scholarly journals Effect of Low-Temperature Conditioning of Excess Dairy Sewage Sludge with the Use of Solidified Carbon Dioxide on the Efficiency of Methane Fermentation

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 150
Author(s):  
Joanna Kazimierowicz ◽  
Izabela Bartkowska ◽  
Maria Walery
Keyword(s):  
Carbon Dioxide ◽  
Sewage Sludge ◽  
Low Temperature ◽  
Chemical Oxygen Demand ◽  
Biogas Production ◽  
Nitrogen Concentration ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Methane Fermentation ◽  
Dissolved Phase

This study aimed to determine the effect of the low-temperature conditioning of excess dairy sewage sludge using solidified carbon dioxide on the efficiency of methane fermentation. An increase in the solidified carbon dioxide to excess dairy sewage sludge volumetric ratio above 0.3 had no significant effect on chemical oxygen demand concentration in the dissolved phase. The highest chemical oxygen demand values, ranging from 490.6 ± 12.9 to 510.5 ± 28.5 mg·dm−3, were determined at solidified carbon dioxide to excess dairy sewage sludge ratio ranging from 0.3 to 0.5. The low-temperature conditioning caused ammonia nitrogen concentration to increase from 155.2 ± 10.2 to 185.9 ± 11.1 mg·dm−3 and orthophosphates concentration to increase from 198.5 ± 23.1 to 300.6 ± 35.9 mg·dm−3 in the dissolved phase. The highest unitary amount of biogas, reaching 630.2 ± 45.5 cm3·g o.d.m.−1, was produced in the variant with the solidified carbon dioxide to excess dairy sewage sludge volumetric ratio of 0.3. Methane content of the biogas produced was at 68.7 ± 1.5%. Increased solidified carbon dioxide dose did not lead to any significant changes in biogas and methane production. The efficiency of biogas production from unconditioned excess dairy sewage sludge was lower by 43.0 ± 3.2%. The analysis demonstrated that the low-temperature conditioning is an energetic viable technology aiding the methane fermentation process.

scholarly journals Biogas Generation from Sonicated Excess Sludge

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2127 ◽  
Author(s):  
Iwona Zawieja ◽  
Renata Włodarczyk ◽  
Mariusz Kowalczyk
Keyword(s):  
Sewage Sludge ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Calorific Value ◽  
Ultrasonic Field ◽  
Excess Sludge ◽  
Methane Fermentation ◽  
Biogas Yield ◽  
Yield Value

The article presents an analysis of the possibilities of biogas production in the process of methane fermentation of sonicated excess sludge. The greater the percentage of methane in biogas, the higher its calorific value. In order to increase the intensity of biogas production containing approximately 70% of methane, sewage sludge is disintegrated. In particular, excess sludge formed as a result of advanced wastewater treatment by the activated sludge method shows low biodegradability. The study aim was to examine the effect of the ultrasonic field disintegration of excess sludge on biogas production. As a result of subjecting the sludge to disintegration by ultrasonic field, there was an increase in the digestion degree of sewage sludge. In the methane fermentation process of modified sludge, an increase of the biogas yield was noted, which confirmed the supportive action of ultrasonic field on the excess sludge biodegradation. In the case of disintegration of excess sludge by ultrasonic field, for the ultrasonic field intensity value of 4.3 W cm−2 and a sonication time equal to 300 s, the highest values of soluble chemical oxygen demand (SCOD), total organic carbon (TOC), and volatile fatty acids (VFAs) concentrations were obtained. In the process of conventional methane fermentation, biogas yield value was 0.303 L g VSS−1, while in the process of methane fermentation of sonicated excess sludge, the value 0.645 L g VSS−1.

scholarly journals Digestate Liquid Fraction Treatment with Filters Filled with Recovery Materials

Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 21
Author(s):  
Ilaria Piccoli ◽  
Giuseppe Virga ◽  
Carmelo Maucieri ◽  
Maurizio Borin
Keyword(s):  
Chemical Oxygen Demand ◽  
Total Nitrogen ◽  
Liquid Fraction ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Green Technology ◽  
Filling Material ◽  
Community Interactions ◽  
Material Particle ◽  
N Removal

