Biostabilization of Tannery Sludge Compost by Vermicomposting

Authors : Yiğit KAMAN, Nur OKUR, Hüseyin Hüsnü KAYIKÇIOĞLU

Pages : 473-480

Doi:10.15832/ankutbd.912938

View : 21 | Download : 8

Publication Date : 2022-09-05

Article Type : Research Paper

Abstract :The aim of this study is to investigate the stabilization of tannery sludge compost mixed with cattle manure at the different ratios by employing an epigeic earthworm Eisenia foetida and bioaccumulation of Cr in tannery sludge by earthworms. Organic cattle manure insert ignore into journalissuearticles values(M); and sludge compost insert ignore into journalissuearticles values(S); were mixed in certain proportions, moistened and Eisenia foetida worms were added. Mixing ratios were as follows: 100% M insert ignore into journalissuearticles values(M100S0);, 70% M + 30% S insert ignore into journalissuearticles values(M70S30);, 50% M + 50% S insert ignore into journalissuearticles values(M50S50); and 30% M + 70% S insert ignore into journalissuearticles values(M30S70);. The experiment was carried out at a constant temperature of 24 oC and in a dark environment according to a randomized plot design with three replicates. The experiment ended after 120 days and the following parameters were evaluated in vermicomposts: pH, electrical conductivity insert ignore into journalissuearticles values(EC);, total nitrogen insert ignore into journalissuearticles values(TN);, total organic carbon insert ignore into journalissuearticles values(TOC);, C:N ratio, and total macro and micro elements. In addition, it was determined total Cr, Cr insert ignore into journalissuearticles values(VI); in vermicomposts and total Cr in E. foetida body. The results for TOC, C:N ratio and total Cr showed decreases in their values at the end of the vermicomposting process, whereas values for pH, EC, TON, Ca, and Mg increase, indicating that the vermicomposting reached the maturity level. All values of Cr insert ignore into journalissuearticles values(VI); of vermicomposts were below the detectable level. During the vermicomposting process, the reduction rates of the total Cr amounts were 96% insert ignore into journalissuearticles values(M70S30);, 96% insert ignore into journalissuearticles values(M50S50); and 30% insert ignore into journalissuearticles values(M30S70);, respectively. While the highest total Cr amount in the earthworm body was determined in M30S70 treatment, the amount of this element in the earthworm body decreased due to the decreasing doses of tannery sludge compost. These results show that E. foetida can bioacumulate the chromium in tannery sludge compost. As a result, it was determined that vermicomposting can be an alternate technology for the recycling and environmentally safe disposal/management of tannery sludge compost using an epigeic earthworm E. foetida.
Keywords : Chemical properities, Eisenia foetida, Tannery sludge compost, total chromium, vermicomposting