Tag Archives: sewage sludge

The study of molybdenum leaching from soils fertilized with sewage sludge and their composts

The study of molybdenum leaching from soils fertilized with sewage sludge and their composts
BOŻYM M., RAJMUND A.

Please cite as: CHEMIK 2014, 68, 10, 874–879

Changes of molybdenum content in soils fertilized with sewage sludge and composts during lysimeter experiment was researched. Additionally, the mobility of this metal was measured using selected extractants (H2O, 0.1M HCl, 1M HCl). Sewage sludges and composts were characterized by more than twice larger molybdenum content than in soils. Nevertheless, the percentage of Mo mobile forms in the soil was similar, regardless of the type of fertilization. Leaching of molybdenum depended on the ionic strength of the extractant. The lowest molybdenum content was determined in aqueous extracts, the highest in 1M HCl. The statistical analysis shows that the leaching of molybdenum from sewage and compost was influenced by pH, overall metal and organic matter content. In case of leaching from soils, the impact of these factors has not been...

Read more

Accumulation of heavy metals by earthworms from vermicomposting sewage sludges

Accumulation of heavy metals by earthworms from vermicomposting sewage sludges
BOŻYM M.

Please cite as: CHEMIK 2014, 68, 10, 868–873

The aim of this study was to analyzed the ability to accumulate heavy metals in the earthworms of sewage sludge treating and to determine the factors influencing the effect. The contents of heavy metals in raw sewage sludge, vermicomposts, earthworms and coprolite were analyzed. It was found that content of heavy metals in vermicompost during the process was increased. Probably this is due to the weight reduction of treated sludges, although the additive of plant material. Earthworms accumulated a higher content of heavy metals as compared with the ground (vermicompost). On the metals accumulation effect in earthworms bodies influenced the content of metals, organic matter and pH of sewage sludge.

Keywords: sewage sludge, vermicompost, earthworms, heavy metals

Read more in pdf

pdf-icon

...
Read more

The energy potential of biogas ? an estimation of biogas production resources in Poland

Alina REJMAN-BURZYŃSKA, Halina MAKSYMIAK-LACH, Eugeniusz JĘDRYSIK ?Central Mining Institute in Katowice Please cite as: CHEMIK 2013, 67, 5, 446?453 Introduction Biogas is produced in the process of organic substance decomposition via methane fermentation and contains 50?75% of methane (CH4) and 25?50% of carbon dioxide (CO2) as well as small amounts of ammonia, hydrogen sulphide, hydrogen, mercaptans and other gases. Only biogas containing at least 40% of methane can be used to produce thermal or electric energy. The main resources used to produce biogas on an industrial scale are organic waste, including wastewater residues, agricultural and food waste, animal manure and organic fractions of municipal waste. The amount and composition of biogas depend on the chemical composition of the resource fed to fermentation and on process parameters (reaction time, temperature). 1 kg of carbohydrates yields, on average, 0.42 m3 of CH4, of proteins ? 0.47 m3 of CH4, while of fats ? 0.75 m3 of CH4, but fats are characterised by a long...
Read more