A new recycling hydrolytic-aerobic combined process was developed to treat the high concentration organic wastewater. Simulated wastewater containing 10 g·L^-1 starch with a CODcr value of 10000 mg·L^-1 wasu...A new recycling hydrolytic-aerobic combined process was developed to treat the high concentration organic wastewater. Simulated wastewater containing 10 g·L^-1 starch with a CODcr value of 10000 mg·L^-1 wasused. At first, the hydrolytic degradation and aerobic degradation process were examined in two batch reactors, respectively. In the stand-alone hydrolytic process, starch in the wastewater almost disappeared after 11 h treatment, but CODCr remained as high as 5803mg·L^-1 after two days. In the aerobic process, the biodegradation rate of starch was much slower during the first 11 h than that in the hydrolytic process, although the CODCr removal efficiency reached 89.6% and more than 90% starch could be degraded after 37.5 h. To determine the interaction effects of the two processes, a series of hydrolytic-aerobic combinations were examined in details. Hydrolytic process played an important role in the whole recycle combination process as it could improve the biodegradability of the high concentration starch wastewater. However, from the other experiments, the negative effect of hydrolytic acidification was found in the hydrolytic-aerobic combination, which suggested that the aerobic microorganisms needed time to adapt themselves to the acidic environment. The effect of the degrading time, which was spent in the hydrolytic and aerobic unit, and the number of circulations, with which the wastewater went through the two units were investigated. It was found that a recycle combination of 6 h hydrolytic process with 12 h aerobic process was highly effective and potentially economical, in which the final removal efficiency of CODcr and efficiency of starch degradation reached 94.1% and 98.8%, respectively.展开更多
Systematic studies on the treatment and reuse of the acid industrial wastewatercontaining Sodium 2-Naphthylsulfonate (β-salt) from 2--Naphthanol of production processby ND--910 resin (made by self)is reported in this...Systematic studies on the treatment and reuse of the acid industrial wastewatercontaining Sodium 2-Naphthylsulfonate (β-salt) from 2--Naphthanol of production processby ND--910 resin (made by self)is reported in this paper.Under the operation conditionsof initial β-salt concentration of 10000-25000mg/L and initial CODcr of 2000040000mg/L, the removal rates of Sodium 2-Naphthylsulfonate and CODcr are over 95%and over 89%, respectively. The effluent can be discharged directly after biologicaldegradation. The working sorption capacity of ND-910 Resin for β-salt is over 230g/Kg.An alkali-water wash procedure is utilized to regenerate resin and the reclaiming rate ofβ-salt is over 98%.展开更多
A sequential three-step programming method is proposed for determining the minimum flowrate of fresh water and corresponding regenerated water in water-using system of single contaminant with regeneration reuse. In st...A sequential three-step programming method is proposed for determining the minimum flowrate of fresh water and corresponding regenerated water in water-using system of single contaminant with regeneration reuse. In step 1, a programming with the objective of min fws is used to determine the minimum flowrate of fresh water, in which the mathematical representation is a mixed integer nonlinear programming (MINLP1). Then under the same constraints with step 1, a programming with the objective of min freg in step 2 and a programming with the objective of min Cr in step 3 are subsequently used to determine the minimum flowrate of regenerated water and the minimum inlet concentration to regeneration process corresponding to the minimum flowrate of fresh water based on step 1. The method is easy to apply because we only need to change the objective function but keep the constraints constant to go along the following steps after step 1. In addition, the relationship between the fresh water flowrate required, fws and inlet concentration to regeneration process, Cr, is investigated. It is found that there exist three relationships between fws and Cr, which indicate three possibilities for C\>: below the pinch, above the pinch or at the pinch. Therefore, a new conclusion is drawn, which differs from that 'regeneration of water at pinch minimizes fresh water flowrate' derived in literature and indicates that in some cases, regeneration at other point also minimizes fresh water flowrate.展开更多
The paper presents a procedure to design water network. First of all, water reuse system, water regeneration reuse system (including regeneration recycle) and wastewater treatment system are designed separately. But t...The paper presents a procedure to design water network. First of all, water reuse system, water regeneration reuse system (including regeneration recycle) and wastewater treatment system are designed separately. But the interaction between different parts demands that each part is designed iteratively to optimize the whole water network. Therefore, on the basis of the separated design a water netvrork superstructure including reuse, regeneration and wastewater treatment is established from the system engineering point of view. And a multi-objective adaptive simulated annealing genetic algorithm is adopted to simultaneously integrate the overall water netvrork to balance the economic and environmental effects. The algorithm overcomes the defect of local optimum of simulated annealing (SA), avoids the pre-maturation of genetic algorithm (GA) and finds a set of solutions (pareto front) in acceptable computer time. Prom the pareto front, a point with minimum fresh water consumption will be extended to zero discharge as our ultimate goal.展开更多
State space approach is an effective method to mass-exchange network (MEN) synthesis. By decomposing the network into two interactive parts, a distribution network and a process operator, the synthesis problem can be ...State space approach is an effective method to mass-exchange network (MEN) synthesis. By decomposing the network into two interactive parts, a distribution network and a process operator, the synthesis problem can be formulated into a mixed integer nonlinear programming (MINLP) model. In this article, a generalized state space model based on typical MEN is established and verified in two cases. A new asymmetrical operator and cost index are also adopted to speed up the solution process. The results demonstrate the efficiency of the proposed approach.展开更多
The wastewater from naphthol As-E production process was treated with macroporous polymeric adsorbent NDA-222. Naphthol As-E and 2,3-acid in the wastewater could be removed completely and the Total Organic Carbon (TOC...The wastewater from naphthol As-E production process was treated with macroporous polymeric adsorbent NDA-222. Naphthol As-E and 2,3-acid in the wastewater could be removed completely and the Total Organic Carbon (TOC) of the wastewater was decreased more than 98% from 1655mg/L to less than 30mg/L. The adsorbates could be desorbed completely with NaOH aqueous solution.展开更多
基金Supported by the National Natural Science Foundation of China (No. 20076037).
