DL/T 807-2019Technical guidelines of scrapping 201? strong base anion exchange resins for water treatment in thermal power plant (English PDF)

4.1 Sampling

Sampling shall be carried out according to the method specified in Appendix A of DL/T 673-2015.

4.2 Determination of water content

4.2.1 The sample preparation shall be carried out according to the method specified in Appendix B of DL/T 673-2015.

4.2.2 The measurement shall be carried out according to the method specified in 4.3 of DL/T 673-2015.

4.3 Determination of strong group content

4.3.1 Sample preparation should be carried out according to the method specified in Appendix A.

4.3.2 The measurement shall be carried out according to the methods specified in 8.2 and 9.2 of GB/T 5760-2000.

4.4 Determination of organic content

It should be carried out according to the method specified in Appendix B.

4.5 Determination of iron content

It should be carried out according to the method specified in Appendix C of DL/T 673-2015.

4.6 Determination of sphericity

It should be carried out according to the method specified in 4.6 of DL/T 673-2015.

4.7 Calculation of the rate of decrease of working exchange capacity

4.7.1 When users have comparable work exchange capacity data, they can be used to calculate the rate of decrease in work exchange capacity.

4.7.2 Determination of working exchange capacity

4.7.2.1 The working exchange capacity shall be determined according to the equipment and requirements specified in DL/T 772 and the actual operating parameters;

4.7.2.2 The standard working exchange capacity shall be measured according to the method specified in DL/T 772, and the reduction rate of working exchange capacity shall be obtained by comparing the result of 4.7.2.1.

4.7.3 In view of the complexity of measuring the working exchange capacity of ion exchange resins, the physical and chemical properties and pollution conditions can also be measured by pressing the following regression formula is used to calculate the rate of decrease in work exchange capacity.

4.7.3.1 Use the decrease rate of the strong group capacity to calculate the decrease rate of the working exchange capacity.

4.7.3.2 Use water content to calculate the rate of decrease in working exchange capacity.

4.7.3.3 Use the iron content in the resin to calculate the rate of decrease in working exchange capacity.

4.7.3.4 Use the organic matter content in the resin to calculate the reduction rate of the working exchange capacity. see Appendix B.

5.1 Analysis of equipment operating conditions

5.1.1 When the water-making equipment has the following conditions during operation, sampling and analysis shall be carried out.

a) There is no significant change in equipment, regeneration and operating conditions, and the periodic water production capacity of continuous 3~5 periodic water production equipment is lower than that of the original system.

Reduce water volume by more than 10%;

b) After the recovery treatment, the water production volume still cannot be restored to more than 90% of the original water production volume;

c) The resistance of the equipment continues to increase for 3 to 5 consecutive cycles, and the operating flow drops by more than 30%. After the large backwash operation, the operating flow cannot be restored to more than 80% of the original flow.

5.2 Sampling

It shall be carried out according to the methods specified in 5.2~5.3 of DL/T 673-2015.

5.3 Test items

The testing shall be carried out according to the items specified in Table 1.

5.4 Retirement rules

5.4.1 When one of the decrease rate of working exchange capacity, the decrease rate of strong group capacity, and the water content reaches the index value in Table 1, it can be judged the resin should be scrapped.

5.4.2 After recovery, if the iron content or organic content in the resin is still greater than the index value in Table 1, the resin can be judged to be scrapped.

5.4.3 After backwashing, take samples from top to bottom to analyze the sphere rate (the sampling height of each layer is 100mm~200mm). If the resin sphere rate of this layer is when the index value in Table 1 is reached, the resin of this layer and the layers above this layer shall be scrapped until the sphericity of the resin of the sampling layer is greater than the index value in Table 1.

6.1 Logo

The collected samples should be packed in sealed plastic bags or jars, and each package of collected samples should be clearly and firmly marked.

The content of the mark includes unit name, sample name, resin brand, equipment name, equipment number, sampling location, sampling date, and sampling signature name.

