Regarding industrial wastewater discharge volume

As required, industrial enterprises should install a separate drainage system for rainwater and wastewater during construction, so as to discharge them separately

This requirement seems a bit unreasonable, but it’s the only option; otherwise, how can traffic be measured?

Separating rainwater from sewage is a requirement set by regulations; of course, if your sewage treatment system has sufficient capacity, it can be connected to the main system

Separating rainwater and sewage flow seems to be the current trend.

Separating rainwater and sewage is the correct approach; it is the standard. It’s a long-term effect – to protect the environment and benefit future generations!

In fact, implementing separate systems for rainwater and wastewater doesn’t require a large investment. By installing such systems from the outset of factory construction, it not only reduces pollution in terms of water treatment and the factory’s environment but also lowers the costs associated with pollution control. Currently, newly built factories almost all have separate systems for rainwater and sewage, and many also have separate systems for clean water and wastewater. This not only reduces the costs and investment required for building pollution control facilities, but also simplifies their operation and management.

What Haiyou said on the 7th floor is absolutely correct. Our company’s drainage system is divided into systems for production wastewater, process sewage, domestic sewage, and rainwater, and it includes a preliminary rainwater collection tank. Among them, production wastewater, domestic wastewater, and initial rainwater are sent to the wastewater treatment plant for treatment until they meet the required standards before being discharged; the purified production wastewater is discharged directly, thereby reducing the operational costs associated with pollution control.

To the 8th floor: It’s rare to find companies in China that have reached such a level; your company must be newly established! ! Also, please provide a detailed explanation on how to separate early-stage rainwater from later-stage rainwater! ! !

In fact, some “wastewater” is not waste and can be reused

Especially for chemical enterprises, it is highly important to establish a separate system for rainwater and wastewater; otherwise, it is similar to the situation of avoiding legal regulations on water pollutant discharge mentioned in the previous \"Question of the Day\". The assessment of comprehensive sewage discharge standards also needs to be separated.

Rainwater and wastewater generated by production are not the same; whether in terms of wastewater treatment costs or environmental regulations, mixing rainwater with production wastewater is uneconomical

Separating rainwater from sewage is necessary, but is it truly impossible to achieve this?

Separating rainwater from wastewater is the principle; however, for some wastewater with extremely high concentrations but low flow rates, diluting it with rainwater is also an option

Generally, chemical manufacturing enterprises that need to treat wastewater among the \"three types of waste\" must ensure proper separation of polluted water from clean water. This involves diverting ordinary cooling water and later-stage rainwater for separate disposal: polluted water is transported via dedicated pipes, while clean water and rainwater are also conveyed through separate pipes (or channels) – clean water can be reused. Early-stage rainwater is pumped into the wastewater treatment facility using lift pumps, whereas later-stage rainwater is discharged directly outside. To achieve separation of rainwater and wastewater, it would likely be necessary to build large reservoirs; upgrading existing factories is probably very complicated and not easy to accomplish. Rainwater from the first 15 minutes also needs to be collected, experts say, as it contains pollutants.

In the layout of sewer systems for urban wastewater treatment, regulations require the use of a separate drainage system that enables the interception, storage, and treatment of initial rainfall. This is not a mandatory requirement, as it is also necessary to prevent waterlogging and to ensure that wastewater treatment facilities have the appropriate capacity. Initial rainfall contains pollutants from the air, as well as dirt from roads, rooftops, and equipment surfaces; these pollutants end up in the water, so it is necessary to treat this water. The regulations stipulate that rainfall during the first 15 minutes should be collected and treated. For new projects, a separate drainage system is recommended; a switching valve should be installed in the rainwater system. Generally, this valve is adjusted manually. I’m not entirely sure about the specific operating procedures, but I think it should be switched to connect with the sewage treatment facilities under normal conditions, and it should be switched to connect with the external rainwater pipes when the rainfall lasts for more than 15 minutes. Different industrial projects may have different requirements; the specific approach should be determined in accordance with the environmental impact assessment and the guidelines provided by local environmental protection authorities. Additionally, I would like to say that in **emission standards, pollutants are not classified based on the nature of the wastewater; for example, Category 2 pollutants are sampled at the discharge points. It seems there are flaws in the interpretation of local policies – if I have clean wastewater and it is determined that it does not exceed the limits, does that mean no further testing is necessary? Isn’t it easy for loopholes to arise in this situation? Additionally, I would like to point out that in industrial wastewater, the proportion of initial rainfall is not high; therefore, it’s not a problem to take initial rainfall into account in the design. Taking chemical plants as an example, to ensure safe wastewater discharge, accident treatment tanks have a large capacity available for regulating flow rates. When the regulation capacity is insufficient, storage can still be used for handling the excess water, after all, it’s only the amount of rainwater collected during the first 15 minutes.

