The performance of tuna fishbone waste as carbon to remove iron (Fe) metal from well water was studied. The parameters of carbon synthesis were set by varying the carbonization temperature of 300, 400, and 500°C. Fishbone carbon was characterized using Scanning Electron Microscopy (SEM-EDX), X-ray Diffraction (XRD), and SSA (nitrogen adsorption). The BET and (BJH) analysis showed that the increase in carbon surface area and pore size was proportional to the increase in carbonization temperature. Fishbone carbon was used as a filtration medium to reduce high levels of iron metal in well water. Samples were taken from wells belonging to residents in Bandar Setia, Medan Tembung. Fishbone carbon was effective as an adsorbent for removing iron metal from well water by the filtration method. The rate of iron removal was 99% for fishbone carbon, carbonized at 400°C.

Potentiometric characteristics are significantly dependent on the composition of the membrane and the properties of the plasticizer. Characterization of membrane electrodes was carried out using (UV-Vis to see absorbance, SEM-EDX to see the morphology and atomic ratio and XRD to see the intensity ratio of u.a). Characterization of PVA membranes: PVC in the composition of 1: 1 ie 0.0350 g PVA and 0.0350 g PVC, plasticizer 0.0100 g KTpClPB with variation of enzyme coating on PVA on 1x, 2x and 3x electrode membranes, followed by each coting 1x 0.0350 g PVC 0.0100 g KTpClPB. The electrode membrane selected was PVA E 1X PVC-KTpClPB 0.0100 g electrode membrane obtained optimum (absorbance, atomic ratio and intensity of u.a).