The Experimental Research On The Treatment Of Polybrominated Diphenyl Ethers By The Way Of Nuclear Flocculation And IC Anaerobic Reactor

Polybrominated diphenyl ethers (PBDEs) have been widely used as flame retardants innumerous consumer products such as electrical apparatus, electronic product, expanded plasticsand decoration materials. They are a group of new type persistent organic pollutants andcommonly detected in atmosphere, water and soil. Some recently studies reported thevolatilization and hydrolysis of BDE-209were very difficult, it can easily accumulate in thesediments. With the increasing of PBDEs in the environment, the research of removal technologyof PBDEs has become increasingly important.The experimental research on the treatment of Decabrominated Diphenyl Ether(BDE-209)by the way of nuclear flocculation and IC anaerobic reactor. BDE-209was analysised by highperformance liquid chromatography (HPLC). Main research contents:(1) The optimumflocculation conditions were determined by orthogonal test and single factor test;(2) Design theIC anaerobic reactor;(3) Start-up the IC reactor and research the removal rate of COD andBDE-209in the starting process;(4) An experiment of the combination of nuclear flocculationand IC anaerobic reactor was performed to search the best effect.The experimental results are summarized as follows:(1) According to the orthogonal test, the initial conditions of pretreatment were determinedas following: The initial PH value was5.5, dosage of PAC was20ml, dosage of nuclearflocculant was25mg, slowly stirring time (100r/min) was30min. At the sme time, the order ofsingle factor test was determined as dosage of nuclear flocculant, dosage of flocculant, initial pHvalue and slowly stirring time.(2) The optimum parameters of nuclear flocculation were determined as following: Theinitial pH value was5.5, dosage of PAC was15ml, dosage of nuclear flocculant was25mg,slowly stirring time (100r/min) is30min. Under these conditions, we can achieve the optimumflocculation effect, the removal rate of BDE-209was about83%.(3) The IC reactor was chosen as the anaerobic reactor for the research. In the experiment,the column organic glass-made IC reactor was designed with570mm high, the effective volumeis4L.(4) Inoculation sludge in the start-up of the reactor was the digested sludge of Jiangxinzhousewage treatment plant, the amount was one-third of the volume of the IC reactor. The start-up of the reactor was completed within62days at room temperature(18~30℃). Granular sludge wasfound in the reactor on the14th day.,the size of granular sludge was continuously increased withthe increase of running time and volume load. When the start-up was completd, the volume loadget up to15.6kg COD/(m~3·d), the removal rate of COD was above70%.(5) According to the experiment of the combination of nuclear flocculation and IC anaerobicreactor, When the COD concentration of influent was about10000mg/L, the BDE-209was0.1mg/L, the removal rate of COD could reach78%, the removal rate of BDE-209was28.2%.