6.2 Storage

The collected samples should be freeze-proof and sealed during storage to prevent moisture loss.

Appendix A

(Normative appendix) Preparation of Hydroxyl Sample of Strong Basic Anion Exchange Resin A.1 Scope of application this method is suitable for the preparation of ion exchange resin hydrogen and oxygen samples in the water treatment operation of thermal power plants.

A.2 Equipment

A.2.1 Plexiglass exchange column. B2.1 in Appendix B of DL/T 673-2015.

A.2.2 Separation funnel. 250mL.

A.2.3 Weighing bottle.

A.3 Reagents and solutions A.3.1 Pure water. should meet the third grade reagent water specified in GB/T 6682.

A.3.2 1mol/L sodium hydroxide solution. Weigh 40g analytically pure sodium hydroxide and dissolve it with water and dilute to 1000mL.

A.3.3 1% phenolphthalein indicator. prepared according to GB/T 603.

A.4 Sample preparation A.4.1 Measure 20mL of.201×7 ion exchange resin, place it in a plexiglass exchange column, remove air bubbles in the resin layer, and drain until the liquid level is higher Resin layer 20mm;

A.4.2 Backwash with tap water, the expansion rate of the resin layer is 50%-100%, until the water is clear;

A.4.3 Add 600mL of 1mol/L sodium hydroxide solution (A.3.2) into the separatory funnel, and flow through the resin layer from top to bottom at a flow rate of 10mL/min;

A.4.4 After washing the separatory funnel and the wall of the exchange column with water, add water to wash the resin layer at a flow rate of 10 mL/min until 1% phenolphthalein indicator (A.

3.3) Until there is no red.

A.4.5 According to GB/T 5757, remove the external moisture of the resin, and transfer the resin to a dry weighing bottle for use.

Appendix B

(Normative appendix) Determination of organic content in ion exchange resin B.1 Scope of application this method is suitable for the determination of organic matter content in ion exchange resins during water treatment operation of thermal power plants.

B.2 Apparatus and equipment B.2.1 Plexiglass exchange column. B2.1 in Appendix B of DL/T 673-2015.

B.2.2 Constant temperature water bath. 0°C~100°C.

B.2.3 Volumetric flask. 1L.

B.2.4 Triangular flask. 250mL.

B.3 Reagents and their preparation Unless otherwise specified, only use analytical reagents.

B.3.1 Pure water. should meet the third-level reagent water specified in GB/T 6682.

B.3.2 10% sodium hydroxide and 2% sodium chloride solution. weigh 100g sodium hydroxide and 20 sodium chloride, dissolve and dilute to 1000mL with water.

B.3.3 10% sodium hydroxide solution. Weigh 100g sodium hydroxide and add water to dissolve and dilute to 1000mL.

B.3.4 (1 3) Sulfuric acid solution. stipulated in DL/T 502.22-2006.

B.3.5 0.01mol/L potassium permanganate standard solution. GB/T 601.

B.3.6 0.01mol/L oxalic acid standard solution. GB/T 601.

B.4 Determination of organic content in resin B.4.1 Take 60 mL of the resin sample and place it in the organic glass exchange column, and backwash with tap water until the effluent is clear.

B.4.2 Measure 50mL of the resin after backwashing, and transfer the resin to 250mL with 100mL of 10% sodium hydroxide 2% sodium chloride solution (B.3.2) the beaker is placed in a water bath at a temperature of 45±2°C, and the solution is changed every 3h for a total of 3 to 5 times.

B.4.3 Collect all the soaking liquid in a volumetric flask, dilute with distilled water to the mark and shake well, and record the soaking liquid volume as V2.

B.4.4 Measure according to the method specified in 6.2 of DL/T 502.22-2006.

B.5 Result calculation B.5.1 Calculation of organic content the content of organic matter (chemical oxygen consumption) in the resin is calculated by (COD)Mn, expressed by mg/L wet resin, calculated according to formula (B.1).