A pilot plant and anaerobic digestion process for raisin finishing wastewater treatment

1987 ◽  
Vol 22 (2) ◽  
pp. 129-138 ◽  
Author(s):  
N. Athanasopoulos ◽  
A.A. Koutinas ◽  
A. Papadimitriou
2006 ◽  
Vol 53 (11) ◽  
pp. 221-226 ◽  
Author(s):  
M. Minamiyama ◽  
S. Ochi ◽  
Y. Suzuki

Many environmental problems caused by endocrine disruptors (EDs) have been reported. It is reported that EDs flow into sewage treatment plants, and it has been pointed out that these may be shifted from the wastewater treatment process to the sludge treatment process. Little is known about the fate of EDs accumulated in sewage sludge, so we carried out a study to clarify the fate of EDs in sewage sludge treatment processes, especially in an anaerobic digestion process. In this study, nonylphenol (NP) was selected as a target ED. Nonylphenol ethoxylates (NPnEO) or nonylphenoxy acetic acids (NPnEC), which were the precursor of NP, were added to an anaerobic digestion process, and mass balance was investigated. The following results were obtained from the anaerobic digestion experiments. (1) NP1EO was injected to an anaerobic digestion testing apparatus that was operated at a retention time of approximately 28 d and a temperature of 35 °C with thickened sludge sampled from an actual wastewater treatment plant. Approximately 40% of the injected NP1EO was converted to NP. (2) NP1EC was injected to an anaerobic digestion testing apparatus with thickened sludge. As a result, almost all injected NP1EC was converted to NP. When NP2EC was injected, NP2EC was not converted to NP until the 20th day.


1985 ◽  
Vol 17 (4-5) ◽  
pp. 529-539 ◽  
Author(s):  
M. Hiraoka ◽  
N. Takeda ◽  
S. Sakai ◽  
A. Yasuda

The effectiveness of an anaerobic digestion process with thermal pretreatment at a comparatively low temperature was examined. The waste activated sludge was thermally pretreated in the process. A laboratory scale experiment and a pilot plant study were conducted. Changes in volatile acids concentration, in major constituents of sludge and in molecular size distribution were examined before and after thermal pretreatment and anaerobic digestion. Thermal pretreatment resulted in an increase of more than 30 percent in digestion gas production. The major substrates decomposed were fats in the pilot plant study. Glyceride fatty acids are decomposed with thermal pretreatment and produce volatile acids such as acetic and propionic acids. The volatile acids are directly utilized by anaerobes to produce methane. Organic matter such as fats and carbohydrates are depolymerized with thermal pretreatment and produce soluble intermediate compounds such as higher fatty acids. The intermediates are utilized in the anaerobic digestion process. These two major effects facilitate the methane production process.


2002 ◽  
Vol 45 (4-5) ◽  
pp. 495-502 ◽  
Author(s):  
J.P. Steyer ◽  
J.C. Bouvier ◽  
T. Conte ◽  
P. Gras ◽  
P. Sousbie

For several years, a 1 m3 fixed bed anaerobic digestion process has been operated for the treatment of distillery vinasses. This reactor has been fully instrumented with the following variables available on-line: pH, temperature, liquid and gas flow rates, gas composition (i.e., CH4, CO2 and H2), concentration of bicarbonate, chemical oxygen demand, total organic carbon, volatile fatty acids and partial and total alkalinity, these last four variables being measured twice by different techniques (i.e., using a TOC analyzer, a titrimetric sensor and an infrared spectrometer). The purpose of this paper is to compare the respective benefits of advanced instrumentation for the monitoring of wastewater treatment processes in general, and for anaerobic digestion in particular. It will also provide some statistical analysis of the time required to operate a fully instrumented wastewater treatment process. It is indeed well admitted in the literature that instrumentation is usually the main limitation step for using closed-loop control. However, it is our opinion that, in the near future, this situation will change. This point is discussed based on our four years practical experience.


2011 ◽  
Vol 356-360 ◽  
pp. 1914-1918
Author(s):  
Yi Xin Yan ◽  
Jian Lei Gao ◽  
Jian Ping Wu

The excess sludge from wastewater treatment plants can be converted to methane or hydrogen through appropriate anaerobic digestion process, which is an effective way to prevent pollution and recover biomass energy. However, the lower conversion rate that results in long residence time and large digester volume limits its application. The ultrasonic technology can be applied to effectively improve the biomass conversion of excess sludege during anaerobic digestion process. In this review, the mechanism and main influencing factors of ultrasonic enhancement were summarized, and the current research situation and future development were presented as well.


2017 ◽  
pp. 558-563
Author(s):  
Svetlana Ofverstrom ◽  
Ieva Sapkaite ◽  
Regimantas Dauknys

In this study, the impact of iron and aluminium salts addition on anaerobic digestion process was investigated. Mixture of primary and activated sludge collected at Vilnius wastewater treatment plant in Lithuania was digested under laboratory conditions by using anaerobic digester (W8, Amfield, UK). To compare the relative digestibility of iron-dosed (Fe-dosed)and aliuminium-iron-dosed (Al-Fe-dosed) sludge with un-dosed sludge three continuous experiments were made. Results showed that iron and aliuminium negatively impacted anaerobic digestion process by reducing the volume of biogas produced. Fe-dosed sludge produced 20-50% less biogas and Al-Fe-dosed sludge produced 30-40% less biogas in comparison to the same un-dosed sludge. VS destruction decreased during dosing of Fe or/and Al salt. Biogas composition was not measured during the experiments.


1986 ◽  
Vol 18 (7-8) ◽  
pp. 239-248 ◽  
Author(s):  
Sung Ryong Ha ◽  
Dwang Ho Lee ◽  
Sang Eun Lee

Laboratory scale experiments were conducted to develop a mathematical model for the anaerobic digestion of a mixture of night soil and septic tank sludge. The optimum mixing ratio by volume between night soil and septic tank sludge was found to be 7:3. Due to the high solids content in the influent waste, mixed-liquor volatile suspended solids (MLVSS) was not considered to be a proper parameter for biomass concentration, therefore, the active biomass concentration was estimated based on deoxyribonucleic acid (DNA) concentration in the reactor. The weight ratio between acidogenic bacteria and methanogenic bacteria in the mixed culture of a well-operated anaerobic digester was approximately 3:2. The proposed model indicates that the amount of volatile acid produced and the gas production rate can be expressed as a function of hydraulic residence time (HRT). The kinetic constants of the two phases of the anaerobic digestion process were determined, and a computer was used to simulate results using the proposed model for the various operating parameters, such as BOD5 and volatile acid concentrations in effluent, biomass concentrations and gas production rates. These were consistent with the experimental data.


2020 ◽  
Vol 53 (2) ◽  
pp. 16840-16845
Author(s):  
Camilo Garcia-Tenorio ◽  
Mihaela Sbarciog ◽  
Eduardo Mojica-Nava ◽  
Alain Vande Wouwer

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