Full-scale Performance Assessment Of A Water Treatment Plant In Guangdong

Nowadays,the worsening quality of water and shortage of water quantity are themain problems facing the urban water supply industry in China. This undoubtedlymakes the treatment of drinking water more difficult.It affects the normal life of peoplebecause of the shortage of water.In the meanwhile, the polluted water source makes itworse. The long-term planning of China’s urban water supply industry should be toimprove the quality of water, improve water services, optimization of water supply costand to ensure the safety of water supply for the overall goals.Therefore,many conventional drinking water treatment plants need to be updated.Firstly,we will perform the performance assessment to these plants.Then low down thecost as much as possible.Waste streams include clarifier waste, settling tank waste waterand spent-filter backwash water,which can make up about4%~7%clean waterproduced by a water treatment plant.If these streams are recycled,they can reduce thepollution of the water at the same time decrease the performance cost.So this paper aims at diagnosing the current situation of DW drinking watertreatment plant which located in Guangdong province and providing quite effectiverecommendations.DW drinking water treatment plant belongs to the typical lowturbidity water treatment works. Its low turbidity period occupies most of the time allthe year round.Through analyzing the design data of DW drinking water treatmentplant,practical running datas of low turbidity period, normal turbidity period and highturbidity period all over2013, assessing each unit of the conventional water treatmentprocess and recycling processes,then come to following conclusions:DW drinking water treatment plant has a various influent flow in24h. Theadjustment ability of its clear water reservoir is seriously insufficient.It has a poorresistance of water quantity.In order to keep the stability of this system,they should takefull advantage of clear well’s adjustive capability.The flocculation tank and settling tankexist invalid sludge discharge,which lead to wasting water and insufficient sludgedischarge.In order to save water and effective sludge discharge,they decrease sludgedischarge time and adjust the operation style of the siphonic drain mud machine ofsettling tank.In order to save water and improve the effect of filter backwash,theyextend gas wash time and decrease water wash time.The production of waste water is different along with the raw water turbidity.Inlow turbidity period,the production of recycled waste water flow is1400m3/d~2100m3/d,and the recycle ratio is1.34%~2.01%.While in normal Turbidity, the productionof recycled waste water flow is2800m3/d~4200m3/d,and the recycle ratio is2.53%~3.80%.In high Turbidity, the production of recycled waste water flow is3500m3/d~4900m3/d,and the recycle ratio is3.11%~4.35%.There are some effects on purification process after recycling, such as TS and NH3-N of settled water and filtered waterincrease.With the reformation of DW drinking water treatment’s conventional treatmentprocess finished,the overall volume of waste water decreased from149650000m3peryear to118830000m3per year.The decreasing range reach to20.59%.It could save67620yuan per year.It could save costs118589yuan annually while the waste water isrecycled.DW drinking water treatment plant’s water resource costs,chemical costs andelectricity costs were total up to26636000yuan overall2013and the electricity costsmade up57%.It could save water resource costs181800yuan while the waste waterwas recycled.The costs of water resource,chemical consumption and electricityconsumption of DW drinking water treatment plant was239696000yuan,17404000yuan,926300yuan respectively while it in low turbidity period, normal period and highturbidity period.