Method for ecologic configuration of oil production high-salt wastewater artificial wetland to realize up-to-standard operation in winter

A method for ecologic configuration of an oil production high-salt wastewater artificial wetland to realize up-to-standard operation in winter, the method comprising:

• (1) performing pretreatment reaction on oil production wastewater through one or a mixture of more than two of NaOH, Na2CO3, CaO, Ca(OH)2, NH3.H2O, polyaluminium chloride (PAC) and polyacrylamide (PAM) according to a weight ratio of (5 to 10):1 for 2 to 4 h, then introducing the wastewater into a sedimentation tank or an air floatation tank for treatment for 1 to 10 h, removing sludge, and regulating a pH value of outlet water to 6 to 8 to prepare pretreated outlet water with the water quality of COD being 150 to 300 mg/L, a suspended matter content being 30 to 50 mg/L and a petroleum content being 10 to 20 mg/L;
• (2) introducing the pretreated outlet water prepared in the step (1) into an oxidation pond for a hydraulic retention time of 3 to 21 days to prepare oxidation pond outlet water with the water quality of COD being 100 to 150 mg/L, a suspended matter content being 20 to 30 mg/L and a petroleum content being 1 to 10 mg/L;
• a reflux pump station is disposed at an oxidation pond water outlet, partial oxidation pond outlet water can be refluxed to an oxidation pond water inlet, and a reflux ratio is 20% to 50%;
• (3) introducing the oxidation pond outlet water prepared in the step (2) into a subsurface flow artificial wetland for a hydraulic retention time of 0.5 to 2 days to prepare subsurface flow artificial wetland outlet water with the water quality of COD being 60 to 100 mg/L, a suspended matter content being 10 to 20 mg/L and a petroleum content being 1 to 5 mg/L;
• and
• (4) introducing the subsurface flow artificial wetland outlet water prepared in the step (3) into a surface flow artificial wetland for a hydraulic retention time of 20 to 30 days at a hydraulic load of at most 0.5 m/d to prepare surface flow artificial wetland outlet water with the water quality of COD being 40 to 50 mg/L, a suspended matter content being 10 to 20 mg/L, a petroleum content being 0.01 to 3 mg/L and a mineralization degree being 15000 to 24000 mg/L;
• wherein
• in the step (3), the subsurface flow artificial wetland is composed of a soil matrix, a water distribution pipe disposed on a bottom of the soil matrix, wrapped with water-permeable nonwoven cloth and configured to deliver the wastewater, and reeds with root systems growing on an inner side of a wall of the water distribution pipe, stems growing on outer side of the wall of the water distribution pipe and a length being greater than a thickness of the soil matrix, and a structure of the subsurface flow artificial wetland is as shown in FIG. 1, wherein the oxidation pond outlet water prepared in the step (2) only flows through the water distribution pipe, a wastewater purification unit is defined in the water distribution pipe, and a distance from the water distribution pipe to a ground surface is 50 to 100 cm;
• and
• in the step (4), the surface flow artificial wetland is composed of a soil matrix, reeds growing on the matrix, water, winter aquatic salt-resistant cold-liking plants, block-stocked fishes, shrimps, crabs, mussels, Mytilus edulis, oysters or clams and an artificial sand dam, and a structure of the surface flow artificial wetland is as shown in FIG. 2, wherein the fishes, the shrimps and the crabs are cultured in a mixed-stocked way, and the mussels, the Mytilus edulis, the oysters or the clams are cultured in a floating body seedling rope hanging or artificial sand dam stocked way.