Low temperature conversion of sludge and shavings from leather industry

2002 ◽  
Vol 46 (10) ◽  
pp. 277-283 ◽  
Author(s):  
I.C.T. Silveira ◽  
D. Rosa ◽  
L.O. Monteggia ◽  
G.A. Romeiro ◽  
E. Bayer ◽  
...  
Keyword(s):  
Low Temperature ◽  
Energy Content ◽  
Batch Reactor ◽  
Organic Content ◽  
Chromium Concentration ◽  
Leather Industry ◽  
Adequate Treatment ◽  
Tanning Process ◽  
Liquid Wastes ◽  
Chemical And Biological Systems

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 physico-chemical 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.

SBR treatment of olive mill wastewaters: dilution or pre-treatment?

2012 ◽  
Vol 65 (9) ◽  
pp. 1684-1691 ◽  
Author(s):  
G. Farabegoli ◽  
A. Chiavola ◽  
E. Rolle
Keyword(s):  
Biological Process ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Adequate Treatment ◽  
Olive Mill Wastewaters ◽  
Other Substances ◽  
Removal Efficiencies ◽  
Pre Treatment ◽  
Olive Mill ◽  
Gac Adsorption

The olive-oil extraction industry is an economically important activity for many countries of the Mediterranean Sea area, with Spain, Greece and Italy being the major producers. This activity, however, may represent a serious environmental problem due to the discharge of highly polluted effluents, usually referred to as ‘olive mill wastewaters’ (OMWs). They are characterized by high values of chemical oxygen demand (COD) (80–300 g/L), lipids, total polyphenols (TPP), tannins and other substances difficult to degrade. An adequate treatment before discharging is therefore required to reduce the pollutant load. The aim of the present paper was to evaluate performances of a biological process in a sequencing batch reactor (SBR) fed with pre-treated OMWs. Pre-treatment consisted of a combined acid cracking (AC) and granular activated carbon (GAC) adsorption process. The efficiency of the system was compared with that of an identical SBR fed with the raw wastewater only diluted. Combined AC and GAC adsorption was chosen to be used prior to the following biological process due to its capability of providing high removal efficiencies of COD and TPP and also appreciable improvement of biodegradability. Comparing results obtained with different influents showed that best performances of the SBR were obtained by feeding it with raw diluted OMWs (dOMWs) and at the lowest dilution ratio (1:25): in this case, the removal efficiencies were 90 and 76%, as average, for COD and TPP, respectively. Feeding the SBR with either the pre-treated or the raw dOMWs at 1:50 gave very similar values of COD reduction (74%); however, an improvement of the TPP removal was observed in the former case.

scholarly journals Production of Biofuel via Catalytic Hydrocracking of Kapuk (Ceiba pentandra) Seed Oil with NiMo/HZSM-5 Catalyst

2018 ◽  
Vol 156 ◽  
pp. 06001 ◽  
Author(s):  
I Gede Andy Andika Parahita ◽  
Yustia Wulandari Mirzayanti ◽  
Ignatius Gunardi ◽  
Achmad Roesyadi ◽  
Danawati Hari Prajitno
Keyword(s):  
Alternative Energy ◽  
Seed Oil ◽  
Batch Reactor ◽  
Liquid Product ◽  
Hydrocarbon Composition ◽  
Organic Content ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Ceiba Pentandra ◽  
Hydrocracking Process

