Junhong Tang

Techno-economic evaluation of a combined bioprocess for fermentative hydrogen production from food waste

In this study, the techno-economic evaluation of a combined bioprocess based on solid state fermentation for fermentative hydrogen production from food waste was carried out. The hydrogen production plant was assumed to be built in Hangzhou and designed for converting 3 ton food waste per day into hydrogen. The total capital cost (TCC) and the annual production cost (APC) were US

Recycling of typical difficult-to-treat e-waste: Synthesize zeolites from waste cathode-ray-tube funnel glass

583092 and US

Enhanced azo dye removal in a continuously operated up-flow anaerobic filter packed with henna plant biomass

88298.1/year, respectively. The overall revenue after the tax was US

Volatile fatty acids produced by co-fermentation of waste activated sludge and henna plant biomass.

146473.6/year. The return on investment (ROI), payback period (PBP) and internal rate of return (IRR) of the plant were 26.75%, 5 years and 24.07%, respectively. The results exhibited that the combined bioprocess for hydrogen production from food waste was feasible. This is an important study for attracting investment and industrialization interest for hydrogen production from food waste in the industrial scale.

Biohydrogen production in the suspended and attached microbial growth systems from waste pastry hydrolysate.

The disposal of waste cathode ray-tubes (CRTs) from old televisions and discarded computer monitors has become a major environmental concern worldwide. In this work, an open-loop recycling method was developed to synthesize zeolites using CRT funnel glass as the raw material. The effects of hydrothermal temperatures and pressure, n(SiO2/Al2O3) molar ratios and hydrothermal time on the resulting products were investigated. The results indicated that hydrothermal temperatures and pressure played critical roles in zeolite synthesis. Amorphous phases were detected at lower temperatures (80-100°C) and pressure (0.47-1.01bar) with n(SiO2/Al2O3)=2.0. At the temperature of 110°C (pressure 1.43bar), NaA formed with a mixture of NaP1 and Faujasite. With further increase in the temperature and pressure, the unstable NaA and Faujasite disappeared, and Hydroxysodalite developed. The influence of n(SiO2/Al2O3) ratios on resulting products revealed a single phase of NaA was formed at the ratio of 1.5 and a mixture of NaA and Faujasite at the ratio of 2.0. Prolonging hydrothermal time, however, could promote zeolite crystallization, and NaA gradually developed with an increase in the time from 2 to 6h at n(SiO2/Al2O3)=1.5. By comparison, crystallization phases were observed only when the time was longer than 8h at n(SiO2/Al2O3)=2.0.

Finite Dilution Inverse Gas Chromatography as a Versatile Tool To Determine the Surface Properties of Biofillers for Plastic Composite Applications.

Effects of henna plant biomass (stem) packed in an up-flow anaerobic bio-filter (UAF) on an azo dye (AO7) removal were investigated. AO7 removal, sulfanilic acid (SA) formation, and pseudo first-order kinetic constants for these reactions (kAO7 and kSA) were higher in the henna-added UAF (R2) than in the control UAF without henna (R1). The maximum kAO7 in R1 and R2 were 0.0345 and 0.2024 cm(-1), respectively, on day 18; the corresponding molar ratios of SA formation to AO7 removal were 0.582 and 0.990. Adsorption and endogenous bio-reduction were the main AO7 removal pathways in R1, while in R2 bio-reduction was the dominant. Organics in henna could be released and fermented to volatile fatty acids, acting as effective electron donors for AO7 reduction, which was accelerated by soluble and/or fixed lawsone. Afterwards, the removal process weakened over time, indicating the demand of electron donation and lawsone-releasing during the long-term operation of UAF.

A comprehensive review on the applications of coal fly ash

Anaerobic co-fermentation of waste activated sludge (WAS) and henna plant biomass (HPB) for the enhanced production of volatile fatty acids (VFAs) was investigated. The results indicated that VFAs was the main constituents of the released organics; the accumulation of VFAs was much higher than that of soluble carbohydrates and proteins. HPB was an advantageous substrate compared to WAS for VFAs production; and the maximum VFAs concentration in an HPB mono-fermentation system was about 2.6-fold that in a WAS mono-fermentation system. In co-fermentation systems, VFAs accumulation was positively related to the proportion of HPB in the mixed substrate, and the accumulated VFAs concentrations doubled when HPB was increased from 25% to 75%. HPB not only adjust the C/N ratio; the associated and/or released lawsone might also have a positive electron-shuttling effect on VFAs production.

Simultaneous dark fermentative hydrogen and ethanol production from waste bread in a mixed packed tank reactor

Waste pastry was hydrolyzed by glucoamylase and protease which were obtained from solid state fermentation of Aspergillus awamori and Aspergillus oryzae to produce waste pastry hydrolysate. Then, the effects of hydraulic retention times (HRTs) (4-12h) on hydrogen production rate (HPR) in the suspended microbial growth system (continuous stirred tank reactor, CSTR) and attached microbial growth system (continuous mixed immobilized sludge reactor, CMISR) from waste pastry hydrolysate were investigated. The maximum HPRs of CSTR (201.8mL/(h·L)) and CMISR (255.3mL/(h·L)) were obtained at HRT of 6h and 4h, respectively. The first-order reaction could be used to describe the enzymatic hydrolysis of waste pastry. The carbon content of the waste pastry remained 22.8% in the undigested waste pastry and consumed 77.2% for carbon dioxide and soluble microbial products. To our knowledge, this is the first study which reports biohydrogen production from waste pastry.

Surface properties studies of bivalve shell waste by the IGC technique: Probing its significant potential application in the polymer industry

An improved understanding of a filler’s surface properties is important for determining the most effective polymer reinforcement fillers. In this work, the surface characteristics of two biofillers, namely, clam shell modified by hydrochloric acid (AMF) and furfural (FMF), were investigated using inverse gas chromatography (IGC). The IGC results showed that the dispersive surface energy (γ(S)(D)) contributed the major part to the total surface energy for the biofillers. The values changed as a function of surface coverages, meaning that both samples were energetically fairly heterogeneous. The γ(S)(D) calculated with the Dorris–Gray method was larger than that calculated with the Schultz method, with a γ(S,Dorris–Gray)(D)/γ(S,Schultz)(D) ratio of 1.10. Compared to AMF, FMF possessed higher γ(S)(D) value; however, this difference was compensated by specific (acid–base) surface energy (γ(S)(AB)). Both samples predominantly interacted with ethanol and acetonitrile, implying an amphoteric nature of the material surfaces. Gutmann acid and base number profiles indicated that the surfaces of both samples were more basic in nature. The FMF showed a lower total work of cohesion (W(Coh)(total)) value compared to the AMF, which could lead to an increase in composite performance.