Evaluation of the energetic potential of sewage sludge by characterization of its organic composition

2016 ◽  
Vol 73 (12) ◽  
pp. 3072-3079 ◽  
Author(s):  
C. Schaum ◽  
D. Lensch ◽  
P. Cornel
Keyword(s):  
Energy Density ◽  
Sewage Sludge ◽  
Elemental Composition ◽  
Oxygen Demand ◽  
Heating Value ◽  
Organic Composition ◽  
Treatment Processes ◽  
Volatile Solids ◽  
Primary Surplus

Abstract The composition of sewage sludge and, thus, its energetic potential is influenced by wastewater and wastewater treatment processes. Higher or lower heating values (HHV or LHV) are decisive factors for the incineration/gasification/pyrolysis of sewage sludge. The HHV is analyzed with a bomb calorimeter and converted to the LHV. It is also possible to calculate the heating value via chemical oxygen demand (COD), total volatile solids (TVS), and elemental composition. Calculating the LHV via the COD provides a suitable method. In contrast, the correlation of the HHV or LHV with the TVS is limited. One prerequisite here is a constant specific energy density; this was given with the types of sewage sludge (primary, surplus/excess, and digested sludge) investigated. If the energy density is not comparable with sewage sludge, for instance with the co-substrate (bio-waste, grease, etc.), the estimation of the heating value using TVS will fail. When calculating the HHV or LHV via the elemental composition, one has to consider the validity of the coefficients of the calculation equation. Depending on the organic composition, it might be necessary to adjust the coefficients, e.g. when adding co-substrates.

scholarly journals Characterization of the Primary Sludge from Pharmaceutical Industry Effluents and Final Disposition

Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 231 ◽  
Author(s):  
Renata Xavier Alberico Freitas ◽  
Lara Aguiar Borges ◽  
Handray Fernandes de Souza ◽  
Fernando Colen ◽  
Alex Sander Rodrigues Cangussu ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Organic Matter Content ◽  
Oxygen Demand ◽  
Physicochemical Characteristics ◽  
Matter Content ◽  
Primary Sludge ◽  
Volatile Solids ◽  
Object Of Study ◽  
Final Disposition

The generation of large volumes of waste by industrial processes has become an object of study because of the necessity to characterize the composition of residues in order to suggest appropriate treatments and to minimize adverse environmental impacts. We performed analyses of total fixed and volatile solids, moisture, and chemical oxygen demand (COD). We found high organic matter content. We also measured physicochemical characteristics, including corrosivity, reactivity, and toxicity. Sewage sludge showed levels of chloride and sodium above the maximum allowed limits. These data suggest the potential for anaerobic digestion as a treatment option for sewage sludge and for its use as a biofertilizer.

scholarly journals Treatment of dairy waste by anaerobic co-digestion with sewage sludge

2016 ◽  
Vol 23 (1) ◽  
pp. 99-115 ◽  
Author(s):  
Agnieszka A. Pilarska ◽  
Krzysztof Pilarski ◽  
Kamil Witaszek ◽  
Hanna Waliszewska ◽  
Magdalena Zborowska ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Organic Carbon ◽  
Organic Waste ◽  
Cheese Whey ◽  
Oxygen Demand ◽  
Volatile Solids ◽  
Biomethane Production ◽  
Digested Sewage Sludge

Abstract The results of anaerobic digestion (AD) of buttermilk (BM) and cheese whey (CW) with a digested sewage sludge as inoculum is described. The substrate/inoculum mixtures were prepared using 10% buttermilk and 15% cheese whey. The essential parameters of the materials were described, including: total solids (TS), volatile solids (VS), pH, conductivity, C/N ratio (the quantitative ratio of organic carbon (C) to nitrogen (N)), alkalinity, chemical oxygen demand (COD). The potential directions of biodegradation of the organic waste types, as used in this study, are also presented. Appropriate chemical reactions illustrate the substrates and products in each phase of anaerobic decomposition of the compounds that are present in buttermilk and cheese whey: lactic acid, lactose, fat, and casein. Moreover, the biogas and biomethane production rates are compared for the substrates used in the experiment. The results have shown that buttermilk in AD generates more biogas (743 m3/Mg VS), including methane (527 m3/Mg VS), when compared with cheese whey (600 m3/Mg VS, 338 m3/Mg VS for biogas and methane, respectively).

