Friday, November 20, 2009

pHASE pH Adjustment Systems.

System Features

    • Skid Mounted
    • Turnkey Construction
    • Minimal Installation Time
    • NEMA 4X, UL 508
    • Small Foot Print
    • State-Of-The-Art Controls
      pHASE pH Adjustment systems are designed to handle a variety of acidic and alkaline waste streams including concentrated discharges. Any acidic or alkaline stream, of any concentration from any source can be safely and effectively neutralized with a pHASE pH adjustment system.
      All systems feature state of the art instrumentation and control systems using our proprietary "Optimized Batch" pH adjustment technology.
      Completely automated operation requires no operator attention other than periodic instrumentation calibrations and maintenance. Remote monitoring via SCADA, building management, or dial-up link available.

      Standard Materials of Construction*
      Treatment Tank: Polypro, FRP
      Reagent Tank(s): Polypro, PE, XLPE
      Pump(s): CPVC, Polypro
      Piping System: PVC, CPVC, Polypro
      *Alternate materials of construction available

    Max Average Flow* (GPM)
    Max Peak Flow* (GPM)
    Treatment Tank Volume (Gallons)
    Skid Dimensions
    40" x 40" x 60"(H)
    48" x 48" x 60"(H)
    34” x 65” x 60” (H)
    34” x 65” x 60” (H)
    44” x 85” x 62” (H)
    44” x 85” x 62” (H)
    44” x 85” x 62” (H)

    For higher flows see our labTREAT and batchTREAT family of pH Adjustment Systems.
    The labTREAT family is specifically designed for effluent streams typical of research laboratories, and semi-conductor fabs.
    The batchTREAT family is designed for high flows and highly acidic / highly alkaline effluent streams.

    Physical Chemistry & Thermochemistry

    This is a collection of problem sets, lecture notes, articles, and labs for physical chemistry, thermochemistry, and thermodynamics.

    Laws of Thermochemistry

    Thermochemical equations are just like other balanced equations except they also specify the heat flow for the reaction. The heat flow is listed to the right of the equation using the symbol ΔH. The most common units are kilojoules, kJ. Here are two thermochemical equations:

    H2 (g) + ½ O2 (g) → H2O (l); ΔH = -285.8 kJ
    HgO (s) → Hg (l) + ½ O2 (g); ΔH = +90.7 kJ

    When you write thermochemical equations, be sure to keep the following points in mind:

    • Coefficients refer to the number of moles. Thus, for the first equation, -282.8 kJ is the ΔH when 1 mol of H2O (l) is formed from 1 mol H2 (g) and ½ mol O2.
    • Enthalpy changes for a phase change, so the enthalpy of a substance depends on whether is it is a solid, liquid, or gas. Be sure to specify the phase of the reactants and products using (s), (l), or (g) and be sure to look up the correct ΔH from heat of formation tables. The symbol (aq) is used for species in water (aqueous) solution.
    • The enthalpy of a substance depends upon temperature. Ideally, you should specify the temperature at which a reaction is carried out. When you look at a table of heats of formation, notice that the temperature of the ΔH is given. For homework problems, and unless otherwise specified, temperature is assumed to be 25°C. In the real world, temperature may different and thermochemical calculations can be more difficult. Certain laws or rules apply when using thermochemical equations:
    • ΔH is directly proportional to the quantity of a substance that reacts or is produced by a reaction.
      Enthalpy is directly proportional to mass. Therefore, if you double the coefficients in an equation, then the value of ΔH is multiplied by two. For example:
      H2 (g) + ½ O2 (g) → H2O (l); ΔH = -285.8 kJ
      2 H2 (g) + O2 (g) → 2 H2O (l); ΔH = -571.6 kJ
    • ΔH for a reaction is equal in magnitude but opposite in sign to ΔH for the reverse reaction.
      For example:
      HgO (s) → Hg (l) + ½ O2 (g); ΔH = +90.7 kJ
      Hg (l) + ½ O2 (l) → HgO (s); ΔH = -90.7 kJ
      This law is commonly applied to phase changes, although it is true when you reverse any thermochemical reaction.
    • ΔH is independent of the number of steps involved.

    This rule is called Hess's Law. It states that ΔH for a reaction is the same whether it occurs in one step or in a series of steps. Another way to look at it is to remember that ΔH is a state property, so it must be independent of the path of a reaction.
    If Reaction (1) + Reaction (2) = Reaction (3), then ΔH3 = ΔH1 + ΔH2

    Amino Acid Structures

    These are the structures for the twenty natural amino acids, plus the general structure for an amino acid.

    Wednesday, November 18, 2009

    Inorganic Chemistry

    If it isn't carbon-based, it's probably covered here. Of course, inorganic reactions of carbon are described, too. You'll find lecture and lab notes, molecular structures, journals, and study guides.

    Types of Inorganic Chemical Reactions

    Elements and compounds react with each other in numerous ways. Memorizing every type of reaction would be challenging and also unncecessary, since nearly every inorganic chemical reaction falls into one or more of four broad categories.

    • Combination Reactions
    Two or more reactants form one product in a combination reaction. An example of a combination reaction is the formation of sulfur dioxide when sulfur is burned in air:
    S (s) + O2 (g) --> SO2 (g)

    • Decomposition Reactions
    In a decomposition reaction, a compound breaks down into two or more substances. Decomposition usually results from electrolysis or heating. An example of a decomposition reaction is the breakdown of mercury (II) oxide into its component elements.
    2HgO (s) + heat --> 2Hg (l) + O2 (g)

    • Single Displacement Reactions
    A single displacement reaction is characterized by an atom or ion of a single compound replacing an atom of another element. An example of a single displacement reaction is the displacement of copper ions in a copper sulfate solution by zinc metal, forming zinc sulfate:
    Zn (s) + CuSO4 (aq) --> Cu (s) + ZnSO4 (aq)
    Single displacement reactions are often subdivided into more specific categories (e.g., redox reactions).

