Fate of nonylphenol polyethoxylates and nonylphenoxy acetic acids in an anaerobic digestion process for sewage sludge treatment

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.

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6262 ◽  
Author(s):  
Roberta Ferrentino ◽  
Fabio Merzari ◽  
Luca Fiori ◽  
Gianni Andreottola

The present study addresses the coupling of hydrothermal carbonization (HTC) with anaerobic digestion (AD) in wastewater treatment plants. The improvement in biomethane production due to the recycling back to the anaerobic digester of HTC liquor and hydrochar generated from digested sludge is investigated and proved. Mixtures of different compositions of HTC liquor and hydrochar, as well as individual substrates, were tested. The biomethane yield reached 102 ± 3 mL CH4 g−1 COD when the HTC liquor was cycled back to the AD and treated together with primary and secondary sludge. Thus, the biomethane production was almost doubled compared to that of the AD of primary and secondary sludge (55 ± 20 mL CH4 g−1 COD). The benefit is even more significant when both the HTC liquor and the hydrochar were fed to the AD of primary and secondary sludge. The biomethane yield increased up to 187 ± 18 mL CH4 g−1 COD when 45% of hydrochar, with respect to the total feedstock, was added. These results highlight the improvement that the HTC process can bring to AD, enhancing biomethane production and promoting a sustainable solution for the treatment of the HTC liquor and possibly the hydrochar itself.


Author(s):  
N. E. Gutorova ◽  
◽  
O. V. Dymnikova ◽  

Introduction. The article deals with the problems of treatment of organic sludge from the purification of municipal wastewater in Rostov-on-Don. To solve this problem, a method of anaerobic (methane) digestion of sewage sludge was proposed. Problem Statement. The objective of this study is to determine the role of anaerobic stabilization for Rostovvodokanal company. Theoretical Part. The differences between mesophilic and thermophilic modes of sediment digestion were determined, a technological line for preparing biogas for use was proposed. Calculations of the main parameters of the anaerobic digestion process in the digester have been made. Conclusion. The results of the analysis showed that with the help of this modernization, the main problems are solved.


2007 ◽  
Vol 2 (1) ◽  
Author(s):  
A. Meda ◽  
C. Schaum ◽  
M. Wagner ◽  
P. Cornel ◽  
A. Durth

TIn 2004, the German Association for Wastewater, Water and Waste (DWA) carried out a survey about the current status of sewage sludge treatment and disposal in Germany. The study covered about one third of the wastewater treatment plants and about two thirds of the entire treatment capacity (expressed in population equivalents) in Germany. This provides an up-to-date and representative database. The paper presents the most important results regarding sludge treatment, process engineering, current disposal paths and sewage sludge quality.


RSC Advances ◽  
2020 ◽  
Vol 10 (59) ◽  
pp. 35718-35728
Author(s):  
Reza Barati rashvanlou ◽  
Abbas Rezaee ◽  
Mahdi Farzadkia ◽  
Mitra Gholami ◽  
Majid Kermani

Micro-aeration as a pretreatment method improves the efficiency of anaerobic digestion of municipal sewage sludge and consequently promotes the methane production.


2014 ◽  
Vol 37 (2) ◽  
pp. 159-163
Author(s):  
Bijaya Nanda Naik ◽  
Harison Masih ◽  
Ajaya Singh

The aerobic thermophilic sewage sludge treatment process was studied at various bioreactor scales through modified bioengineering design approach. The effectiveness of the biological system was controlled by varying the process operating conditions of bioreactor to enhance microbial degradation efficiency. The inactivation of pathogen each promoted by increase of temperature, while the residual CFU was lowered by reducing the total solids content of sewage sludge. The optimum sludge degradation through aerobic thermophilic process occurred in temperature range of 58 - 62oC but temperature more than 60oC was suitable for hygienic inactivation. Dual digestion systems of an aerobic theromophilic treatment followed by anaerobic thermophilic stabilization stage shows greater treatment and efficiency in degrading the organic sludge constituting up to seventy per cent. DOI: http://dx.doi.org/10.3329/jbas.v37i2.17556 Journal of Bangladesh Academy of Sciences, Vol. 37, No. 2, 159-163, 2013


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.


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