The main objective of the project is to demonstrate the feasibility of recycling pickling-tanning baths, ensuring the quality of the final product at ali times and achieving, on the one hand, the reduction of saline pollution (50%) caused by pickling and tanning baths and, on the other hand, the reduction of chromium salt (14%) in tanning wastewater. With regards to the anatytical parameters of the bath, the results show that the parameters analysed (pH, conductivity, density, chlorides, sulphates, chrome, solids in suspension and fats) are stabilised and the values obtained do not imply interferences in the pickling-tanning process. In parallel to the execution of these analyses, physical and chemical tests for quality control of the leathers were carried out, both on wet-blue and crust leathers. The results showed that there were no significan! differences in the leathers obtained with...

This paper experimentally studies the separation of pollutants in waste water from industry meal and fish oil, through a process of dissolved air flotation (DAF). The experimental results showed a removal of 60% SS, 98% and 66% BOD FOG.

We presented the design of a dissolved air flotation system (DAF) to separate coagulated solids (dye) in the wastewater of a textile plant. The obtained yields of removal of suspended solids (SS) they are 82%. The size of the float to treat 35 m3/h of residual water of a textile is 5,7 m.

A rapid and highly efficient treatment process for waste waters containing dye was investigated by combining the process of chemical coagulation/flocculalion. About 70% of DBO , DB05 and 80% of dyes was removed simultaneously.

The conventional method of chrome tanning, employed in Leather industry, results In a very poor exhaustion of chrome, thereby adding to the toxicity of the effluent. One of !he cleaner processing options recommended is that the chrome which is let out in the effluent, may be recovered for reuse to ensure not only economy of usage of chrome, but also effective management of this toxic substance. The waste water tannery contents 3 200 mg/L of Cr ( pH = 3,2 ). The methodology involves precipitation of chrome with an alkali with pH = 9, 1 and consume of O, 12 kg de MgO for one kg equivalen! de Cr2 Or The efficiency of recovery of Cr is 99,9 % (Cr water treatment 0,007 mg/L) with use Magnesia 65% MgO of purity. The supernatant liquor is separated, allowing the resulting precipitate to settle down. This precipitate is treated with sulfuric acid again, which can be reused.

The main objective of the project is to demonstrate the feasibility of recycling pickling-tanning baths, ensuring the quality of the final product at ali times and achieving, on the one hand, the reduction of saline pollution (50%) caused by pickling and tanning baths and, on the other hand, the reduction of chromium salt (14%) in tanning wastewater. With regards to the anatytical parameters of the bath, the results show that the parameters analysed (pH, conductivity, density, chlorides, sulphates, chrome, solids in suspension and fats) are stabilised and the values obtained do not imply interferences in the pickling-tanning process. In parallel to the execution of these analyses, physical and chemical tests for quality control of the leathers were carried out, both on wet-blue and crust leathers. The results showed that there were no significan! differences in the leathers obtained with...

This paper experimentally studies the separation of pollutants in waste water from industry meal and fish oil, through a process of dissolved air flotation (DAF). The experimental results showed a removal of 60% SS, 98% and 66% BOD FOG.

We presented the design of a dissolved air flotation system (DAF) to separate coagulated solids (dye) in the wastewater of a textile plant. The obtained yields of removal of suspended solids (SS) they are 82%. The size of the float to treat 35 m3/h of residual water of a textile is 5,7 m.

Se presentan los resultados de un estudio de tratamiento físico-químico de aguas residuales de las industrias textiles, documentando la influencia de concentraciones de reactivos usados y de las variaciones de condiciones de tratamiento para obtener condiciones óptimas de operación. Los rendimientos obtenidos son el 70% en la remoción de DQO y DBO5 y el 80% para la remoción de tinte.

The conventional method of chrome tanning, employed in Leather industry, results In a very poor exhaustion of chrome, thereby adding to the toxicity of the effluent. One of !he cleaner processing options recommended is that the chrome which is let out in the effluent, may be recovered for reuse to ensure not only economy of usage of chrome, but also effective management of this toxic substance. The waste water tannery contents 3 200 mg/L of Cr ( pH = 3,2 ). The methodology involves precipitation of chrome with an alkali with pH = 9, 1 and consume of O, 12 kg de MgO for one kg equivalen! de Cr2 Or The efficiency of recovery of Cr is 99,9 % (Cr water treatment 0,007 mg/L) with use Magnesia 65% MgO of purity. The supernatant liquor is separated, allowing the resulting precipitate to settle down. This precipitate is treated with sulfuric acid again, which can be reused.

This work concerns the design and construction of a flotation equipment - laboratory size - for the treatment of waste water of the fishmeal industry.

This work concerns the design and construction of a flotation equipment - laboratory size - for the treatment of waste water of the fishmeal industry.