Krzysztof Gondek

The effect of low-temperature transformation of mixtures of sewage sludge and plant materials on content, leachability and toxicity of heavy metals

The aim of the study was to determine the influence of the process of low-temperature transformation and the addition of plant material to sewage sludge diversifying the content of mobile forms of heavy metals and their ecotoxicity. The experimental design included: sewage sludge+rape straw, sewage sludge+wheat straw, sewage sludge+sawdust, sewage sludge+bark and sewage sludge with no addition. The mixtures were subjected to thermal transformation in a chamber furnace, under conditions without air. The procedure consisted of two stages: the first stage (130°C for 40 min) focused on drying the material, whereas in the second stage (200°C for 30 min) proper thermal transformation of materials took place. Thermal transformation of the materials, caused an increase in total contents of heavy metals in comparison to the material before transformation. From among elements, the cadmium content changed the most in materials after thermal transformation. As a result of thermal transformation, the content of water soluble form of the heavy metals decreased significantly in all the prepared mixtures. Low toxicity of the extracts from materials for Vibrio fischeri and Lepidium sativum was found in the research, regardless of transformation process. L. sativum showed higher sensitivity to heavy metals occurring in the studied extracts from materials than V. fischeri, evidence of which are the positive significant correlations between the content of metals and the inhibition of root growth of L. sativum.

Assessment of respiration activity and ecotoxicity of composts containing biopolymers.

The research was conducted to determine if introducing biodegradable polymer materials to the composting process would affect selected biological properties of mature compost. Determination of biological properties of composts composed of testing their respiration activity and toxicity. Respiration activity was measured in material from the composting process by means of OxiTop Control measuring system. The ecotoxicity of composts was estimated by means of a set of biotests composed of three microbiotests using five test organisms. Introduction of polymer materials caused a decrease in respiration activity of mature compost. Similar dependencies as in the case of mass loss were registered. Compost to which a biodegradable polymer with the highest content of starch was added revealed the smallest difference in comparison with organic material composted without polymers. Lower content of starch in a polymer caused lower respiration activity of composts, whereas microorganism vaccine might have accelerated maturing of composts, thus contributing to the smallest respiration of compost. In composts containing biopolymers the following were observed: an increase in germination inhibition--2.5 times, roots growth inhibition--1.8 times, growth inhibition of Heterocypris incongruens--four times and luminescence inhibition of Vibrio fischeri--1.6 times in comparison with the control (compost K1). Composts containing biopolymers were classified as toxicity class III, whereas the compost without polymer addition as class II.

SEWAGE SLUDGE BIOCHARS MANAGEMENT – ECOTOXICITY, MOBILITY OF HEAVY METALS AND SOIL MICROBIAL BIOMASS

Production of biochar from sewage sludge may be a promising solution for sewage sludge management and improvement of soil properties, including carbon dioxide sequestration. The aim of the present study was to compare the effects of biochars derived from different sewage sludges on soil physicochemical and biological properties, ecotoxicity, and plant yield. Three biochars (produced at a temperature of 300 °C) were applied into sandy acid soil in doses of 0.5, 1, and 2% (w/w). Depending on the type and dose, the application of sewage sludge biochars into the soil caused diverse effects on the parameters of soil biological activity (microbial biomass [Cmic], soil respiration, and value of metabolic quotient). No correlation between the applied dose of biochars and inhibition of Vibrio fischeri luminescence was observed. The factor with a stronger impact on the activity of V. fischeri was the type of biochar. The use of the OSTRACODTOXKIT F test (MicroBioTests) showed that the addition of sewage sludge biochar (regardless of its dose) reduced the soil toxicity to Heterocypris incongruens compared with the control soil. A significant increase of Poa pratensis L. biomass was obtained in soils with 1 and 2% additions of each of the biochars. The addition of biochars in doses of 1 and 2% to the soil had greater effect on the content of mobile forms of Cu, Pb, and Cd than the 0.5% dose compared with the control. Environ Toxicol Chem 2018;37:1197-1207.

Content of PAHs, activities of γ-radionuclides and ecotoxicological assessment in biochars

Abstract The aim of this research was to determine the effect of thermal conversion temperature and plant material addition to sewage sludge on the PAHs content and the activity of selected γ-radionuclides in biochars, and to conduct an ecotoxicological assessment. The pyrolysis of the mixtures of sewage sludge and plant materials at 300°C and such temperature caused an increase in the contents of 2- and 3-ring hydrocarbons. During the pyrolysis of organic materials at 600°C, the amount of the following compounds was reduced in biochars: benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3c,d]pyrene, dibenzo[a,h]anthracene, and benzo[g,h,i]perylene. Among γ-radioisotopes of the elements, natural radiogenic isotopes were dominant. 137Cs was the only artificial radioactive isotope. The pyrolysis of the mixtures of municipal sewage sludge and plant materials revealed that isotope 40K had the highest radioactive activity. In the case of other analysed nuclides, activities of 212Pb, 214Pb, 214Bi, and 137Cs were determined after the sample pyrolysis. The extracts from the mixtures of sewage sludge and plant materials were non-toxic to Vibrio fischeri.

