The SMP buffer contains p-nitrophenol and potassium chromate, both hazardous substances. A solution without toxic substances, the so-called Santa Maria buffer (TSM) was developed to reproduce performance of the SMP buffer used to estimate potential acidity of soils in Rio Grande do Sul and Santa Catarina (SMP-RS/SC). Acid titrations of the SMP- RS/SC buffer and various mixtures of the components of the new buffer were performed, using multiparametric regression analysis to obtain the optimal TSM composition. The efficiency of TSM […]

Tannery residues are potential pollution sources in several regions of Brazil, mainly in the State of Rio Grande do Sul. One of the alternatives for the final destination of the sludge resulting from the waste water treatment of tanning industries is the disposal and recycling in the soil. To evaluate the effects of two waste types originated from primary treatment of tannery residual water on soil microbial populations, an open air pot experiment was carried out in a Paleudult soil […]

Large amounts of solid wastes are produced in tanneries, which use chromium (III) to obtain wet blue leather hides. The solid residues (leather scraps and strips) contain around 3 % chromium (III), which represent a serious environmental problem and, presently, have no adequate destination. The leather waste after chromium extraction (collagen) was used as a nitrogen source for elephantgrass- Pennisetum purpureum Schum cv. Napier. Four doses of collagen (4, 8, 16, and 32 t ha-1) and three additional treatments (control; mineral fertilizer N; […]

The search for methods to determine the content of soil organic matter (SOM) that do not generate hazardous waste is important. SOM oxidation with dichromate is used in most Brazilian soil laboratories and it generates chromium-contaminated waste. The objective of this study was to evaluate the weight loss-on-ignition (LOI) method in comparison to the wet digestion procedure based on sulfuric acid-chromium solution as commonly used in soil analysis laboratories of Rio Grande do Sul (RS) and Santa Catarina (SC) states, […]

Tannery and coal residues are potential pollution sources in numerous regions of Brazil, mainly in the Rio Grande do Sul and Santa Catarina States. In order to evaluate the effects of tannery residue and coal mining refuse on soil properties and cultivated plants, a field experiment was carried out in 1996/97 at the UFRGS Experimental Station, in the Eldorado do Sul county, State of Rio Grande do Sul, Brazil. Corn (Zea mays L.) and soybean (Glycine max L. Merrill) were […]

This experiment was conducted in leaching tubes filled with soils classified as Typic Quartzipsament (AQ), Typic Hapludox (LV) and Rhodic Typic (LE). Sewage sludge was periodically added and incorporated to the soils in a total amount corresponding to 156,0 t ha-1 (dry weight basis), for an incubation period of 310 days. The soils were then treated with water and the following salt solutions: 0.9 mol L-1 KCl; 0.9 mol L-1 KNO3; 0.3 mol L-1 K2SO4 and 0.3 mol L-1 Ca(NO3)2. […]