anaerobic digestion pretreatment Articles

  • Anaerobic Digest

    Washington, DC: NOSB Considers Digestate Use Petition The National Organic Standards Board (NOSB) of the U.S. Department of Agriculture (USDA) has agreed to consider a petition from Cenergy USA, the makers of Magic Dirt™, to allow use of digestate from anaerobic digestion plants in organic agriculture. Magic Dirt is made from digested dairy manure fibers. The soil amendment products ...


    By BioCycle Magazine

  • Thermal hydrolysis as pretreatment of digestion feed

    AbstractA large number of different processes are today on the market for treatment of biodegradable waste. The two principal biological treatment methods available are aerobe treatment (composting) and anaerobe treatment (digestion/fermentation). In Norway so far, aerobe treatment has been the most popular solution. Both windrow composting and tunnel composting systems are in use. The first ...


    By Cambi Group AS

  • Pretreatment followed by anaerobic digestion of secondary sludge for reduction of sewage sludge volume

    The influence of two pretreatment methods, thermal treatment and low-pressure wet oxidation, on the sludge digestion efficiency was examined. Batch thermophilic anaerobic digestion was used to evaluate the effectiveness of the pretreatment methods in terms of volatile suspended solids (VSS) digestion efficiency and gas production. The results showed that the gas production was not proportional ...


    By IWA Publishing

  • Semi-continuous mesophilic anaerobic co-digestion of thermally pretreated scum

    The objective of this study is to investigate the mesophilic, anaerobic, co-digestion of scum with thickened waste activated sludge (TWAS) and primary sludge (PS). Observations of the reactor waste show that higher pretreatment temperatures assist in scum integration and appear to limit coagulation and separation effects associated with digesting fats, oils and greases. The 0.40 kg VS/m3 · d ...


    By IWA Publishing

  • Comprehensive review and compilation of pretreatments for mesophilic and thermophilic anaerobic digestion

    Organic matter hydrolysis prior to anaerobic digestion has been shown to improve biogas production (30–50%) and reduce solids (20–60%) by ultrasound, chemical, conventional heating, and microwave pretreatments. Numerous studies have been performed to determine the extent of digestion improvement but few focus on financial feasibility of these processes. A comprehensive model was created using ...


    By IWA Publishing

  • Performance of Continuous Flow Anaerobic Sludge Digesters after Microwave Pretreatment

    Effects of microwave (MW) pretreatment on waste activated sludge (WAS) in mesophilic semicontinuous (SC) anaerobic digesters with acclimatized inoculum at sludge retention times (SRTs) of 5, 10 and 20 d are presented. Preliminary batch digesters were also studied in order determine the optimum MW temperature (T), MW intensity (I), WAS concentration (C) and volume percentage of WAS pretreated (PT) ...

  • Effect of thermal alkaline pretreatment on the anaerobic digestion of wasted activated sludge

    The effect of alkaline pretreatment of waste-activated sludge, using two models to study the sequential hydrolysis rates of suspended (Sanders' surface model) and dissolved (Goel's saturation model) solids, on the mesophilic and thermophilic anaerobic digestion rate is evaluated. The pretreatment, which reduces the size of the solids, increases the reaction rate by increasing the surface area and ...


    By IWA Publishing

  • Operational Experience of Advanced Anaerobic Digestion

    Abstract Anaerobic processes have been used in wastewater treatment systems for more than a century. Initially they were used to stabilise the solids produced, and generally consisted of simple concrete tanks in which the solids were placed as thin slurry and allowed to decompose anaerobically. However, using advanced pre-treatment processes in conjunction with traditional anaerobic ...


  • Effect of solid-state NaOH pretreatment on methane production from thermophilic semi-dry anaerobic digestion of rose stalk

    The effects of solid-state NaOH pretreatment on the efficiency of methane production from semi-dry anaerobic digestion of rose (Rosa rugosa) stalk were investigated at various NaOH loadings (0, 1, 2, and 4% (w/w)). Methane production, process stability and energy balance were analyzed. Results showed that solid-state NaOH pretreatment significantly improved biogas and methane yields of 30-day ...


    By IWA Publishing

  • Sewage sludge pretreatment by microwave irradiation combined with activated carbon fibre at alkaline pH for anaerobic digestion

    This research focuses on the effects of microwave-assisted activated carbon fibre (ACF) (MW-ACF) treatment on sewage sludge at alkaline pH. The disintegration and biodegradability of sewage sludge were studied. It was found that the MW-ACF process at alkaline pH provided a rapid and efficient process to disrupt the microbial cells in the sludge. The results suggested that when irradiated at ...


