The role of pulse parameters on nanoparticle property is investigated self-consistently based on a couple of fluid model and aerosol dynamics model in a capacitively coupled parallel-plate acetylene（C2H2） discharge....The role of pulse parameters on nanoparticle property is investigated self-consistently based on a couple of fluid model and aerosol dynamics model in a capacitively coupled parallel-plate acetylene（C2H2） discharge. In this model, the mass continuity equation, momentum balance equation, and energy balance equation for neutral gas are taken into account.Thus, the thermophoretic force arises when a gas temperature gradient exists. The typical results of this model are positive and negative ion densities, electron impact collisions rates, nanoparticle density, and charge distributions. The simulation is performed for duty ratio 0.4/0.7/1.0, as well as pulse modulation frequency from 40 kHz to 2.7 MHz for pure C2H2 discharges at a pressure of 500 mTorr. We find that the pulse parameters, especially the duty ratio, have a great affect on the dissociative attachment coefficient and the negative density. More importantly, by decreasing the duty ratio, nanoparticles start to diffuse to the wall. Under the action of gas flow, nanoparticle density peak is created in front of the pulse electrode,where the gas temperature is smaller.展开更多
The coagulation bath system of carbon fiber precursor is a complicated and multivariable coupling system. Based on the model of industrial production,the full dynamic decoupling control of the coagulation bath system ...The coagulation bath system of carbon fiber precursor is a complicated and multivariable coupling system. Based on the model of industrial production,the full dynamic decoupling control of the coagulation bath system of carbon fiber precursor is achieved in combination with multivariable feed-forward-like decoupling and proportional-integral-differential( PID) control. Compared with the conventional PID decoupling control,the experiment results show that the proposed method has a better control effect. The use of the controller can achieve complete decoupling of three parameters from coagulation bath system. The method should have great applications.展开更多
Mobile emergency pilot water plant was used to carry out pilot study of KMnO4 pre-oxidation enhanced coagulation treating high-algae source water. Research showed that the optimal dosages of coagulant and KMnO4 in the...Mobile emergency pilot water plant was used to carry out pilot study of KMnO4 pre-oxidation enhanced coagulation treating high-algae source water. Research showed that the optimal dosages of coagulant and KMnO4 in the process were 6 and 0. 4- 0. 6 mg / L respectively. Under the dosage,removal rate of water turbidity after precipitation rose by 11% than simple coagulation,and removal rate of algae rose by 15%. Removal rates of total amount of odor and GSM by the process were respectively 73% and 59%. The removal rate of total amount of algae by KMnO4 preoxidation was 40%,and removal effect of THM precursors was obvious.展开更多
The effects of bisulfite-activated permanganate technology(PM/BS)as a pre-oxidation process on enhancing Microcystis aeruginosa(M.aeruginosa)removal by post coagulation were investigated.The results demonstrated that ...The effects of bisulfite-activated permanganate technology(PM/BS)as a pre-oxidation process on enhancing Microcystis aeruginosa(M.aeruginosa)removal by post coagulation were investigated.The results demonstrated that pretreatment with PM/BS process effectively promoted the algae removal by coagulation with Al2(SO4)3 as the coagulant and this phenomenon was more obvious with the increase of water hardness.Compared to the sole coagulation,PM/BS pre-oxidation combing with coagulation could neutralize the zeta potential of algal cells effectively,decrease the algal cell size,and lead to the formation of more compact flocs due to the in-situ generated Mn02.The effect of oxidant dosages on algal organic matter(AOM)was also studied and no obvious release of macromolecular substances was observed with the dosage of KMn04 increasing from 3.0 mg/L to 7.0 mg/L,suggesting the integrity of algal cells at a high KMn04 dosage.Moreover,PM/BS pre-oxidation could lead to the decrease of most analyzed disinfection by-products(DBPs)at a Al2(SO4)3 dosage of 40.0 mg/L.The algae removal efficiency was also significantly enhanced by PM/BS pre-oxidation in the test using real algae-laden water.This study indicated that PM/BS process might be a potential assistant technology for algae removal by subsequent coagulation.展开更多
