High-scale Surface Water Turbidity And Scale Removal Process Test Research And Equipment Development

Due to geological features and water source structure,scale problems are common in surface water supply systems,which is also one of the main factors that have long questioned the safety of water quality.The traditional scale removal process to reduce hardness also exacerbates the inadequate intake of healthy calcium and magnesium,so the new water purification process that eliminates drinking water scale and water turbidity and retains the original calcium and magnesium in water is the key to healthy drinking water.Based on the principle of scale generation,the core technology of acid-base balance aeration control scale was developed,and then combined with the micro-flocculation direct filtration process,the surface water source turbidity and scale removal process and equipment were developed.The equipment integrates various functions of mixing,flocculation,aeration,filtration and backflushing,and realizes the simultaneous removal of turbidity and scale of high-scale surface water.Taking the water source of a water plant in Shaanxi Province as the research object,verify the turbidity and scale removal effect of the process and equipment on the high scale surface water source,analyze and optimize the key operating parameters of the equipment such as dosing amount and dosing sequence,and conduct long-term operation tests.Check the long-term stability of the equipment.To study the removal effect of turbidity and scale removal technology and equipment on organic micro-pollutants,by analyzing the DOC,UV₂₅₄ and three-dimensional fluorescence spectrum of the effluent from the equipment,explore the removal efficiency of turbidity and scale removal technology for organic micro pollutants.Combined with the previous test results,a high-quality purified water process plan was proposed for large and medium-sized water plants with high-scale surface water as the source.The main conclusions of the paper are as follows:（1）For high-scale surface water sources,When the dosage of coagulant is 8mg/L and 12mg/L and the dosage of scale inhibitor is 0.21‰,the effluent of the equipment is clear and bright,the turbidity is reduced from 15-20NTU to 0.2-0.3NTU,and the temporary hardness of the effluent is Below 10mg/L,the alkalinity is reduced from 210～230mg/L to 100～120mg/L,the turbidity after boiling is reduced from 10～15NTU to 0.4～0.5NTU,the p H value is stable at about 7.20～7.30,after the water sample is boiled It is clear,there are basically no floating objects visible on the water,and the sensory is good.The water quality meets the requirements of Standards for Drinking Water Quality（GB 5749-2006）.（2）Under the constraints of target alkalinity,the order of addition of coagulant and scale inhibitor has a significant effect on the turbidity,p H and alkalinity of the equipment effluent.For polyaluminum chloride（PAC）,under the conditions of different dosage and filtration rate,the turbidity,p H value and alkalinity of the effluent water after adding the scale inhibitor first and the coagulant are lower than that of the coagulant first and then the scale inhibitor.For polyaluminum sulfate（PAS）and polyaluminum ferric chloride（PAFC）,the turbidity,p H value and alkalinity of the effluent water after adding the scale inhibitor first and the coagulant are higher than that of the coagulant first and then the scale inhibitor.The effluent quality is poor.（3）Simultaneous removal process of turbidity and scale can effectively remove organic micro-pollutants in water.By comparing and analyzing the three-dimensional fluorescence spectrum of the equipment inlet and outlet water,it is found that the removal effect of fulvic acid and humic acid in water is very obvious,and the removal rate of DOC is reached 24.45%,the removal rate of UV₂₅₄ reached 50.0%,which was greatly improved compared to the conventional treatment process.