Odor[ edit ] Salts of strong acids and strong bases " strong salts " are non- volatile and often odorless, whereas salts of either weak acids or weak bases " weak salts " may smell like the conjugate acid e. That slow, partial decomposition is usually accelerated by the presence of water, since hydrolysis is the other half of the reversible reaction equation of formation of weak salts. Unlike molecular compounds, salts dissociate in solution into anionic and cationic components.
Processes used in Japan have been described by Okazaki The minimal requirements for the profitable operation of an alginate extraction plant have been estimated by Moss and Doty They discuss the minimal seaweed input, colloid output and capital investment needed; they also list estimates of production costs.
This analysis is made for agar and carrageenan as well as alginate. The difficulties of the processes arise from the physical separations which are required, such as the need to filter slimy residues from viscous solutions or to separate gelatinous precipitates which hold large amounts of liquid within their structure and which resist both filtration and centrifugation.
Processes for the manufacture of sodium alginate from brown seaweeds fall into two categories. Figure 6 is a diagram of the processes, simplified to show their essential difference. In one, the principal intermediates are calcium alginate and alginic acid.
In the other, no calcium alginate is formed, only alginic acid. The advantage of the first process is that calcium alginate can be precipitated in a fibrous form which can be readily separated; it can then be converted into alginic acid which is still fibrous and can also be readily separated.
A further advantage of this process is that some calcium alginate can be allowed to remain in the final sodium alginate produced.
This gives the manufacturer another method of controlling the viscosity of the final product, as discussed later in the "Properties" section. The second process does save one step, the formation of calcium alginate, but it also has some disadvantages.
When alginic acid is precipitated in this process, it forms a gelatinous precipitate which is very difficult to separate and the overall losses of alginic acid are generally greater than in the former process.
The removal of liquid "dewatering" from within the gel structure of the separated alginic acid also presents difficulties in this second process. The water content in the dewatered alginic acid is often high, so that alcohol must be used as a solvent for the conversion to sodium alginate. This usually makes the process more expensive unless the alcohol recovery rate is very good, and this is not easy to achieve.
For each process the principles, methods and problems are discussed below. The last is seaweed which, when fresh, is chopped into small pieces and treated with a dilute formalin solution; this wet weed can be stored in cool concrete containers for several months.
Dried weed is rehydrated by soaking for several hours. Several producers do not break up the seaweed into smaller pieces. However, reduction to small pieces, preferably mm square, has two advantages.Fig.
Applications of surface-modified nanoparticles and, more broadly, nanostructures. Functional nanoparticle-surfactant combinations are involved in medical applications, structural materials, energy conversion processes, catalysts, as well as in cleaning and purification systems.
Hardness in water is defined as the presence of multivalent cations. Hardness in water can cause water to form scales and a resistance to soap. GENERAL METHODS APPEARANCE AND PHYSICAL PROPERTIES Boiling Point and Distillation Range. The following method employs ml of sample.
In cases where it is necessary or would be desirable to use a smaller sample, the method of McCullough et al. [J. Chem.
Ed. 47, 57 ()], which employs only 50 µl of sample, may be used. Most of the large brown seaweeds are potential sources of alginate. The properties of the alginate varies from one species to another, so the choice of which seaweeds to harvest is based on both the availability of particular species and the properties of the alginate that they contain.
The main. Nutrition of Commercial Pecan nut orchards 1. Introduction. The most important environmental factors that influence photosynthesis, flowering, fruit set, fruit growth and fruit quality are light, water and nutrition.
Most of the large brown seaweeds are potential sources of alginate. The properties of the alginate varies from one species to another, so the choice of which seaweeds to harvest is based on both the availability of particular species and the properties of the alginate that they contain.