Challenge your abilities: How low is the cost of wastewater treatment?

Our company's wastewater composition is similar to yours. Our COD is 4000mg/l, ammonia nitrogen is 1200mg/l, sodium chloride is 18%, PH2. Our wastewater has been contacted by many scientific research institutions and environmental protection companies. The cheapest one costs 50 yuan, and the treatment effect is not good. Some are as high as 100 yuan. The effect is OK, but we cannot afford it. So far, there is no better way to deal with it. I don’t know what the purpose of the poster’s question is, but I’m very interested. If there is anything that can be solved, you can recommend it to us.

The wastewater from upstairs should be easier than our wastewater. Our wastewater contains a lot of organic and inorganic phosphorus. Sedimentation treatment will produce a lot of sludge. It would be best if part of the PN can be removed at the same time to generate fertilizer. However, the cost of using advanced oxidation for such a high COD will be high.

Some time ago, we produced a new product with wastewater. The volume was very small, but the COD was as high as 75,000. We tried several companies but couldn't do it. It was very difficult! ! !

Total phosphorus 10000ppm, organic phosphorus or inorganic phosphorus, phosphoric acid or phosphorous acid? What are the organic matter in it? If the phosphorus is mainly phosphoric acid, it is recommended to add lime milk to neutralize it, and finally reach alkalinity, forming calcium phosphate and calcium hydrogen phosphate precipitates. Keep the pH value above 11, and use the supported air membrane method (permeable membrane desorption-absorption technology) to separate ammonia nitrogen (including ammonia and organic amines). It is important to understand how large the COD is, what organic matter is in the wastewater, and then find out the reasonable treatment technology.

Please talk about the detailed impurities in your wastewater.

Please talk about the detailed impurities in your wastewater. The COD is as high as 75,000, which is interesting in itself.

Inorganic phosphorus in wastewater is mainly phosphorous acid, and organic phosphorus is mainly organophosphorus pesticides and their by-products. The reason for high COD is organophosphorus pesticides and formaldehyde, formic acid, etc. contained in them. The headache is that the water contains about 10% salt. Phosphorus and ammonia nitrogen can be removed by chemical precipitation, and COD can be removed by advanced oxidation or electrochemical oxidation. Salt removal is more troublesome. It would be great if it could be made into brine for the alkali plant, but it is very difficult.

The brine can be concentrated from 10% to 25%~27% using multi-effect (4-effect) evaporation, which our partners are doing. Soda ash plants and chlor-alkali plants have high requirements on the quality of salt water. Nitrogen and phosphorus must be removed cleanly, especially in chlor-alkali plants, which require COD to be less than 50 ppm, ammonia + ammonium to be less than 1 ppm, and ammonia + amine + ammonium to be less than 5 ppm.

The first thing to determine is that it is not feasible to use biochemical methods for this type of wastewater. Secondly, physical and chemical methods must be used. Since the pH value is low, the iron + carbon micro-electrolysis method can be used. First, the oxidation method can be used to remove most of the COD, while lowering the pH value, which can reduce the cost of neutralizing the pH value. Then adjust the pH value to remove high phosphorus through precipitation. The reason is that the iron ions generated by micro-electrolysis react with phosphate ions to form precipitation. The magnesium ammonium phosphate method is then used to perform ammonia removal precipitation reaction. After solid-liquid separation, the COD is measured, and then membrane treatment is used. Since the sodium chloride content is 11%, the biochemical reaction is greatly inhibited or poisoned, and biochemistry is not suitable. We don’t know the cost of membrane treatment, but front-end treatment should be around 20 yuan/ton.

Front-end processing is only 20 yuan? Even after such pretreatment, the COD will be very high, and advanced oxidation needs to be added, which may not meet the standards. It is also difficult to handle such high sodium chloride membrane treatment, neither RO nor NF is feasible.

If the quantity is small, incineration can be used. The key is that the cost of incineration is astonishingly high if the quantity is large.

Yes, as mentioned before, I don’t know what the organic components are. It is best to enrich the organic components first and then incinerate them. The other parts are relatively easy to deal with. And the pH value is also very amazing, it can be used as an acid. For example, neutralizing the water consumption of papermaking and so on.

It can be treated with high-efficiency air flotation-pure oxygen biochemical method, but the cost of pure oxygen biochemical treatment is high.

Hello! Feel like you are a chemical engineering professional. Hope to become friends and learn from you * .

We have salt-tolerant strains that can grow at 18% salinity. You can try it.

It is recommended to recover acid-remove COD-make phosphate fertilizer

Make a bold assumption: What if this wastewater is introduced into a nearby domestic sewage plant with a daily treatment capacity of 100,000 tons? ? ? This post was last edited by zfc318 on 2009-4-10 08:13 ]

The transportation fee is calculated at 15 yuan/ton, and the handling fee is 10 to 20 yuan/ton. Can this price be obtained?

I have come across three types of water from a pesticide factory, with the highest COD being hundreds of thousands. I feel that it is difficult to be sure that pesticide water can be produced without specific small or pilot tests. Anyway, it is more difficult to get it done. The pilot test of that factory took more than half a year.