Effect of Ultrasonic Energy Density of Ultrasonic Sludge Hydrolysis

2015 ◽  
Vol 1092-1093 ◽  
pp. 844-847
Author(s):  
Yu Chen ◽  
Lin Hao ◽  
Dong Mei Wang
Keyword(s):  
Energy Density ◽  
Sewage Sludge ◽  
Ultrasonic Treatment ◽  
Oxygen Demand ◽  
Low Energy ◽  
Evaluation Index ◽  
Index Study ◽  
Sludge Hydrolysis ◽  
Soluble Chemical Oxygen Demand ◽  
Hydrolysis Of

Regard the added soluble chemical oxygen demand value (SCOD), TN, TP, VFA as the evaluation index, study the hydrolysis effect of different ultrasonic intensity of sewage sludge. The results show that: with the energy density of 0.75W/L, 1.5W/L, 3W/L after ultrasonic treatment of sludge, SCOD than the original clay increased a lot. Hydrolysis of five days later, having little difference of SCOD concentration in the sludge, and the 0.75W/L SCOD reached the peak, indicating little sound energy density difference of SCOD in sludge, and the low energy density effected better, while the concentration of TN, TP, VFA were increased with the increase of the energy density.

scholarly journals Influence of acidogenic fermented fish by-products with rice bran for sludge reduction and biogas recovery in anaerobic co-digestion

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Hee-Jeong Choi
Keyword(s):  
Sewage Sludge ◽  
Chemical Oxygen Demand ◽  
Rice Bran ◽  
Tap Water ◽  
Oxygen Demand ◽  
Lag Phase ◽  
Sludge Reduction ◽  
Acidogenic Fermentation ◽  
Volatile Solids ◽  
By Products

The purpose of this study was to investigate the effects of acidogenic fermentation broth with rice bran (RFFB), tap water (TFFB), or raw fishery by-products (FBs) on sludge reduction and biogas production in an anaerobic co-digestion process. Acidogenic fermentation of FBs with rice bran was faster and produced more volatile fatty acids than that with tap water. Reduction efficiencies for chemical oxygen demand, volatile solids, and total solids were highest in RFFB. In the kinetic analysis, λ (d), which represents the duration of the lag phase, was shortest with RFFB (1.09 d) and highest in sewage sludge (8.86 d). As the loading amount of volatile solids and chemical oxygen demand increased, the amount of cumulative biogas also increased. Amount of produced methane and energy recovery were highest with RFFB (5.71 kWh). Anaerobic co-digestion of FFB and sewage sludge allowed reduced sludge and recovered energy using the discarded waste as an organic carbon source.

scholarly journals Influence of Wastewater Treatment and The Method of Sludge Disposal on the Gasification Process

2014 ◽  
Vol 21 (2) ◽  
pp. 255-268 ◽  
Author(s):  
Sebastian Werle ◽  
Mariusz Dudziak
Keyword(s):  
Wastewater Treatment ◽  
Sewage Sludge ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Fixed Bed ◽  
Treatment Plant ◽  
Experimental Investigations ◽  
Heating Value ◽  
Treatment Processes ◽  
Sludge Disposal

Abstract Municipal wastewater treatment results in the production of large quantities of sewage sludge, which requires proper environmentally accepted management before final disposal. Sewage sludge is a by-product of current wastewater treatment technologies. Sewage sludge disposal depends on the sludge treatment methods used in the wastewater treatment plant (anaerobic or aerobic digestion, drying, etc.). Taking into consideration presented given this information, a study concerning the effects of wastewater treatment processes and sewage sludge drying method on the sewage sludge gasification gas parameters was performed. Gasification is a prospective alternative method of sludge thermal treatment. For the purpose of experimental investigations, a laboratory fixed bed gasifier installation was designed and built. Two types of sewage sludge feedstock, SS1 and SS2, were analyzed. Sewage sludge SS1 came from a wastewater treatment plant operating in the mechanical and biological system while sewage sludge SS2 was collected in a mechanical, biological and chemical wastewater treatment plant with simultaneous phosphorus precipitation. The sludge produced at the plants was subject to fermentation and then, after being dehydrated, dried in a cylindrical drier on shelves heated up to 260ºC (sewage sludge SS1) and using hot air at a temperature of 150ºC in a belt drier (sewage SS2). The analysis shows that the sewage sludge properties strongly depend on the wastewater sources and the wastewater treatment processes. The gasification results, presented as a function of the amount of gasification agent, show that the greater oxygen content of SS1 caused a reduction in the reaction temperature. Paradoxically, this effect caused an increase in the quantity of combustible components in the gas. As expected, increasing the air flow rate caused a decrease in the heating value of the gas produced. A higher amount of oxidizer increases the amounts of noncombustible species and the volumetric fraction of nitrogen, thus reducing the heating value of the obtained gas. The higher hydrogen content in SS1 affects the gasification gas composition. As a result, combustible components are the majority of the syngas.

