Time filter

Source Type

Meng P.,Shandong University | Meng P.,Taishan University | Pei H.,Shandong University | Pei H.,Shandong Provincial Engineering Center on Environmental Science and Technology | And 4 more authors.
Bioresource Technology | Year: 2014

Microorganisms play a vital role in degradation of multiple pollutants in constructed wetlands (CWs). Thus, the search for methods to improve microbial degradation in CWs is crucial. This study provides a review of critical parameters including availability of organic carbon, redox condition, temperature, pH, presence of plants, media characteristics and their influences on microbial processes. Current strategies focusing on regulation of carbon source, redox condition, and choice of substrates to enhance microbial activity in CWs are also described. A special emphasis is given to the application of bioaugmentation to enhance microbial activities in wetland in future research. © 2014 Elsevier Ltd.

Sun F.,Shandong University | Pei H.-Y.,Shandong University | Pei H.-Y.,Shandong Provincial Engineering Center on Environmental Science and Technology | Hu W.-R.,Shandong University | And 4 more authors.
Separation and Purification Technology | Year: 2013

The damage of cyanobacterial cells and the release of their intracellular microcystins (MCs) present an enormous threat to drinking water. Effective control of cyanobacteria both in coagulation and floc storage processes plays an important significance in avoiding the additional release of MCs during water treatment. In this paper, the cell integrity acted as a key factor to assess the damage of polyaluminum chloride (PACl) coagulation/flocculation process on Microcystis aeruginosa cells. Effects of coagulant dose, coagulation stirring and floc storage time were comprehensively evaluated to regulate M. aeruginosa cell lysis and MCs release. Results showed that all cells were removed intactly by the surface charge neutralization with PACl in the coagulation process. While in floc storage process, PACl caused obvious damage to cells and led to a large amount of MCs release after the protective effects of EPSs produced by M. aeruginosa cells were destroyed or decomposed. Coagulation stirring could cause cells lyse earlier than the natural lysis, but this damage was slighter than that of coagulant PACl, which obviously aggravate the cell lysis of M. aeruginosa in flocs after 2 days. This study is not only significant for the effective removal of cyanobacterial cells from drinking water sources but instructive for the prevention of secondary pollution of MCs during water recirculation from the sludge treatment to the head of the process. © 2013 Elsevier B.V. All rights reserved.

Song M.,Shandong University | Pei H.,Shandong University | Pei H.,Shandong Provincial Engineering Center on Environmental Science and Technology | Hu W.,Shandong University | And 2 more authors.
Bioresource Technology | Year: 2013

In this study, the potential of 10 algae species for biodiesel production were evaluated by determining their fatty acid profiles, biodiesel properties besides growth rate, biomass concentration and lipid productivity. Among seven strains with high growth and lipid accumulation properties, excluding Kirchneriella lunaris and Lyngbya kuetzingii, five species Selenastrum capricornutum, Chlorella vulgaris, Scenedesmus obliqnus, Phaeodactylum tricornutum and Isochrysis sphacrica were finally selected for biodiesel production due to their possessing higher lipid productivity and favorable biodiesel properties. The best strain was P.tricornutum, with lipid content of 61.43±0.95%, lipid productivity of 26.75mgL-1 d-1, the favorable fatty acid profiles of C16-C18 (74.50%), C14:0 (11.68%) and C16:1 (22.34%) as well as suitable biodiesel properties of higher cetane number (55.10), lower iodine number (99.2gI2/100g) and relatively low cloud point (4.47°C). © 2013 Elsevier Ltd.

Han F.,Shandong University | Pei H.,Shandong University | Pei H.,Shandong Provincial Engineering Center on Environmental Science and Technology | Hu W.,Shandong University | And 4 more authors.
Energy Conversion and Management | Year: 2015

Specifically growth-state-based schemes for cultivation optimization of microalgae Chlorella sp. were researched for the lipid enhancement in biodiesel production, compared with common optimization experiments. The optimized conditions of initial cell density, light intensity and aeration flow in common optimization were about 0.45 cm-1 (in OD686, i.e. 0.15 g/L), 6000 lux and 0.2 vvm (mL mL-1 min-1) respectively, taking into account the lipid yield and energy consumption. The maximum dry weight and lipid content were 1.2 g/L and 33.6% respectively. Then three specific schemes for cultivation conditions adjustment were conducted to study the effects of changing conditions along with growth state for the potential enhancement of biomass and lipid production. The results showed that excellent enhancement of both biomass dry weight of 1.9 g/L and lipid yield of 0.6 g/L was achieved. The new and specific cultivation method significantly improved the biomass and lipid production by 52.7% and 64.7% respectively, compared with the aforementioned three common optimization experiments. The GC-MS analysis indicated that C16-C18 components accounted for more than 90% of fatty acid, and the fatty acid had better properties than that in common cultivation. © 2014 Elsevier Ltd. All rights reserved.

Xu H.,Shandong University | Pei H.,Shandong University | Pei H.,Shandong Provincial Engineering Center on Environmental Science and Technology | Xiao H.,Shandong University | And 2 more authors.
AIP Advances | Year: 2015

Si is well-known semiconductor that has a fundamental bandgap energy of 1.12 eV. Its photogenerated electrons in the conduction band can react with the ubiquitous oxygen molecules to yield O2- radicals, but the photogenerated holes in the valance band can't interact with OH- to produce OH radicals. In this paper, we study the degradation of methyl orange (MO) by hydrogen-terminated porous Si (H-PSi) in the presence and in the absence of light. The absorption spectra of the degraded MO solutions indicated that the H-PSi had superior degradation ability. In the dark, the reduction of dye occurs simply by hydrogen transfer. Under room light, however, some of the dye molecules can be reduced by hydrogen transfer first and then decomposed in the conduction and valance bands. This result should be ascribed to its wide band gap energies centered at 1.79-1.94 eV. © 2015 Author(s).

Discover hidden collaborations