文摘A new recycling hydrolytic-aerobic combined process was developed to treat the high concentration organic wastewater. Simulated wastewater containing 10 g·L^-1 starch with a CODcr value of 10000 mg·L^-1 wasused. At first, the hydrolytic degradation and aerobic degradation process were examined in two batch reactors, respectively. In the stand-alone hydrolytic process, starch in the wastewater almost disappeared after 11 h treatment, but CODCr remained as high as 5803mg·L^-1 after two days. In the aerobic process, the biodegradation rate of starch was much slower during the first 11 h than that in the hydrolytic process, although the CODCr removal efficiency reached 89.6% and more than 90% starch could be degraded after 37.5 h. To determine the interaction effects of the two processes, a series of hydrolytic-aerobic combinations were examined in details. Hydrolytic process played an important role in the whole recycle combination process as it could improve the biodegradability of the high concentration starch wastewater. However, from the other experiments, the negative effect of hydrolytic acidification was found in the hydrolytic-aerobic combination, which suggested that the aerobic microorganisms needed time to adapt themselves to the acidic environment. The effect of the degrading time, which was spent in the hydrolytic and aerobic unit, and the number of circulations, with which the wastewater went through the two units were investigated. It was found that a recycle combination of 6 h hydrolytic process with 12 h aerobic process was highly effective and potentially economical, in which the final removal efficiency of CODcr and efficiency of starch degradation reached 94.1% and 98.8%, respectively.
文摘Systematic studies on the treatment and reuse of the acid industrial wastewatercontaining Sodium 2-Naphthylsulfonate (β-salt) from 2--Naphthanol of production processby ND--910 resin (made by self)is reported in this paper.Under the operation conditionsof initial β-salt concentration of 10000-25000mg/L and initial CODcr of 2000040000mg/L, the removal rates of Sodium 2-Naphthylsulfonate and CODcr are over 95%and over 89%, respectively. The effluent can be discharged directly after biologicaldegradation. The working sorption capacity of ND-910 Resin for β-salt is over 230g/Kg.An alkali-water wash procedure is utilized to regenerate resin and the reclaiming rate ofβ-salt is over 98%.
基金Supported by the National Fundamental Research Development Program of China(No.2000026308).
文摘A sequential three-step programming method is proposed for determining the minimum flowrate of fresh water and corresponding regenerated water in water-using system of single contaminant with regeneration reuse. In step 1, a programming with the objective of min fws is used to determine the minimum flowrate of fresh water, in which the mathematical representation is a mixed integer nonlinear programming (MINLP1). Then under the same constraints with step 1, a programming with the objective of min freg in step 2 and a programming with the objective of min Cr in step 3 are subsequently used to determine the minimum flowrate of regenerated water and the minimum inlet concentration to regeneration process corresponding to the minimum flowrate of fresh water based on step 1. The method is easy to apply because we only need to change the objective function but keep the constraints constant to go along the following steps after step 1. In addition, the relationship between the fresh water flowrate required, fws and inlet concentration to regeneration process, Cr, is investigated. It is found that there exist three relationships between fws and Cr, which indicate three possibilities for C\>: below the pinch, above the pinch or at the pinch. Therefore, a new conclusion is drawn, which differs from that 'regeneration of water at pinch minimizes fresh water flowrate' derived in literature and indicates that in some cases, regeneration at other point also minimizes fresh water flowrate.
文摘The paper presents a procedure to design water network. First of all, water reuse system, water regeneration reuse system (including regeneration recycle) and wastewater treatment system are designed separately. But the interaction between different parts demands that each part is designed iteratively to optimize the whole water network. Therefore, on the basis of the separated design a water netvrork superstructure including reuse, regeneration and wastewater treatment is established from the system engineering point of view. And a multi-objective adaptive simulated annealing genetic algorithm is adopted to simultaneously integrate the overall water netvrork to balance the economic and environmental effects. The algorithm overcomes the defect of local optimum of simulated annealing (SA), avoids the pre-maturation of genetic algorithm (GA) and finds a set of solutions (pareto front) in acceptable computer time. Prom the pareto front, a point with minimum fresh water consumption will be extended to zero discharge as our ultimate goal.
基金Supported by the National Natural Science Foundation of China (NSF 29836140).
文摘State space approach is an effective method to mass-exchange network (MEN) synthesis. By decomposing the network into two interactive parts, a distribution network and a process operator, the synthesis problem can be formulated into a mixed integer nonlinear programming (MINLP) model. In this article, a generalized state space model based on typical MEN is established and verified in two cases. A new asymmetrical operator and cost index are also adopted to speed up the solution process. The results demonstrate the efficiency of the proposed approach.
文摘The wastewater from naphthol As-E production process was treated with macroporous polymeric adsorbent NDA-222. Naphthol As-E and 2,3-acid in the wastewater could be removed completely and the Total Organic Carbon (TOC) of the wastewater was decreased more than 98% from 1655mg/L to less than 30mg/L. The adsorbates could be desorbed completely with NaOH aqueous solution.
