NOVEL COMBINATION OF TRISODIUM CITRATE AND TRISODIUM PHOSPHATE IN REACTIVE DYEING OF COTTON: AN ATTEMPT TO REDUCE ENVIRONMENTAL IMPACT

"Reactive dyes are most widely used for dyeing cellulosic fabrics due to their excellent wet fastness properties, the brilliancy of shades and a wide gamut of colours. However, the exhaustion of reactive dye requires a large quantity of inorganic electrolyte, which results in excessive total dissolved solids (TDS) values of the resultant effluent. Such high TDS-containing effluents are challenging to treat and require advanced treatment techniques. The discharge of high-TDS containing effluent into water-bodies can increase the salinity of the aquatic system, which can affect the delicate biochemistry of the aquatic life. This necessitates the exploration of alternative chemicals for reducing the TDS of the effluents in reactive dyeing. The current study explores the alternate combination of trisodium citrate (TSC) and trisodium phosphate (TSP) as an eco-friendly replacement of inorganic salts and alkali in the dyeing of cotton by the exhaust process. The TSC-TSP combination resulted in an insignificant variation in exhaustion, fixation and fastness ratings compared to the conventional salt-soda combination. The colour values showed marginal variations in the individual cases of dyes. However, the use of the TSC-TSP combination showed a great promise in reducing the TDS of the effluent (by 66%), which is a major concern in effluent treatment. TSC being organic, some increase in COD/BOD values was obtained; however, the effluent remained in a category of easily treatable ones. "

Microbial Decontamination of Beef Carcass Surfaces by Lactic Acid, Acetic Acid, and Trisodium Phosphate Sprays

The present study was undertaken to investigate the effect of lactic acid (LA), acetic acid, (AA) and trisodium phosphate (TSP) spray on the microbiological population of beef carcass surfaces slaughtered in a traditional abattoir in Zagazig, Egypt. Higher microbial populations were determined on the shoulder than on the thigh surfaces, and meat sampling by tissue excision technique yielded significantly higher ( P < 0.01 ) microbial count than swabbing method. The application of LA (2%), AA (2%), and TSP (12%) sprays for 30 seconds significantly ( P < 0.01 ) reduced the microbial population counts on the beef surfaces by 0.9 to 2.2 logs. A complete inhibition of enterococci growth was achieved by LA and AA sprays. In general, LA and AA sprays were more efficient as antimicrobial agents than the TSP spray. Among the studied organisms, enterococci were the most reducible bacteria by LA and AA, followed by Enterobacteriaceae and coliforms, while Staphylococcus aureus being the least. This study also indicated that microbial populations determined on the shoulder were higher than on the thigh surfaces, and meat sampling by tissue excision technique yielded significantly higher ( P < 0.01 ) microbial count than swabbing method.

Effect of Sodium Hexametaphosphate and Trisodium Phosphate on Dispersion of Polycarboxylate Superplasticizer

Enhancement in dispersion of polycarboxylate superplasticizer (PCE) could be obtained by incorporating retarders in normal concrete. The generally believed reason was that the consumption of free water and polymer at the beginning was reduced by retarding cement hydration. This theory could not convincingly explain why sodium hexametaphosphate (SHMP) was able to promote the dispersion capacity of PCE, while trisodium phosphate (TSP) could not, despite that both TSP and SHMP could obviously retard the cement hydration. The adsorption behavior of PCE and phosphate was investigated and the mechanism was analyzed in order to gain deeper understanding. The results showed that TSP and SHMP delayed the cement hydration, impeded adsorption process of PCE, and increased thickness of adsorption layer. It was interesting that TSP reduced the dispersion, but SHMP enhanced. The reason for this contradiction was due to the difference in composition of adsorption layer. In the PCE-TSP system, this layer was composed of the precipitates (formed by TSP and Ca2+) and the invalided PCE (caused by these precipitates in the immediate vicinity of the cement grains); the invalided PCE was due to the decrease of PCE dispersion. In the PCE-SHMP system, “Inner-phosphate (multi-layers) + Outer-PCE (single layer)” structure was formed to make the PCE work more effective, hence enhancing the dispersion. These results were expected to be useful for the design of highly efficient dispersants.