Factors Influencing Composting Poultry Waste

Organic recycling of waste, taking into account sanitary safety, should be a fundamental method for recovering the nutrients present in the waste for plants and organic matter. It also refers to by-products of animal origin, which are not intended for consumption by humans. In the present research , composting of hydrated poultry slaughterhouse waste with maize straw was carried out. A combination with fodder yeast and post-cellulose lime was also introduced, which modified chemical and physicochemical properties of the mixtures. The experiment was carried out by recording the biomass temperature for 110 days in 1.2×1.0×0.8 m reactors with perforated bottoms enabling active aeration. The following parameters were taken into consideration in the composted material: carbon, nitrogen, sulfur, respiratory activity, microorganisms, fractions of compost obtained after washing on sieves. Small amounts of fodder yeast favoured the development of microorganisms and caused a sanitary risk in the final product. At the initial stage, the temperature of raw compost in that object was several degrees lower than in the case of the composted mass without yeast addition. The addition of post-cellulose lime at ratios 6.5:1:6.5 (maize straw: poultry slaughterhouse waste: post-cellulose lime) caused a change in the time of microbiological activity, and led to its inhibition in the final process. In comparison to objects with poultry waste, the highest degree of hygienization was found in the compost with post-cellulose lime (with pH close to neutral). By adjusting the ratios of substrates we can influence the microbiological activity, but the amounts of individual substrates should be determined taking into account the quality of the obtained compost.

WYKORZYSTANIE ODPADÓW Z UBOJNI DROBIU DO PRODUKCJI KOMPOSTU

Poultry industry generates large amounts of waste, which in the biological treatment process creates a number of problems. One of them is a high amount of fat and creatine which is hard to decompose. Composting process was carried out with the waste from poultry farms and abattoirs mixed with maize straw, which was used to improve the structure and to increase the amount of carbon in the substrate. The chemical composition of composts from poultry waste involving maize straw meets the minimum requirements for organic fertilizers. It seems that recycling of organic waste from the poultry industry should be the primary method of nutrient recovery for plants and organic matter contained in them, however on condition that the health safety is preserved.

Quantity and Quality of Organic Matter in Soil after Application of Various Organic Materials/Ilość I Jakość Materii Organicznej W Glebie Po Aplikacji Różnych Materiałów Organicznych

Abstract Organic carbon concentrations in soil, irrespective of the year of research increased significantly after application of organic materials for the soil fertilization in comparison with the soil from the NPK mineral treatment. The content of low molecular humus compounds extracted from soil using H2SO4 solution was small, regardless of the applied fertilization or year of research. However, after the third year of research a significant increase in this humus fraction content was noted in soil of all treatments where fertilization was applied. After the third year of research, carbon content in alkaline extract rose significantly in soil of all treatments where fertilization with organic materials was applied, in comparison with the soil from mineral NPK treatment. The content of humic acid carbon in soil was lower than fulvic acid carbon, which resulted in lower than one values of Cha : Cfa ratio. However, obtained results point to marked increase in both humus fractions in results of residual effect of applied fertilization. Residual effect of applied fertilization apparently increased the value of absorbance coefficient A4/6, which points to a decreased degree of condensation of humic acid molecule and greater aliphatisation. Abstrakt Zawartość węgla organicznego w glebie, niezależnie od roku badań, znacznie zwiększyła się po zastosowaniu do nawożenia gleby materiałów organicznych, w porównaniu do gleby z obiektu, w którym zastosowano nawożenie mineralne NPK. Zawartość niskocząsteczkowych związków próchnicznych wyekstrahowanych z gleby roztworem H2SO4 była niewielka bez względu na zastosowane nawożenie oraz rok badań. Niemniej, po trzecim roku badań stwierdzono istotne zwiększenie zawartości tej frakcji próchnicy w glebie wszystkich obiektów, w których zastosowano nawożenie. Po trzecim roku badań zawartość węgla w ekstrakcie alkalicznym istotnie zwiększyła się w glebie wszystkich obiektów, w których zastosowano nawożenie materiałami organicznymi, w porównaniu do zawartości w glebie z obiektu, w którym zastosowano nawożenie mineralne NPK. Zawartość węgla kwasów huminowych w glebie była mniejsza od zawartości węgla kwasów fulwowych, co skutkowało mniejszymi od jedności wartościami ilorazu Ckh:Ckf. Uzyskane wyniki wskazują jednak na znaczące zwiększenie obu frakcji próchnicy w wyniku następczego działania zastosowanego nawożenia. Efektem następczym zastosowanego nawożenia było zwiększenie współczynnika absorbancji A4/6, co wskazuje na zmniejszenie stopnia skondensowania cząsteczki kwasów huminowych oraz większą alifatyzację.

