Hydraulic Behavior and Copper Ions Treatment for Flow Over Modified Gabion Stepped Weir

Abstract

In this research; attempt to modify the traditional gabion stepped weir (TGSW) was investigated. Gravel was replaced by new available locally and inexpensive media which is Porcelnite and lime stone. The efficiency of dissipating flow energy, classify the flow types and its efficiency in removal copper (Cu) from simulated wastewater. Six of different discharges values were carried out for investigate hydraulics behavior, water surface profile, the energy dissipation for modified gabion stepped weir (MGSW) and TGSW. Three flow rates (2.5, 5 and 15) L/m is chosen for testing the weir efficiency in removal of Cu with initial concentration of 3 mg/L. The results showed the maximum energy dissipation occurred with lime stone (MGSW), for small (nappe) and high (transition) flow rates, whereas the increase of relative energy dissipation (R.E.D) at high flow rate (Q=18 L/m)  equal 26.35 % compared with flat sloped weirs, 16.35 % compared with stepped weir without any addition and 10% more than (TGSW), While the R.E.D of porcelnite rock was low and equal to 10 % at high flow rates (transition flow). For environmental result show porcelnite rocks (MGSW) has a good ability for removing of copper metal (Cu), whereas the removal efficiency was 90% at initial of system operating and 58% after 6 hours from operating, while the gravel media (TGSW) was inefficiency for removal of (Cu) even for low flow rates whereas (RE% = 23.59, 15.56 and 10.13 %) at three flow rates respectively.

Keywords: energy dissipation, modified gabion, stepped weir, Porcelenite, lime stone removal efficiency, copper ions.