Evaluation by Kinetic Models of Anaerobe Digestion Performances for Various Substrates and Co-substrates

2017 ◽  
Vol 68 (11) ◽  
pp. 2614-2617
Author(s):  
Adrian Eugen Cioabla ◽  
Gabriela Alina Dumitrel ◽  
Ioana Ionel

Anaerobic digestion is a complex process that allows the conversion of organic wastes into biogas with minimal costs and benefits for the environment. The goal of this study is to evaluate the anaerobic digestion potential of two common agricultural biomass wastes (degraded corn and degraded wheat) used as single substrates or as co-substrates together with wastewater from a waste water treatment plant. The results reveal that the co-digestion is an improved solution, both in terms of biogas amount produced and its methane concentration. Two kinetic models (modified Gompertz model and logistical growth model) were applied to study the methane production. For each case, the kinetic parameters were estimated. One demonstrates that the modified Gompertz model fitted very well the measured methane potential, for all studied cases.

Author(s):  
Maria V. Morar

In our country, the developments of the measures for the prevention of the environmental pollution are aligning to the UE Directives. The costs for the treatment of the water wastes are continuously increasing, following to the also increasing of the investments costs. Therefore it is necessary to accord attention for the alternatives of cleaning, treating, respective recycling of the agro-industrial wastes and their reintroduction in the natural circuit. At the processing of the food results wastes with high organic charge. The effluents form the processing of dairy products, sugar, starch, beer yeasts as well as breweries or distilleries are getting fast into acids fermentation, finally resulting organic acids. Such process water wastes can be released in the canalization by dilution or by a suitable treating. As an example, for the distillery wastes (distillery slops) with a high dry matter contents (4-20%), the waste water treatment plant shall be designed properly (with mechanical separation step and biological treatment) to ensure the capacity of purifying according to the high flow and increased concentration, due to the high CBOD5 concentration. The treatment of such water wastes can be realized with aerobic processes, which suppose a high energetic consumption. While in the aerobic purifying processes 50 % of the CBOD5 is involved in the forming of biomass and slurry in excess, in the anaerobic treatment processes (anaerobic or methane digestion) a high part of the substrate (until 70 %) is metabolized through the metabolic transformation of bacterial flora, with production of biogas. Therefore, the concentrated water wastes, with potential for the energy production could offer a possibility of energy replacement in the own processing units. The paper presents a review of the anaerobic digestion for different wastes from the agro-industrial processing and their potential for the biogas production. There are presented possibilities of mixture, respectively of co-digestion of different wastes the agro-industrial processing with other wastes from the agriculture (from cereals processing, biomass, manure etc). Simultaneously biogas plants from the praxis with functioning characteristics are presented.


2010 ◽  
Vol 5 (1) ◽  
Author(s):  
J. Chauzy ◽  
JC. Martin ◽  
D. Cretenot ◽  
JP Rosiere

For large cities which cannot afford to sustain land disposal of sludge, Wet Air Oxidation appears to be an interesting option, perceived as environmentally friendly to a public opinion some times reluctant toward conventional incineration. However, due to significant investment costs, it is relevant to reduce upstream the amount of sludge by anaerobic digestion. This paper presents the North Brussels WWTP (1.1 Million pe), which was started-up in 2006. The sludge treatment consists of thermal hydrolysis of dewatered sludge followed by high load mesophilic anaerobic digestion and Wet Air Oxidation. The Wet Air Oxidation final product is then dewatered and dried to over 90% solids content, prior to being disposed as a cover product for landfills.


Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 26 ◽  
Author(s):  
Pengfei Li ◽  
Wenzhe Li ◽  
Mingchao Sun ◽  
Xiang Xu ◽  
Bo Zhang ◽  
...  

There is a lack of literature reporting the measurement and prediction of biochemical methane potential (BMP) of vegetable crop residues (VCRs) and similarly, the kinetic assessment on the anaerobic digestion process of VCR is rarely investigated. In this paper, the BMP tests of five different vegetable (snap bean, capsicum, cucumber, eggplant, and tomato) crop residues were conducted at feed to inoculum ratio (F/I) of 2.0 under mesophilic (36 ± 1 °C) conditions. A series of single-variable and multiple-variable regression models were built based on organic components (hemicellulose, cellulose, lignin, total fat, total sugar, and crude protein) for BMP prediction. Three kinetic models, including the first-order kinetic model, the Chen and Hashimoto model, and the modified Gompertz model, were used to simulate the methane yield results of VCR and obtain valuable model parameters simultaneously. As a result, the BMPs and volatile solids (VS) degradation degree of different VCRs were respectively in the range of 94.2–146.8 mL g−1 VS and 40.4–49.9%; the regression prediction models with variables lignin (R2 = 0.704, p = 0.076), variables crude protein and lignin (R2 = 0.976, p = 0.048), and variables total fat, hemicellulose, and lignin (R2 = 0.999, p = 0.027) showed the best performance on BMP prediction among the single-factor, two-factor, and three-factor models, respectively. In addition, compared to the other two kinetic models, the modified Gompertz model could be excellently fitted (R2 = 0.986–0.998) to the results of BMP experiment, verification deviations within 0.3%.


