VULNERABILITY OF GROUNDWATER CONTAMINATION BY MODIFIED SIMPLE VERTICAL VULNERABILITY (SVV): A CASE STUDY OF COPPER CONTAMINATION IN MANTRIJERON DISTRICT, YOGYAKARTA CITY, INDONESIA

• Main Authors: , PHETNAKHONE XAIXONGDETH, , Prof. Dr. Dwikorita Karnawati, M.Sc., Ph.D.
• Format: Theses and Dissertations NonPeerReviewed
• Published: [Yogyakarta] : Universitas Gadjah Mada 2014
• Subjects: ETD
• Online Access: https://repository.ugm.ac.id/126884/; http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=67121
• Institution: Universitas Gadjah Mada

Batik home industry occurs wide spread in Yogyakarta City, which produce a large amount of waste water with contain high contaminant such as copper (Cu). Although Cu is an essential element for daily consumption, when Cu becomes abundant in soil side effects can occur. Hence, groundwater vulnerability for Cu must be applied in order to screen the sensitivity of an aquifer to being adversely. In previous study, it was reported that only few methods can assess specific groundwater. However, there is no report on the relationship between groundwater vulnerability and chemical reaction factor for Cu. Therefore, new chemical reaction factor was created to modify simple vertical vulnerability (SVV) method for Cu. In this context, the objective of this study is to modified SVV method by chemical reaction factor that related to Cu sorption capacity of unsaturated soil. The sorption capacity of the unsaturated soil for Cu is evaluated by using batch experiments. In addition, XRD, XRF and chemical extraction, and sequential extraction experiments were determined mineralogy, chemical composition and the dominant form of Cu in the soils. Using data from sequential extraction experiments, geochemical modeling could figure out distribution of Cu in the study area. XRF, chemical extraction and sequential extraction results show that plagioclase feldspar is main mineral contain in every soil type at the study area with small amount of kaolinite and ferrihydrite found in clay fraction. Chemical composition is dominant by SiO2, Al2O3, CaO, and Fe2O average concentration are 56.30 wt.%, 21.60 wt.%, 8.03wt.%, and 6.99 wt. % respectively. The sequential extraction determined the dominant form of Cu in the soil as (1)soluble ion, (2) exchangeable, (3) bound to amorphous, poor crystalline iron and aluminum minerals, (4) bound to iron minerals, or (5) bound to clay mineral. The Cu sorption is mainly influenced by iron amorphous phase and Cu concentration detected in this phase is 65-86.4%. The batch experiments were performed for four types of soil using artificial Cu solution (0.01, 0.1, 1, and 10 mmol/L), with same adsorbent of 10g/L. The result showed that the lower the initial concentration of Cu solution, the better the Cu adsorption capacity. The solution of 0.01mmol/L has the best adsorption capacity with 98-99%.The sorption capacity of soil in the study area is related to ferrihydrite and kaolinite content in clay fraction. The higher the clay fraction content, the higher the Cu sorption capacity. The high clay fraction content is observed in loamy fine sand (6.61%) and fine sandy loam (4.69%), while lower clay content characterizes in sandy loam (2.78%) and sand (1.89%). Surface complexation model were performed by using ferrihydrite and kaolinite content in clay fraction based on the results of XRF, chemical extraction, sequential extraction and batch sorption experiments. Moreover, the input data was based on secondary data and duplicated from batch sorption experiment condition. The result shows that Cu adsorption to ferrihydrite is higher than kaolinite, about 200 times in low initial concentration (Cu 0.01 mmol) and 6-9 times in high initial concentration (Cu 0.1 and 1mmol). This modeling result agrees with the result of sequential extraction, indicating the sorption capacity was affected by both ferrihydrite and kaolinite in clay fraction, however ferrihydrite is main mineral for Cu sorption. Based on the result of sequential extraction, batch sorption experiment and geochemical modeling, the chemical reaction factor was assigned base on clay fraction because ferrihydrite and kaolinite is main component of clay fraction. Moreover, the SVV_Cu method derived by combine chemical reaction factor with soil parameter. The result of SVV_Cu method show that the study area is moderate, low and very low groundwater vulnerability, this indicates that groundwater at the study area is moderate, high and very high protection. At site condition, the groundwater quality, Cu is low concentration which refers to good protection. This result agrees with SVV_Cu method that the study area has high protection of groundwater, indicating SVV_Cu method is appropriate for Cu.