DR-801C Enterprise Standard Term Detailed Explanation: Background Value Water Depth

Revised as per QDR0027-2021, Revised QDR0027-2024

▲ 3.5 Marginal pollution

Refers to pollutants that are insoluble or slightly soluble in water, forming a marginal state of pollution, such as petroleum substances in water.

Petroleum pollution in oceans, lakes, reservoirs, etc. belongs to this situation. It has a clear margin and is a marginal pollution area. Because its physical and chemical properties are insoluble in water, this kind of pollution has uneven distribution characteristics and rapid edging phenomenon, showing uneven horizontal plane and uneven vertical water surface direction. Our practice shows that the oily water sample after 20-30 seconds of vigorous stirring can be separated from oil and water in less than 5 seconds, and it can't be mixed manually, so it can only be solved by scientific layout.

▲ 3.6 Non-marginal pollution

It refers to a pollutant dissolved in water, a homogeneous phase pollution state in which more than two or more substances are mixed to become a molecular state. This is easy to understand. The common total phosphorus, total nitrogen and COD belong to this category, which is dissolved in water.

▲ 3.7 Background Value Water Depth Background value water depth

This is the concept first proposed and used in the world. Here, it specifically refers to the distance (or depth) from the detection of petroleum substances in environmental water to the detection of zero (or constant value). When the project was appraised in 1999, it was proposed that 30-50cm under the water surface was dissolved oil. Because the prototype built with lathe at that time was very simple, there was no way to do such difficult actions as the dynamic model of oil movement in water, so the formulation of 30-50cm was also a conjecture without scientific basis. DR-801C can do it, DR-801C Intercept Oil-in-Water Stratified Sampler (Download) -Intercept Oil-in-Water Stratified Sampler, Convenient Oil-in-Water Stratified Sampler, Convenient Intercept Oil-in-Water Stratified Sampler, Domestic Intercept Oil-in-Water Stratified Sampler, Stratified Sampler Manufacturer, Shanghai Haoqi Energy Saving and Environmental Protection Technology Co., Ltd.

The concept of "background value water depth" is meaningful, because our DR-801C uses "ideal water column (or imaginary water column)" to measure the oil concentration of environmental water body. In the same water column, those with large water depth need to be collected in layers, and the surface oil film + dissolved oil should be combined and calculated; If the water depth is shallow <15cm, the whole layer can be collected.

The Mariana Trench is 11,000 meters deep, and there is an oil flower floating on its sea surface. Will a "Mariana Trench Oilfield" be calculated?

How important is the concept of "background value water depth"!