Anaerobic-contact oxidation-stabilization pond process treatment chemical pharmaceutical wastewater

Anaerobic-contact oxidation-stabilization pond process treatment chemical pharmaceutical wastewater Liu Jinda Gao Jihua Huateng Deng Wenguili Abstract A chemical pharmaceutical waste water contains biologically toxic organic chlorides and high concentrations of organic compounds, and is based on the local geography and climate and other natural conditions. The oxygen-contact oxidation-stabilization pond process has been successfully processed. Describes the process design parameters and the effectiveness of the process.

Haikou City, a Fine Chemical Co., Ltd., is a chemical pharmaceutical company producing pharmaceutical intermediate products, the main product is vinblastine. The daily displacement is 20m3. The main pollutants in water are protein, cellulose, xylitol, organic acids and organic chlorides. The COD is as high as 10000mg/L and the BOD/COD is about 0.35.

After scientific and technological research, the company took full advantage of the favorable geographical, climatic and other natural conditions in the region and used anaerobic-contact oxidation-stabilization pond technology to treat the production wastewater and acclimate the dominant bacteria species, achieving a COD removal rate as high as 99.7%.

1 Determination of process flow The chemical pharmaceutical wastewater is high in organic matter content, contains organic chlorides, and is toxic to aerobic microorganisms, so it is difficult to degrade under natural conditions and has serious environmental pollution. The acclimated anaerobic microorganisms can destroy the long-chain structure of organochlorines, breaking them into smaller molecules and biodegrading them. Based on this principle, the company has selected two stages of anaerobic pretreatment, two-stage contact oxidation as the main process treatment, and three-stage stable pond as the post-order treatment process in combination with the favorable conditions of existing pits in the plant area. See the process.

Wastewater Treatment Process 2 Structure Design Parameters and Efficacy 4m. Function is to equalize water quality and quantity.

(2) Anaerobic ponds. Semi-base steel structure. Upflow anaerobic sludge blanket reactor (UASB) was used. The reactor is characterized by high sludge sludge concentration and high activity. Wastewater enters from the bottom of the homogenizer and firstly reacts with the anaerobic microorganisms in full contact with the sludge bed to degrade the organics in the wastewater.

Wastewater of this project is difficult to biochemically and toxic. The design considers the local average annual temperature to be high (22~24*C), normal temperature operation, and the use of a relatively long hydraulic retention time (HRT) of 8 days. The results show that the design meets The process requirements.

(3) Biological contact oxidation pool. Semi-base steel structure.

Biological contact oxidation technology combines the advantages of high sludge activity of activated sludge and high sludge load of biofilm method, and it has the advantages of high volume load, less sludge yield, strong impact resistance, stable process operation, and convenient management. . This project adopts a two-stage process with the aim of acclimating the predominant strains at different stages to improve the biochemical effect and impact resistance.

The oxygen tank HRT is 15h, the sedimentation tank HRT is 7h, and the oxygen tank HRT is 16h. The total water to gas ratio is 1016. The packing is a solid slag packing.

(4) Three stable ponds. Grade 1 ponds are converted to original ponds with an HRT of 60 days and an average water depth of 2 meters; secondary ponds are converted to original ponds with an HRT of 33 days and an average water depth of 2 meters; tertiary ponds are new ponds with an HRT of 60 days and an average water depth of 2 meters. Stable ponds are ancient sewage One of the treatment methods, there is a strange effect under the appropriate conditions. The water purification mechanism is the symbiosis, coexistence and cooperative work of the bacteria and algae; biochemical action and photosynthesis promote each other. Algae photosynthesis produces oxygen, promotes oxidative degradation of organic matter by aerobic microorganisms, and effectively removes germs, viruses, and parasite eggs in sewage by predation by microorganisms, ultraviolet radiation in sunlight, killing of antibiotics, and changes in pH. These are the unique features of stable ponds. Stabilization pond can not only remove the organic matter, aerobic, anoxic, anaerobic three state alternate function, but also has the function of phosphorus and nitrogen removal. The use of multi-stage ponds in series helps to optimize the symbiosis system and improve the degradation of organic matter.

