Integrated Technology for Rural Sewage Treatment

Applicating Company

Liaoning Innovation Environment Group Corp.，Ltd

Technology Name

Integrated Technology for Rural Sewage Treatment

Technical principle

Multi-stage AO with double engines, biological multiplication, high-efficiency denitrifying bacteria and cold resistant mixed bacteria inoculation technologies are adopted. Multi - lattice aerobic -simultaneous oxygen adjustable area is set with a flexible operation mode. According to the change of water quality, denitrification AO, phosphorus removal AO, denitrification and phosphorus removal A2O, inverted A2O and multi-stage AO can be switched and adjusted, which will end up in achieving the goal of removing pollutants such as carbon, nitrogen and phosphorus.

By adjusting the reaction time, aeration intensity, mud and mix return flow of anaerobic, anoxic and aerobic in various functional areas, the system effectively solves the problems of low Chemical Oxygen Demand of rural domestic sewage, large variation of water quality and great fluctuation in different periods, poor biochemical performance, unstable operation and difficulty in reaching the standard.

Scope of application

Applies to rural sewage treatment.

Process flow and description

Constructions:

1）Grid

A grid is set up before the domestic sewage enters the regulating tank to remove soft entanglements, large solid particles and floating matter of the domestic sewage, in order to protect the life of the subsequent working pumps and reduce the system treatment workload.

2）Regulating Tank

After the treatment of domestic sewage by the grid, the adjustment and homogenization of water quality and quantity is conducted in the regulating tank, which ensures the balanced and stable water quantity and quality in subsequent biochemical treatment system. Pre-aeration system for oxygenation is set up for mixing, so that the suspended particles and odor in the sewage precipitation can be prevented, and organic matter in the sewage can be degraded efficiently. The impact resistance and treatment effect of the whole system is improved.

3） Regulating Tank Lifting Pump

A submersible pump is installed in the regulating tank and the homogenized sewage is lifted to the later stages of treatment.

4) Sedimentation Tank

Solid-liquid separation is carried out to remove stripped biofilm and suspended sludge from the biochemical tank, resulting in a true purification of the sewage.

5）A-stage Biological Treatment Tank (Anoxic Tank)

The sewage is further mixed, making full use of the efficient bioelastic filler in the pool as a bacterial carrier, relying on part-oxygen microorganisms to convert insoluble organic matter in the sewage into soluble organic matter, and hydrolyze large molecules into small molecules to facilitate further oxidation and decomposition in the back channel O-level biological treatment pool. At the same time, the nitrate carbon nitrogen through the reflux can be partially nitrified and denitrified under the action of nitrifying bacteria to remove ammonia nitrogen.

6）O-stage Biological Treatment Tank (Anoxic Tank)

This tank is the core part of the sewage treatment and is divided into two sections. The first section removes various organic substances from the sewage under high organic load through biochemical degradation and adsorption with the joint participation of a large number of microbial communities of different species attached to the filler. It significantly reduces the organic content of the sewage. In the later section, under low organic load, the ammonia nitrogen in the sewage is degraded by the action of nitrifying bacteria under adequate oxygen conditions, and the COD value in the sewage is also reduced to a lower level, so that the sewage can be purified.

7）Secondary Sedimentation Tank

Solid-liquid separation is carried out to remove stripped biofilm and suspended sludge from the biochemical tank, resulting in a true purification of the sewage.

8) Disinfection Tank

  Outlet water from Secondary Sedimentation Tank flow into the disinfection tank for disinfection to make the water quantity meet the requirements of health indicators and qualified for discharge.

9) Sludge Tank

The sludge from the secondary sedimentation tank is discharged regularly into the sludge tank for sludge thickening and aerobic digestion. The sludge supernatant is discharged back into the regulating tank for reprocessing, and the remaining sludge is pumped out regularly (two to three times a year).

10) Fan

The fan is for oxygenated aeration and mixing in A/O biochemical and regulating tank.

11）PLC Control Cabinet

The PLC integrated control cabinet has protection functions such as overload, short circuit and phase loss protection. It has a compact structure, stable operations and complete functions. It can be combined according to the size of the actual control plan. Both single cabinet automatic control and multiple cabinets through the industrial Ethernet or industrial field bus network to form a centralized (DCS) control system can be achieved. PLC control cabinets can be adapted to various industrial automation control situations of various scales.

Promotion Prospect

1) The construction and promotion of this project solve the problem of rural sewage treatment.

In response to the long cold season, fluctuating water quality, fluctuating treatment load and the lack of professional operation and maintenance personnel in rural areas, Innovation Environment Group developed the integrated technology of "full low oxygen, simultaneous denitrification" sewage activated sludge treatment. The project is highly resistant to shock loading, easy to operate and has a stable water output.
Meanwhile, the project doubles the efficiency of biological treatment and reduce electricity consumption by over 50% compared to conventional processes;

Good COD removal, complete NH3-N and TN removal and adequate phosphorus removal can be realized under low dissolved oxygen conditions

As the construction of the biochemical section is halved, the equipment footprint of the project is only 50-70% of the traditional processes, which can save space and build size, reduce investment costs and operating costs.

The amount of residual sludge is about 50% of the traditional processes. It is a best choice for integrated rural wastewater treatment in terms of operational efficiency, comprehensive energy consumption, investment costs and maintenance difficulties.

The application of this project reduces the energy consumption of conventional rural sewage treatment technology, solves the problem of fluctuating water quality and quantity of rural sewage, and guarantees the effluent quality. The effluent pollutant index is completely superior to the Urban Sewage Treatment Plant Discharge Standard (GB18918-2002) Level A Standard.

2)The construction and promotion of this project meet the urgent needs of domestic ecological construction development.

The application of this project improves the living environment in rural areas and the quality of the living environment. In rural areas, the treated domestic sewage can be used as irrigation water or for other purposes in order to save fresh water resources. At the same time, improved environmental conditions in rural areas can reduce the spread of pollution-related diseases and reduce the economic losses.

3) The construction and promotion of this project have a positive effect on the healthy and sustainable development of our society and economy.

The application of this project improves the reuse rate of water resources, alleviate the contradiction between supply and demand of water resources in western Liaoning and other areas, and promote the development of agricultural production, as well as improve the ecological and environmental conditions in rural areas, relieve the population pressure in cities and promote the harmonious development of society.