    • Double Displacement Reactions
    Double displacement reactions also may be called metathesis reactions. In this type of reaction, elements from two compounds displace each other to form new compounds. Double displacement reactions may occur when one product is removed from the solution as a gas or precipitate or when two species combine to form a weak electrolyte that remains undissociated in solution. An example of a double displacement reaction occurs when solutions of calcium chloride and silver nitrate are reacted to form insoluble silver chloride in a solution of calcium nitrate.
    CaCl2 (aq) + 2 AgNO3 (aq) --> Ca(NO3)2 (aq) + 2 AgCl (s)
    A neutralization reaction is a specific type of double displacement reaction that occurs when an acid reacts with a base, producing a solution of salt and water. An example of a neutralization reaction is the reaction of hydrochloric acid and sodium hydroxide to form sodium chloride and water:
    HCl (aq) + NaOH (aq) --> NaCl (aq) + H2O (l)
    Remember that reactions can be belong to more than one category. Also, it would be possible to present more specific categories, such as combustion reactions or precipitation reactions. Learning the main categories will help you balance equations and predict the types of compounds formed from a chemical reaction.

    Citric Acid Cycle

    Citric Acid Cycle - Overview of the Citric Acid Cycle

    The Citric Acid Cycle is also known as the Krebs
    Cycle or Tricarboxylic Acid (TCA) Cycle.
    It is a series of chemical reactions that
    takes place in the cell that breaks down
    food molecules into
    carbon dioxide, water, and energy.

    The citric acid cycle, also known as the Krebs cycle or tricarboxylic acid (TCA) cycle, is a series of chemical reactions in the cell that breaks down food molecules into carbon dioxide, water, and energy. In plants and animals, these reactions take place in the mitochondria of the cell as part of cellular respiration. Many bacteria perform the citric acid cycle too, though they do not have mitochondria so the reactions take place in the cytoplasm of bacterial cells. Sir Hans Adolf Krebs, a British biochemist, is credited with discovering the cycle. Sir Krebs outlined the steps of the cycle in 1937.
    The overall reaction for the citric acid cycle is:
    Acetyl-CoA + 3 NAD+ + Q + GDP + Pi + 2 H2O --> CoA-SH + 3 NADH + 3 H+ + QH2 + GTP + 2 CO2
    where Q is ubiquinone and Pi is inorganic phosphate
    In order for food to enter the citric acid cycle, it must be broken into acetyl groups, (CH3CO). At the start of the citric acid cycle, an acetyl group combines with a four-carbon molecule called oxaloacetate to make a six-carbon compound, citric acid. During the cycle, the citric acid molecule is rearranged and stripped of two of its carbon atoms. Carbon dioxide and 4 electrons are released. At the end of the cycle, a molecule of oxaloacetate remains, which can combine with another acetyl group to being the cycle again.
    Substrate --> Products (Enzyme)
    Oxaloacetate + Acetyl CoA + H2O --> Citrate + CoA-SH (citrate synthase)
    Citrate --> cis-Aconitate + H2O (aconitase)
    cis-Aconitate + H2O --> Isocitrate (aconitase)
    Isocitrate + NAD+ Oxalosuccinate + NADH + H + (isocitrate dehydrogenase)
    Oxalosuccinate á-Ketoglutarate + CO2 (isocitrate dehydrogenase)
    α-Ketoglutarate + NAD+ + CoA-SH --> Succinyl-CoA + NADH + H+ + CO2 (α-ketoglutarate dehydrogenase)
    Succinyl-CoA + GDP + Pi --> Succinate + CoA-SH + GTP (succinyl-CoA synthetase)
    Succinate + ubiquinone (Q) --> Fumarate + ubiquinol (QH2) (succinate dehydrogenase)
    Fumarate + H2O --> L-Malate (fumarase)
    L-Malate + NAD+ --> Oxaloacetate + NADH + H+ (malate dehydrogenase)

    Sunday, November 15, 2009

    Chemistry Glossary and Dictionary

    This chemistry glossary offers definitions for terms which are commonly used in chemistry and chemical engineering. An engineering glossary is available, too.

    absolute error
    absolute pressure
    absolute temperature
    absolute uncertainty
    absolute zero
    absorption cross section
    absorption spectroscopy
    absorption spectrum
    acid anhydride
    acid-base titration
    acid dissociation constant - Ka acidic solution
    activated complex
    activation energy - Ea actual yield
    addition polymer
    addition reaction
    alkali metal
    alkaline earth metal
    alkyl group
    alpha particle
    alternating copolymer
    analytical chemistry
    aromatic compound
    aqueous solution
    Arrhenius rate equation
    atomic mass
    atomic mass unit (amu)
    atomic number
    atomic radius
    atomic weight
    Avogadro's Law
    Avogadro's number

    A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

    Quick Emulsifier Chemistry Demonstration

    Soap is good at cleaning because it acts as an emulsifier, enabling one liquid to disperse into another immiscible liquid. While oil (which attracts dirt) doesn't naturally mix with water, soap can suspend oil/dirt in such a way that it can be removed.
    It's easy to demonstrate the action of an emulsifer. All you need are two immiscible liquids and a little dishwashing detergent or soap.

    Emulsifier Demo Materials

    • water
    • kerosene or oil
    • dishwashing detergent or soap
    • flask or clear glass

    Perform the Demonstration

    1. Add some kerosene or oil together with some water in a flask. Swirl the contents around to try to mix them. What happens?
    2. Add a squirt of dishwashing liquid. Swirl or shake the flask to mix the ingredients. How has the layer of kerosene or oil been changed?

    What could be easier, right?