How should wastewater be treated to ensure low COD in the effluent?
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This year, the Environmental Protection Bureau has issued requirements to the environmental protection bureaus of various counties, as well as to the various departments and directly affiliated units of the municipal bureau: in order to further intensify efforts to comprehensively address pollution in river basins, continuously improve the quality of water environments, and ensure achievement of the annual goals for improving the environmental quality of these basins, it is necessary to control the impact of water pollutant emissions on water environments at their source. The following suggestions are put forward regarding the implementation of water pollutant discharge standards for projects involving water use: First, with regard to the standards for water pollutant discharge in new projects, starting from today, new, modified, or expanded projects that discharge wastewater directly into rivers must comply with the standards set for key protection areas or Level 1 standards under Shandong Province’s comprehensive water pollutant discharge standards (COD concentration < 60 mg/L, ammonia nitrogen concentration < 10 mg/L). For the construction, renovation, and expansion of urban sewage treatment plants, Standard A of Grade 1 in the \"Emission Standards for Pollutants from Urban Sewage Treatment Plants\" (GB18918-2002) shall be applied (COD concentration < 50 mg/L, ammonia nitrogen concentration < 5(8) mg/L). II. Regarding the requirements of the existing standards for the discharge of water pollutants, projects that are under construction or already completed must carry out further wastewater treatment improvements; by the end of 2011, their water pollutant discharges must meet the requirements of the comprehensive discharge standards for water pollutants in key protected areas or the first-level standards set by Shandong Province. By the end of 2012, existing municipal sewage treatment plants were to meet the requirements of Standard A under the \"Emission Standards for Pollutants from Municipal Sewage Treatment Plants\" (GB18918-2002). For the wastewater treatment in my company, the COD level of the water exiting the monitoring points is between 70 and 100; the ammonia nitrogen level is also acceptable. I would like to hear from other experts’ opinions on what measures should be taken in future wastewater treatment projects to ensure that the COD level meets the required standards before the water can be discharged
I’ve talked for so long without getting to the point. What is your company’s wastewater treatment process? Process? Wastewater volume? Raw water COD?
Reply to 2# shaozifeng1987: Our company uses a three-stage A/O2 wastewater treatment process, and the COD level in the effluent from the monitoring tank is around 100. The current goal is to introduce new projects in the subsequent water discharge stage in order to reduce the COD of the discharged water to below 60. What project to choose? Let’s discuss it; for good projects, we can learn from them*
This post was last edited by shaozifeng1987 on 2011-4-12 at 17:01. Urban wastewater should be able to meet first-class discharge standards using the three-stage A/O2 process; it is recommended to improve the existing process. Such as the hydraulic retention time at various stages, sludge removal, and preliminary pretreatment.
Preprocessing issues Preprocessing issues Preprocessing issues
Our company deals with refinery wastewater, which enters the wastewater treatment plant in two main forms: one is the purified water resulting from the treatment of acidic water, and the other is the cooling water generated by various facilities. The wastewater treatment process is roughly as follows: collection tank – oil separation tank – primary and secondary air flotation tanks – A/OO-A/OO-A/OO – sedimentation tank – intermediate tank – sand filtration – monitoring tank – effluent. The water treatment capacity is generally around 50 cubic meters; the volume of the A/O tank is approximately 900 cubic meters. There are a total of 9 tanks in the three-stage A/OO system, connected in series. But the processing effect is average; it can be said to not be very good. I don’t know what’s going on; experts keep coming to provide guidance, but there’s no improvement at all. Ah, it’s frustrating~~
This post was last edited by wyf600 on 2011-5-3 23:12. Reducing the COD level from 10-50 is often really more difficult than reducing it from 1000-100. Is the volume of the aerobic tank too large? (The specific figures aren’t clearly stated.) I’m not sure what the conditions of the incoming water are; perhaps the operation method can be changed, such by using combinations of processes like hydrolysis and acidification.
Hello, is 900 cubic meters the total volume for level 3 AO?
Reply to 8# yfc-hb: 900 cubic meters is the volume of one tank; there are nine tanks in total, arranged in the sequence A/O/O-A/O/O-A/O/O, with each tank having a volume of around 800 to 900 cubic meters.
It's very simple! For chemical treatment in the mixed reaction tank, we used M180-3, and the results were very good
Reply to 1#: If it doesn’t work, try using ultrafiltration. Sometimes, even though the effluent appears clean, there are some aggregated tiny particles present that affect the test results. Therefore, I recommend trying ultrafiltration. We have encountered this problem before as well.