Example of Jinan Customs Sewage Treatment and Reuse Project

1. Wastewater quality and quantity

The sewage source is divided into two streams, one stream comes from daily water use in office buildings, and the rest is from catering and domestic sewage (the sewage does not contain toxic and harmful substances); The designed water treatment capacity is 60-80m3/d, with a peak value of 8m3/d.

1. Design Basis

Based on the documents C Comprehensive Wastewater Discharge Standard, Domestic Miscellaneous Water Quality Standard, Outdoor Drainage Design Specification, and Building Reclaimed Water Design Specification.

The treated effluent consists of three streams: water for washing vehicles, water for watering greenery, and water discharged in compliance with standards. The water used for washing vehicles meets the national standard (GB 25.1-69) "Water Quality Standards for Domestic Miscellaneous Water", and the water used for greening and standard discharge meets the first level standard in the national standard (GB 8978-96) "Comprehensive Wastewater Discharge Standard".

sewage treatment plantThe process flow is shown in Figure 10-19

1. Due to the fact that the water treated by the grille comes from office buildings and restaurants, there are large suspended solids in the sewage. The function of the grille is to intercept and remove larger suspended and floating particles, which has an important protective effect on the water pump and subsequent treatment structures.
2. The wastewater from the CASS pool is automatically discharged into the CA SS pool after removing and intercepting suspended and floating solids through a grid. The C ASS pool is a key biochemical treatment structure in this treatment process. A large pool is divided into two compartments, with holes at the bottom of the partition wall to allow water to flow into each compartment

The organic matter in the sewage is oxidized and decomposed by microorganisms, and the purified sewage is discharged into the intermediate water tank. Due to the operation mode of CASS pool, the dissolved oxygen in the pool is constantly changing, which has a good phosphorus and nitrogen removal effect. When settling at rest, it is the ideal settling state, so the effluent quality is good.

One underwater jet aerator is installed in the CASS pool to oxygenate the sewage, and one adjustable skimmer is also equipped. When the underwater jet aerator is working normally, it is controlled by the programmable controller in the control cabinet and adopts automatic mode, working intermittently according to the set time parameters.

The PS-1 skimmer is a matching product specially developed for LASS tanks. The Ps-1 type skimmer consists of a skimmer and a centralized control cabinet. The skimmer is installed in the sewage treatment tank; The centralized control cabinet is located on the ground and is not a backup. In addition, all structures and equipment are geographical.

1. Two submersible sewage pumps are installed in the middle water tank, one for greening or discharge, and one for washing vehicles. The greening water pump operates automatically, and the pump is started when the water level in the middle water tank rises to the middle water level. When the water level in the pool drops, the pump will stop at low water level. In case of a malfunction, manual control can be used. The water pump for washing vehicles is manually controlled and can be turned on when needed and off when not in use.
2. Membrane filtration water purifier and backwash air compressor. Membrane filtration water purifier uses biofilm filtration and adsorption to remove organic matter that is difficult to biodegrade from wastewater. It is the key equipment for this sewage treatment process. The backwash air compressor is responsible for supplying gas to the membrane filtration water purifier to flush out impurities remaining on the surface of the biofilm. The mixture of impurities and water flows into the CASS tank through the discharge outlet for treatment. The membrane filtration water purifier is linked with the air compressor and sewage lift pump.

This system adopts automatic control, automatic operation, automatic backwashing, and has the advantages of small footprint, good water discharge effect, and automatic maintenance

1. The power equipment of the electronic control system CASS pool can be centrally controlled in the ground control cabinet.

In the middle of the water, the sewage is lifted by a one liter pump, and the membrane filter water purifier and backwash air compressor are linked. That is, when the sewage lift pump is started, the beer filter water purifier and the corresponding solenoid valve membrane filter water purifier are simultaneously startedSewage treatment metering pumpWhen turned off, start the backwash air compressor and corresponding solenoid valve to shut down the sewage pump.