Porównanie zawartości wybranych metali ciężkich w próbkach kompostów

Celem pracy jest porównanie wybranych parametrów fizykochemicznych jak ChZTCr, C/N oraz zawartości wybranych metali ciężkich, w kompostach różniących się udziałem procentowym osadów ściekowych i frakcji organicznej odpadów komunalnych w biomasie stanowiącej wsad do bioreaktora.

The article presents the results of the influence of the percentage of sewage sludge and organic fraction in biomass subjected to composting for the content of selected heavy metals (Cu, Cr, Cd, Ni and Pb). Samples of compost produced in a laboratory scale static bioreactor with capacity of 60 liters, with forced aeration. Input to the bioreactor was mixture consisting of sewage sludge collected from sewage treatment plant in the catchment area of the city with 100 thousands inhabitants and organic fraction of municipal waste from landfill. Sewage sludge collected for composting after the dewatering devices contained 70÷75% of water. The organic waste fraction obtained by sieving non-sorted waste through a sieve with mesh diameter of 4 cm, and then through a sieve with a diameter of 2 cm. Unfortunately the resulting faction, apart from biodegradable waste, contained glass and plastic, which served as the structure creating material, however, negatively affected the quality of the compost. Water content in organic fraction of waste is around 50%. Studies have shown that the concentration of the metals studied depends on the initial content of the material intended for composting. The lead content in the compost depends mainly on the amount of organic fraction of municipal solid waste, and the concentration of Cr and Ni on the percentage of sewage sludge composed biomass.