How to manage separate collection of waste during the rainy season

Generally, there is both oily and non-oily wastewater. In the event of flooding, we have specialized drainage pipes available as a backup! Even when discharged, the water is treated before being released or recycled, so the probability of pollution incidents is relatively low!

We built dikes around the oily wastewater to prevent surface rainwater from flowing into it, directing the rainwater instead into separate clean-water drainage channels. Additionally, we sealed the small openings in the oily wastewater wells to stop rainwater from entering. This greatly reduced the amount of oily wastewater, lowered the processing load on the wastewater treatment plants, and also prevented pollution incidents caused by water filling the oily wastewater wells and oil leaking out, which could harm the environment.

The floor drains for oily wastewater are sealed with sandbags. Under normal conditions, the oily wastewater from this area is treated in the wastewater treatment system; during rain, the drainage channel is used instead (the drains equipped with open channels inside the device are activated to prevent large amounts of water from accumulating within the device).

In our company, the rainwater pipes and the oil-containing waste pipes are separate; they are treated separately at the wastewater treatment plant. It is recommended that you also keep these two types of pipes separate and not combine them

Rainwater pipes and oil pipes are definitely separated; I’m afraid no organization would dare to use them interchangeably. The rainwater issue is relatively easier to handle; we have installed valves in the drainage channels leading to the main flood drainage ditch, which are opened during heavy rainfall to ensure proper flood discharge. The most important thing for oil pipelines is to prevent blockages. Every year, before the rainy season arrives, the company assigns teams to clean and clear the passages, and once the back routes are unobstructed, there are generally no major problems. It is also essential to set up cofferdams, and during rainfall, efforts should be made to minimize or eliminate wastewater discharge in order to prevent the increase in flow in the wastewater pipelines from causing oil leakage.

Now, new refineries are all equipped with rainwater recycling systems

Our manhole openings are sealed with shutters, and then covered with tarpaulins and sandbags, so no rainwater can get in at all when it rains. The sewer cover inside the device is equipped with a weir to prevent oil from leaking out. The factory has built its own large sewage buffer tanks, which have proven to be effective.

The sewage wells and device side ditches are separated by gates and sandbags. Normally, water flows into the septic tank; during light rain, the water is drained into the side ditch after 60 minutes, and the septic tank is sealed ； Switch after 20 minutes during light to moderate rain ； Switch every 5 minutes during heavy rain ； This reduces the impact of rainfall on sewage treatment plants.

Now clean production is required, so there generally won’t be oil on the floors! Open the cofferdam when it rains, and close it when it doesn’t!

1. Build dikes around areas where oil-containing wastewater may be generated, to prevent surface rainwater from flowing into the drains for such wastewater, thereby reducing the strain on wastewater treatment plants； It can also prevent oily wastewater from contaminating clean water channels ； 2. Collect the rainwater from the early stage of heavy rainfall separately (which may contain trace amounts of surface oil) in an accident water tank or accident water buffer tank, and then send it to the sewage treatment plant for treatment on a slow basis ； 3. After the initial period of rainfall, the small holes in the oil-contaminated manhole covers get blocked, and the oil-contaminated drains in the production area are also sealed off. This significantly reduces the amount of oily wastewater, thereby lowering the processing load on wastewater treatment plants. It also prevents pollution incidents caused by oil leaking from filled oil-contaminated wells, which could harm the environment.