Identifikasi Pencemaran Airtanah Bebas Menggunakan Geolistrik di Lokasi Sekitar Industri Penyamakan Kulit

Abstract

Identifikasi pencemaran airtanah pada limbah cair penyamakan kulit dapat dilakukan dengan metode geolistrik karena limbah cair industri penyamakan kulit mengandung unsur logam berat krom yang berpengaruh terhadap nilai Daya Hantar Listrik (DHL) dan nilai tahanan jenis airtanah. Penelitian ini dilakukan di sebagian Desa Sitimulyo, Piyungan, Bantul. Oleh karena itu tujuan dari penelitian ini adalah 1) memetakan pencemaran airtanah oleh limbah cair industri penyamakan kulit berdasarkan persebaran nilai DHL dan 2) mengidentifikasi pencemaran airtanah oleh limbah cair di sekitar kawasan industri penyamakan kulit berdasarkan nilai tahanan jenis. Metode penelitian ini menggunakan pengukuran tinggi muka airtanah dan DHL sebanyak 36 titik sumur, pendugaan geolistrik metode Electrical Resistivity Tomography (ERT) sebanyak 3 lintasan dengan kedalaman sebesar 11,8 m-15,9m serta uji kandungan krom pada air limbah cair dan airtanah sebanyak 10 sampel air. Uji kandungan krom pada air limbah cair dan airtanah digunakan sebagai validasi data. Hasil penelitian menunjukkan bahwa telah terjadi pencemaran airtanah bebas di sekitar kawasan industri penyamakan kulit dan disekitar saluran drainase yang tidak kedap air. Hal ini dikarenakan nilai DHL airtanah sebesar >900 µmhos/cm, nilai tahanan jenis airtanah <10 Ωmeter, dan kandungan krom pada sampe air >0,05mg/L. Pencemaran airtana di titik geolistrik 1 (G1) teridentifikasi pada kedalaman 5 meter dengan nilai tahanan jenis antara 3,30-9,16 Ωmeter. Hal ini dikonfirmasi dengan nilai DHL pada sumur terdekat G1 memiliki nilai DHL sebesar 1613 µmhos/cm. Pada titik geolistrik 2 (G2), pencemaran airtanah teridentifikasi pada kedalaman 7 meter dengan nilai tahanan jenis 3,05-7,81 Ωmeter. Nilai DHL sumur terdekat dengan titik G2 adalah sebesar 1516 µmhos/cm. Selanjutnya di titik geolistrik 3 (G3), pencemaran airtanah teridentifikasi pada kedalaman 3,73 meter dengan nilai tahanan jenis 1,33-8,61 Ωmeter dengan nilai DHL sumur terdekat 1144 µmhos/cm. Identification of groundwater contamination in leather tanning liquid waste can be carried out by using the geoelectric method because the tannery industrial liquid waste contains heavy metal elements chromium which affect the value of electrical conductivity (DHL) and the value of groundwater resistivity. This research was conducted in a part of Sitimulyo Village, Piyungan, Bantul. Therefore, the objectives of this study are 1) to map the groundwater pollution by the tannery industrial liquid waste based on the distribution of the value of DHL and 2) to identify groundwater contamination by liquid waste around the tannery industrial area based on the resistivity value. This research method uses groundwater level measurements and DHL as many as 36 well points, geoelectric estimation of the Electrical Resistivity Tomography (ERT) method for 3 passes with a depth of 11.8 m-15.9m and a test of the chromium content in liquid wastewater and groundwater as much as 10 water sample. The chromium content test in wastewater and groundwater was used as data validation. The results showed that there has been contamination of unconfined groundwater around the tannery industrial area and around non-waterproof drainage channels. This is because the groundwater DHL value is> 500 µmhos / cm, the groundwater resistivity value is <10 Ωmeter, and the chromium content of the water sample is> 0.05mg / L. Water pollution at geoelectric point 1 (G1) was identified at a depth of 5 meters with a resistivity value between 3.30-9.16 Ωmeter. This is confirmed by the DHL value of the nearest well G1 which has a DHL value of 1613 µmhos / cm. At geoelectric point 2 (G2), groundwater contamination is identified at a depth of 7 meters with a resistivity value of 3.05-7.81 Ωmeter. The DHL value of the well closest to point G2 is 1516 µmhos / cm. Furthermore, at geoelectric point 3 (G3), groundwater contamination was identified at a depth of 3.73 meters with a resistivity value of 1.33-8.61 Ωmeter with the nearest well's DHL value of 1144 µmhos / cm.

Study of Industrial Liquid Waste Pollution Using Geoelectrical Method in Sukaregang, Garut, West Java

“…The error percentage on the SR-3 line is 7.8% with 25 iterations. Based on the rock resistivity table, the condition of soil and contaminated with liquid waste is characterized by a layer that has a low resistivity, which is between 1.33-8.61 m [17]. This is because industrial wastewater often contains dissolved metal elements that have high conductivity/electrolyte properties.…”

“…Areas polluted by industrial waste will usually contain metals from waste chemicals, which will cause the conductivity value to be higher or the resistivity to be lower. Therefore the polluted area (soil/ aquifer) will have a low resistivity value, which is around 1-20 m [15,16], and or around 1.33-8.61 m [17].…”

Groundwater and surface water interaction in the downstream part of Luk Ulo River, Kebumen Regency, Central Java Province, Indonesia

“…Figure 2. Groundwater level measurement (Wibowo, 2021) The Geographic Information System (GIS) method builds groundwater flow nets (flownets). The Flow nets are the most potent analytical tools hydrologists use to analyze groundwater (Fetter, 1988).…”

“…The division of contours and direction of groundwater flow is used to identify the relationship of groundwater to surface water (Luk Ulo River) (Figure 5.). In addition, the direction of groundwater flow can also be used to identify wells whose groundwater has been polluted and the source of pollution (Wibowo, 2021). The results obtained that in the north, the groundwater level (TMA) is 27-13 masl, while in the southern part, the TMA is 23-11 masl.…”