scholarly journals Comparison of Different Electricity-Based Thermal Pretreatment Methods for Enhanced Bioenergy Production from Municipal Sludge

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 2006 ◽  
Author(s):  
E. Hosseini Koupaie ◽  
T. Johnson ◽  
C. Eskicioglu
Keyword(s):  
Energy Production ◽  
Municipal Wastewater ◽  
Wastewater Sludge ◽  
Conventional Heating ◽  
P Value ◽  
Net Energy ◽  
Rf Heating ◽  
Thermal Pretreatment ◽  
Bioenergy Production ◽  
Sequential Pretreatment

This paper presents results for a comprehensive study that compares the performance of three electricity-based thermal pretreatment methods for improving the effectiveness of anaerobic digestion (AD) to process municipal wastewater sludge. The study compares thermal pretreatment using conventional heating (CH), microwave (MW), and radio frequency (RF) heating techniques. The effectiveness of the pretreatment methods was assessed in terms of chemical oxygen demand (COD) and biopolymers solubilization, AD bioenergy production, input electrical energy, and overall net energy production of the sequential pretreatment/AD process. The heating applicators for the bench-scale testing consisted of a custom-built pressure-sealed heating vessel for CH experiments, an off-the-shelf programmable MW oven operating at a frequency of 2.45 GHz for MW heating experiments, and a newly developed 1 kW RF heating system operating at a frequency of 13.56 MHz for RF heating experiments. Under identical thermal profiles, all three thermal pretreatment methods achieved similar sludge disintegration in terms of COD and biopolymer solubilization as well as AD bioenergy production (p-value > 0.05). According to the energy assessment results, the application of CH and MW pretreatments resulted in overall negative energy production, while positive net energy production was obtained through the sequential pretreatment/AD process utilizing RF pretreatment.

Physical properties of dewatered wastewater sludge for landfilling

1996 ◽  
Vol 34 (3-4) ◽  
pp. 533-540 ◽  
Author(s):  
A. Koenig ◽  
J. N. Kay ◽  
I. M. Wan
Keyword(s):  
Shear Strength ◽  
Hong Kong ◽  
Municipal Wastewater ◽  
Compressibility Factor ◽  
Wastewater Sludge ◽  
Municipal Wastewater Treatment ◽  
Intrinsic Resistance ◽  
Coefficient Of Consolidation ◽  
Minimum Requirement ◽  
Geotechnical Stability

In the context of landfilling dewatered wastewater sludge in Hong Kong, with landfills up to 140 m high, one of the most significant properties of sludge is its physical nature with regard to moisture characteristics and associated geotechnical stability. Commonly, lower limits are set on total solids content, but no geotechnical stability criteria are applied with the exception of Germany where a minimum requirement for vane shear strength is set at 25 kN/m2. The purpose of this study was to determine and evaluate dewatered wastewater sludge from three Hong Kong municipal wastewater treatment plants with regard to the following physical and geotechnical properties: (i) vane shear strength; (ii) consolidation characteristics such as compression index, compressibility factor, coefficient of consolidation and compressibility coefficient; and (iii) hydraulic characteristics such as permeability and intrinsic resistance. Although dewatered sludge exhibits quite different characteristics as compared to soils, predictive logarithmic relationships may be established between various properties which are consistent with the critical state model for soils, conventional filtration and consolidation theory. Such representation provides a valuable basis for understanding the sludge characteristics and behaviour to landfill design.

