Papers by Author: Lian Jun Wang

Abstract: Two integrated processes, ultrafiltration and iron-carbon micro-electrolysis, in industry-scale test for treating abandoned drawing lubricant with water quantity of 1000L/h were studied. In the process of stable operation, 83.5% to 93.4% chemical oxygen demand (COD) and more than 99% turbidity was removed by ultrafiltration. Then throughout the technology of iron-carbon micro-electrolysis, the COD of ultrafiltration concentration could be further eliminated 95%. With the treatment of integrated processes, the abandoned drawing lubricant got effectively disposal. The research also showed that this combined process had broad application prospects in the treatment of all kinds of metal-working fluids, eg. cutting fluid, lubricating fluid and emulsified liquid.

Abstract: Sulfonated poly(arylene ether sulfone)s (SPAES) with different sulfonation degree (DS) were synthesized through aromatic nucleophilic substitution polymerization, and subsequently used to prepare ultrafiltration membranes by the phase inversion method. The performance and morphological structures of the prepared SPAES membranes were investigated and evaluated for ultrafiltration applications. With DS of 3%, the prepared ultrafiltration membrane showed the largest water permeability with bovine serum albumin rejection over 99%.

Abstract: In this work, tin dioxide was chosen to make tubular ceramic membrane. The morphology was characterized by SEM, XRD and Poremaster. The SEM analysis reveals that the distribution of membrane pore is uniform. The average pore size is 2 μm. Pure water flux is 5.26 m3^{Superscript text}•m^-2•h-¹ at 0.1 Mpa. Porosity of tin dioxide membrane is 40%.

Abstract: The novel Ti/PbO₂ electrodes have been prepared by electrodeposition and anodization. The electrodes were characterized by SEM, XRD and linear sweep voltammetry (LSV). The SEM and XRD analysis reveal that Sn in the Pb-Sn alloy changes the β-PbO₂/α-PbO₂ ratio and the structure of the PbO2 layer. Sn content in Pb-Sn alloy is beneficial for the formation of β-PbO₂. LSV analysis shows that the novel Ti/PbO2 electrodes have high oxygen evolution potential, which can reach 1.75V.

Abstract: The chemically activated method has been applied to prepare activated carbon from the incinerated medical waste. The preparation process of activated carbon was investigated under various conditions set by several factors, including the type of active agent used, the ratio of active agent and carbonized product, the activation temperature, the dwell time and heating rate. The results demonstrated KOH had shown the best performance as the active agent. The optimal preparation conditions could be described as follows: ratio of KOH and carbonized product 3:1, heating rate 5 °C/min, activation temperature 800 °C with activation time 1 hour. The activated carbon prepared under the optimal preparation conditions showed good adsorption performance. The adsorption capacities for methylene blue and iodine were 24~28 ml/0.1g and 965~1150 mg/g, respectively. BET surface area of activated carbon obtained was as high as 985.1634~1387.4586 m²/g. The activated carbon prepared from medical waste exhibited excellent characteristics of sorbent.

Abstract: The constructed Sb-doped SnO2 electrode was obtained for electrochemical degradation of RDX. The influences of current density and initial concentration of RDX on electrochemical degradation of RDX were studied. Kinetics analysis shows that the electrochemical degradation of RDX follows the pseudo first-order reaction. The mechanism of electrochemical degradation of RDX was also discussed.

Abstract: Recalcitrant and toxic organic pollutants such as aniline from numerous industrial wastewaters can not be efficiently removed using the conventional methods. This study reported a concept for mineralization of aniline in an anoxic reactor, where enhanced biodegradation of aniline were achieved under anoxic conditions. The results indicated that with the presence of nitrate, the degradation rate of aniline was greatly improved compared with the absence of nitrate. From the UV-vis adsorption spectra, COD analysis and denitrification performance analysis, it could be inferred that the cleavage of benzene ring of aniline occurred, aniline could be mineralization by microorganisms under the anoxic condition. However, aniline removal rate was lower compared to aerobic degradation process, and thus needs a significant improvement.

Abstract: The geopolymer was chosen to immobilize the municipal solid waste incineration (MSWI) fly ash because of its strong fixing capacity for heavy metals. The fly ash-based geopolymer was synthesized from metakaolinite with MSWI fly ash under activation of sodium silicate solution, and then cured at relative humidity (RH) between 40% and 90% at 20°C. The ability of immobilization of heavy metals in MSWI fly ash with the geopolymer was evaluated in terms of the compressive strength and leaching concentration. The experimental results confirmed that the compressive strength of the resulting solidified body could achieve 35.13 MPa after 7 days of curing. Meanwhile, the leaching concentrations of Pb, Zn, Cu and Cr were 0.0230 mg/kg, 0.186 mg/kg, 0.231 mg/kg, and 6.56 mg/kg, respectively. We confirm that geopolymerisation is an effective alternative in the disposal of various hazardous wastes containing heavy metals.