Constructed wetlands (CWs) represent a green technology for digestate liquid fraction (DLF) treatment. However, previous research has warned about their performance when treating wastewater with high suspended solid and organic loads. In addition, the high NH4-N concentration typical of this wastewater can compromise vegetation establishment and activity. In view of this, a digestate pretreatment is needed. This study aimed to test the performance of filters filled with recovery materials, such as brick and refractory material, for DLF pretreatment. The effect on DLF physical (electrical conductivity, pH, dissolved oxygen, and temperature) and chemical (total nitrogen, ammonia–nitrogen, nitrate–nitrogen, total phosphorus, soluble phosphorus, and chemical oxygen demand) characteristics was monitored during eight weekly cycles. The effect of filtration on total nitrogen and ammonia–nitrogen removal began after about one month of loading, suggesting that an activation period is necessary for bacteria. For effective N removal, the presence of multiple digestate recirculations per day through the filters appears mandatory to guarantee the alternation of nitrification and denitrification conditions. For P removal, filling material particle size appeared to be more important than its composition. Unclear performances were observed considering chemical oxygen demand. Further studies on filling media and microbial community interactions, and the long-term efficiency of filters, are desirable.

Alkali pre-treatment of Sorghum Moench for biogas production

2013 ◽  
Vol 67 (9) ◽  
Author(s):  
Karina Michalska ◽  
Stanisław Ledakowicz
Keyword(s):  
Anaerobic Digestion ◽  
Chemical Oxygen Demand ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Total Phenolic ◽  
Methane Generation ◽  
Pre Treatment ◽  
Alkali Hydrolysis ◽  
Almost All

AbstractThis work studies the influence of the alkali pre-treatment of Sorghum Moench — a representative of energy crops used in biogas production. Solutions containing various concentrations of sodium hydroxide were used to achieve the highest degradation of lignocellulosic structures. The results obtained after chemical pre-treatment indicate that the use of NaOH leads to the removal of almost all lignin (over 99 % in the case of 5 mass % NaOH) from the biomass, which is a prerequisite for efficient anaerobic digestion. Several parameters, such as chemical oxygen demand, total organic carbon, total phenolic content, volatile fatty acids, and general nitrogen were determined in the hydrolysates thus obtained in order to define the most favourable conditions. The best results were obtained for the Sorghum treated with 5 mass % NaOH at 121°C for 30 min The hydrolysate thus achieved consisted of high total phenolic compounds concentration (ca. 4.7 g L−1) and chemical oxygen demand value (ca. 45 g L−1). Although single alkali hydrolysis causes total degradation of glucose, a combined chemical and enzymatic pre-treatment of Sorghum leads to the release of large amounts of this monosaccharide into the supernatant. This indicates that alkali pre-treatment does not lead to complete cellulose destruction. The high degradation of lignin structure in the first step of the pre-treatment rendered the remainder of the biomass available for enzymatic action. A comparison of the efficiency of biogas production from untreated Sorghum and Sorghum treated with the use of NaOH and enzymes shows that chemical hydrolysis improves the anaerobic digestion effectiveness and the combined pre-treatment could have great potential for methane generation.

scholarly journals Synthesis and properties of zeolite/N-doped porous carbon for the efficient removal of chemical oxygen demand and ammonia-nitrogen from aqueous solution

RSC Advances ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 6452-6459 ◽  
Author(s):  
Guangzhi Xin ◽  
Min Wang ◽  
Lin Chen ◽  
Yuzhou Zhang ◽  
Meicheng Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Chemical Oxygen Demand ◽  
Porous Carbon ◽  
Mesoporous Carbon ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Efficient Removal ◽  
Porous Activated Carbon

A novel adsorbent zeolite/N-doped porous activated carbon (ZAC) was prepared by the synthesis of zeolite and mesoporous carbon to remove ammonia nitrogen (NH4+–N) and chemical oxygen demand (COD) from aqueous solution.

