Papers by Author: Hui Xia Feng

Abstract: Fe₂O₃/H₂O₂, a kind of Fenton-like agent, was used to degrade an anion surfactant, sodium dodecyl benzene sulfonate(SDBS)，in an aqueous solution. Through a number of batch degradation experiments under various conditions, it was found that the reactivity of the system increased by increasing temperature. The SDBS degradation ratio will increase by, respectively, increasing H₂O₂ concentration and Fe₂O₃ dosage at some extent, but too high H₂O₂ concentration or Fe₂O₃ dosage will decrease the degradation efficiency. pH value has some influences on the reactivity of the system; from 2 to 10, the system maintains high efficiencies all the time. It also can be seen that Fe₂O₃/H₂O₂ Fenton-like reaction almost has the same efficiency as homogeneous Fenton reaction, while the former has a widely pH range (2-10), and Fe₂O₃ can be separated easily and has no secondary pollutants.

Abstract: The corrosion inhibition behaviour of four selected Mannich bases compounds,namely 3-((N-methyl,N-phenyl)-methyl)2,4-Acetylacetone(MPMAA),3-((N-phenyl)-methyl) 2,4-Acetylacetone (PMAA),3-((N, N-diethyl)-methyl) 2, 4-Acetylacetone(DMAA) and 3-((N, N-methyl)-methyl) 2, 4-Acetylacetone (MMAA) as corrosion inhibitors for mild steel in 1M HCl solutions. Tafel polarization methods were performed to determine the corrosion parameters and inhibition efficiencies. Experimental results showed that PMAA is an excellent inhibitor for mild steel corrosion in 1M HCl solutions; showing a maximum efficiency 92.3% at concentration of 40mg/L. Polarization studies showed that the Mannich bases compounds can be regarded as mixed-type inhibitors and the inhibition efficiency of the four inhibitors followed the order PMAA > MPMAA > DMAA > MMAA. Then scanning electron microscope (SEM)techniques were also employed to examine the mechanism of corrosion inhibition property.

Abstract: In sequencing batch reactor aerobic granular sludge was cultivated, and the influence of influent C/N ratio to aerobic granular sludge was studied. The results showed that the granulation and the settling ability of the sludge were poor in high C/N, however, low C/N was beneficial to the accumulation of microorganism in reactor and MLSS could reach to as high as 8740 mg/L. Lower C/N ratio would lead to increase of particle size and disintegrate of loose structure and overgrowth on filamentous microbe, these were disadvantage of the stability of the system. It was not obvious that influent C/N ratio affected on the organic removal. The COD removal maintained at 87% after the preliminary form particles were formed in reactor. When C/N ratio was 100:15~100:35, the phosphorus removal efficiency was good. If C/N ratio was too high or too low, the formation of sludge granulation would be affected in the process. The influence of C/N ratio to ammonia nitrogen removal efficiency was obvious. While C/N ratio was 100:10, granular sludge had good simultaneous nitrification and denitrification performance, and the average removal of ammonia nitrogen attained to 91%. But low C/N ratio was able to inhibit the activity of nitrifying bacteria and denitrifying bacteria. At that time, ammonia nitrogen removal rate declined sharply in the system.

Abstract: Fe₂O₃ and Fe₂O₃/attapulgite(ATP) catalyst was used for Fenton reaction to degrade an anion surfactant, sodium dodecyl benzene sulfonate(SDBS)，in an aqueous solution. Comparative studies indicated that Fe₂O₃/ATP-catalyzed Fenton system and Fe₂O₃-catalyzed Fenton system have the same catalysis capability. These two systems all have a widely pH range (2-10), and the catalysts can be reused and have no secondary pollutants. It also can be seen that Fe₂O₃/ATP-catalyzed Fenton-like reaction has much efficiency than Fe₂O₃-catalyzed Fenton reaction.

