scholarly journals Application of ultrasonic disintegration to waste activated sludge for increasing of biogas production by anaerobic digestion

2020 ◽  
Vol 2 (2) ◽  
pp. 17-21
Author(s):  
Ion Viorel Patroescu ◽  
Razvan Laurentiu Dinu ◽  
Mihai Stefanescu ◽  
Valeriu Robert Badescu ◽  
Nicolae Ionut Cristea ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Biogas Production ◽  
Treatment Plant ◽  
Experimental Tests ◽  
Organic Load ◽  
Municipal Wastewater Treatment ◽  
Biological Sludge ◽  
Sludge Stabilization

The municipal wastewater treatment is the source of significant amounts of primary and secondary sludge which is under the present legislation referring to quality and management aspects. It is estimated that a half of wastewater treatment plant costs are due to the sludge management. Anaerobically sludge stabilization, capitalization as energy source, in order to diminish the costs and sludge volume decreasing, are the aims of the main operational steps of sludge treatment, as a part of wastewater treatment plant. The improvement of sludge anaerobically stabilization process must be possible by acting in the rate limiting step - hydrolysis in order to rise the organic carbon solubilization. The increase of soluble carbon can be possible by adding a pretreatment step of waste biological sludge, ultrasonic disintegration being one option. This paper emphasized the experimental results regarding anaerobically stabilization of the thickened waste biological sludge by ultrasonication taking into account the results of blank test, without ultrasonication. Experimental tests show that ultrasonic disintegration of the sludge having initial dried substances content (d.w) 2.72% and soluble organic load COD of 598 mg O2/L led to soluble COD concentration of 4950-6710 mg O2/L after sonication with specific energy in the range of 3.06 - 14.24 kWh/kg d.w. Anaerobically stabilization during 25 test days at 36 0C of the mixture 40% disintegrated biological sludge and 60% digested sludge (inoculum) mixture led to 30-38.6% increase of biogas production comparing with parallel test with non-sonicated sludge.

scholarly journals Anaerobic Codigestion of Municipal Wastewater Treatment Plant Sludge with Food Waste: A Case Study

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Zubayeda Zahan ◽  
Maazuza Z. Othman ◽  
William Rajendram
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Biogas Production ◽  
Treatment Plant ◽  
Surface Model ◽  
Municipal Wastewater Treatment ◽  
Biogas Yield ◽  
Municipal Wastewater Treatment Plant ◽  
Anaerobic Reactors

The aim of this study was to assess the effects of the codigestion of food manufacturing and processing wastes (FW) with sewage sludge (SS), that is, municipal wastewater treatment plant primary sludge and waste activated sludge. Bench scale mesophilic anaerobic reactors were fed intermittently with varying ratio of SS and FW and operated at a hydraulic retention time of 20 days and organic loading of 2.0 kg TS/m3·d. The specific biogas production (SBP) increased by 25% to 50% with the addition of 1%–5% FW to SS which is significantly higher than the SBP from SS of 284±9.7 mLN/g VS added. Although the TS, VS, and tCOD removal slightly increased, the biogas yield and methane content improved significantly and no inhibitory effects were observed as indicated by the stable pH throughout the experiment. Metal screening of the digestate suggested the biosolids meet the guidelines for use as a soil conditioner. Batch biochemical methane potential tests at different ratios of SS : FW were used to determine the optimum ratio using surface model analysis. The results showed that up to 47-48% FW can be codigested with SS. Overall these results confirm that codigestion has great potential in improving the methane yield of SS.

Modern Biogas Generation Method Based on Ultrasonic and Anaerobic Fermentation of Municipal Wastewater Biological Sludge

2020 ◽  
Vol 70 (12) ◽  
pp. 4601-4604
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Anaerobic Fermentation ◽  
Treatment Plant ◽  
Organic Load ◽  
Soluble Form ◽  
Medium Size ◽  
Ultrasonic Pretreatment ◽  
Biological Sludge

Classical biogas generation during the municipal wastewater treatment flow is based on anaerobically fermentation of biological sludge.The efficiency of organic matter conversion into higher biogas volume depends on organic load (COD/BOD) of active biological sludge, especially in soluble form. Soluble COD amount can be rise by non-conventional pretreatment methods as ultrasonic application. Ultrasonic pretreatment of biological sludge increases the amount of biogas from anaerobic digestion phase comparing with traditional process. This paper shows the influence of ultrasonic field on biological sludge fermentation. Ultrasonic treatment step was performed in a field, in a medium size wastewater treatment plant, at industrial pilot scale level using biological sludge, before anaerobic fermentation phase. Laboratory fermentation tests have proved that ultrasonic pretreatment lead to biogas higher production with 84%. Keywords: ultrasonic, wastewater treatment plant, biological sludge, anaerobic, biogas

scholarly journals Assessment of Microplastics in a Municipal Wastewater Treatment Plant with Tertiary Treatment: Removal Efficiencies and Loading per Day into the Environment

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1339
Author(s):  
Javier Bayo ◽  
Sonia Olmos ◽  
Joaquín López-Castellanos
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Treatment Plant ◽  
Source Control ◽  
Municipal Wastewater Treatment ◽  
Tertiary Treatment ◽  
Stable Performance ◽  
Wastewater Samples

This study investigates the removal of microplastics from wastewater in an urban wastewater treatment plant located in Southeast Spain, including an oxidation ditch, rapid sand filtration, and ultraviolet disinfection. A total of 146.73 L of wastewater samples from influent and effluent were processed, following a density separation methodology, visual classification under a stereomicroscope, and FTIR analysis for polymer identification. Microplastics proved to be 72.41% of total microparticles collected, with a global removal rate of 64.26% after the tertiary treatment and within the average retention for European WWTPs. Three different shapes were identified: i.e., microfiber (79.65%), film (11.26%), and fragment (9.09%), without the identification of microbeads despite the proximity to a plastic compounding factory. Fibers were less efficiently removed (56.16%) than particulate microplastics (90.03%), suggesting that tertiary treatments clearly discriminate between forms, and reporting a daily emission of 1.6 × 107 microplastics to the environment. Year variability in microplastic burden was cushioned at the effluent, reporting a stable performance of the sewage plant. Eight different polymer families were identified, LDPE film being the most abundant form, with 10 different colors and sizes mainly between 1–2 mm. Future efforts should be dedicated to source control, plastic waste management, improvement of legislation, and specific microplastic-targeted treatment units, especially for microfiber removal.

scholarly journals Energy Valorisation of Wastewater Treatment Plant Sludge through Thermal Gasification: An Economic Perspective

Proceedings ◽  
2021 ◽  
Vol 52 (1) ◽  
pp. 3
Author(s):  
Luis F. Carmo-Calado ◽  
Roberta Mota-Panizio ◽  
Gonçalo Lourinho ◽  
Octávio Alves ◽  
I. Gato ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Electricity Production ◽  
Baseline Scenario ◽  
Municipal Wastewater Treatment ◽  
Plant Processing ◽  
Sludge Drying ◽  
Calorific Power

The technical-economic analysis was carried out for the production of sludge-derived fuel from a municipal wastewater treatment plant (WWTP). The baseline for the analysis consists of a sludge drying plant, processing 6 m3 of sludge per day and producing a total of about 1 m3 of combustible material with 8% of moisture and a higher calorific power of 18.702 MJ/kg. The transformation of biofuel into energy translates into an electricity production of about 108 kW per 100 kg of sludge. The project in the baseline scenario demonstrated feasibility with a payback time of about six years.

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