Romanian experience regarding agricultural use of municipal sludgeRomanian experience regarding agricultural use of municipal sludge
This present paper describes one of the Romanian experience regarding agricultural use of municipal sludge resulted from wastewater treatment. The tests were done on 300 ha including lad tests, compatibility with sludge, chemical and biological tests for sludge, rules in use depending on type of crops, land slope and geochemical structure, biological interactions, impact on production etc. The sludge monitoring was conducted on heavy metals, pH (including interactions with soils), humidity (different levels of humidity in sludge distribution), nutrients etc. On the lands were used sewage sludge from the Wastewater Treatment Station (WWTP) Galati, Romania. On sewage sludge and soil were determined a lot of physico-chemical parameters: pH (upH), total organic carbon (TOC) (mg·L-1), N-total (mg·L-1), P-total (mg·L-1), N-NH4 (mg·L-1), N-NO2 (mg·L-1), N-NO3 (mg·L-1), Fe-total (mg·L-1), Cr-total (mg·L-1), Cu (mg·L-1), Zn (mg·L-1), Cd (mg·L-1), Pb (mg·L-1), Ni (mg·L-1). Determination methods were electrometrical methods (pH, C, TSD) with a multiparameter portable HI 9828 HANNA electrodes committed; Spectrophotometric methods with a spectrophotometer Spectroquant NOVA 60 - Merck and specific parameter kits - Merck.
Legal aspects related to Romanian environmental rules are introduced in comparison with other EU countries. There are also some aspects related with public impact of agricultural sludge use as well as the large opinion of land owners after 3 years of experiments in SE regions in Romania.
Keywords: agricultural sludge use, chemical and biological tests, pollutants, sewage sludge.