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Consumables
Published in Carl Bozzuto, Boiler Operator's Handbook, 2021
Frequently, people do not think of salt as a water treatment chemical. It is, and it is one of the cheapest and safest to handle. Be sure to make the best use of it first. Ensure that the water softeners are regenerated with adequate brine concentrations. Regenerate them before they are depleted to minimize consumption of phosphate or other scale treatments, which are a lot more expensive than salt. The water softener essentially substitutes the sodium in the salt for the calcium and magnesium that may be in the makeup water. Sodium salts are very soluble in water and become more soluble as the temperature of the water increases. The removal of the calcium and magnesium from the water eliminates the potential for those salts to form hard scale when the boiler water is heated. Proper care of the water softener is a worthwhile investment.
Irrigation: Saline Water
Published in Brian D. Fath, Sven E. Jørgensen, Megan Cole, Managing Water Resources and Hydrological Systems, 2020
Most waters used for irrigation have electrical conductivities less than 2 dS m−1.[1] When water higher than this level is used, there can be serious negative effects on both plants and soils. As salinity in the root zone increases, the osmotic potential of the soil solution decreases and therefore reduces the availability of water to plants. At some point, the concentration of salts in the root zone can become so great that water will actually move from the plant cells to the root zone because of the osmotic effect. Salts containing ions such as boron, chloride, and sodium can also be toxic to plants when accumulated in large quantities in the leaves. The extent that plant growth is affected by saline water is dependent on the crop species. Some plants, such as barley and cotton, are much more resistant to salt than crops like beans. Rhoades, Kandiah, and Marshali[1] list the tolerance levels of a wide range of fiber, grain, and special crops; grasses and forage crops; vegetable and fruit crops; woody crops; and ornamental shrubs, trees, and ground cover. Soils are also negatively impacted by salt, particularly sodium salts. Sodium ions tend to disperse clay particles and this has deleterious effects on infiltration rate, structure, and other soil physical properties.
Chemicals from Paraffin Hydrocarbons
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
Free naphthenic acids are corrosive and are mainly used as their salts and esters. The sodium salts are emulsifying agents for preparing agricultural insecticides, additives for cutting oils, and emulsion breakers in the oil industry. Other metal salts of naphthenic acids have many varied uses. For example, calcium naphthenate is a lubricating oil additive, and zinc naphthenate is an antioxidant. Lead, zinc, and barium naphthenate derivatives are wetting agents used as dispersion agents for paints. Some oil-soluble metal naphthenate derivatives, such as those of zinc, cobalt, and lead, are used as driers in oil-based paints. Among the diversified uses of naphthenate derivatives is the use of aluminum naphthenate derivatives as gelling agents for gasoline flame throwers (napalm). Manganese naphthenate derivatives are well-known oxidation catalysts.
Recovery and reuse of alginate in an immobilized algae reactor
Published in Environmental Technology, 2021
Olga Murujew, Rachel Whitton, Matthew Kube, Linhua Fan, Felicity Roddick, Bruce Jefferson, Marc Pidou
Preliminary tests were run to identify the most suitable chemical for bead dissolution. Three sodium salts were investigated: sodium chloride (NaCl), sodium carbonate (Na2CO3) and trisodium citrate (Na3C6H5O7; Na-citrate). These salts were selected because they are readily available and cheap and/or had been previously used to dissolve calcium alginate [8]. Solutions were made up to at least 0.5 M to have excess sodium ions. Algae beads (1 g, 61–67 beads) were added to 25 mL of each of the sodium solutions and magnetically stirred for 20–150 min. In the subsequent experiments, beads (EB and AB) were dissolved by stirring for 1–2 h in 0.5 M Na-citrate solution (Merck, Batch No MC1M610493). Preliminary tests showed that a ratio of 1:2 Na-citrate:sodium alginate was suitable for dissolution of the beads. Where stated (i.e. supplemented beads), sodium alginate powder was added (equivalent to 1% weight/volume) to the recovered alginate (RA) solutions to overcome the dilution incurred by dissolution. After the dissolution of the algae beads, the algal biomass was separated with vacuum filtration with a 3 µm cellulose acetate filter. However, this proved inefficient with regard to alginate yield in the filtrate. A centrifugation method, detailed below, was subsequently used for the separation of the algal biomass from the alginate for the continuous nutrient removal experiments.
Thermophilic anaerobic digestion of cattail and hydrothermal carbonization of the digestate for co-production of biomethane and hydrochar
Published in Journal of Environmental Science and Health, Part A, 2020
Bo Zhang, Gail Joseph, Lijun Wang, Xin Li, Abolghasem Shahbazi
Due to their availability and lower cost, the most common molten salts are typically chlorides, sulfates, carbonates and hydroxides. Ensuring safety and minimizing environmental pollution, the following three sodium salts were chosen: Na2CO3, NaHCO3 and NaCl. In a typical process, hydrochar was mixed with one salt in a ratio of 1:3, and then the mixture was homogenized with a mortar and pestle. The powdered mixture was transferred to a ceramic crucible and was placed in an electric furnace equipped with a continuous nitrogen flow. After flushing with nitrogen for 30 min, the furnace was ramped at 10 °C/min to the carbonization temperature of 900 °C and kept at this temperature for 1 h. The furnace was cooled to ambient temperature by switching off the power; meanwhile, the nitrogen flow was maintained until the temperature reached room temperature. The as-obtained product (i.e. activated hydrochar) was crushed into particles using a mortar and pestle and washed with sufficient amount of water to remove the salts. The activated hydrochar was dried in an oven at 105 °C for 12 h.