Penilaian keberadaan logam berat Cu dan Zn pada area pertanian bawang merah (Allium Ascalonicum) di Desa Srigading, Kecamatan Sanden, Kabupaten Bantul, Provinsi DIY

SHOLIKHAH, Umi Nur, Dr.Eko Sugiharto

2010 | Tesis | S2 Ilmu Kimia

Keberadaan Cu dan Zn dalam sampel air, tanah, dan tanaman telah dipelajari di Desa Srigading, Kecamatan Sanden, Kabupaten Bantul, Propinsi DIY. Penentuan titik sampel secara komposit pada lahan pertanian. Pengambilan sampel dilakukan sebanyak 3 kali yaitu awal tanam (A), saat tanam (B) dan akhir tanam (C).Pengukuran pH dan Daya Hantar Listrik (DHL) sampel air dilakukan secara in situ selanjutnya sampel diawetkan dengan HNO3 5N dan dianalisis menggunakan AAS. Sampel tanah dan sampel tanaman yaitu bawang merah dan sawi (pembanding) diambil, diekstrak menggunakan metode ekstraksi campuran asam dan dianalisis kandungan logam beratnya menggunakan AAS. Sampel tanah yang diambil pada kedalaman 30 cm dikarakterisasi meliputi pH, DHL, tekstur, bahan organik, C-organik, N-total, P-HCl 25%, K-HCl 25%, P-Olsen, KTK, dan kadar air.Sebagai data pendukung, dilakukan análisis sampel pupuk.Hasil analisis tekstur tanah menunjukkan sebagian besar tanah di lokasi sampling mempunyai kadar lempung, bahan organik dan KTK yang relatif tinggi.Ketiga faktor tersebut berpengaruh terhadap keberadaan logam berat di tanah.Mayoritas logam berat Cu dan Zn ditemukan pada sampel tanah sebagai polutan keras (4,0600 hingga 4,8967) dan sedang (3,1125 hingga 3,4442). Keberadaan logam Cu dan Zn dipengaruhi oleh penggunaan pupuk maupun obat-obatan dimana kedua bahan tersebut mengandung logam berat Cu dan Zn. Logam Cu dan Zn bersifat kompetisi baik dalam sampel air, tanah maupun tanaman sehingga kecenderungan logam yang mendominasi berbeda pada ketiga sampel tersebut. Hasil pemetaan menggunakan GIS (Geographical Information System) menunjukkan pola sebaran logam berat Cu dan Zn dipengaruhi oleh konsentrasi logam, semakin tinggi konsentrasi logam maka semakin luas penyebarannya.

Appraising availability Cu and Zn metals in water, soil and plant have been studied at Srigading Village, Sanden District, Bantul Regency, DIY Province. Sampling points were determined by composite method. Samples were collected 3 times, they were in the beginning, middle and after of plantation period. The measurement of pH and electric conductivity in water samples were done by in situ then preserved by adding HNO3 5N. Water samples were analyzed using AAS in the laboratory. Soil, onion and mustard (as comparator) were extracted with a mix of acids and analyzed by AAS. Soil samples were taken 30 cm, below the surface and characteristics such as pH, electric conductivity (EC), texture, organic matter, C-organic, N total, P-HCl 25%, K-HCl 25%, P-Olsen, Cation Exchange Capacity (CEC) and water content were determined. In order to support heavy metal availability, fertilizers were also analyzed.The results show that most of the soil have high amount of clay, organic matter and CEC which influences heavy metal availability in soil. Large amount of heavy metal Cu and Zn were found in the soil sample as hard pollutant (4,0600 - 4,8967) and midlle pollutants (3,1125 -3,4442). The existence of Cu and Zn were influenced by the use of fertilizers or other chemicals such as plant growth which has already contained the heavy metal. Heavy metal Cu and Zn acts competitively against each other either in water, soil or plant so the tendency of metals to dominate is different in those three samples. Mapping by GIS showed that Cu and Zn metals distribution was depend on their concentration and the higher concentration will increase the spreading area

Kata Kunci : Tembaga (Cu), Seng (Zn), Copper (Cu), Zinc (Zn)