M. Suchowska-Kisielewicz

Green Energy from Biogas in a Polish-German Sewage Treatment Plant

The article presents the experiences in the cogeneration energy from biogas at the Gubin-Guben sewage treatment plant. It has been shown that the production of biogas allows coverage of up to 65% of its electricity demand. In the year 2011, after obtaining a license for “green energy” from biogas, the cost of the purchase of energy in comparison with the year 2010 was lower by about (€36,000). The consumption of electricity with respect to 1 m3 of sewage amounts to 0.51 kWh/m3.

EVALUATION OF BIODEGRADABILITY OF WASTE BEFORE AND AFTER AEROBIC TREATMENT

Abstract An important advantage of use of an aerobic biostabilization of waste prior to its disposal is that it intensifies the decomposition of the organic fraction of waste into the form which is easily assimilable for methanogenic microorganisms involved in anaerobic decomposition of waste in the landfill. In this article it is presented the influence of aerobic pre-treatment of waste as well as leachate recirculation on susceptibility to biodegradation of waste in anaerobic laboratory reactors. The research has shown that in the reactor with aerobically treated waste stabilized with recilculation conversion of the organic carbon into the methane is about 45% higher than in the reactor with untreated waste stabilized without recirculation.

The influence of preliminary aerobic treatment on the efficacy of waste stabilisation under leachate recirculation conditions

Abstract This article presents the changes in the chemical composition of leachate and the concentrations and quantity of methane production in each individual decomposition phases, determined for untreated and after aerobic treatment of waste stabilised in anaerobic reactors with and without leachate recirculation. The research results demonstrate that leachate recirculation intensifies the decomposition of both aerobically treated and untreated waste. The methane production in the reactor with untreated, stabilised waste with recirculation was 28% higher; and in the reactor with aerobically treated waste, the methane production was 24% higher than in the reactors without recirculation. An important finding of the study is that aerobic treatment of waste prior to landfilling effectively reduces the quantity of pollutant emissions in leachate and biogas from waste and increases the availability for methane micro-organisms of organic substrates from difficult-to-decompose organic substances.

Testing of co-fermentation of poultry manure and corn silage

Abstract The development of the production of poultry meat is connected with an increase in the quantity of the manure. The chemical characteristics predisposes this waste to processing by methane fermentation method. This study investigated the influence of ammonia and volatile fat acids on mesophilic anaerobic digestion of poultry manure. The aim of the studies was: to determine the degree of biodegradation of the poultry manure as well as manure and corn silage mixed in various proportions in the process of mesophilic fermentation, to evaluate the impact of mineral nitrogen and volatile fat acids on the course of fermentation, and to establish optimum proportions of these types of waste. The tests confirmed the positive effect of co-fermentation of poultry manure with corn silage. The most favourable ratio for mixing the substrates is the equal percentage of their dry matter in the mixture. With such waste mixing proportions, the degree of degradation of organic substances contained in the manure amounted to 61.8% and was higher than in the mono-digestion of manure and corn silage.

IMPACT OF FERTILISATION WITH SEWAGE SLUDGE ON THE CONTENT OF LEAD IN SALIX VIMINALIS BIOMASS

Abstract Sewage sludge is considered to be high quality fertilizer. Therefore, in Poland, it is used to fertilize energy plants. On the one hand, it allows using large amount of sewage sludge on the other hand it contributes to the production of renewable energy. The study was based on monitoring the plantation of energetic willow Salix viminalis fertilized with sewage sludge from wastewater treatment plant in Sulechow. The aim of the investigation was to study changes of the lead content in different parts collected during a year and analyze the differences in the accumulation of lead in the plants planted at different times. The results of the study showed that the amount of lead content in the biomass willow was not influenced by sewage sludge used as a fertilizer.

Kinetic Constants of Decomposition of the Municipal Solid Waste Prior to and after Mechanical-Biological Processing. Field Scale / Stałe Kinetyczne Rozkładu Zmieszanych Odpadów Komunalnych Przed I Po Mechaniczno-Biologicznym Przetworzeniu. Skala Polowa

Abstract One of the major tasks of municipal waste management in European Union countries is the systematic reduction of waste that is removed and transported to landfills. This refers particularly to biodegradable waste. One of the methods employed to decrease waste amount is Mechanical-Biological Treatment (MBT) of the waste, before it is stored. The article presents characteristics of MSW and biologically pre-treated municipal solid waste, organic carbon loads emitted in biogas and leachate during waste deposition in a landfill. Its decomposition rate constants were determined on the basis of modified Zacharof and Butler’s stochastic model. The values of decomposition rate constants determined for MSW had similar change trends to those presented in the literature: the hydrolysis constant had the lowest value (2.6 × 10-5 d-1), the highest acid phase constant (4.1 × 10-4 d-1), while the methane phase constant - 2.2 × 10-4 d-1. The PMSW decomposition rate constants in each anaerobic waste degradation phase had similar change trends, though their values were higher, by 21, 11 and 19%, respectively. Istotnym zadaniem gospodarki odpadami komunalnymi w krajach UE jest systematyczne zmniejszanie ilości odpadów komunalnych usuwanych na składowiska, w tym zwłaszcza odpadów ulegających biodegradacji. Jedną z metod stosowanych do realizacji tego celu jest mechaniczno-biologiczne przetwarzanie odpadów komunalnych (MBP) przed ich składowaniem. W artykule przedstawiono charakterystykę surowych odpadów komunalnych (ZOK) i wstępnie przetworzonych biologicznie, ładunki węgla organicznego emitowane w biogazie i odciekach podczas ich składowania oraz wyznaczono stałe szybkości rozkładu tych odpadów w oparciu o zmodyfikowany stochastyczny model Zacharof’a i Butler’a. Wartości wyznaczonych dla ZOK stałych szybkości rozkładu mieściły się w bardzo szerokich zakresach prezentowanych w literaturze, a ich relacje zachowywały podobne tendencje zmian; stała hydrolizy miała najniższą wartość (2,6×10-5 d-1), co potwierdziło limitujący jej wpływ na szybkość rozkładu, stała fazy kwaśnej najwyższą (4,1×10-4 d-1), a stała fazy metanowej - 2,2×10-4 d-1). Stałe szybkości rozkładu PMSW w poszczególnych fazach beztlenowej degradacji odpadów zachowywały podobne tendencje zmian, jednakże ich wartości były wyższe, odpowiednio o 21, 11 i 19%.