Technical assistance: Issues regarding SS and turbidity in circulating water
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This post was last edited by hesonchang214 on 2010-4-21 17:02. I would like to ask fellow sailors: 1. What is the relationship between SS and turbidity in circulating water? 2. What is the typical turbidity in circulating water? 3. In the recirculating water side filtration, what standards should the SS and turbidity of the water discharged from the side filtration meet? Thank you all!
Turbidity and SS are two different concepts; both are included among the quality assessment parameters for water in circulating water systems or biochemical treatment effluents. In simple terms, turbidity refers to the degree of turbidity in water, and it is not necessarily caused solely by the presence of suspended particles； SS is the deterioration of water quality caused by the presence of insoluble substances in the water. The turbidity of general circulating water is controlled at around 20 ppm, with SS at 10–20 ppm.
The concept of water turbidity in our country – the degree of turbidity, commonly referred to as turbidity level. Due to the presence of suspended and colloidal particles in water, water that is originally colorless and transparent becomes turbid; the degree of this turbidity is referred to as turbidity. The unit for turbidity is expressed in “degrees”; it corresponds to a turbidity level of 1 degree, or Jackson, when 1 mg of SiO2 (or an equivalent amount of milligrams of kaolin or diatomite) is present in 1 liter of water. SS refers to solid substances suspended in water, including water-insoluble inorganic substances, organic substances, as well as sediment, clay, microorganisms, etc. The suspended solids content in water is one of the indicators used to measure the degree of water pollution. Suspended solids are the main cause of water turbidity. Organic suspended solids in water bodies tend to undergo anaerobic fermentation upon deposition, leading to water quality deterioration. China’s comprehensive wastewater discharge standards are divided into three levels, which specify the maximum allowable concentrations of suspended solids in wastewater and effluents. China’s groundwater quality standards and drinking water hygiene standards define suspended solids in water using turbidity as an indicator. Determination of suspended solids: refers to the solids that remain on the filter media and are dried at 103–105°C until a constant weight is reached. The method of determination involves passing the water sample through filter media, then drying the solid residues and the filter media; the suspended solids (total non-filterable residue) are obtained by subtracting the weight of the filter media from the measured weight. Measurement of turbidity: Turbidity indicates the degree to which suspended particles in water interfere with the passage of light. Determined by photometry.
Thank you! Also: I would like to know what the outlet parameters for turbidity and SS are for the side filtration system in the circulating water 3# cdpulin
4# wangzhibao99: The general requirement for turbidity is less than 20, but when the heat exchanger is of plate type, finned tube type, or spiral plate type, it should be less than 10. SS is an indicator in wastewater, and this indicator is generally not used as a reference standard for make-up water in circulating water systems.
Suspended solids and turbidity are different. The index is less than 20
It can be considered that turbidity is the degree to which suspended particles that are not soluble in water and substances that are soluble in water affect light. And suspended solids are one type of turbidity. If the suspended solids are less, the turbidity will definitely be lower, but there is no linear relationship. Personal opinion
Our turbidity control range is below 30 FTU, and under normal conditions the turbidity is below 10 FTU; the turbidity of the water coming out of the side filtration process should be less than 5 FTU