THE REDUCTION OF Cr(VI) IN SOIL BY Microbacterium sp. STRAIN SpR3 IN VERMICOMPOST CARRIER

Reduksi Cr(VI) pada Tanah Menggunakan Microbacterium sp. Strain SpR3 dengan Bahan Pembawa Vermikompos Kromium hexavalen [Cr(VI)] adalah polutan yang berasal dari kegiatan industri. Microbacterium sp. strain SpR3 dapat digunakan sebagai agen bioremediasi Cr(VI). Kemampuan agen biologi untuk mereduksi Cr(VI) umumnya meningkat bila diinokulasi dalam media pembawa. Tujuan penelitian ini adalah untuk menganalisis kemampuan Microbacterium sp. strain SpR3 dalam mengurangi Cr(VI) serta membandingkannya dengan kondisi ketika diinokulasi dalam media pembawa vermikompos. Pengamatan dilakukan selama tujuh hari pada tiga perlakuan yang berbeda, yakni Microbacterium sp. strain SpR3 dengan dan tanpa media pembawa vermikompos yang diinokulasi pada tanah steril yang mengandung 50 ppm Cr(VI), dan tanah steril tanpa inokulasi bakteri yang mengandung 50 ppm Cr(VI). Variabel yang diamati adalah jumlah bakteri, konsentrasi, dan kecepatan reduksi Cr(VI) oleh bakteri tersebut di dalam tanah pada T0 (hari ke-0) dan T7 (hari ke-7). Hasil penelitian ini menyimpulkan bahwa vermikompos bisa digunakan sebagai media pembawa Microbacterium sp. strain SpR3 karena dapat meningkatkan jumlah bakteri sampai 2 × 1010 CFU g-1 di dalam tanah dan dapat mengurangi Cr(VI) dengan kecepatan 0,095 mg L-1 jam-1. Hexavalent chromium [Cr(VI)] is a pollutant originated from industrial activities. Microbacterium sp. strain SpR3 can be used as Cr(VI) bioremediation agent. The ability of bioagent to reduce Cr(VI) usually improves when inoculated in a carrier. This research aimed to assess the ability of Microbacterium sp. strain SpR3 to reduce Cr(VI) in soil and compare its ability when inoculated in vermicompost carrier. Observations were carried out for seven days on three different treatments, namely Microbacterium sp. strain SpR3 with and without vermicompost inoculated in sterile soils containing 50 ppm Cr(VI), and sterile soils containing 50 ppm Cr(VI) without bacterial inoculation. The observed variables were the number of bacteria, the concentration of Cr(VI) and the rate of Cr(VI) reduction by these bacteria in the soil at T0 (day 0) and T7 (day 7). It was concluded that vermicompost could be used as a carrier of Microbacterium sp. strain SpR3 as it could increase the number of the bacteria to 2 × 1010 CFU g-1 in soil and could reduce Cr(VI) at the rate of 0.095 mg L-1 h-1.

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Magnetite nanoparticles for reduction of hexavalent chrome in soil of an industrial park, Cerro Colorado - Arequipa [Nanopartículas de magnetita para reducción de cromo hexavalente en suelo de un parque industrial, Cerro Colorado – Arequipa]

Journal of Nanotechnology ◽

10.32829/nanoj.v3i1.101 ◽

2019 ◽

Vol 3 (1) ◽

pp. 12

Author(s):

Mardelly Ruiz Marcelo ◽

Cecilia Cermeño Castromonte ◽

Elmer Benites Alfaro

Keyword(s):

Hexavalent Chromium ◽

Magnetite Nanoparticles ◽

Soil Samples ◽

Industrial Park ◽

Industrial Activities ◽

Chromium Vi ◽

Hexavalent Chrome ◽

Cerro Colorado

One of the most important contamination problems in receiving bodies due to industrial activities is the presence of chromium (VI). One way to reduce the aggressiveness of said contaminant is its reduction to the form of chromium (III). The investigation determined the efficiency of magnetite nanoparticles in the treatment of soil contaminating with chromium (VI), to reduce it to chromium (III) of an Industrial Park at the district Cerro Colorado, province and department of Arequipa.22 samples of 1 kg of soil were taken, then homogenized according to the extraction distances, considering at the end only 3 samples called “Shore”, “6 Meters” and “9 Meters”, whose concentrations were: 146 mg / kg, 126 mg / kg and 67 mg / kg of Cr (VI) respectively. These samples were subjected to 3 treatments (T1, T2 and T3) with 3 repetitions each using 15, 30 and 45 grams doses of Magnetite nanoparticles for three weeks. At the end of the treatment using the EPA 3060 method, the Chrome (VI) analysis was performed. The 3 treatments “T1”, “T2” and “T3”, had significant differences for the final concentrations of Hexavalent Chromium in the soil; but it was in Treatment 3 in the soil samples "Shore", "6 Meters" and "9 Meters", where a greater effect was achieved in the reduction of Cr (VI) to Chromium (III) with an efficiency of 99.96%, 99.93% and 99.93% respectively, 45 grams of magnetite nanoparticles were used for this treatment.

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