Sodium sulfite

About: Sodium sulfite is a research topic. Over the lifetime, 2548 publications have been published within this topic receiving 18523 citations. The topic is also known as: Na2SO3 & Anhydrous sodium sulfite.

Chemische Eigenschaften von TMP und CTMP, hergestellt aus Kiefernholz und UF-Harz-gebundenen mitteldichten Faserplatten (MDF)

Abstract: Thermo-mechanical (TMP) and chemo-thermo-mechanical pulps (CTMP) were prepared from pine wood and from UF-bonded MDF made from pine wood. For preparing TMP pine chips as well as UF-bonded MDF were digested under pressure at 170 °C. Thereafter, the digested chips and MDF were defibrated at 170 °C using a single disc refiner. CTMP was prepared from pine wood with 0.25% NaOH (based on dry wood) under the conditions set forth above. CTMP was also made from MDF under two conditions using 0.15% sodium hydroxide (% based on dry MDF) and a mixture of sodium sulphite (1%) and sodium hydroxide (0.25%). The pulps show distinct differences in their properties: TMP from UF-bonded MDF shows lower extractive content in cold and hot water, lower pH-value and higher buffering capacity towards alkali of the cold water extractives than the CTMP counterpart. Moreover, CTMP prepared by using sodium hydroxide alone as a pulping agent increases the content of formate and acetate ions in the cold water extractives. The use of a mixture of sodium sulfite and sodium hydroxide as a pulping agent decreases, however, significantly the content of formate and acetate ions in the cold water extractives. This may be due to the buffering action of sodium sulfite. In general, CTMP decreases the formaldehyde release of the fibres, as measured by the flask method. In presence of sodium sulfite as a pulping agent for recycled MDF, the formaldehyde release is slashed to almost 30% of its original value. The formaldehyde release of CTMP from UF-bonded boards seems to be in the same range as that of TMP from virgin wood.

Carbomer gel and preparation method thereof

Abstract: The invention discloses carbomer gel and a preparation method thereof, relates to a medicament for treating gynecopathy and the preparation method thereof and specifically relates to the carbomer gel and the preparation method thereof. The invention provides the carbomer gel with good efficacy and convenience in preparation and the preparation method thereof. The carbomer gel comprises the following components in percentage by weight (accounted by 100%): 3%-8% of carbomer, 3%-5% of triethanolamine, ethylenediamine or sodium hydroxide, 20%-30% of glycerol or propylene glycol, 0.5%-1% of benzyl alcohol, benzoic acid or sodium benzoate, 0.01-0.03% of ethylenediaminetetraacetic acid disodium or sodium sulfite and the balance of water.

Process for regenerating scrubbing solutions

Abstract: A method of regenerating a scrubbing solution containing sodium sulfite, sodium bisulfite, sodium sulfate and sometimes sodium hydroxide circulated in scrubbers to remove sulfur oxides from gas streams where sodium sulfite is converted to sodium bisulfite as sulfur dioxide is absorbed in the scrubbing solution. A portion of the circulating scrubbing solution is bled off for regeneration and reacted with calcium oxide in pebble lime while the pebble lime is impinged against an impingement surface at a velocity of at least 8-10 feet per second to convert the sodium bisulfite back to sodium sulfite and form calcium sulfite precipitate. The calcium sulfite is removed from the regenerated scrubbing solution and the regenerated scrubbing solution returned to the circulating scrubbing solution in the scrubbers.

Treatment of organic compound-containing water

Abstract: PURPOSE: To efficiently treat water dissolving various organic compds. and make it harmless, by adjusting the water to be treated at pH≥6.5, adding a reducing material to lower oxidation-reduction potential in the water to lower than a prescribed level to remove oxidative material, and at the same time, using a metallic reducing agent for transforming organic compounds to be harmless. CONSTITUTION: Organic compds.-containing water to be treated is adjusted at pH≥6.5, and at the same time, a reductive material (e.g., sodium sulfite) to lower oxidation-reduction potential in the water to ≤300mV is added to the water so as to remove oxidative materials such as dissolved oxygen in the water. In that condition, organic compds. are efficiently made harmless by using metallic reducing agents. At that time, chlorine ion and oxidative ion-free electrolyte (e.g., sodium sulfate) are added to accelerate anodic reaction on the metal interface, resulting in quick transformation of the organic compds. into harmless ones. COPYRIGHT: (C)1989,JPO&Japio

Measurement and Correlation for the Solubility of Sodium p-Toluenesulfonate, Sodium Sulfite, and Sodium p-Methylphenoxide in Aqueous Sodium Hydroxide Solutions and Sodium Sulfite in Aqueous Ethanol Solutions

Abstract: The solubilities of sodium p-toluenesulfonate (NaPTS), sodium sulfite (Na2SO3), and sodium p-methylphenoxide (NaCRS) in aqueous NaOH solutions and Na2SO3 in aqueous ethanol solutions were investigated using a dynamic method over the temperature range from 277 to 341 K at atmospheric pressure. The experimental results showed that the solubilities of NaPTS, Na2SO3, and NaCRS in aqueous NaOH solutions and Na2SO3 in aqueous ethanol solutions decreased distinctly with the solute-free mass fraction of NaOH (w40) and ethanol (w50). Further, there were obvious transition points in the solubility–temperature curves of NaPTS and Na2SO3 in aqueous NaOH solutions, and the transition points shifted to lower temperature as w40 rose. The forming of transition point was due to the different equilibrium solid phase, which was revealed by characterization of the equilibrium solid phase. But the transition points in the solubility–temperature curves of Na2SO3 in aqueous ethanol solutions remained constant at different w50 v...