scholarly journals A Review of Seaweed Pre-Treatment Methods for Enhanced Biofuel Production by Anaerobic Digestion or Fermentation

Fermentation ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 100 ◽  
Author(s):  
Supattra Maneein ◽  
John J. Milledge ◽  
Birthe V. Nielsen ◽  
Patricia J. Harvey
Keyword(s):  
Heavy Metals ◽  
Anaerobic Digestion ◽  
Relative Content ◽  
Biofuel Production ◽  
Treatment Methods ◽  
Treatment Processes ◽  
Polysaccharide Composition ◽  
Pre Treatment

Macroalgae represent a potential biomass source for the production of bioethanol or biogas. Their use, however, is limited by several factors including, but not restricted to, their continuous supply for processing, and low biofuel yields. This review examines recent pre-treatment processes that have been used to improve the yields of either biogas or bioethanol from macroalgae. Factors that can influence hydrolysis efficiency and, consequently, biofuel yields, are highly affected by macroalgal composition, including content of salts, heavy metals, and polyphenols, structural make-up, as well as polysaccharide composition and relative content of carbohydrates. Other factors that can influence biofuel yield include the method of storage and preservation.

scholarly journals Applied WEEE pre-treatment methods: Opportunities to maximizing the recovery of critical metals

2018 ◽  
Vol 20 (4) ◽  
pp. 706-711 ◽  
Keyword(s):  
Raw Materials ◽  
Hazardous Substances ◽  
Critical Metals ◽  
Treatment Methods ◽  
Treatment Processes ◽  
Ferrous Metals ◽  
General Recommendation ◽  
Recovery Treatment ◽  
Non Ferrous Metals ◽  
Pre Treatment

<p>WEEE is a fast-growing waste stream that includes potentially hazardous substances, but also valuable secondary raw materials, which can be recovered by adequate recycling and recovery treatment. In the last years, the research interest has moved from the conventional recycling (recovery of ferrous and non-ferrous metals, plastic, glass and other “mass relevant” fractions presented in WEEE), to the innovational recycling, aimed to recover trace elements, such as critical metals (CMs) and rare earth elements (REEs). Currently, the majority of CMs and REEs are lost during the pre-treatment processes. In this paper, an overview of the most relevant e-waste categories and products in terms of CMs and REEs presence, a description of currently applied pre-treatment methods and fate of the observed group of metals during pre-processing phase, as well as general recommendation in order to avoid losses of CMs and REEs within the WEEE treatment chain, are elaborated.</p>

scholarly journals Low intensity surplus activated sludge pretreatment before anaerobic digestion

2017 ◽  
Vol 43 (4) ◽  
pp. 50-57 ◽  
Author(s):  
Jan Suschka ◽  
Klaudiusz Grübel
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Biogas Production ◽  
Additional Energy ◽  
Low Intensity ◽  
Treatment Processes ◽  
Sludge Disposal ◽  
Mass Minimization ◽  
Pre Treatment

AbstractSewage sludge (municipal, or industrial) treatment is still a problem in so far that it is not satisfactorily resolved in terms of cost and final disposal. Two common forms of sludge disposal are possible; the first being direct disposal on land (including agriculture) and the second being incineration (ash production), although neither of these methods are universally applied. Simplifying the issue, direct sludge disposal on land is seldom applied for sanitary and environmental reasons, while incineration is not popular for financial (high costs) reasons. Very often medium and large wastewater treatment plants apply anaerobic digestion for sludge hygiene principles, reducing the amount to be disposed and for biogas (energy) production. With the progress in sewage biological treatment aiming at nutrient removal, primary sludge has been omitted in the working processes and only surplus activated sludge requires handling. Anaerobic digestion of waste activated sludge (WAS) is more difficult due to the presence of microorganisms, the decomposition of which requires a relatively long time for hydrolysis. In order to upgrade the hydrolysis effects, several different pre-treatment processes have already been developed and introduced. The additional pre-treatment processes applied are aimed at residual sludge bulk mass minimization, shortening of the anaerobic digestion process or higher biogas production, and therefore require additional energy. The water-energy-waste Nexus (treads of) of the benefits and operational difficulties, including energy costs are discussed in this paper. The intensity of pre-treatment processes to upgrade the microorganism’s hydrolysis has crucial implications. Here a low intensity pre-treatment process, alkalisation and hydrodynamic disintegration - hybrid process - were presented in order to achieve sufficient effects of WAS anaerobic digestion. A sludge digestion efficiency increase expressed as 45% biogas additional production and 52% of the total or volatile solids reduction has been confirmed.