Two-phase anaerobic co-digestion of food waste and sewage sludge

2014 ◽  
Vol 71 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Feng Wang ◽  
Wei-Ying Li ◽  
Xue-Nong Yi
Keyword(s):  
Sewage Sludge ◽  
Food Waste ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Future Research ◽  
Two Phase ◽  
Volatile Solids ◽  
Acidogenic Reactor ◽  
And Performance ◽  
Solids Mixing

The feasibility and performance of food waste and sewage sludge co-digestion were investigated to gain insight into their resource utilization. In this study, two-phase anaerobic digestion (TPAD) was operated under a total solids mixing ratio of 1:1 and different sludge retention times (SRTs). Results show that an acidogenic reactor with a 5-day SRT obtained the highest acidification efficiency, and its acetic acid content was dominant. The organic removal rate of a methanogenic reactor (MR) with a 20-day SRT and its corresponding TPAD system with a 25-day SRT were both the highest among the MRs and TPAD systems. Volatile solids and total chemical oxygen demand average removal efficiencies of the TPAD system with a 25-day SRT reached 64.7 and 60.8%, respectively. The MR with a 30-day SRT obtained the minimum ratio of volatile fatty acid to alkalinity (0.12). The methane content generated from the different MRs fluctuated at around 70%. All of the above results can provide reference for future research.

The use of ultrasound to accelerate the anaerobic digestion of sewage sludge

1997 ◽  
Vol 36 (11) ◽  
pp. 121-128 ◽  
Author(s):  
A. Tiehm ◽  
K. Nickel ◽  
U. Neis
Keyword(s):  
Sewage Sludge ◽  
Residence Time ◽  
Continuous Fermentation ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Residence Times ◽  
Anaerobic Digesters ◽  
Rate Limiting Step ◽  
Volatile Solids ◽  
Sludge Hydrolysis

The slow degradation rate of sewage sludge in anaerobic digesters is due to the rate limiting step of sludge hydrolysis. The effect of ultrasound pretreatment on sludge degradability was investigated using ultrasound at a frequency of 31 kHz and high acoustic intensities. Ultrasound treatment resulted in raw sludge disintegration as was demonstrated by increase of Chemical Oxygen Demand in the sludge supernatant and size reduction of sludge solids. Semi-continuous fermentation experiments with disintegrated and untreated sludge were done for four months on a half-technical scale. One fermenter was operated as a control with a conventional residence time of 22 days. Four fermenters were operated with disintegrated sludge and residence times of 22, 16, 12, and 8 days, respectively. In the fermenters operated with identical residence times of 22 days reduction of volatile solids was 45.8% for untreated sludge and 50.3% for disintegrated sludge. The fermentation of disintegrated sludge was stable even at the shortest residence time of 8 days with biogas production 2.2 times that of the control fermenter. Due to ultrasound disintegration a better degradability of raw sludge was achieved that permitted a substantial increase in throughput.

scholarly journals Characterization of the Gaseous and Odour Emissions from the Composting of Conventional Sewage Sludge

Atmosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 211 ◽  
Author(s):  
Daniel González ◽  
Nagore Guerra ◽  
Joan Colón ◽  
David Gabriel ◽  
Sergio Ponsá ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Emission Factor ◽  
Main Process ◽  
Gaseous Emissions ◽  
Sulphur Compounds ◽  
Composting Process ◽  
Volatile Solids ◽  
Odour Emissions ◽  
Sludge Composting

