Application Of TMF-DTL Technology In The Quantitative Reduction Process Of Concentrated Water From Reverse Osmosis

The technology of anoxic/oxic（A/O）-ultrafiltration（UF）-DTL reverse osmosis（DTL-RO）was adopted in wastewater treatment in industrial park.The effluent from DTL-RO was reused and the concentrated water was discharged directedly to evaporation pond.However,the amount of concentrated water annually grew as increasing companies moved in.The existing evaporation pond was operating at full load and could not receive more concentrated water.Therefore,quantitative reduction of concentrated water from DTL-RO became an urgent task.To solve this problem,DTL-RO combined with tubular micro-filtration（TMF）were introduced.This paper discussed the technology details and carried out process design and operation cost analysis to provide reference for its application in the concentrated water reduction treatment project.The main conclusions were as follows:1)A pilot-experiment was carried out and the operating parameters of each unit were optimized.The research indicated that the desalination rate and the removal efficiency of COD,total hardness,Cl^-and SO₄^2-were 95.6%,93.4%,90.2%,95.9%and 96.8%,respectively.Each index of effluent reached the reuse requirements.2)TMF and DTL-RO,the two core technologies in this project,were investigated based on the pilot experiment.The design capacity was 6000m³·d^-1,and detailed model selection and process design for each system were defined.The discharge volume of concentrated water in the park was greatly decreased and the pressure of evaporation ponds was relieved.3)From the perspective of effect and economy,the indicators of Ca²⁺,Mg²⁺and SiO₂,as well as the removal rate of TDS and COD meet the standard of Industrial Circulated Cooling Water.The running cost was 7.77 yuan/t.