GB/T 37758-2019Technical guidelines for the treatment and reuse of mine water with high TDS (English PDF)

3.1 Mine water

Wastewater generated from the accumulation of groundwater inflow, surface water infiltration, operational drainage during mine construction and mineral extraction processes.

3.2 Mine water with high total dissolved solids (TDS)

Mine water with total dissolved solids (TDS) greater than or equal to 1000 mg/L.

4.5 The selection of technology for the treatment and reuse of mine water with high

TDS shall be determined, based on water quality, water quantity, discharge standard requirements, following a technical and economic comparison.

5.1 General requirements

5.1.1 The design scale of mine water with high TDS purification and treatment projects shall be determined, in accordance with relevant design codes for mine water supply and drainage.

5.1.2 Mine water with high TDS treatment generally includes conventional treatment, depth pre-treatment, pre-treatment. Conventional treatment processes may employ technologies such as pre-sedimentation conditioning, oil separation, coagulation, sedimentation, filtration, clarification, iron and manganese removal filtration, disinfection. Depth pre-treatment should utilize technologies such as media filtration, activated carbon adsorption, precision filtration, microfiltration, ultrafiltration; depth treatment should employ desalination technologies such as nanofiltration and reverse osmosis.

5.1.3 The influent water quality for the engineering design of conventional and advanced treatment systems for mine water with high TDS shall be determined, based on actual measured data; water quality analysis parameters are listed in Appendix A. Analytical methods for these parameters are provided in Appendix B.

5.1.4 Membrane separation technologies shall be selected, based on influent water quality, target effluent water quality, recovery rate requirements.

5.1.5 Reuse of mine water with high TDS encompasses both internal enterprise use and external supply. Reuse applications include coal and mineral processing within the mining area; underground or surface spraying for dust suppression and fire protection; landscape and environmental water; as well as domestic water, other industrial water, municipal miscellaneous water, agricultural water.

5.2 Conventional treatment

5.2.1 Technologies for the conventional treatment of mine water with high TDS may refer to Appendix C; new treatment processes may be adopted as technology advances.

5.2.2 When mine water with high TDS contains suspended particles and colloidal matter, a coagulation-sedimentation/clarification-filtration process may be used; the basic process flow is shown in Figure C.1.Coagulants selected shall be compatible with the membrane material and conducive to enhancing membrane flux; common coagulant types and their properties are listed in Appendix D.

5.2.3 When the iron content in mine water with high TDS exceeds 0.3 mg/L or the manganese content exceeds 0.1 mg/L, processes for iron and manganese removal shall be added; the basic treatment processes are shown in Figures C.2 and C.3.

5.2.4 When the petroleum content in mine water with high TDS exceeds the limits specified in Table 1, an oil removal process shall be added; the basic treatment process is shown in Figure C.4.

5.2.5 When mine water with high TDS requires discharge after conventional treatment, it shall meet the discharge criteria specified in GB 20426, GB 25466, GB 25467, GB 26451, GB 30770, etc.

5.3 Depth pre-treatment

5.3.1 Water quality testing shall be conducted on mine water with high TDS following conventional treatment; further treatment shall be applied to remove residual pollutants such as suspended solids, sharp particles, sparingly soluble salts, microorganisms, oxidizing agents, organic matter.

5.3.2 Combined processes of media filtration + activated carbon adsorption, or microfiltration/ultrafiltration processes, may be adopted. When using microfiltration/ultrafiltration processes, the influent water quality shall meet the basic requirements listed in Table 1; other parameters may be determined based on the technical specifications provided by the membrane manufacturer.

5.3.3 A security filter shall be installed upstream of the microfiltration/ultrafiltration system.

5.3.4 Physical or chemical sterilization and disinfection treatments should be applied to the mine water with high TDS.

5.3.5 Activated carbon filters should be installed, or a reducing agent should be dosed into the influent, to remove residual chlorine and other oxidizing agents; the residual chlorine content shall be less than or equal to 0.1 mg/L.

5.3.6 Acid, antiscalants, or ion exchange treatment should be applied; chemical dosing points shall be located upstream of the security filter.

5.3.7 Membrane element fouling and chemical cleaning methods shall comply with the requirements of HJ 579.

5.3.8 Backwash water from the pre-treatment unit shall be returned to the conventional mine water treatment unit. […]