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Abstract

Lead contaminated soil bioremediation using microbial consortium has been conducted on laboratorioum scale. Four types of lead accumulating bacteria, PG 65-06 (A): PG 97-02 (B): MR 1.12-05 (C) and A1 (D) with a ratio of 1:1:1:1 is used as microbial consortium. The study was conducted in 60 days with microbial inoculum variation of 5%, 10%, 15% (v/w) and the addition of 5% microbial inoculum with rice straw as bulking agents. Observations were conducted every 10 days which concentration of Pb, microbial activity, physico-chemical properties of soil before and after bioremediation as parameters. The addition of microbial consortium was proficient to remediate lead contaminated soil with a higher rate than the addition of 5% microbial inoculum with rice straw, which characterized by decreasing concentrations of soluble-exchangeable lead into residuals lead. The optimal condition occured in 40 days of incubation for addition of microbial inoculum 10% (v/w), and 50 days incubations for addition of 5% microbial inoculum with rice straw. The additions of rice straw enhanced indigenous microbial activity indicated by increasing quantity of soil microbes and CO2 production compared to addition of microbial inoculum. Characteristics of contaminated soil that has been remediated by microbes’ consortium improved because the content of the soil macronutrients and micronutrients in remediated soil was better than previous.

Key words : bioremediation, lead, microbes consortium, deinking

ABSTRAK

Bioremediasi tanah yang terkontaminasi timbal (Pb) menggunakan konsorsium mikroba telah dilakukan pada skala laboratorium. Empat jenis bakteri pengakumulasi Pb, PG 65-06 (A): PG 97-02 (B): MR 1.12-05 (C) dan A1 (D) dengan perbandingan 1:1:1:1 digunakan sebagai konsorsium mikroba. Penelitian dilakukan selama 60 hari dengan variasi penambahan inokulum mikroba 5%, 10%, 15% (v/w) dan penambahan inokulum 5%+ jerami padi sebagai bulking agents. Pengamatan dilakukan setiap 10 hari sekali dengan parameter konsentrasi logam Pb, aktivitas mikroba tanah, serta analisis sifat fisika-kimia tanah pada awal dan akhir proses bioremediasi. Penambahan konsorsium mikroba dapat mempercepat proses remediasi logam Pb pada tanah terkontaminasi dibandingkan dengan konsorsium mikroba 5%+jerami, yang ditandai dengan menurunnya konsentrasi logam Pb dari fase tertukarkan menjadi fase residual. Perubahan fase tersebut optimal pada waktu inkubasi 40 hari pada penambahan inokulum 10% (v/w) dan pada waktu inkubasi 50 hari pada penambahan mikroba 5%+jerami.  Penambahan jerami meningkatkan aktivitas mikroba indigenous yang ditunjukkan dengan meningkatnya jumlah mikroba tanah dan produksi CO2 yang dihasilkan dibandingkan penambahan inokulum mikroba. Karakteristik tanah terkontaminasi yang telah diremediasi oleh konsorsium mikroba menjadi lebih baik karena kandungan unsur hara tanah baik makro maupun mikro meningkat dibandingkan sebelum diremediasi.

Kata kunci : bioremediasi, Pb, konsorsium mikroba, deinking