Study On Experimentation Of The Gas-field Wastewater Treatment By Electrocoagulation-floatation

The gas-field wastwater,which is one kind of stratum water, is exploited along with the production of natural gas.It will cause environmental problems such as soil hardening and ground water contamination if not treated properly.At present, there are three gas-field water treatment methods: discharging, reinjecting, and reusing.The electrocoagulation-floatation process is a new technique in water and wastewater treatment. This process has been successfully used to remove organic from food wastewater,printing and dyeing wastewater,oil-Wastewater,kitchen wastewater,kitchen kastewater and so on. The basic principles are:iron electrodes sacrifice themselves to form hydroxide of iron and its multi-hydroxyl polymer by electrolysis which have the coagulation to the colloid and the suspension solid in the wasterwater.Meanwhile, tiny H2 and O2 bubbles generated in electrolysis help to float the floc that adsorpt the pollutant, leading to effective pollutant removal from wastewater. Involves four typical function mechanisms:electrolysis coagulation,electrolysis flotation,electrolysis oxidation and electrolysis deoxidization.The electrocoagulation-floatation process is characterized by compact equipment, simple operation, and low operating cost.The electrocoagulation-floatation for oily gas-field wastewater was studied with the reactor designed by myself. The study on the oil and COD removal efficiency of the simulated and practical gas-field wastewater by electrocoagulation and coagulation-electroflotation were carried out on the iron and stainless steel electrodes, respectively. The factors affecting the removal efficiency were analysed with orthogonal test and other methods. The conclusions are as follows:The key factors affecting the pollutant removal efficiency during the electrocoagulation-floatation process are as follows: current density>electroflotation time> pH value.The optimum operating condition was as follows: the current density was 3.7mA/m2, the pH value was 7, and the time was 30min.At this condition, the removal efficiency of oil,CODcr and SS reached 82.1%,80.7%,79.4%,respectively.Energy consumption of the experiment was 3.75 kWh/m3.In addition, studied and discussed the main factors of chromium wastewater treatment by electrocoagulation-floatation technology.In the condition of laboratory,the energy consumption of the experiment was 1.33 kWh/m3...