According to the lessons we have learned so far, various processes involve with hydrogen consumption and would produce wastewater. Cooling water, process water and stream, storm water, and sanitary sewage water are the four types of wastewater that were introduced in lesson 10. Process water and stream is the most polluted wastewater among four since it directly contact with petroleum fraction. Storm water could also be toxic due to exposure to pollutants and spills by accident. The pollutants that found in wastewater include toxic aromatic compounds, heteroatom compounds, strong acids, dissolved gases, suspended and dissolved solids. Compare to process water and storm water, cooling water and sanitary sewage water are less toxic and need less treatment to directly send to public treatment plants.

Refinery wastewater cannot be treated in municipal wastewater treatment plants mainly due to its capacity of treating heavy toxic chemical wastewater. Most public wastewater facilities are building to treat household wastewater and wastewater from industrial. There are some heavy chemical wastewater plants, but not many of them. As we talked about refinery wastewater previously, it contains different types of heavy toxic chemical such as H2S that municipal wastewater treatment plants hardly to treat and probably will harm the plants. It is important that refinery wastewater go through primary treatment which is physical treatment to strip H2S and remove oil and solids. Refinery wastewater also needs to go through the secondary treatment which uses microorganisms to further remove organic contaminants. After these two treatments, refinery wastewater became more applicable for public treatment facilities.

References:

1. F SC 432 class website lesson 10

https://cms.psu.edu/section/content/default.asp?WCI=pgDisplay&WCU=CRSCNT&ENTRY_ID=F20C6357261A4AE2A750C141B721E8C1

2.EPA. Washington, DC (2004). “Primer for Municipal Waste water Treatment Systems.”

Click to access primer.pdf

3. The Washington State Department of Ecology, “Water Pollution Prevention Opportunities in Petroleum Refineries” Ecology Publication No.02-07-017

Click to access 0207017.pdf

Post your response to the blog discussing why refinery wastewater cannot be treated in municipal wastewater treatment plants.

Among the various supporting processes comes the treatment of wastewater. Refineries use a great amount of water in many different processes including desalting, distillation, cracking, and coking. As stated in Lesson 10, there are a few types of wastewater, including cooling water, process water and steam, storm water, and sanitary sewage water. Process water and steam is usually heavily polluted since it comes in direct contact with petroleum distillates. Several pollutants can be found in wastewater, such as aromatic compounds, heteroatoms like amines, phenols, and cyanides, and acids which all have the potential to harm humans or other wildlife.

It is very important that wastewater be treated prior to being sent off to a municipal wastewater treatment plant. Sour water is contaminated with solid particles that must be stripped of like sulfur in a stripping unit, and oils that must be separated by skimming the oil that floats on top of the denser water. A secondary treatment process utilizes microorganisms as biological contactors to help separate the pollutants from the wastewater. Much of this necessity stems from the implementation of the Clean Water Act of 1972 and the incorporation of National Pollutant Discharge Elimination permits (NPDE). There are multiple stages the wastewater must go through before it is suitable enough to be treated at public facilities.