Abstract: Fe₂O₃/attapulgite(ATP) catalyst was successfully prepared for Fenton reaction to degrade an anion surfactant, sodium dodecyl benzene sulfonate(SDBS)，in an aqueous solution. BET, SEM, FT-IR were performed to characterize Fe₂O₃/ ATP catalyst. Comparative studies indicated that the SDBS degradation ratios were much higher in presence of Fe₂O₃/ATP and H₂O₂ than those in presence of Fe₂O₃/ATP or H₂O₂ only, which suggested that the Fe₂O₃/ATP-catalyzed Fenton-like reaction governed the SDBS removal process. It also can be seen that Fe₂O₃/ATP-catalyzed Fenton-like reaction almost has the same efficiency as homogeneous Fenton reaction, while the former can be reused and has no secondary pollutants.

Abstract: Fe₂O₃/attapulgite(ATP) catalyst was successfully prepared for Fenton reaction to degrade anion an surfactant, Sodium dodecyl benzene sulfonate(SDBS). Through a number of batch degradation experiments under various conditions, it was found that the reactivity of the system increased by increasing Fe₂O₃/ATP dosage and temperature. The SDBS degradation ratio will increase with increasing H₂O₂ concentration at some extent. But too high H₂O₂ concentration will make degradation efficiency decrease. The system maintains high efficiencies all experimental pH value(2-10).

Abstract: Sulfur dioxide is one of the major pollutants resulting from fuel combustion. In this study, CaO and attapulgite were utilized as raw material for synthesizing CaO/attapulgite(CaO/ATP) desulfurizer. The performance of samples was studied in dynamic conditions. Major factors affecting the desulfurization such as weight ratio of CaO to total, types of modifiers, desulfurizer particle size, bed temperature were investigated. The desulfurization agent synthesized under optimal synthesis conditions with an CaO content of 30 wt% and an NaOH modifier, and the desulfurization reaction processed under optimal synthesis conditions with water content of 20~30wt%, a particle size of 1/10 of desulfurization tower diameter and room temperature, exhibit sulfur tolerance of 17.97wt%.

Abstract: In this paper, flocculation process was applied to the treatment of potato starch wastewater. The Influence of flocculent types, dosage of flocculants, pH, dosage of coagulant aid polyacrylamide (PAM) and sedimentation time on flocculation efficiency was studied, and principal factors of influence flocculation pretreatment of potato starch wastewater and the optimum flocculation conditions were determined by orthogonal experiment. On the optimum conditions which had the advantage of better treatment efficiency with chemical oxygen demand (COD) removal rate of 40.55% , the suitable pH(7) in favour of the following biological treatment, high yield of sludge of 1.59g/L wastewater which could be used as animal feed or fertilizer and increase economic benefits.

Abstract: With water as solution, ferric chloride (FeCl₃∙6H₂O) as oxidant, sulfuric acid (SA) as dopant, prepared polypyrrole/montmorillonite (PPy/MMT) via chemical oxidation polymerization. We researched the effect that the content of the polypyrrole to the conductivity of composite in the condition of n (Py): n (FeCl₃∙6H₂O): n (SA) =1: 1: 0.5. Using IR, XRD, IR, TEM and SEM modern characterization methods to characterize internal structure of composites, the results show PPy were intercalated into the inner space of MMT. The surfaces of MMT intercalated are coated by conductive polypyrrole particles with equal size and uniform arrangement. MMT dispersed among conductive polypyrrole matrix and overlapped each other, which formed a conductive network. Using percolation theory, we analyzed the conductivity of composites that conform to the classical statistical percolation theory.

Abstract: Potassium permanganate process is an advanced oxidation technique that can provide a resolution removing organic matter in contaminated water. In this paper, the combination of composite potassium permanganate and a certain coagulant used in this process, which it was particularly suited to rapidly oxidize and degrade pollutants. It was an effective enhanced coagulation, advanced oxidation technique that could be conducted in a normal micro-polluted water environment. A series of experiment results demonstrated that the best adding quantity of composite potassium permanganate was 1.5-3.0mg/l, the best adding quantity of PFS as the coagulant was 25mg/l. Under the above conditions, potassium permanganate oxidation obviously reduced to each pollution index and greatly improved the water quality of purification of micro-polluted water. Furthermore, the organic removal rate with composite potassium permanganate was more than the unitary potassium permanganate process and the current traditional process.