Author(s):  
Kristína Šefčovičová ◽  
Igor Bodík ◽  
Veronika Kvorková ◽  
Juraj Michálek ◽  
Andrey Korshunov ◽  
...  

Abstract This article deals with pharmaceutical compounds as micropollutants in anaerobic digestion of sludge from waste water treatment plant (WWTP). Part of the work included the research into presence of pharmaceuticals in different types of waters. Description of anaerobic fermentation process is also important in terms of optimal conditions. The practical aim of the investigation was preparation of a model of anaerobic fermentation of sewage sludge, where influence of pharmaceuticals on mesophilic anaerobic digestion was monitored. Wash out of micropollutants from sludge in big semicontinuous anaerobic reactors was running since October 2013. The resulting non-adapted sludge from mesophilic reactor was used since March 2014 for pharmaceuticals tests in half-a-litre glass bottles with a septum cap. The compounds of interest were diclofenac, tramadol, ibuprofen, carbamazepine and amoxicillin and their concentration in the tested sludge was 10 μg/L and 500 μg/L. The results showed that pharmaceuticals have different influence on the amount of produced biogas even if they are from the same therapeutic group. In the low concentration, the inhibition was present for diclofenac, carbamazepine and amoxicillin, at the high concentration, while diclofenac showed almost no influence. Other compounds caused a stimulative effect on the process. The mixture of all pharmaceuticals of interest in low concentration was stimulative at first, while it was inhibotory since mid-time of the test.


2016 ◽  
Vol 9 (2) ◽  
Author(s):  
Dinda Rita K. Hartaja ◽  
Imam Setiadi

Generally, wastewater of nata de coco industry contains suspended solids and COD were high, ranging from 90,000 mg / l. The high level of of the wastewater pollutants, resulting in nata de coco industry can not be directly disposed of its wastewater into the environment agency. Appropriate technology required in order to process the waste water so that the treated water can meet the environmental quality standards that are allowed. Designing the waste water treatment plant that is suitable and efficient for treating industrial wastewater nata de coco is the activated sludge process. Wastewater treatment using activated sludge process of conventional (standard) generally consists of initial sedimentation, aeration and final sedimentation.Keywords : Activated Sludge, Design, IPAL


1991 ◽  
Vol 23 (4-6) ◽  
pp. 825-834 ◽  
Author(s):  
T. H. Lessel

The upgrading and nitrification was required for the waste water treatment plant in Geiselbullach. As space for more aeration tanks was not available, the possibility of increasing the MLSS by the use of submerged bio-film reactors was tested in a half technical scale pilot plant with three different reactor materials. Each tested reactor material caused a significant increase of MLSS and the nitrification reaction. The rope-type material was selected for the practical application, as it had not the same disadvantages of the other tested systems, which proved operational problems. After one year of continuous operation for nitrification in the full scale plant the influences on the biomass characteristics were investigated. Design criterias and details and operational data are reported.


1991 ◽  
Vol 24 (10) ◽  
pp. 161-170 ◽  
Author(s):  
M. D. Sinke

Until a century ago, The Hague's waste water was discharged directly into the city's canals. However, the obnoxious smell and resultant pollution of local waters and beaches then necessitated the implementation of a policy of collecting and transferring waste water by means of a system of sewers. By 1937, it was being discharged, via a 400 metre-long sea outfall, directly into the North Sea. By 1967, however, the increasing volume of waste water being generated by The Hague and the surrounding conurbations called for the construction of a primary sedimentation plant. This had two sea outfalls, one 2.5 km long and the other 10 km long, the former for discharging pre-settled waste water and the latter for discharging sludge directly into the North Sea. This “separation plant” was enlarged during the period 1986-1990. On account of the little available area - only 4.1 ha - the plant had to be enlarged in two stages by constructing a biological treatment section and a sludge treatment section with a capacity of 1,700,000 p.e. (at 136 gr O2/p.e./day). In order to gain additional space, a number of special measures were introduced, including aerating gas containing 90% oxygen and stacked final clarifiers. Following completion of the sludge treatment section, it has become possible, since 1st May 1990, to dump digested sludge into a large reservoir (“The Slufter”), specially constructed to accommodate polluted mud dredged from the Rotterdam harbours and waterways. As a result of these measures, there has been a reduction of between 70% and 95% in North Sea pollution arising from the “Houtrust” waste water treatment plant. Related investment totalled Dfl. 200 million and annual operating and maintenance costs (including investment charges) will amount to Dfl. 30 million. Further measures will have to be taken in the future to reduce the discharge of phosphorus and nitrogen. So this enlargement is not the end. There will be continued extension of the purification operations of the “Houtrust” waste water treatment plant.


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