scholarly journals EFFECT OF THERMAL PRETREATMENT ON THE SOLUBILIZATION OF ORGANIC MATTERS IN A MIXTURE OF PRIMARY AND WASTE ACTIVATED SLUDGE

2015 ◽  
Vol 9 (1) ◽  
pp. 82-88 ◽  
Author(s):  
Ahmed M. Aboulfotoh ◽  
E.H. El Gohary and O.D. El Monayeri
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Treatment Time ◽  
Chemical Properties ◽  
High Energy ◽  
Gas Production ◽  
Waste Activated Sludge ◽  
Thermal Pretreatment ◽  
Treatment Methods ◽  
Pre Treatment

The increased demand for advanced techniques in anaerobic digestion over the last few years has led to the employment of various pre-treatment methods prior to anaerobic digestion to increase gas production. These pre-treatment methods alter the physical and chemical properties of sludge in order to make it more readily degradable by anaerobic digestion. Although the thermal pre-treatment presents high energy consumption, the main part of this energy to heat can be recovered from the biogas produced in the anaerobic process. In this research a mixture of primary and waste activated sludge was thermally pretreated at 100, 125, 150, 175 and 200o C in order to determine the effect of thermal pretreatment on improving the solubilization of sludge by increasing the soluble organic fraction (expressed as soluble COD and VFA). Experimental results proved that the solubilization ratio of sludge is depends on the treatment time and the applied temperature and the optimal temperature ranged between 175 and 200o C. The COD solubilization ratio (at 175o C) increased from 11.2% to 15.1% and 25.1% when the time of treatment increased from 60 min to 120 and 240 min respectively. The experimental data could be fitted to obtain an empirical model (Known as the enzyme-kinetic equation) relating the COD solubilization ratio of sludge and VFA concentration to the applied temperature and the heating time.

scholarly journals EFFECT OF THERMAL PRETREATMENT ON THE SOLUBILIZATION OF ORGANIC MATTERS IN A MIXTURE OF PRIMARY AND WASTE ACTIVATED SLUDGE

2015 ◽  
Vol 9 (1) ◽  
pp. 82-88 ◽  
Author(s):  
Ahmed M. Aboulfotoh ◽  
E.H. El Gohary and O.D. El Monayeri
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Treatment Time ◽  
Chemical Properties ◽  
High Energy ◽  
Gas Production ◽  
Waste Activated Sludge ◽  
Thermal Pretreatment ◽  
Treatment Methods ◽  
Pre Treatment

The increased demand for advanced techniques in anaerobic digestion over the last few years has led to the employment of various pre-treatment methods prior to anaerobic digestion to increase gas production. These pre-treatment methods alter the physical and chemical properties of sludge in order to make it more readily degradable by anaerobic digestion. Although the thermal pre-treatment presents high energy consumption, the main part of this energy to heat can be recovered from the biogas produced in the anaerobic process. In this research a mixture of primary and waste activated sludge was thermally pretreated at 100, 125, 150, 175 and 200o C in order to determine the effect of thermal pretreatment on improving the solubilization of sludge by increasing the soluble organic fraction (expressed as soluble COD and VFA). Experimental results proved that the solubilization ratio of sludge is depends on the treatment time and the applied temperature and the optimal temperature ranged between 175 and 200o C. The COD solubilization ratio (at 175o C) increased from 11.2% to 15.1% and 25.1% when the time of treatment increased from 60 min to 120 and 240 min respectively. The experimental data could be fitted to obtain an empirical model (Known as the enzyme-kinetic equation) relating the COD solubilization ratio of sludge and VFA concentration to the applied temperature and the heating time.

scholarly journals Effective Pre-Treatments for Enhancement of Biodegradation of Agricultural Lignocellulosic Wastes in Anaerobic Digestion – A Review