Hydrothermal liquefaction of municipal wastewater sludge and nutrient recovery from the aqueous phase

Biofuels ◽  
2021 ◽  
pp. 1-6
Author(s):  
Vinod Kumar ◽  
Krishna Kumar Jaiswal ◽  
Mikhail S. Vlaskin ◽  
Manisha Nanda ◽  
M. K. Tripathi ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Municipal Wastewater ◽  
Hydrothermal Liquefaction ◽  
Wastewater Sludge ◽  
Nutrient Recovery

scholarly journals Energy Recovery Potential in Industrial and Municipal Wastewater Networks Using Micro-Hydropower in Spain

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 691
Author(s):  
Aida Mérida García ◽  
Juan Antonio Rodríguez Díaz ◽  
Jorge García Morillo ◽  
Aonghus McNabola
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Energy Recovery ◽  
Energy Production ◽  
Municipal Wastewater ◽  
Distribution Networks ◽  
Total Power ◽  
Energy Potential ◽  
Total Energy Consumption ◽  
Recovery Potential

The use of micro-hydropower (MHP) for energy recovery in water distribution networks is becoming increasingly widespread. The incorporation of this technology, which offers low-cost solutions, allows for the reduction of greenhouse gas emissions linked to energy consumption. In this work, the MHP energy recovery potential in Spain from all available wastewater discharges, both municipal and private industrial, was assessed, based on discharge licenses. From a total of 16,778 licenses, less than 1% of the sites presented an MHP potential higher than 2 kW, with a total power potential between 3.31 and 3.54 MW. This total was distributed between industry, fish farms and municipal wastewater treatment plants following the proportion 51–54%, 14–13% and 35–33%, respectively. The total energy production estimated reached 29 GWh∙year−1, from which 80% corresponded to sites with power potential over 15 kW. Energy-related industries, not included in previous investigations, amounted to 45% of the total energy potential for Spain, a finding which could greatly influence MHP potential estimates across the world. The estimated energy production represented a potential CO2 emission savings of around 11 thousand tonnes, with a corresponding reduction between M€ 2.11 and M€ 4.24 in the total energy consumption in the country.

Modeling and Design of Building-Integrated Thermoelectrics

2011 ◽  
Author(s):  
Leon M. Headings ◽  
Gregory N. Washington
Keyword(s):  
Thermal Response ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Conventional Heating ◽  
Net Energy ◽  
Arbitrary Boundary ◽  
Heating And Cooling ◽  
Temperature Oscillations ◽  
Wall Structures ◽  
And Control

The goal of this research is to develop a framework for replacing conventional heating and cooling systems with distributed, continuously and electrically controlled, building-integrated thermoelectric (BITE) heat pumps. The coefficient of performance of thermoelectric heat pumps increases as the temperature difference across them decreases and as the amplitude of temperature oscillations decreases. As a result, this research examines how thermal insulation and mass elements can be integrated with thermoelectrics as part of active multi-layer structures in order to minimize net energy consumption. In order to develop BITE systems, an explicit finite volume model was developed to model the dynamic thermal response of active multi-layer wall structures subjected to arbitrary boundary conditions (interior and exterior temperatures and interior heat loads) and control algorithms. Using this numerical model, the effects of wall construction on net system performance were examined. These simulation results provide direction for the ongoing development of BITE systems.

Anaerobic thermophilic digestion of sewage sludge with a thickened sludge recycle

2012 ◽  
Vol 65 (3) ◽  
pp. 403-409 ◽  
Author(s):  
A. Ya. Vanyushina ◽  
Yu. A. Nikolaev ◽  
A. M. Agarev ◽  
M. V. Kevbrina ◽  
M. N. Kozlov
Keyword(s):  
Retention Time ◽  
Municipal Wastewater ◽  
Hydraulic Retention Time ◽  
Biogas Production ◽  
Wastewater Sludge ◽  
Recycling Process ◽  
Digested Sludge ◽  
Volatile Solids ◽  
Solids Retention ◽  
Thermophilic Digestion

The process of anaerobic thermophilic digestion of municipal wastewater sludge with a recycled part of thickened digested sludge, was studied in semi-continuous laboratory digesters. This modified recycling process resulted in increased solids retention time (SRT) with the same hydraulic retention time (HRT) as compared with traditional digestion without recycling. Increased SRT without increasing of HRT resulted in the enhancement of volatile substance reduction by up to 68% in the reactor with the recycling process compared with 34% in a control conventional reactor. Biogas production was intensified from 0.3 L/g of influent volatile solids (VS) in the control reactor up to 0.35 L/g VS. In addition, the recycling process improved the dewatering properties of digested sludge.

