Z. Sadecka

Occurrence of heavy metals and PAHs in soil and plants after application of sewage sludge to soil

AbstractThe results of investigations on heavy metals and polycyclic aromatic hydrocarbons (PAHs) content in mixed soil fertilized with sewage sludge are presented. The concentration of these micropollutants in various parts of a basket willow Salix viminalis grown on this substratum was also analyzed. Aerobically stabilized, dewatered, and hygienized sewage sludge (a dose of 90 tons of dry matter per hectare) was used to fertilize the soil. S. viminalis was planted on the soil amended with sewage sludge. The samples for analyses were taken after five vegetatives; they were both soil samples and parts of plants (roots, stems, and leaves). The concentration of heavy metals and PAHs was analyzed in the samples. The concentration of heavy metals in soil after five seasons of fertilizing with sewage sludge was at most cases higher than defined in soil at the beginning of the experiment. The concentration of Cr in soil after five years of S. viminalis cultivation was, however, lower than at the outset. The ave...

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.

Impact of selected insecticides on the anaerobic stabilization of municipal sewage sludge

AbstractThe aim of the studies was to indicate whether the insecticides have toxic impact on the course of the process of sewage sludge methane fermentation and their biochemical durability is. The research proved that representatives of insecticides from the group of chlorinated hydrocarbons and phosphoorganic compounds can be toxic to anaerobic biocenosis. The series of insecticide toxicity with respect to anaerobic biocenosis is the following: Chloroorganic compounds > phosphoorganic compounds. The compounds studied can be put into a series with respect to their toxicity as follows: metoxychlor > chlorfenvinphos > fenitrothion > malathion, and for commercial products as follows: Metox > Enolofos > Owadofos > Sadofos. Pesticides from the group of chlorinated hydrocarbons and phosphoorganic compounds can be biodegraded in anaerobic conditions. The degree of decomposition was as follows, for: metoxychlor 99.3–99.9%, chlorfenvinphos 38.1–97.6%, fenitrothion 75.3–99.9%, and malathion, 84.2–99.9%. The study ...

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 Effectiveness of Organic Pollutants Removal in Constructed Wetland with Horizontal Sub-Surface Flow / Efektywność Usuwania Zanieczyszczeń Organicznych W Oczyszczalni Hydrofitowej

Abstract This paper presents the results of the research work related to the removal efficiency from wastewater organic pollutants and suspended solids at HSSF (horizontal subsurface flow) constructed wetland. The average effectiveness defined as loss of value COD in wastewater has reached 77%, for BOD5 - 80% and TOC - 82%. The effect of seasonal temperature changes and the period of plant vegetation and rest on the effectiveness of wastewater treatment were also analyzed. The results of the presented research showed a decrease in the efficiency of removing organic pollutants from wastewater and suspended solids in the autumn and winter. During the vegetation the object in Małyszyn has been characterized by the effectiveness of wastewater treatment at the level of 78% for COD, 82% for BOD5, and in the non-vegetation period the effectiveness has decreased up to 75% for COD and 74% for BOD5. During the plants growth the total suspension was removed in 88%, whereas during the plants rest efficiency of removing lowered to 69%. Streszczenie W pracy przedstawiono wyniki badań dotyczące efektywności usuwania ze ścieków zanieczyszczeń organicznych w oczyszczalni hydrofitowej. Średnia skuteczność oczyszczania wyrażona jako obniżenie wartości ChZT w ściekach była na poziomie 77%, dla BZT5 80%, a dla OWO 82%. Analizowano również wpływ sezonowych zmian temperatury oraz okresu wegetacji i spoczynku roślin na skuteczność oczyszczania ścieków. Wyniki badań wykazały obniżenie efektywności usuwania zanieczyszczeń organicznych ze ścieków wyrażonych przez ChZT i BZT5 oraz zawiesiny ogólnej w okresie jesienno-zimowym. W okresie wegetacyjnym obiekt w Małyszynie charakteryzował się efektywnością oczyszczania ścieków na poziomie: 78% dla ChZT, 82% dla BZT5, a w sezonie pozawegetacyjnym skuteczność uległa obniżeniu do 75% w przypadku ChZT oraz 74% dla BZT5. Zawiesina ogólna w okresie wegetacji trzciny usuwana była w 88%, a w okresie powegetacyjnym w 69%.

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.

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.