3 Operational effect analysis The monitoring of the operating effect was entrusted to the relevant environmental protection department. The monitoring was conducted for 2 consecutive days on December 5 and 6, 2001. A pilot test study on the daily sampling of 3 petrochemical wastewater for recycling cooling water was conducted. Yao Hong Zhang Jingcheng Ma Fang Li Gui, Bai Tiansheng, Liu Xueyan, Ma Youqian, et al. Use the secondary treatment of petrochemical wastewater from a chemical plant in Daqing as a water source for industrial circulating cooling water. Through the investigation of the water quality before and after the reuse of wastewater and relevant treatment technologies, it was determined that aeration was used. Biofilter and ozone biological activated carbon treatment process pilot study. The test results show that the quality of the effluent can meet the water quality requirements of circulating cooling water after the process.

In recent years, with the development of petroleum industry production, a lot of water resources have been consumed. In the petrochemical industry, the largest amount of water is recycled cooling water, accounting for 80%~85% of the total water consumption of the petrochemical industry. 11. Daqing Since a chemical plant was put into operation in 1989, due to the increase in the processing capacity of crude oil, the increase in the amount of recycled water, and the change in operating conditions, the original water supply facilities could not meet the requirements. In order to save fresh water resources and alleviate the current situation of water scarcity and water environmental pollution, it is proposed to supplement the secondary treatment of petrochemical wastewater in chemical wastewater treatment plants with advanced treatment to the industrial circulating cooling water system.

The commonly used chemical wastewater advanced treatment technology has traditional technical times. The average value of the 6 samples and the treatment effect of the treatment facilities at all levels of the project COD removal rate /% SS removal rate /% workshop outlet regulating pond effluent anaerobic pond effluent contact oxidation The monitoring and analysis results of the total discharge efficiency of the discharged water from the pool outlet stable pond indicated that the COD removal rate of the treatment project was 99.7%, and the main pollutants were degraded in the anaerobic tank. The anaerobic pond outlet water was 1 080 mg/L, which was in compliance with the contact. The influent requirement of the oxidation tank, if the COD is too high, the aerobic biochemistry is difficult. It can be seen that the anaerobic tank parameter design is reasonable. The COD removal rate of the aerobic contact oxidation tank was 60%, and the effluent concentration was 432 mg/L, which was in line with the inlet requirements of the oxidation pond.

Oxidation ponds have a COD removal rate of 94%, effluent only 25mg/L, surgery, ozone-activated carbon technology, membrane technology, and biofiltration technology.

Traditional technologies include coagulation+precipitation+filtration+disinfection and other units, which have the disadvantages of large area, complicated operation, and unstable water quality.

Membrane technology has a high removal efficiency of pollutants, but it has strict requirements on the quality of influent water. It also has the disadvantages of large initial investment, high operating costs, and complex maintenance management. The bio-filtration technology makes full use of the interception and adsorption of the filter media and the biodegradation of the attached biofilm on the filter media to obtain better pollutant removal effects, especially for the advanced treatment of aeration biological filter in recent years. It has been extensively researched and applied, and its combination of three functions of adsorption, filtration, and biodegradation is also satisfactory.

5 Benefit Analysis Based on the daily discharge of 20m3, COD72t will be emitted to the environment less every year, and the direct operating cost of suspended solids will be 0.58 yuan/m3, which is lower in the cost of difficult organic wastewater treatment projects. It can be seen that the economic and social benefits of this project are good.

6 Conclusion In this project, a comprehensive microbial degradation process has been used to successfully treat organic wastewater that is difficult to bio-degrade at high concentrations. In particular, the rational use of local favorable natural conditions and existing pits has achieved the aim of controlling pollution and beautifying the environment. The stabilizing pond in this project is a facultative pond, and attention should be paid to the timely cleaning of small duckweed in the pond in order to prevent its large-scale growth from affecting the optimized combination conditions of the photosynthesis disruption algae symbiosis system, so that the stable pond loses the function of degrading organic matter.

* Author Communications Office: 050061, Shigang Street, Shijiazhuang City, Hebei Province, China Academy of Geological Sciences, Environmental Engineering and Technology Design and Research Institute