All possible results caused by a COD gauge with a limited stroke with the transformation of load in crack tip opening displacement test are analyzed.

Detection of CODcr by Microwave Digestion Photometric Method and Its Unified Benefits Analysis;

The correlation of BOD5 and CODcr were analyzed in this paper according to the measured data of water quality of Cihu Lake in Hubei Province and the mathematical statistics, and meanwhile some questions in applying the correlation are also presented.

Properties of modified bentonite were characterized by various analysis techniques and modified bentonites were applied to pretreatment of high strength landfill leachate with CODCr up to 20,000~37,000mg/L.

The experimental results show that the declining rates of chromaticity and chemical oxygen demand(COD) can extend to 84% and 60% respectively.

The main defects of the standard method for the determination of chemical oxygen demand in water by potassium dichromate, such as measurement time consuming, Hg salt polluting, Cl~- disturbance were ameliorated by increasing acidity and adding catalyst silver sulfate.

It is shown that colority and chemical oxygen demand of the wastewater can be decreased to thirty times and less than 300 mg/L respectively by 10% iron(Ⅲ) chloride liquor and powdered carbon.

This experiment was conducted to determine the loss rates of four kinds of pellets with drying method and the COD values with potassium permanganate method after different periods of pellets immersion in distilled water.

The results show that the COD value of different types of glass raw materials differs from each other greatly; the optimal proportion of H2SO4:H3PO4 is 4:1; the optimal acid added order is phosphoric acid first and sulfuric acid the second; the optimal digestion time for chemical raw materials is 15min, and for mineral raw materials is 30min.