以河床井水为应急水源的可行性研究

A feasibility proposal on using the riverbed well water as a temporary water resource in emergency

为解决城市水源地突发污染事故引起的自来水厂断水问题,提出了以河床井水代替受污染河水作为应急水源的应急预案,在取水口附近的河床打一口水井,当城市水源地发生突发污染事故时,关闭取水头水阀,开启水井水阀,以河床井水作为应急水源,并通过模拟试验验证了其可行性。结果表明,在细沙体积分数为40%的土壤条件下,原水苯胺质量浓度分别为952 mg/L、781 mg/L、580 mg/L、452mg/L、352 mg/L、182 mg/L的试验中,出水苯胺质量浓度开始超标的时间随土壤渗透系数减小而延迟,与原水苯胺质量浓度无关。当土壤渗透系数为1.94×10^(-5)-3.64×10^(-5)cm//s时,出水苯胺质量浓度开始超标的时间为84~144 h,以河床井水作为应急水源可以避免由河水突发污染引起的84 h内的自来水厂断水事故。土壤对苯胺的吸附量仅占原水中苯胺含量的14.95%~2.86%,其对出水苯胺质量浓度开始超标的时间的影响可以忽略,出水苯胺开始出现的时间主要由土壤渗透系数决定。出水苯胺最大质量浓度随原水苯胺质量浓度增大呈线性增加,线性方程为y=0.4979x-3.7029,R^2=0.9775。研究表明,以河床井水作为应急水源,能够有效地降低城市因突发污染事故而引起的自来水厂断水的可能性。

To meet the water needs in emergency,this paper intends to put forward a feasibility proposal on using the riverbed well water as a water source in emergency.As is often the case in China in recent years,drinking water pollution accidents have been taking place from year to year.In order to resolve the problem of clean water supply both for the city and the countryside,the paper would like to propose a kind of emergency solution for the drinking water emergency by digging a well in a place near or around the water intake.In case when any emergency pollution incidents would happen in a city water source area,all the water-supply channels can be shut off and they will be replaced by turning on the valve of the proposed newly-made water well to supply water needed instead of the original one.The proposal we have brought about has been provided with the feasibility of the solution testified through simulated experiments.The results show that：under the condition when the sandy soil content rate in the soft-filling soil is 40%,the raw water aniline contents rate of the six trials are equal to 952 mg/L,781 mg/L,580 mg/L,452 mg/L,352 mg/L,182 mg/L,respectively.When the soil permeability coefficient is from 1.94 × 10（-5） cm/s to 3.64 × 10（-5） cm/s,it has been found that the period for the aniline concentration of effluent likely to exceed the surface drinking water standard at a rate between 84 h to144 h.In addition,it is possible to use the water from the river-bed well as an emergency source to get rid of the accidents of water shortage period by 84 h.What is more,since the soil adsorption capacity of aniline is only between 2.86%and 14.95%,the effect of the soil adsorption capacity on the time of effluent aniline concentration proves to be negligible.Besides,the maximum effluent aniline content rate turns to increase linearly with that of the raw water,with the correlation equation being y = 0.4979x- 3.7029,R2 = 0.9775.Thus,it proves realistic and available to use the water from the river bed well as an emergency water source to reduce the chance likeliness for the city water plant to terminate its water supply in case of unexpected water-supply pollution accidents.