Analysis and treatment of biowaste compost leachate : diploma thesis

Kompostiranje je prepoznato kao ekološki prihvatljiv način zbrinjavanja biorazgradljivog otpada njegovim prevođenjem u kompost. Pri tome nastaju i procjedne vode koje mogu sadržavati različite opasne tvari s negativnim utjecajem na okoliš. Stoga je potrebna obrada procjedne vode prije ispuštanja u prirodni recipijent. U ovom radu praćena je količina i sastav procjedne vode nastale tijekom procesa kompostiranja biootpada u rotacijskom komposteru valjkastog oblika (zatvoreni sustav) i otvorenoj posudi (otvoreni sustav). U procjednim vodama praćeni su pH, električna vodljivost, mutnoća, KPK, BPK te dušik po Kjeldahlu. Rezultati su pokazali da su procjedne vode karakterizirane visokim organskim opterećenjem, visokom koncentracijom amonijaka, niskim pH, visokom provodnošću i mutnoćom, a nastale količine pokazuju izraziti opadajući trend. U cilju obrade otpadne vode nastale tijekom kompostiranja biootpada, simulirana je procjedna voda iz kompostne mase uzorkovanenakon 21. dana kompostiranja. Simulirana procjedna voda obrađena je postupkom koagulacije i elektrokoagulacije, bez i s dodatkom zeolita. Učinkovitost postupaka obrade praćena je preko parametara pH, električne vodljivosti, mutnoće, KPK te dušika po Kjeldahlu. Također je praćena potrošnja aluminijevih elektroda tijekom elektrokoagulacije s i bez dodatka zeolita. Provedena je analiza operativnih troškova postupka elektrokoagulacije (utrošak električne energije, materijala elektroda te zeolita).Composting has been recognized as an environmentally friendly way of disposing of biodegradable waste by converting it into compost. Composting process also produce the leachate that contain various hazardous substances with a negative impact on the environment. Therefore, leachate treatment is required before discharge into the natural recipient. In this paper, the amount and composition of leachate generated during the biowaste composting process in a cylindrical rotary composter (closed system) and an open container (open system) were monitored. pH, electrical conductivity, turbidity, COD and Kjeldahl nitrogen were monitored in the leachate. The results showed that leachates are characterized with high organic load, high ammonia concentration, low pH, high conductivity and turbidity, while the resulting leachate amounts showing decreasing trend. In order to treat wastewater generated during composting of biowaste, leachate was simulated from the compost mass sampled on the 21st day of composting. The simulated leachate was treated by coagulation and electrocoagulation, without and with the addition of zeolite. The efficiency of the treatment process was monitored through the parameters of pH, electrical conductivity, turbidity, COD and Kjeldahl nitrogen. Consumption of aluminum electrodes during electrocoagulation with and without the addition of zeolite was also monitored. An analysis of the operating costs of the electrocoagulation procedure (consumption of electricity, electrode material and zeolite) was performed