Many different alternatives exist to manage and treat sewage sludge, all with the common drawback of causing environmental and odour impacts. The main objective of this work is to present a full inventory of the gaseous and odorous emissions generated during the bench-scale composting of conventional sewage sludge, aiming at assessing the process performance and providing global valuable information of the different gaseous emission patterns and emission factors found for greenhouse gases (GHG) and odorant pollutants during the conventional sewage sludge composting process. The main process parameters evaluated were the temperature of the material, specific airflow, average oxygen uptake rate (OUR), and final dynamic respiration index (DRI), resulting in a proper performance of the sewage sludge composting process and obtaining the expected final product. The obtained material was properly stabilized, presenting a final DRI of 1.2 ± 0.2 g O2·h−1·kg−1 Volatile Solids (VS). GHGs emission factor, in terms of kg CO2eq·Mg−1 dry matter of sewage sludge (DM–SS), was found to be 2.30 × 102. On the other hand, the sewage sludge composting odour emission factor (OEF) was 2.68 × 107ou·Mg−1 DM–SS. Finally, the most abundant volatile organic compounds (VOC) species found in the composting gaseous emissions were terpenes, sulphur compounds, ketones, and aromatic hydrocarbons, whereas the major odour contributors identified were dimethyldisulphide, eucalyptol, and α-pinene.

scholarly journals Optimization of anaerobic co-digestion of sewage sludge using bio-chemical substrates

2018 ◽  
Author(s):  
◽  
Nhlanganiso Ivan Madondo
Keyword(s):  
Sewage Sludge ◽  
Energy Content ◽  
Oxygen Demand ◽  
Methane Yield ◽  
Batch Experiment ◽  
Batch Test ◽  
System Productivity ◽  
Biogas Yield ◽  
Volatile Solids ◽  
Substrate To Inoculum Ratio

The anaerobic process is increasingly becoming a subject for many as it reduces greenhouse gas emissions and recovers carbon dioxide energy as methane. Even though these benefits are attainable, proper control and design of the process variables has to be done in order to optimize the system productivity and improve stability. The aim of this research was to optimize methane and biogas yields on the anaerobic co-digestion of sewage sludge using bio-chemical substrates as co-substrates. The first objective was to find the bio-chemical substrate that will generate the highest biogas and methane yields. The anaerobic digestion of these substrates was operated using 6 L digesters at 37.5℃. The substrate which generated the highest biogas and methane yield in the first batch experiment was then used for the second batch test. The objective was to optimize the anaerobic conditions (substrate to inoculum ratio, co-substrate concentration and temperature) in-order to optimize the biogas and methane yields. The second batch test was achieved using the conventional One-Factor-At-A-Time (OFAT) and the Design of Experiment (DOE) methods. Final analysis showed that the bio-chemical substrates could be substrates of interest to biogas generators. Amongst the substrates tested in the first batch experiment glycerol (Oleo-Chemical Product waste) generated the highest methane and biogas yields of 0.71 and 0.93 L. (g volatile solids added)-1, respectively. It was believed that glycerol contains significant amount of other organic substances such as lipids that have higher energy content than the other bio-chemical substrates, thus generating larger biogas and methane yields. Moreover, digestion of sewage sludge alone produced biogas yields of 0.19 L /g VS and 0.33 L/g COD, and methane yields of 0.16 L/g VS and 0.28 L/g COD. Generally, co-digestion yields were higher than digestion yields of sewage alone. Using the OFAT method the results of the second batch test on glycerol demonstrated highest amounts of volatile solids (VS) reduction, chemical oxygen demand (COD) reduction, biogas yield and methane yield of 99.7%, 100%, 0.94 L (g VS added)-1 and 0.75 L (g VS added)-1 at a temperature, substrate to inoculum ratio and glycerol volume of 50℃, 1 (on VS basis) and 10 mL, respectively. Above 22 mL and substrate to inoculum ratio of 1, the process was inhibited. The DOE results suggested that the highest methane and biogas yields were 0.75 and 0.94 L (g VS added)-1, respectively. These results were similar to the OFAT results, thus the DOE software may be used to define the biogas and methane yields equations for glycerol. In conclusion, anaerobic co-digestion of bio-chemical substrates as co-substrates on sewage sludge was successfully applied to optimize methane and biogas yields.

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