Low temperature conversion of sludge and shavings from leather industry

Abstract

Brazil has one of the largest herds of cattle in the world, with more than 170 million heads. Over 400 farms have exported more than 2,875 ton (in 1997) of leather to Europe. The wet blue tanning process uses chemicals such as chromium compounds and produces liquid wastes that must be treated by physicochemical and biological systems. About 15,000 ton per month of dewatering sludge with 24% solids content is disposed of into landfills. During the process, pre-tanned skins (wet blue leather) are shaved to the desired thickness and the shavings, like sludge, are among the wastes that must have special attention. The organic content and chromium concentration are high. About 12% of the leather production from cattle hides are shavings, and its chromium concentration ranges from 3.5 to 5.5% of dry matter. The Environmentally friendly leather project, a co-operation between Brazilian and German tanneries, universities and technical schools, is looking for process optimisation, waste minimisation and adequate treatment for solid and liquid wastes from the leather industry. This work presents results of Low Temperature Conversion of chrome-containing sludge and shavings in a laboratory batch reactor, offering a solution for these hazardous wastes, recovering the energy content and transforming metals in insoluble sulphides.

Growth, nodulation and nitrogen fixation of cowpea in soils amended with composted tannery sludge

“…However, this industry is also responsible for the release of more than 1,000,000 tons of tannery sludge each year (Pacheco, 2009), of which 3 % are solid residues (Silveira et al, 2002). The high annual production of tannery sludge has created a series of economic, social and environmental problems.…”

Filter Cake, Residue of the Sugarcane Industry - A Evaluation by Slow Pyrolysis

“…As fontes de biomassas (agrícolas, florestais ou aquáticas) que podem ser utilizadas incluem casca de coco, bagaço de cana, sabugo de milho, pinhão manso, mamona, soja, borra de café, casca de licuri, casca de arroz, aparas florestais, aguapé, entre outras. [3][4][5][6][7] O processo de pirólise é uma alternativa renovável e de fundamental importância para a destinação adequada de resíduos, podendo agregar valor aos bioprodutos, que podem ser aplicados como: biocombustíveis, insumos químicos, fertilizantes, antioxidante, remediação de solos, filtros, processos de adsorções e muitos outros segmentos. [8][9][10][11] Neste trabalho será abordado um estudo de pirólise lenta do resíduo da torta de filtro, proveniente das indústrias sucroalcooleiras, com o objetivo de produzir, principalmente, biocarvão e verificar suas possíveis aplicações como bioadsorvente para corantes de efluentes industriais, adubo orgânico e combustível.…”

Protein Biofertilizer Development and Application on Soybean Cultivated Degraded Soil

“…However, increasingly higher local restrictions on waste disposal in landfills and high incineration costs have prompted ºi costurile ridicate de incinerare au stimulat cãutarea unor tratamente alternative. Multe grupuri ºtiinþifice ºi-au orientat cercetãrile în direcþia gãsirii unui proces de reciclare ºi tratare a acestor deºeuri [3][4][5][6][7].…”

“…Many scientific groups have directed their research towards finding a recycling and treatment process for this waste [3][4][5][6][7].…”