Quoting a sentence from above. “Additionally, I would like to say that in **emission standards, pollutants are not classified based on the nature of the wastewater; for example, Category 2 pollutants are sampled at the discharge points. It seems there are flaws in the interpretation of local policies – if I have clean wastewater and it is determined that it does not exceed the limits, does that mean no further testing is necessary? Isn’t it easy for things to slip through here? Shouldn’t the final outlet for clean water also be located alongside the outlets for industrial wastewater? ? ?

In fact, for systems that separate rainwater from wastewater and separate pollutants from clean water, this is mainly relevant to newly established enterprises; especially in the case of separating rainwater from wastewater, older enterprises generally do not take this into consideration. However, separating pollutants from clean water is very important for enterprises, particularly those that are polluting. By preprocessing the concentrated wastewater through such separation, investment in preprocessing can be reduced. Then, before aerobic biological treatment, the polluted water and the preprocessed concentrated wastewater can be mixed together for treatment, which not only reduces the load on the biological treatment tanks but also ensures the reliability of achieving standard water quality. Separating rainwater from wastewater is essential for companies that generate polluted water. Controls on environmental pollution are becoming increasingly strict; if these controls are not properly implemented, pollution incidents caused by rainwater carrying pollutants away can not only severely disrupt a company’s operations but also affect the lives and work of local residents. The consequences of such incidents can be severe, so pollution-causing enterprises should take proactive steps to implement separation systems, whether by upgrading existing facilities or building new ones, in order to prevent such problems from occurring.

Original poster, what I’m trying to say is that all wastewater should be measured uniformly. The environmental protection agency has regulations regarding discharge outlets, and these outlets need to be registered. Is it possible for people to evade supervision by discharging clean water through such outlets (since the testing frequency and measures may vary depending on the outlet)? It’s a matter related to regulatory measures, and I’m not entirely sure about this either:handshake

What was said on the 16th floor is very accurate. The industrial park that our company is currently building (covering an area of around 1,500 mu) includes facilities for pesticide production, polymer materials manufacturing, equipment production, as well as supporting heat and power generation units. The system implements separate handling for clean water and wastewater, as well as for concentrated production wastewater, dilute production wastewater, domestic wastewater, and rainwater. Each facility pre-treats its concentrated production wastewater to meet level 3 standards; this wastewater then flows through pipelines to the regional wastewater treatment plant, while domestic wastewater travels through buried sewage pipes to the same plant. After biochemical treatment, the wastewater meets the required standards before being discharged (either into municipal wastewater treatment plants or directly into the environment). Online monitoring devices are installed at the discharge points, with all data connected to a network across the province. Each factory site installs emergency tanks with a capacity of 500–800 cubic meters as needed, while the regional area has emergency tanks with a capacity of 7,000 cubic meters. Switch valves (electric) are indeed installed on the rainwater pipes, and these valves are controlled by the regional sewage treatment station. Although the cost is quite high, this is the trend in environmental protection over the next few years, especially in provinces like Zhejiang where the environment is not sacrificed at any cost. Experts from the Provincial Environmental Protection Bureau and the Provincial Environmental Impact Assessment Center both said that we have too many sewage treatment facilities, which is a waste (their exact words: it’s either the beginning or the end; one of them must be left exposed to the sun). . . But the person who makes the company’s decisions must be present. . . Our company is quite proud of its efforts in environmental protection. :L Last edited by gzgz on 2009-4-7 16:20 ]

Separating rainwater, sewage, and wastewater is the best approach. But previous factories failed to handle this properly, so new enterprises need to do it well. If possible, old factories can also be upgraded. Nowadays, environmental protection requirements are becoming increasingly strict; wastewater must be treated centrally and discharged in compliance with standards, with separate systems for rainwater and wastewater – which is beneficial in terms of reducing the pressure and costs associated with wastewater treatment.