-deoxyadenosine, cytidine, 2-deoxycytidine, guanosine, and 2-deoxyguanosine as well as some of their ribosyl O-protected derivatives, to the corresponding bis-N-Boc carbamates S.37 (Sikehi et al., 2006). For guanosine compounds, the carbonyl group of the base…

    Words: 1143 - Pages: 5
  • The Causes Of Mandatory Acidosis

    than anything else. It is important to take care of the body from any harm. One thing that the body is capable of is maintaining pH levels and buffers. A pH is the power of hydrogen and buffers prevent extreme shifts in pH. The blood has a specific type of buffer that is maintained at pH level of 7.4. If the buffers shifts and levels of pH go to 7 or 7.8, it can be deadly. The blood buffer contains carbonic acid which dissociates into bicarbonate acid and hydrogen ions. This equation can also be…

    Words: 1276 - Pages: 5
  • Lipids In Milk Lab Report

    The Rf values were obtained by reacting the lipids on the TLC plates with iodine, to visually show how far the lipids moved up the TLC plate. For the identification of the amount of lipids in milk, the milk was combined with an organic mixture of CHCl3/MeOH, to isolate the lipid layer. By centrifuging the organic solvent with milk the heavy lipids sink to the bottom while the water layer which contain water soluble carbohydrates, peptides and small amino acids float to the top. Since the organic…

    Words: 746 - Pages: 3
  • Freshwater Plankton Case Study

    Freshwater Treatment for Amoebic Gill Disease Freshwater treatment for AGD requires checking for few things before and during the treatment to carry out a successful and effective treatment. 1. Freshwater Source: The freshwater source should be checked for temperature, total ammonia nitrogen and ammonia percentage, pH, hardness, salinity and any harmful plankton. Temperature: Freshwater with temperature closer to the temperature that treating fish are being reared in is best choice. Colder…

    Words: 1943 - Pages: 8
  • Isolation Of Naphthalene Lab Report

    that was used during the steam bath could have had some of the product on it which would have been removed with the stick. It is less clear why the benzoic acid was overproduced. Some of the organic layer may have been drawn off with it, but the vacuum filtration should have left only the benzoic acid. There could have been an error in weighing the filter paper before the procedure. There also could have been contaminants in the basic extract, causing more than just the benzoic acid to be…

    Words: 2501 - Pages: 11
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