    By IWA Publishing

  • DC WASA adopts thermal hydrolysis for anaerobic digestion pretreatment: conceptual design details for the largest Cambi™

    ABSTRACT The District of Columbia Water and Sewer Authority (DC WASA) has decided to incorporate thermal-hydrolysis pretreatment in conjunction with mesophillic anaerobic digestion as the backbone of a long-term biosolids treatment plan to produce Class A biosolids. The Authority has been lime stabilizing their raw solids from the Blue Plains Plant for many years, transporting them to the State ...


    By Cambi Group AS

  • Enhancement of waste activated sludge anaerobic digestion by a novel chemical free acid/alkaline pretreatment using electrolysis

    Anaerobic digestion of waste activated sludge (WAS) is relatively poor due to hydrolysis limitations. Acid and alkaline pretreatments are effective in enhancing hydrolysis leading to higher methane yields. However, chemical costs often prohibit full-scale application. In this study, 12 V two-chamber electrolysis using an anion exchange membrane alters sludge pH without chemical dosing. pH ...


    By IWA Publishing

  • Managing Compostable Bags At Anaerobic Digestion Plants

    The highest and best use for treating residential food waste is through source separation, sending organics first to anaerobic digestion (to capture energy), followed by aerobic composting (to return nutrients to the soil). Sending food waste to anaerobic digestion (AD) facilities requires appropriate tools and planning for capturing high volumes of material with low contamination. Compostable ...


    By BioCycle Magazine

  • Anaerobic digestion of macroalgae: methane potentials, pre-treatment, inhibition and co-digestion

    In the present study we tested four macroalgae species – harvested in Denmark – for their suitability of bioconversion to methane. In batch experiments (53 °C) methane yields varied from 132 ml g volatile solids−1 (VS) for Gracillaria vermiculophylla, 152 ml g VS−1 for Ulva lactuca, 166 ml g VS−1 for Chaetomorpha linum and 340 ml g VS−1 for Saccharina ...


    By IWA Publishing

  • The Effect of the Microsludgetm Treatment Process on Anaerobic Digestion Performance

    ABSTRACT Thickened waste activated sludge (TWAS) from biological treatment processes is less amenable to anaerobic digestion than primary sludge. This is due to TWAS being composed mostly of cellular material and extracellular polymeric substances (EPS) instead of more easily digestible carbohydrates and fats that are typically found in primary sludge. In an attempt to improve TWAS digestion ...

  • Using Anaerobic Biomass Digestion to Produce Hydrogen and Biofuel

    For many years, hydrogen has been considered as an alternative to fossil fuels. Now, Scientists are aiming to develop an environmentally friendly method to produce hydrogen from biomass by optimizing anaerobic digestion systems.1 Climate change, dwindling fuel resources and energy prices have spearheaded intensive efforts to detect and optimize ...


    By Edinburgh Instruments Ltd

  • Residential SSO To High Solids Anaerobic Digestion

    Source separated organics, including kitchen and garden waste, are processed in a dry AD plant. Resulting biomethane is injected into an adjacent natural gas pipeline. Winterthur, a city in the canton of Zürich in northern Switzerland, has the country’s sixth largest population, estimated at more than 100,000. In 2011, the City of Winterthur launched a 2050 energy policy to ...


    By BioCycle Magazine

  • On-Site Food Waste Pretreatment

    Guide to equipment and systems for businesses, institutions and venues that manage food waste on-site. Businesses, institutions and venues that generate large volumes of food waste have an increasing number of options to manage this organics stream, starting with tools and knowledge to prevent and reduce what is generated in the first place, followed by donation of excess and prepared ...


    By BioCycle Magazine

  • Sludge electrooxidation as pre-treatment for anaerobic digestion

    Anaerobic digestion of wastewater sludge is the preferred method for sludge treatment as it produces energy in the form of biogas as well as a stabilised product that may be land applied. Different pre-treatments have been proposed to solubilise organic matter and increase biogas production. Sludge electrooxidation with boron-doped diamond electrodes was used as pre-treatment for waste ...


    By IWA Publishing

  • Anaerobic digestion of sunflower oil cake: a current overview

    Due to the chemical and physical structure of a lignocellulosic biomass, its anaerobic digestion (AD) is a slow and difficult process. In this paper, the results obtained from a batch biochemical methane potential (BMP) test and fed-batch mesophilic AD assays of sunflower oil cake (SuOC) are presented. Taking into account the low digestibility shown during one-stage experiments the methane yield ...


    By IWA Publishing

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