Sodium Lignosulphonate Research Articles

Three-dimensional water-quality-transport model compared with field observations

An ecological model, coupled with a hydrodynamic one, is applied to Lake Näsiselkä, the southernmost sub-basin of Lake Näsijärvi, Central Finland. Its surface area is 93 km 2, mean depth 15 m, maximum depth 61 m, and through-flow 64 m 3/s. The transport velocities to the ecological model are computed with a three-dimensional hydrodynamic sub-model. Its results are compared with the flow velocities measured in 1981. In the ecological model the transport velocities change according to the weather conditions, through-flow and temperature stratification. The ecological mdoel computes the dissolved oxygen, total phosphorus, phytoplankton biomass, biological oxygen demand and sodium lignosulphonate taking into account their decay, settling, mutual reactions, loading and transport with water flow. The model validity is tested with extensive field observation data of the year 1982 and more sparse data of the summer 1983. The results show reasonable agreement with the measured values. The model is used to test the effects of human activities (industrial loading and through-flow regulation) on the water quality. Industrial loading affects the oxygen and algal distributions in the lake whereas the executed regulation has not appreciably changed the natural conditions in the water body.

Influence of lignosulphonate, glucose and gluconate on the C 3A hydration

The influence of desugarized sodium lignosulphonate, glucose and sodium gluconate on the C 3A hydration has been examined using DTG analysis. At relatively low concentration levels of admixtures in the aqueous phase (1 to 3 g/l), such as those practically used for concrete mixes, lignosulphonate and glucose retard only slightly the C 3A hydration. Sodium gluconate is significantly more efficient in retarding C 3A hydration than lignosulphonate and glucose.

Determination of floc sizes in kaolin suspensions dispersed by sodium lignosulphonate

Settling rates and sediment volumes have been measured for kaolin suspensions using a hindered settling technique. The influence of lignosulphonate was investigated at different concentrations of sodium chloride. The floc sizes were obtained from measurements of the sediment volumes, settling rates and floc to kaolin volume ratios. The calculated. floc sizes were in reasonable agreement with microscopic observations. The effect of lignosulphonate and sodium chloride could be explained on the basis of reduced edge-to-face association resulting from adsorption of the lignosulphonate molecules which neutralize the edge charge of the kaolin particles.

Fibre formation in the hydrostatic extrusion of linear polyethylene — sodium lignosulphonate blends

A blend consisting of equal amounts (by weight) of linear polyethylene and a technical grade of sodium lignosulphonate (a water soluble substance), was processed using hydrostatic extrusion with extrusion ratios varying from 5 to 20. The resulting extrudate contained thin (2 to 5μm) fibres of the linear polyethylene in a matrix of the lignosulphonate. The fibres were basically continuous throughout the extrudate. Their stiffness was of the same order as that observed for pure hydrostatically extruded polyethylene. The fibre phase was easily isolated by dissolving the matrix material in water.

Acute and subacute oral toxicity of AHR-2438B, a purified sodium lignosulphonate, in rats

The acute oral LD 50 of AHR-2438B in rats was found to be >40 g/kg. In subacute toxicity tests, rats were given AHR-2438B in the drinking-water at levels of 0 (control), 0·025, 0·25, 2·5 or 10 g/100 ml for 16 wk. No adverse effects on growth, organ weights, haematology, urine analysis or serum transaminase and alkaline-phosphatase activities were observed at the three lowest dose levels. Histological examination of tissues from animals at these dose levels revealed no abnormalities. On the other hand, at the highest dose level, male rats showed a decrease in weight gain and animals of both sexes showed skin lesions at the base of the tail, increased leucocyte counts, anaemia and an increase in the absolute and relative weights of the liver, kidneys and spleen. Histological changes in these animals were consistent with reticulo-endothelial activation in the liver and with vacuolar degeneration of the proximal convoluted tubules in the kidney. The no-effect level of AHR-2438B in the drinking-water was found to be 2·5 g/100 ml, equivalent to a daily intake of 2·83 g/kg in males and 2·42 g/kg in females. These dose levels are approximately 50 times the estimated maximum intake for antipepsin activity in man.

BIOLOGICAL DECOMPOSITION OF CHEMICAL LIGNIN: III. APPLICATION OF A NEW ULTRA-VIOLET SPECTROGRAPHIC METHOD TO THE ESTIMATION OF SODIUM LIGNOSULPHONATE IN CULTURE MEDIA

An ultra-violet spectrographic method has been developed for estimating the amount of sodium lignosulphonate present in solutions. The method has been applied to the measurement of lignosulphonate losses in liquid media after fungous growth and the results are compared with those obtained under similar conditions by the β-naphthylamine precipitation method. The spectrographic method gave slightly lower values but was free from certain errors present in the chemical method. The results confirmed previous observations that fungi are capable of decomposing lignosulphonates.