tailieunhanh - Standard Methods for Examination of Water & Wastewater_1

Với một lý nước thải, quy trình cần được áp dụng để điều trị nó: sinh học, hóa chất, hoặc vật lý? Được điều trị bằng một sự kết hợp của các quá trình? Những câu hỏi này không có thể được trả lời, trừ khi các thành phần của nước thải được biết đến. Vì vậy, trước khi bất kỳ nước thải được xử lý, nó quan trọng là các thành phần của nó được xác định. | 2 Constituents of Water and Wastewater Given a wastewater what process should be applied to treat it biological chemical or physical Should it be treated with a combination of processes These questions cannot be answered unless the constituents of the wastewater are known. Thus before any wastewater is to be treated it is important that its constituents are determined. On the other hand what are the constituents of a given raw water that make it unfit to drink Are these constituents simply in the form of turbidity making it unpleasant to the eye in the form of excessive hardness making it unfit to drink or in the form bacterial contamination making it dangerous to drink Water and wastewater may be characterized according to their physical chemical and microbiological characteristics. These topics are discussed in this chapter. PHYSICAL AND CHEMICAL CHARACTERISTICS The constituent physical and chemical characterizations to be discussed include the following turbidity physical color physical taste physical temperature physical chlorides chemical fluorides chemical iron and manganese chemical lead and copper chemical nitrate chemical sodium chemical sulfate chemical zinc chemical biochemical oxygen demand chemical solids physical pH chemical chemical oxygen demand chemical total organic carbon chemical nitrogen chemical phosphorus chemical acidity and alkalinity chemical fats and oils and grease chemical and odor physical . The characterization will also include surfactants physical priority pollutants chemical volatile organic compounds chemical and toxic metal and nonmetal ions chemical . These constituents are discussed in turn in the paragraphs that follow. Turbidity Done photometrically turbidity is a measure of the extent to which suspended matter in water either absorbs or scatters radiant light energy impinging upon the suspension. The original measuring apparatus that measures turbidity called the Jackson turbidimeter was based on the absorption .