Knowledge about anaerobic wastewater treatment that even doctors specializing in this field may not be familiar with – Part 2: Environmental Catalysis

Thread Content

The first article is about anaerobic biochemistry, while the second one is about advanced physical chemistry. I once joked with my clients that anaerobic technology is passed down by teachers, while catalytic oxidation technology is passed down by ancestors. Hehe, it’s just a joke, but it’s not an exaggeration. My mother founded an environmental protection company in 1986, and in the early 1990s, her company began using an early form of modern environmental catalytic oxidation technology – the iron-carbon method – to treat chemical wastewater. Catalytic oxidation technology is suitable for the pretreatment of chemical wastewater. Substances that are generally not biodegradable require this technology as a pretreatment. I don’t intend to explain the principles of catalytic oxidation here; otherwise, I won’t be satisfied until I’ve written at least 10,000 words (Lao Yuan, you should know my style when writing academic articles). The technology of environmental catalytic oxidation isn’t actually that mysterious; it simply involves knowing how to utilize catalysts. In the case of water treatment, the agents used are usually hydroxyl radicals, but are there any other radicals that can also be effective? Of course. So what other useful free radicals are there? You don’t know? I don’t know either! ) to reach the most effective substances in oxidized water. Catalytic oxidation is so practically useful that many modern reaction mechanisms are full of flaws. Let’s talk about hydroxyl radicals. May I ask which professor or scholar can tell us how many are produced per minute or per second? With how many substances does it react? As a professor I know put it well: many theories in chemical engineering arise from actual situations and outcomes; we explain those that we can understand, while for those we cannot, we apply the theory that seems most fitting to provide an explanation. This is not a lack of respect for academia; if there is a better academic explanation in the future, then we should just give it to that explanation. Once, this professor mentioned something during a chat; it was during a defense of a doctoral thesis. The students' project is microelectrolysis, which is an improvement on the iron-carbon method. During that time, the professor asked a question, but no one was able to answer it. The question is, is iron carbon reduced or oxidized? Hehe, that professor said he couldn’t give a clear answer to this question, and I can’t either. Theoretically, iron filings represent a reduction method, whereas catalytic oxidation is an oxidation method. If you are also an expert, you can ask yourself the question as well; there’s no need to tell me if you have a clear answer. I think the practical significance of current catalytic oxidation processes is greater than discussing such issues. Next, I would like to share my insights on catalytic oxidation. I designed many iron-carbon devices when I was in school, and they worked quite well. I really don’t like the name “iron-carbon”. It can be considered the pioneer of environmental catalytic oxidation, and such a simple configuration yet manages to achieve excellent results. It cannot be said that it is not a marvel of science. However, iron-carbon has many disadvantages, and caking is its fatal flaw. Moreover, iron-carbon works well in wastewater streams containing dyes and pigments, but it hardly performs effectively in the treatment of some high-concentration organic wastewater. In the field of catalysis, I submitted an application for an innovation fund back in 2002, and it was approved. Research over the years has also yielded various achievements. For a greener future for China, I open my toolbox and offer some suggestions to my colleagues as a starting point for further discussion: 1. Master the use of Fenton’s reagent; if you want to make progress in catalytic oxidation, start by working with this reagent. 2. Although iron-carbon compounds are useful, they have many drawbacks, so don’t rely on them excessively. 3. Choose catalyst promoters wisely – they can help you achieve better results with less effort. 4. Solid catalysts aren’t simply just metals fixed onto a carrier; otherwise, it would be better to buy a vase, as porcelain also contains elements such as iron, silicon, and aluminum. Yet they aren’t catalysts because those elements are “dead”. Remember to maintain the activity of the metal. 5. Do not blindly trust precious metals; for platinum-based and iron-based solutions, it’s not true that the more expensive they are, the better they will be. What matters most is the environment in which they are used – in some cases, iron-based solutions are even more effective than platinum-based ones. Use this money to buy a platinum ring for my wife. 6. We must believe in objective laws: catalytic oxidation under high temperature and pressure can reduce the COD level of water from tens of thousands to levels that meet first-class discharge standards. I believe that catalytic oxidation at normal temperature and pressure, with certain auxiliary measures such as ultrasound or strong electric currents, can also reduce the COD level of water from tens of thousands to levels meeting first-class discharge standards, though to an extent of about half. I simply can’t believe that catalytic oxidation under normal temperature and pressure alone can reduce the COD of water from tens of thousands to levels meeting first-class discharge standards. 7. Choose your carrier carefully; there are two other specifications for aluminum oxide, not to mention some less common carriers. Alright, no more talk. As the old saying goes: \"The road ahead is long and arduous; I will search high and low.\"