Biofuel is one of alternative energy that is being developed today to solve the problem of limited fossil fuel as an energy source. The goal of this study is to produce biofuel from kapuk (Ceiba pentandra) seed oil (KSO) through catalytic hydrocracking process using NiMo/HZSM-5 catalyst. NiMo/HZSM-5 catalyst was obtained by impregnation of nickel and molybdenum as metallic precursors on HZSM-5 catalyst as support using incipient wetness impregnation method. It was found that the surface area of the catalyst was 222.1350 m2/g, the pore diameter was 3.0148 nm and the pore volume was 0.1674 cm3/g. The diffraction peaks of nickel oxide phase and the metallic phase of nickel were observed at 2θ of 62.5102° and 51.7283°. Molybdenum oxide phases were observed at 2θ of 53.5674° and 60.4682°. The catalytic hydrocracking process was performed using slurry pressure batch reactor at the temperature of 350°C for 2 h. The obtained liquid product was analyzed using GC-MS in order to determine the organic content. It has been found that the highest compounds were the palmitic acid with 23.14 area%. Besides, the hydrocarbon composition consisted of 33.93 area% (i.e. 4.34 area% cycloparaffins, 16.02 area% n-paraffins, 12.26 area% olefins, and 1.30 area% of aromatics) and 58.73 area% of carboxylic acid. Thus, it can be concluded that NiMo/HZSM-5 catalyst can convert KSO into biofuel through catalytic hydrocracking process at the temperature of 350°C for 2 h.

scholarly journals Study of the dechroming of tanned leather wastes

2004 ◽  
Vol 58 (2) ◽  
pp. 64-68
Author(s):  
Tatjana Botic ◽  
Nadezda Iliskovic ◽  
Dijana Drljaca
Keyword(s):  
Solid Waste ◽  
Alkaline Hydrolysis ◽  
Leather Industry ◽  
Primary Target ◽  
Initial Amount ◽  
Economic Saving ◽  
Tanning Process ◽  
Leather Wastes ◽  
Oxidation Agent ◽  
Tanning Industry

According to European legislation, it is not possible to dump any chromium-containing waste in Europe. The minimization of wastes is a key element in that strategy. It involves the application of clean technologies: low and non-waste technologies. The tanning industry generates substantial quantities of chromium-containing solid waste in the form of shavings and trimmings. The recycling and reuse of those wastes must be the primary target in optimizing processes of the leather industry. The problem is in a satisfying chromium separation from collagen fibers. Common hydrolysis processes-alkaline or acidic-give gelatins containing residual chromium (III). By using an oxidation agent (H2O2) before alkaline hydrolysis, in was demonstrated that chromium from chromium-containing leather wastes can be almost fully recovered by the previous oxidation of Cr(III) to Cr(VI). This chromium can be reused in the tanning process. That would represent an economic saving. The best result of the dechroming process was a gelatin hydrolyzate with only 1.11 in respect to the initial amount.

Long term experiences of sequencing batch reactor-system and wetland treatment from a municipal wastewater treatment plant in Sweden, operated with low temperature wastewater

2014 ◽  
Vol 9 (2) ◽  
pp. 235-242 ◽  
Author(s):  
S. Morling ◽  
A. Franquiz ◽  
J. Måhlgren ◽  
Å. Westlund
Keyword(s):  
Wastewater Treatment ◽  
Low Temperature ◽  
Wastewater Treatment Plant ◽  
Sequencing Batch Reactor ◽  
Municipal Wastewater ◽  
Batch Reactor ◽  
Combined Treatment ◽  
Treatment Plant ◽  
Municipal Wastewater Treatment ◽  
Total N

A biological wastewater treatment plant, Nynäshamn treating municipal wastewater and septic sludge operated with a combination of sequencing batch reactor (SBR) units and constructed wetland is presented in this paper. The plant has to treat low temperature wastewater in winter time, still with demands for a biological nitrogen removal. Treatment results from a 13 year operation period are presented. Special attention was given to the nutrient removal during low temperature conditions. The combination of a SBR system along with classical chemical precipitation and a polishing step based on ‘natural’ extensive treatment has been a sustainable way to keep the discharge levels low. The combined treatment with SBR and the wetland at the Nynäshamn plant has resulted in improved discharge levels typically as follows (annual mean values); BOD7 3 mg/l, to be compared with the formal consent value of <15 mg/l, total P < 0.1 mg/l, to be compared with the formal consent value of <0.5 mg/l and total N 7 mg/l, to be compared with the formal consent value of <15 mg/l. It is also important to underline that the change of process train has resulted in a substantial saving of the precipitant agent for phosphorus removal. The needed dosage is now 50% of the previous dose, before the implementation of the SBR-units.

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