2020 ◽  
Vol 23 (3) ◽  
pp. 105-110
Author(s):  
Fatemeh Rahimi-Ajdadi ◽  
Masoomeh Esmaili
Keyword(s):  
Anaerobic Digestion ◽  
Crop Residues ◽  
Biogas Production ◽  
Biofuel Production ◽  
Agricultural Crop ◽  
Advantages And Disadvantages ◽  
Lignocellulosic Wastes ◽  
Pre Treatment ◽  
Anaerobic Digestibility ◽  
Emission Of Greenhouse Gases

AbstractAgricultural crop residues like stems, straws and leaves are valuable resources for biofuel production, especially methane, due to anaerobic digestion. Biogas from agricultural lignocellulosic wastes is capable of attaining sustainable energy yields without environmental pollution. Farmers in many developing countries burn these wastes throughout their fields, imposing environmental hazard due to emission of greenhouse gases. The main problem in this field is the recalcitrance of the agricultural lignocellulose waste that limits its enzymatic degradation and hydrolysis efficiency and consequently decreases biogas production. Therefore, efficient pre-treatments prior to anaerobic digestion are essential. Various pre-treatment methods are used for increasing the anaerobic digestibility of lignocellulose biomass, such as physical (mechanical, thermal, etc.), chemical, biological and combined pre-treatments. This paper reviews different pre-treatments used in anaerobic digestion for the agricultural lignocellulosic wastes and explains the advantages and disadvantages of each. The most frequently used pre-treatments for main agricultural wastes in process of biogas production are also introduced.

Recent advances in green pre-treatment methods of lignocellulosic biomass for enhanced biofuel production

2021 ◽  
pp. 129038
Author(s):  
Nurul Suhada Ab Rasid ◽  
Amnani Shamjuddin ◽  
Athran Zuhail Abdul Rahman ◽  
Nor Aishah Saidina Amin
Keyword(s):  
Lignocellulosic Biomass ◽  
Biofuel Production ◽  
Treatment Methods ◽  
Recent Advances ◽  
Pre Treatment

scholarly journals Comparison of dry and wet milling pre-treatment methods for improving the anaerobic digestion performance of the Pennisetum hybrid

RSC Advances ◽  
2017 ◽  
Vol 7 (21) ◽  
pp. 12610-12619 ◽  
Author(s):  
Dong Pengyu ◽  
Li Lianhua ◽  
Zhen Feng ◽  
Kong Xiaoying ◽  
Sun Yongming ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Ball Mill ◽  
Planetary Ball Mill ◽  
Methane Yield ◽  
Wet Milling ◽  
Treatment Methods ◽  
Pre Treatment

A planetary ball mill increased the specific methane yield of thePennisetumhybrid by 42%.

Improving the sludge disintegration efficiency of sonication by combining with alkalization and thermal pre-treatment methods

2012 ◽  
Vol 65 (10) ◽  
pp. 1809-1816 ◽  
Author(s):  
S. Şahinkaya ◽  
M. F. Sevimli ◽  
A. Aygün
Keyword(s):  
Oxygen Demand ◽  
Treatment Method ◽  
Waste Activated Sludge ◽  
Treatment Methods ◽  
Treatment Processes ◽  
Lack Of Information ◽  
Proposed Model ◽  
Soluble Chemical Oxygen Demand ◽  
Pre Treatment ◽  
Sludge Settleability

One of the most serious problems encountered in biological wastewater treatment processes is the production of waste activated sludge (WAS). Sonication, which is an energy-intensive process, is the most powerful sludge pre-treatment method. Due to lack of information about the combined pre-treatment methods of sonication, the combined pre-treatment methods were investigated and it was aimed to improve the disintegration efficiency of sonication by combining sonication with alkalization and thermal pre-treatment methods in this study. The process performances were evaluated based on the quantities of increases in soluble chemical oxygen demand (COD), protein and carbohydrate. The releases of soluble COD, carbohydrate and protein by the combined methods were higher than those by sonication, alkalization and thermal pre-treatment alone. Degrees of sludge disintegration in various options of sonication were in the following descending order: sono-alkalization &gt; sono-thermal pre-treatment &gt; sonication. Therefore, it was determined that combining sonication with alkalization significantly improved the sludge disintegration and decreased the required energy to reach the same yield by sonication. In addition, effects on sludge settleability and dewaterability and kinetic mathematical modelling of pre-treatment performances of these methods were investigated. It was proven that the proposed model accurately predicted the efficiencies of ultrasonic pre-treatment methods.

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