Deri sanayi arýtma çamurunun kompostlaþtýrýlmasý sýrasýndaki biyokimyasal deðiþiklikler ve oluþan kompostun kalitesi | Biochemical changes during composting of tannery sludge and assessment of compost quality

anglais. Leather processing is an important economic activity in our country whereas a convenient method about the disposal of its waste has not been found yet. Sludge from leather processing contains large concentrations of inorganic nitrogen (N) and N-rich organic residues. Apart from organic material, which releases valuable nutrients for decomposition, tannery sludge may contain chromium (Cr) and pathogens mainly of fecal origin, and toxic organic components, all of which pose a serious threat to the environment. Composting is recognized as one of the most cost-effective and environmentally sound alternatives for organic waste recycling. The aim of this study was to assess the changes in some biochemical properties of tannery sludge during composting and also to reveal agricultural point of view of the appropriateness of mature compost. Tannery sludge was composted for 150 days to achieve mature compost. The compost was analyzed by an electrolytic conductivity (EC) of 6.16 dS m-1, cation exchange capacity of 50.24 meq 100 g-1, a respiration rate of 1.48 mg CO2-C g-1 compost-C day-1, pH 8.5 and C:N ratio 8:1. Total concentration of lead (Pb) was 39.75 mg kg-1 dry compost, chromium (Cr) was 1097.5 mg kg-1 dry compost, cadmium (Cd) was 2.43 mg kg-1 dry compost, cobalt (Co) was 9.88 mg kg-1 dry compost and nickel (Ni) was 23.53 mg kg-1 dry compost. Cr concentration in mature compost was close to threshold value allowed by Soil Pollution Control Regulation (TKKY), but the concentrations of the other heavy metals were under their threshold values. In this study phytotoxic effect exemined by measuring as cress (Lepidium sativum L.) germination in mature compost and no germination was observed. Decrease all of the studied biological parameters during composting indicates that compost has stabilized. But high Cr content, phytotoxic effect, high pH, and EC levels of tannery sludge compost limit its use in agricultural soils.

turc. Ülkemizde deri iþleme önemli bir ekonomik sektör olmasýna karþýn, atýklarýnýn bertarafý konusunda halen geçerli bir yöntem bulunamamýþtýr. Deri sanayi atýk çamurlarý, yüksek miktarlarda azot ve azotça zengin organik materyaller içermektedir. Bu organik maddenin ayrýþmasý sýrasýnda yüksek miktarlarda besin elementinin ortama verilecek olmasýnýn yanýnda deri atýk çamuru, çevre için ciddi bir tehdit oluþturabilecek yüksek miktarlarda krom, fekal orijinli patojenler ve toksik organik bileþikleri de içerebilir. Kompostlama, organik atýklarýn geri kazanýmý için en ekonomik ve çevre dostu bir yaklaþým olarak bilinmektedir. Bu çalýþmanýn amacý; deri sanayi atýk çamurunun kompostlaþtýrýlmasý sýrasýnda meydana gelen bazý biyokimyasal deðiþimleri izlemek ve oluþan olgun kompostun tarýmsal kullanýlabilirliðini ortaya koymaktýr. Olgun kompost elde edebilmek amacýyla deri atýk çamuru 150 günlük kompostlama iþlemine tabi tutulmuþtur. Oluþan kompostun elektriksel iletkenliði (EC) 6,16 dS m-1, katyon deðiþim kapasitesi (KDK) 50,24 me 100 g-1, CO2-oluþumu 1,48 mg CO2-C g-1 gün-1, pH' sý 8,5 ve C:N oraný 8:1 olarak saptanmýþtýr. Toplam aðýr metal konsantrasyonlarýndan ise kurþun (Pb) 39,75 mg kg-1, krom (Cr) 1097,5 mg kg-1, kadmiyum (Cd) 2,43 mg kg-1, kobalt (Co) 9,88 mg kg-1 ve nikel (Ni) 23,53 mg kg-1 düzeylerinde tespit edilmiþtir. Komposttaki Cr miktarý, "Toprak Kirliliðinin Kontrolü Yönetmeliði" nde belirtilen sýnýr deðere yakýn bir konsantrasyona sahip olurken, diðer aðýr metaller sýnýr deðerlerin oldukça altýnda çýkmýþtýr. Fitotoksik etkinin incelendiði olgun kompostta tere (Lepidium sativum L.) tohumlarýnýn çimlenmesi gerçekleþmemiþtir. Kompost oluþum sürecinde incelenen tüm biyolojik parametrelerde azalmanýn gerçekleþmesi, kompostun stabil hale geldiðini göstermektedir. Fakat deri sanayi arýtma çamurundan elde edilen kompostun sýnýr deðere yakýn Cr içeriði, fitotoksik etkisi, yüksek pH ve EC deðerlerinden dolayý tarým alanlarýnda kullanýlmasýnýn sakýncalý olacaðý kanýsýna varýlmýþtýr

3 tables

Summaries (En, Tr)

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