Study On The Recycling And Utilization Of High Concentration Wastewater From Mixing Plant

A large mount of waste water slurry will be produced in concrete mixing plant.Improper treatment of waste water slurry will lead to the waste of resources,environmental damage,resource waste and so on,and recycling is the most ideal way to treat waste water slurry.At present,most mixing stations use tertiary sedimentation method to recycle wastewater waste slurry,but the concentration of wastewater is relatively low.In addition,in the process of recycling,the high concentration of wastewater and unstable composition often occur in the homogenate tank of sedimentation tank,which will lead to the difficulty of recycling and the decline of recovery efficiency.However,there is little research on the recovery and utilization of high concentration wastewater.In view of this,this paper systematically studied the recovery and utilization of high concentration wastewater from mixing plant.Firstly,the properties of high concentration wastewater in mixing plant were studied.Then,the influence of high concentration wastewater concentration,dosage and hydration time on cement performance was studied.Thirdly,the effects of high concentration wastewater on C30 and C60 concrete properties were studied.The results show that:(1)High concentration wastewater can be used as mixing water.The concentration and density of wastewater have a good linear correlation in a certain range.(2)The addition of high concentration waste water has no effect on the stability of cement,but it will reduce the water consumption of the standard consistency of cement and the fluidity of the cement.The effect of the mixing of high concentration wastewater on the setting time of cement is lengthened and then shortened.The inclusion of high concentration wastewater has a certain improvement on the inclusion of mortar,but with a dosage of more than 30%,the mortar fluidity decreases significantly.The incorporation of high concentration wastewater can enhance the strength of mortar and reduce the shrinkage of mortar.(3)The application of high concentration waste water to C30 concrete and waste water can reduce the working performance of concrete,but it will help to reduce the loss.The mixing of waste water can increase the compressive strength of concrete in a certain amount of content,among which 8% of the waste water in the hydration time of 12 h recovery is more ideal,especially when the waste water content is 30%,the most obvious,3d strength probably can increase 1.5MPa,7d strength probably can improve 2MPa,28 d strength probably can increase 3MPa.The effect of high concentration wastewater on the working performance of C60 concrete is relatively large,but the compressive strength is obviously improved.(4)The addition of high concentration wastewater is beneficial to the improvement of chloride ion permeability and carbonization resistance of concrete with different strength.(5)According to the actual situation of the mixing station and combined with the test results,a more reasonable and high concentration wastewater reclamation and treatment process is put forward,and relevant suggestions are given.