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Research And Development And The Principle Of Toxic Warning Equipment For Wastewater Treatment Plant

Posted on:2015-07-02Degree:MasterType:Thesis
Country:ChinaCandidate:G W YangFull Text:PDF
GTID:2181330422981354Subject:Municipal engineering
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In recent years, with the rapid development of the industrial economy of thecommunity, chemical industry, metallurgy, paper and other corporate pollutionaccident cccurred was increasing gradually. Industrial enterprises may occur accidents,wastewater will not be treated completely in the production process. Toxic pollutantswill be discharged into the municipal sewage treatment plant through the urbansewage pipe network, and make great impact to wastewater treatment plant.Evenmake biological treatment system crashes, and thus need to re-work time-consumingbacteria culture, tremendous impact on the normal operation of the wastewatertreatment plant. In response to these problems, there is a need to set up a toxicitywarning system to monitor influent for sewage treatment plant.In order to advance onto the early warning of toxic substances in wastewater, leaving adequate responsetime to the operator. There has an important practical significance for daily operationof the sewage treatment plant.This study is based on oxygen uptake rate (Oxygen Uptake Rate, OUR),researchand development work of influent toxicity warning device for the sewage treatmentplant based on the method of DO mutation and the inhibition rate index. Monitoringthe activated sludge through continuous acquisition the mixed liquid solid from thebiochemical pool.Then we can determine whether there has the biological toxicsubstances in the wastewater through monitoring the DO mutation index.In theexperiment, we use the heavy metals, toxic organics and acid and other inhibitorysubstances inhibitoring the sludge microorganisms in the reactor(hereinafter referredto as micro-organisms).To study the effect of different concentrations of toxicsubstances produced to microorganisms. Then we are bale to optimize the biologicalreactor.Completely mixed reactor is made up by plexiglass, and it is designed into acylindrical container, its volume is700mL.There are orifice for the mud flow into,inlets and overflow outfall around the reactor, respectively.When we pumped doses oftoxic substances into the bioreactor which was in the state of equilibrium at thenormal conditions, the DO index of the bioreactor will be rised at the same time, andthe increased portion of DO is released from the inhibitory activated sludge.When thesystem according to the volume ratio of Q1: Q2=1:3(Q1is sludge, Q2is thewastewater),and the concentration of Cu2+ions pumped into the reactor were3,8,15mg/L, then we can get the index of DO mutation rate was28.68%,36.82%,43.8%respectively; while the concentration of Cr6+ions were3,8,15mg/L, the index of DOmutation rates was13.26%,18.94%,24.24%respectively. When using toxic organic compounds and acid shock the system, the result is also clear. Under such operatingconditions,we can determine the degree of toxicity at different gradients of toxicsubstances.In the study of environmental factors on the toxicity we found that themicroorganism was(MLSS smaller) more sensitive to the toxic substance at thesmaller MLSS, and the greater rate of mutation DO generated within a certain range;at the same condition,retention time (HRT) is longer, the time of contact reactionbetween activated microorganism and the toxic substance is longer, and the DOmutation rate is greater; At the same time, we also investigated the influence of CODload, temperature and the influent pH of the watewater when the system was impactedby toxic substance. Then we found the optimal parameter of warning reactor, MLSSwas1000mg/L, HRT was2min. In this condition, we can get an obvious result.In this condition, we study on the effect of heavy metals copper, toxic organicsphenol and acid inhibit the microorganism of the reactor, then we can get theinhibition rate of dissolved oxygen corresponding to the amount of toxic substance.Then we simulate the condition that SBR system was suffered by several toxicsubstances, taking the removal rate of COD and ammonia nitrogen indicators as areference, and achieved the alarm parameters for the early warning device throughcombine with the physical and chemical inhibition rate and the index of DO inhibition.Alarm parameters as follows: When the DOY≤30%without warning; while30%<DOY≤45%for the general alarm, the plant operator needs appropriate attention;while45%<DOY≤60%for medium alarm, take appropriate measures; when DOY>60%of serious alarm, you need to take emergency measures.
Keywords/Search Tags:activated sludge, toxic substances, reactor, toxicity warning
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