Actualities Investigation And Experimental Study On Treatment For Railway Oily Wastewater

Oily wastewater is very difficult to treat with. It comes from many sources, very harmful, and has very complex components, after oily wastewater goes into water, the Ecology and the Environment will be influenced, so we should pay attention to the oily wastewater treatment. This article is based on the research of the actuality railway oily wastewater, focused on water quality of the railway oily wastewater, proposed the treatment technology and the treatment parameters of the railway oily wastewater.This experiment includes Single experiment and the process simulation experiment, and many different water Quality factors have been used within this experiment, they are: chemical oxygen demand(COD), content of oil, turbidity, pH, LAS, Pb, water temperature, absorbance and etc. Railway oily wastewater has been used as the experiment water. For the single experiment part, we adjust the each technology factor and setup, to study the influence of each factor to the de-oiling rate within this technology, and to make sure the best factor combinations and the operation requirement, then to provide the credible design basis for the large-scaled productive treatment design.After detecting the water sample, which we have collected, we have got the railway oily wastewater quality data, pollutants changing ranges are:petroleum:1.898-25.020mg/L; COD: 20.61-415.70mg/L; LAS:3.273-176.000μg; pH 6.73-7.66; turbidity:2.1-82.8NTU; water temperature does not change a lot, all around 20℃; Pb cannot be found after the water simple been delivered to the laboratory.This technology is mainly studying on the precipitation, coagulation, air flotation and filtration. The precipitation experiment result shows that, standing time would influence the separation. Except pH, rest removal rates all raises when the standing time extends. Through the beaker experiment and the coagulant compatibility experiment, we have determined the iron trichloride and the PAC Combination will be the coagulant. We have operated the process simulation experiment based on the research of Coagulation orthogonal experiment, air flotation orthogonal experiment, and the filtration experiment, we have determined the operation requirement for this technology to treat the oily wastewater should be:coagulant concentration:15mg/L; PH:7;fast stirring rate:140r/min; fast stirring time:25s; slow stirring rate:30r/min; slow stirring time:2.5min. For the Flotation treatment, Aeration rate selection should be 10.6L/h, aeration time should be 20 min. considering the convenience of using, and the aeration Mode has been chosed as 2 tubes aeration. Anthracite has been chosed as the filter media within the filtration; it reached the good removal effect under this condition after the operation, and also decreased the operation fee. The wastewater after the treatment, petroleum, COD and the turbidity all reaches the request of《Integrated Wastewater Discharge Standard》(GB8978-1996) first degree discharge standard, and the《Railway Reclaimed Water》(TB/T3007-2000). It has a very food removal Result, but does not have a good removal rate of the LAS.