Wastewater sludge treatment at the municipal wastewater treatment facilities with the purpose of its further utilization

2021 ◽  
pp. 46-51
Author(s):  
Ю.А. Егорова ◽  
В.И. Кичигин ◽  
О.И. Нестеренко ◽  
А.А. Юдин
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Sludge ◽  
Mineral Fertilizers ◽  
Municipal Wastewater Treatment ◽  
Urban District ◽  
Sludge Treatment ◽  
Technological Waste ◽  
Treatment Facilities ◽  
Water And Wastewater

Осадки городских очистных канализационных сооружений являются самым массовым технологическим отходом, создающим проблемы утилизации для любого города. Рассмотрены возможные методы обработки осадков сточных вод на городских очистных канализационных сооружениях городского округа Самара с целью их последующей утилизации. Обозначены причины и приведены документальные подтверждениянекорректности возложения ответственности за обращение с такими отходами только на организации водопроводно-канализационного хозяйства. Рассмотрен способ захоронения обезвоженного осадка сточных вод в обвалованном полигоне. Установлено, что обработанные на очистных сооружениях осадки относятся к V классу опасности для окружающей среды. Обработанные, стабилизированные, подсушенные, обезвреженные отходы осадков сточных вод (малоопасный осадок с песколовок при очистке хозяйственно-бытовых и смешанных сточных вод, практически не опасный осадок с песколовок при очистке хозяйственно-бытовых и смешанных сточных вод и избыточный ил биологических очистных сооружений в смеси с сырым осадком) могут быть использованы в качестве наполнителей бетонно-цементных смесей и органоминеральных удобрений или переданы для утилизации сторонним организациям. Sludge from the municipal wastewater treatment facilities is the most massive technological waste that causes trouble for any city. Possible methods of wastewater sludge treatment at the municipal wastewater treatment facilities of the Samara Urban District with the purpose of its further utilization are considered. The reasons are indicated and documentary evidence of the incorrectness of assigning the responsibility for processing such wastes only to the water and wastewater utilities is provided. The method of landfilling dewatered wastewater sludge in a ridged landfill is considered. It has been established that the sludge processed at the wastewater treatment facilities is referred to the V class of environmental hazard. Sludge subjected to the treatment, stabilization, drying and neutralization (low hazardous sludge from grit chambers for domestic and mixed wastewater treatment; almost non-hazardous sludge from grit chambers for domestic and mixed wastewater treatment and excess sludge from biological treatment facilities mixed with raw sludge) can be used as fillers for concrete-cement mixtures and organo-mineral fertilizers or transferred for disposal to outside companies.

scholarly journals Investigating the effects of different cationic charge flocculation polymers on municipal wastewater sludge dewatering

2021 ◽  
Author(s):  
Megan Abrahams ◽  
Mujahid Aziz ◽  
Godwill Kasongo
Keyword(s):  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Operating Cost ◽  
Wastewater Sludge ◽  
Municipal Wastewater Treatment ◽  
Bench Scale ◽  
Treated Effluent ◽  
Solids Concentration ◽  
Municipal Wastewater Treatment Plants ◽  
Polymer Flocculant

Abstract The minimization of sludge produced by municipal wastewater treatment plants (MWWTPs) is critical as its handling accounts for approximately 50% of the total operating cost. The challenges in predicting dewatering performance can be overcome by optimizing the sludge treatment process, especially conditioning and dewatering. This study aimed to investigate sludge dewaterability at four different MWWTPs, using a gravity drainage test unit and a bench-scale press. The effect of differently treated effluent used as a solvent to mix the flocculation polymers was observed during dewatering. The membrane bioreactor (MBR) treated effluent yielded the highest filtrate volume in the lowest amount of time, with the least polymer flocculant dosage. The Box Behnken Design model fitted the data and proved a relationship between polymer dosage, cake solids concentration, and cake height during the bench-scale press tests.

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