Search results for "ANAEROBIC DIGESTION"
showing 10 items of 134 documents
Emissions of Greenhouse Gases and Climate Politics in the Latvian Waste Sector
2015
According IPCC guidelines for determination of greenhouse gases in waste management (IPCC 2006) the quantity of greenhouse gases must be determined for the emissions of CO2, CH4, N2O for such treatment activities: disposal of solid waste, biological treatment of solid waste and incineration and open burning of waste. Presented report reviles the current situation of this field in Latvia and conclusions on its minimization actions. The data received from Latvian environmental data bases shows that the quantity of disposed unsorted municipal waste is rising and created sanitary landfill system with anaerobic digestion of bio mas (the content of it in the disposed waste reaches 40–50 %) is pro…
Enhancing methane production from lignocellulosic biomass by combined steam-explosion pretreatment and bioaugmentation with cellulolytic bacterium
2017
Background Biogas production from lignocellulosic biomass is generally considered to be challenging due to the recalcitrant nature of this biomass. In this study, the recalcitrance of birch was reduced by applying steam-explosion (SE) pretreatment (210 °C and 10 min). Moreover, bioaugmentation with the cellulolytic bacterium Caldicellulosiruptor bescii was applied to possibly enhance the methane production from steam-exploded birch in an anaerobic digestion (AD) process under thermophilic conditions (62 °C). Results Overall, the combined SE and bioaugmentation enhanced the methane yield up to 140% compared to untreated birch, while SE alone contributed to the major share of methane enhancem…
Anaerobic and sequential anaerobic-aerobic treatments of municipal landfill leachate at low temperatures
1996
Abstract Anaerobic treatment of municipal landfill leachate (COD 1–4 g l −1 , NH 4 -N c. 0.16 g l −1 ) was studied at 11 and 24°C by using laboratory-scale UASB and hybrid reactors. Aerobic post-treatment of the anaerobically treated leachate was also studied at 24°C using an activated-sludge process. In the 11°C reactors, a COD removal of up to 60–65% was obtained with 1.5-2 day HRT and 0.7-1.5 kg COD m −3 day −1 organic loading rates. At 24°C, a COD removal of up to 75% was achieved with a 10 h HRT. The highest organic loading rate applied was 10 kg COD m −3 day −1 at 24°C. Inorganic material accumulated in the reactor sludges at both temperatures. However, the specific methanogenic activ…
Use of rumen microorganisms to boost the anaerobic biodegradability of microalgae
2017
[EN] A laboratory bioreactor using rumen microorganisms to treat Scenedesmus spp. biomass was operated for 190 days. At first the bioreactor operated as a Rumen-like Fermenter (RF) with a Sludge Retention Time (SRT) of 7 days. The RF was subsequently transformed into an anaerobic digestion system including two configurations: continuously-stirred tank reactor and anaerobic membrane bioreactor in which different SRT values of up to 100 days were assessed. Methane production peaked at 214 mL CH4 g−1 CODIn with a SRT of 100 days. COD removal and BDP peaked at above 70% and 60%, respectively, at the highest SRT, with no pre-treatment prior to microalgae digestion. The waste sludge product…
Effect of temperature and organic nutrients on the biodegradation of linear alkylbenzene sulfonate (LAS) during the composting of anaerobically diges…
2004
Limits on the application of biosolids (anaerobically processed sludges from wastewater treatment plants) as fertilizers for the amendment of soil are becoming greater because of the accumulation of recalcitrant substances, making necessary the use of techniques that bring the concentration of xenobiotics to lower concentrations than those permitted. In general, the biosolids composting process is sufficient to reduce the usual concentration of linear alkylbenzene sulfonates (LAS) to low levels. In this work, an assessment is made on the effect of temperature in the capacity of enriched bacterial populations to biodegrade LAS, together with the influence that the available nutrients may hav…
Sicilian potential biogas production from Citrus industry by-product
2017
In Europe, Italy is the second nation after Spain in Citrus production and 49% ca. of national fruit production is located in Sicily. The by-product obtained from the industrial processing of Citrus fruits into juice and essential oils is called “pastazzo” or Citrus Waste (CW). This study is aimed at evaluating the Sicilian potential biogas and energy production from the above “pastazzo” and verifying the possibility of using this by-product for Anaerobic Digestion (AD) process within 30 km from processing plants. The areas cultivated with Citrus species in Sicily and their distribution in the various municipal districts were mapped and analysed by means of QGIS software, together with the …
Effects of temperature on post-methanation of digested dairy cow manure in a farm-scale biogas production system.
2003
A post-methanation process that could be adopted at farm-scale, operating at temperatures prevailing in farm manure digester post-storage tanks, was evaluated. Digested manure samples from a farm digester (35 degrees C) and post-storage tank (5-10 degrees C) were incubated in parallel batches at 5-20 degrees C and as reference at 35 and 55 degrees C. Specific methane yields (kg(-1) volatile solids (VS)(added waste)) were 0.20-0.26 m3 at 35-55 degrees C and 0.085-0.09 m3 at 10-20 degrees C for digester material (345 days of incubation) and 0.16-0.21 m3 at 35-55 degrees C, 0.053-0.087 kg(-1) VS(added waste) m3 at 15-20 degrees C and 0.026 m3 at 10 degrees C for post-storage tank material (250…
Assessment of the Energy Potential of Chicken Manure in Poland
2019
Animal waste, including chicken manure, is a category of biomass considered for application in the energy industry. Poland is leading poultry producer in Europe, with a chicken population assessed at over 176 million animals. This paper aims to determine the theoretical and technical energy potential of chicken manure in Poland. The volume of chicken manure was assessed as 4.49 million tons per year considering three particular poultry rearing systems. The physicochemical properties of examined manure specimens indicate considerable conformity with the data reported in the literature. The results of proximate and ultimate analyses confirm a considerable effect of the rearing system on the e…
Storing energy crops for methane production: Effects of solids content and biological additive
2007
The effect of storage on chemical characteristics and CH4 yield (taking into account loss of VS during storage) of a mixture of grasses and ryegrass, ensiled as such (low solids content) and after drying (medium and high solids) with and without biological additive, were studied in field and laboratory trials. Up to 87% and 98% of CH4 yield was preserved with low solids grass (initial TS 15.6%) and high solids ryegrass (initial TS 30.4%), respectively, after storage for 6months, while under suboptimal conditions at most 37% and 52% of CH4 yield were lost. Loss in CH4 yield was mainly due to VS loss, presumably caused by secondary fermentation as also suggested by increasing pH during storag…
Impact of crop species on bacterial community structure during anaerobic co-digestion of crops and cow manure
2008
The bacterial communities in three continuously stirred tank reactors co-digesting cow manure with grass silage, oat straw, and sugar beet tops, respectively, were investigated by 16S rRNA gene-based fingerprints and clone libraries. The analyses revealed both clearly distinct and similar phylotypes in the bacterial communities between the reactors. The major groups represented in the three reactors were Clostridia, unclassified Bacteria, and Bacteroidetes. Phylotypes affiliated with Bacilli or Deltaproteobacteria were unique to the sugar beet and straw reactor, respectively. Unclassified Bacteria dominated in sugar beet reactor while in the straw and grass reactor Clostridia was the domina…