基金Project supported by the Natural Science Foundation of Heilongjiang Province,China(Grant Nos.A2015011 and A2015010)the Postdoctoral Scientific Research Developmental Fund of Heilongjiang Province,China(Grant No.LBH-Q14159)+1 种基金the National Natural Science Foundation of China(Grant No.11404180)the Program for Young Teachers Scientific Research in Qiqihar University,China(Grant No.2014k-Z11)
文摘The role of pulse parameters on nanoparticle property is investigated self-consistently based on a couple of fluid model and aerosol dynamics model in a capacitively coupled parallel-plate acetylene（C2H2） discharge. In this model, the mass continuity equation, momentum balance equation, and energy balance equation for neutral gas are taken into account.Thus, the thermophoretic force arises when a gas temperature gradient exists. The typical results of this model are positive and negative ion densities, electron impact collisions rates, nanoparticle density, and charge distributions. The simulation is performed for duty ratio 0.4/0.7/1.0, as well as pulse modulation frequency from 40 kHz to 2.7 MHz for pure C2H2 discharges at a pressure of 500 mTorr. We find that the pulse parameters, especially the duty ratio, have a great affect on the dissociative attachment coefficient and the negative density. More importantly, by decreasing the duty ratio, nanoparticles start to diffuse to the wall. Under the action of gas flow, nanoparticle density peak is created in front of the pulse electrode,where the gas temperature is smaller.
基金the Key Project of the National Nature Science Foundation of China(No.61134009)Program for Changjiang Scholars and Innovation Research Team in University from the Ministry of Education,China(No.IRT1220)+1 种基金Specialized Research Fund for Shanghai Leading Talents,Project of the Shanghai Committee of Science and Technology,China(No.13JC1407500)the Fundamental Research Funds for the Central Universities,China(No.2232012A3-04)
文摘The coagulation bath system of carbon fiber precursor is a complicated and multivariable coupling system. Based on the model of industrial production,the full dynamic decoupling control of the coagulation bath system of carbon fiber precursor is achieved in combination with multivariable feed-forward-like decoupling and proportional-integral-differential( PID) control. Compared with the conventional PID decoupling control,the experiment results show that the proposed method has a better control effect. The use of the controller can achieve complete decoupling of three parameters from coagulation bath system. The method should have great applications.
基金Supported by Major Science and Technology Program for Water Control and Treatment,China(2012ZX07404-003)Taishan Scholar Post Project,China(ts200640025)
文摘Mobile emergency pilot water plant was used to carry out pilot study of KMnO4 pre-oxidation enhanced coagulation treating high-algae source water. Research showed that the optimal dosages of coagulant and KMnO4 in the process were 6 and 0. 4- 0. 6 mg / L respectively. Under the dosage,removal rate of water turbidity after precipitation rose by 11% than simple coagulation,and removal rate of algae rose by 15%. Removal rates of total amount of odor and GSM by the process were respectively 73% and 59%. The removal rate of total amount of algae by KMnO4 preoxidation was 40%,and removal effect of THM precursors was obvious.
基金supported by the National Natural Science Foundation of China(No.21976133)。
文摘The effects of bisulfite-activated permanganate technology(PM/BS)as a pre-oxidation process on enhancing Microcystis aeruginosa(M.aeruginosa)removal by post coagulation were investigated.The results demonstrated that pretreatment with PM/BS process effectively promoted the algae removal by coagulation with Al2(SO4)3 as the coagulant and this phenomenon was more obvious with the increase of water hardness.Compared to the sole coagulation,PM/BS pre-oxidation combing with coagulation could neutralize the zeta potential of algal cells effectively,decrease the algal cell size,and lead to the formation of more compact flocs due to the in-situ generated Mn02.The effect of oxidant dosages on algal organic matter(AOM)was also studied and no obvious release of macromolecular substances was observed with the dosage of KMn04 increasing from 3.0 mg/L to 7.0 mg/L,suggesting the integrity of algal cells at a high KMn04 dosage.Moreover,PM/BS pre-oxidation could lead to the decrease of most analyzed disinfection by-products(DBPs)at a Al2(SO4)3 dosage of 40.0 mg/L.The algae removal efficiency was also significantly enhanced by PM/BS pre-oxidation in the test using real algae-laden water.This study indicated that PM/BS process might be a potential assistant technology for algae removal by subsequent coagulation.
