Аннотация:During the storage and/or transportation of fecal sludge (FS), it is treated with biocides, such as quaternary ammonium compounds and biguanide derivatives, to control microbial activity and unpleasant odors. These biocides are very effective, which, however, have drawbacks in the disposal of biocide-treated FS, such as toxicity to activated sludge in biological wastewater treatment plants. In this work, the feasibility of using biocides naturally degradable in alkaline medium for more environmentally friendly management of FS was evaluated. The original strategy was based on alkalinization of the medium due to gradual decomposition of urea in FS. The four selected biocides were shown to effectively control microbial activity and degrade after biocidal function, allowing such biocide-treated FS to be disposed of in wastewater treatment plants in an environmentally sound manner without harming the activated sludge.