Characteristics of selected fractions of heavy metals in biologically and thermally transformed sewage sludge

AbstractTransformation of sewage sludge is basically a multistage and technologically complex process. Obtaining effective and cost-effective results of sewage sludge processing for environmental applications is an important issue in this waste management. Additional enrichment of sewage sludge during its process of treatment into biowaste, such as bark, straw, or sawdust, gives the sludge appropriate physical properties which facilitate their later transformation or immediate application. On the basis of conducted investigations, it was stated that total heavy metal content in the tested mixtures of sewage sludge with straw, sawdust, and bark transformed thermally and biologically does not exclude their use for agricultural or reclamation purposes, whereas a supplement of the above-mentioned components causes an effect of diluting the content of all determined heavy metals. On the other hand, the process of thermal transformation of the mixtures contributed to increasing Cd, Pb, Cu, and Zn content. No su...

Fungistatic activity of composts with the addition of polymers obtained from thermoplastic corn starch and polyethylene - An innovative cleaner production alternative

Compost extracts with the addition of polymers obtained from thermoplastic corn starch and polyethylene are novel organic amendments, which can be typically applied to suppress soil-borne diseases. Considering the diversity of biologically active substances, including those growth-promoting and stabilizing various pathogens contained in extracts, composts have a large potential to successfully replace the massively used pesticides. The effect of various concentrations of water compost extracts with the addition of polymers obtained from thermoplastic corn starch and polyethylene on the linear growth, biomass, and sporulation of the following polyphagous fungi was assessed under in situ and in vitro conditions: Fusarium culmorum (W.G. Smith), Fusarium graminearum Schwabe, Sclerotinia sclerotiorum (Lib.) de Bary, Rhizoctonia solani Kühn, Alternaria alternata (Fr.) Keissler. The studies revealed that the fungistatic activity was determined by the kind and concentration of compost extract added to the medium, as well as by the fungus kind. The analyzed compost extracts blocked the linear growth of the tested fungi on average by 22%, biomass increment by 51%, and sporulation by 57%. F. culmorum and S. sclerotiorum proved to be the most sensitive to the tested compost extracts. It was found that the extract from compost with the addition of polymer with the highest share of polyethylene blocked the sporulation of F. culmorum by 87% and F. graminearum by 92%. In turn, composts with the addition of polymers with the highest share of a biocomponent weakened the fungistatic activity of composts. The authors demonstrated that the addition of microbiological inoculum to one of the composts enhanced the fungistatic activity with respect to S. sclerotiorum, F. graminearum, and F. culmorum. The obtained results can be used to better understand the growth-promoting and suppression effects of compost extracts with polymer addition, help to enhance crop production, and constitute a paradigm shift towards the development of the next generation of compost with applications in a range of new fields.

Effect of wheat and Miscanthus straw biochars on soil enzymatic activity, ecotoxicity, and plant yield

Abstract The variety of technological conditions and raw materials from which biochar is produced is the reason why its soil application may have different effects on soil properties and plant growth. The aim of this study was to evaluate the effect of the addition of wheat straw and Miscanthus giganteus straw (5 t DM ha−1) and biochar obtained from this materials in doses of 2.25 and 5 t DM ha−1 on soil enzymatic activity, soil ecotoxicity, and plant yield (perennial grass mixture with red clover). The research was carried out under field conditions on soil with the granulometric composition of loamy sand. No significant effect of biochar amendment on soil enzymatic activity was observed. The biochar-amended soil was toxic to Vibrio fischeri and exhibited low toxicity to Heterocypris incongruens. Application of wheat straw biochar and M. giganteus straw biochar in a dose of 5 t DM ha−1 contributed to an increase in plant biomass production by 2 and 14%, respectively, compared to the soil with mineral fertilisation. Biochars had a more adverse effect on soil enzymatic activity and soil ecotoxicity to H. incongruens and V. fischeri than non-converted wheat straw and M. giganteus straw, but significantly increased the grass crop yield.