After shallow filtration, the secondary biochemical effluent can be reused as defoaming water of aeration tank and washing water of filter cloth of sludge dehydrator. Stable operation of subordinate system
This paper expounds the line, effluent quantity and effluent quality, and analyzes the economic benefits produced by this device.
Secondary biochemical effluent; Filtering; Treatment and reuse
Qilu Ethylene Wastewater Treatment Plant is an ethylene project of Qilu Company.
Set up special environmental protection measures to undertake all petrochemical equipment of ethylene.
Production, life and treatment of polluted rainwater in installation and supporting projects; and
Launch mission. The core of the treatment process is pure oxygen aeration technology, which is in the process
The process can be divided into Ⅰ and Ⅱ series and Ⅲ and Ⅳ series. After treatment, the effluent reaches
Secondary standard of Integrated Wastewater Discharge Standard (GB 8978- 1996)
Requirements, through the submarine pipeline finally discharged into Xiaoqing River. sewage disposal
Requirements for outlet weirs of series Ⅰ and Ⅱ and series Ⅲ and Ⅳ pure oxygen aeration tanks.
Defoaming water is used for defoaming, and the water demand is120m3/h; Its sludge treatment
The core equipment is two imported belt sludge dehydrators for transportation.
There must be high-pressure water washing filter cloth on the production line to ensure that
In order to maintain the filter press effect, the water consumption is 45m3 /h h.
According to the water pinch utilization technology, the water outlet of the upper unit in the device
Water can be directly or simply treated and used as the next unit.
Water can save industrial fresh water and improve the reuse rate of water.
Reduce the cost of enterprises and achieve good economic benefits.
1 secondary biochemical effluent, defoaming water in oxygen exposure pool, and filter cloth washing of dehydrator
Water quality analysis of washing water
Sewage treatment plants I and II series mainly deal with olefin plants and plastics plants.
Production and domestic sewage from factories, storage and transportation plants and other auxiliary production facilities
Moreover, this part of sewage has high biodegradability and contains pollution.
Less things, easy to handle, through the grid-aeration grit chamber-pre-grit chamber-
Homogenization tank-acidification tank-pure oxygen aeration tank-secondary sedimentation tank treatment
After analysis, the effluent quality is shown in table 1.
According to the water quality analysis in Table 1, the content of pollutants in water is very small.
The concentration of suspended solids is low, and the turbidity is not great. And cancel the pure oxygen aeration tank.
The quality requirements of soaking water and filter cloth washing water of sludge dehydrator are not high.
Very high, mainly to control the size of suspended particles in water. pure
The outlet hole diameter of defoaming water nozzle in oxygen aeration tank is 2 mm, and the pollution is
The diameter of the outlet hole of the filter cloth washing water nozzle of the mud dehydrator is 1 mm.
Therefore, as long as the effluent from series I and II secondary biochemical treatment is treated,
Treat the suspended solids, and control the particle diameter of the suspended solids to be less than.
1mm can meet the requirements of defoaming water and sludge dehydration in pure oxygen aeration tank.
Water quality requirements of filter cloth washing water.
Table1I and II series effluent quality after secondary biochemical treatment
Chemical oxygen demand/millilitre-1 suspended matter/millilitre-1 turbidity /NTU
72.3 38 30.5
102 29 27.2
108 29 24.2
65.3 28 23.8
79.130 23.7
1 14 30 3 1.0
143 46 3 1.6
127 53 43.5
68.3 57 66.0
68.2 65 66.0
2 process flow design
According to _ _ _ _ _ _ Ⅰ and Ⅱ series for secondary biochemical treatment, effluent quality and
Defoaming water of pure oxygen aeration tank and washing water of filter cloth of sludge dehydrator.
quality requirements