The Study of Prediction of Agricultural Source Pollution Emissions of Ammonia Nitrogen (AN) and Chemical Oxygen Demand (COD) Based on Bionic Neural Network Algorithm

2013 ◽  
Vol 461 ◽  
pp. 544-552 ◽  
Author(s):  
Hong Peng Guo ◽  
Gan Yu Feng ◽  
Chun Xia Liu ◽  
Xiao Yi Zhang
Keyword(s):  
Neural Network ◽  
Chemical Oxygen Demand ◽  
Rapid Development ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Average Error ◽  
Research Results ◽  
Network Algorithm ◽  
Neural Network Algorithm ◽  
Pollution Emissions

Nearly 40% of Chinese water pollution comes from agricultural sources of pollution, and the annual emissions are difference. If we want to control pollution emissions effectively, we need to accurately predict the amount of agricultural emissions of Ammonia Nitrogen (AN) and Chemical Oxygen Demand (COD). Due to the complex mechanism of the agricultural non-point source pollution, its emissions are very difficult to measure. Currently, the Bionics Research is in a stage of rapid development, and it continues to expand into many new areas of research. So the comprehensive study of Bionics and pollutant control study will be a good choice. This research used bionic BP（Back Propagation） neural network algorithm, and used pollution census data from 2002 to 2007 and established neural network model with neural network algorithm. And we predicted the agricultural sources of emissions of AN and COD with the data from 2008 to 2010. Finally we compared the predicted value and the actual value. Research results showed that, with using the bionic BP neural network, agricultural sources emissions of AN and COD are evaluated actually and the results indicate that the average error is under 5.0%. Research results proved that the model is effective. The neural network is a scientific predict method for the agricultural sources emissions of AN and COD. It can be widely used in the prediction of agricultural sources emissions of AN and COD.

Effect of Ultrasonic Pretreatment for the Anaerobic Digestion of Sewage Sludge

2012 ◽  
Vol 531 ◽  
pp. 528-531 ◽  
Author(s):  
Na Wei
Keyword(s):  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Oxygen Demand ◽  
High Concentration ◽  
Ultrasonic Pretreatment ◽  
Soluble Chemical Oxygen Demand ◽  
Pre Treatment ◽  
Settling Characteristics

Anaerobic digestion is an economic and environmentally friendly technology for treating the biomass material-sewage sludge, but has some limitations, such as the low efficient biogass production. In this paper ultrasound was proposed as pre-treatment for effective sludge anaerobic digestion. Sludge anaerobic digestion experiments with ultrasonic pretreatment was investigated. It can be seen that this treatment effectively leaded to the increase of soluble chemical oxygen demand(SCOD) and volatile fatty acids(VFA)concentration. High concentration of VFA leaded to a increase in biogas production. Besides, the SV of sludge was reduced and the settling characteristics of sludge was improved after ultrasonic pretreatment. It can be concluded that sludge anaerobic digestion with ultrasonic pretreatment is an effective method for biomass material transformation.

scholarly journals Electrohydrodynamic, oven and natural drying of mint leaves and effects on the physiochemical indices of the leaves

2020 ◽  
Vol 66 (No. 3) ◽  
pp. 89-96
Author(s):  
Chibuzo Nwankwo ◽  
Chigozie Francis Okoyeuzu ◽  
Ikpeama Ahamefula
Keyword(s):  
Carbon Dioxide ◽  
Food Waste ◽  
High Efficiency ◽  
Biogas Production ◽  
Chemical Properties ◽  
Oxygen Demand ◽  
Liquefied Petroleum Gas ◽  
Physico Chemical ◽  
Efficiency Performance ◽  
Natural Drying

The efficiency of three modified plastic digesters (3.6 m<sup>3</sup> each) using food waste for biogas generation in cooking food was evaluated. The experiment was laid out based on a completely randomised design. A plastic tank was modified as a biodegradation system for food waste digestion to generate a biogas. The biochemical and chemical oxygen demand ranged from 44.58 to 49.62% and 130.42 to 139.20%, respectively, before digestion, but decreased significantly (P &lt; 0.05) after digestion. The pH of the fermenting slurry fluctuated (6.24–6.86) and an average biogas of 0.574 m<sup>3</sup> (505–601 L·day<sup>–1</sup>) per day was generated from the three experimental waste proportions which would be sufficient to cook three meals per day for 3 to 4 people. The methane gas significantly increased (P &lt; 0.05) while the carbon-dioxide significantly decreased (P &lt; 0.05) at the peak of the biogas production. The generated biogas significantly cooked (P &lt; 0.05) faster than kerosene, but not faster than liquefied petroleum gas. The flammable biogas generation and high significant (P &lt;0.05) percentage change in the physico-chemical properties of the wastes after digestion implied high efficiency performance of the digesters modified from the plastic tanks.

Purification Effect of Lolium multiflorum Ecological Floating Beds System in Urban Malodorous River at Low Temperature

2012 ◽  
Vol 518-523 ◽  
pp. 2686-2689
Author(s):  
Yu Hong Chai ◽  
Wen Yao Yan ◽  
Ming Xin Wang
Keyword(s):  
Low Temperature ◽  
Chemical Oxygen Demand ◽  
Total Nitrogen ◽  
Growth Rates ◽  
Low Temperatures ◽  
Lolium Multiflorum ◽  
Oxygen Demand ◽  
Total Biomass ◽  
Water Plant ◽  
Natural Rivers

An ecological floating beds system was constructed to treat natural urban malodorous river in Changzhou at low temperature. Taking Lolium multiflorum as an example of water plant, the characteristics and contribution of its uptake to total nitrogen (TN), NH4+-N, total phosphorus (TP) and chemical oxygen demand (CODMn) in the system were studied in a period of 80 days. Significant growth of the plant Lolium multiflorum was observed with total biomass ranging from 53 g to 785 g, and the highest growth rates were 8.82 and 9.23 for biomass of above water and under water part, respectively. Different concentrations of TN, NH4+-N, TP and COD were found between in the floating beds and out the floating beds. The highest removal rates of TN, NH4+-N, TP and CODMn using Lolium multiflorum ecological floating beds system were 16.8%, 33.0%,10.8% and 17.8%, respectively. The purification effect of ecological floating beds shows it can be well applied to cleaning natural rivers at low temperatures.

Quantitative Eco-Compensation Criterion in Taihu Lake Area of Jiangsu Province, China

2013 ◽  
Vol 726-731 ◽  
pp. 4095-4100
Author(s):  
Rong Rong Xie ◽  
Yong Pang
Keyword(s):  
Chemical Oxygen Demand ◽  
Total Phosphorus ◽  
Taihu Lake ◽  
Census Data ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Pollution Source ◽  
Jiangsu Province ◽  
Lake Area ◽  
Chinese Yuan

To redress the deteriorating environment, policies regarding river eco-compensation have been issued in China since 2008. Due to the high cost, eco-compensation has not been well implemented in the Taihu pilot region. Therefore, how to determine the compensation criterion is already a priority. In this paper, a compensation criterion model based on the treatment costs of sewage was introduced. Using the pollution source census data covering 2007, 2009, 2010 and 2011 in the Taihu lake area of Jiangsu province, the average eco-compensation criterion for chemical oxygen demand (COD) is 2,000 Chinese Yuan (CNY) ± 325 CNY per ton and ammonia nitrogen (NH4-N) and total phosphorus (TP) are 8,000 CNY ± 1,300 CNY and 80,000 CNY ± 13,000 CNY per ton, respectively. The new method can provide an important template for managers when drafting river eco-compensation schemes.

Effects of chemical oxygen demand (COD)/N ratios on pollutants removal in the subsurface wastewater infiltration systems with/without intermittent aeration

2016 ◽  
Vol 73 (11) ◽  
pp. 2662-2669 ◽  
Author(s):  
Siyu Song ◽  
Jing Pan ◽  
Shiwei Wu ◽  
Yijing Guo ◽  
Jingxiao Yu ◽  
...  
Keyword(s):  
Chemical Oxygen Demand ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Oxygen Deficiency ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Intermittent Aeration ◽  
Oxidation Reduction ◽  
The Matrix ◽  
Pollutants Removal

The matrix oxidation reduction potential level, organic pollutants and nitrogen removal performances of eight subsurface wastewater infiltration systems (SWISs) (four with intermittent aeration, four without intermittent aeration) fed with influent chemical oxygen demand (COD)/N ratio of 3, 6, 12 and 18 were investigated. Nitrification of non-aerated SWISs was poor due to oxygen deficiency while higher COD/N ratios further led to lower COD and nitrogen removal rate. Intermittent aeration achieved almost complete nitrification, which successfully created aerobic conditions in the depth of 50 cm and did not change anoxic or anaerobic conditions in the depth of 80 and 110 cm. The sufficient carbon source in high COD/N ratio influent greatly promoted denitrification in SWISs with intermittent aeration. High average removal rates of COD (95.68%), ammonia nitrogen (NH4+-N) (99.32%) and total nitrogen (TN) (89.65%) were obtained with influent COD/N ratio of 12 in aerated SWISs. The results suggest that intermittent aeration was a reliable option to achieve high nitrogen removal in SWISs, especially with high COD/N ratio wastewater.

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