Applications of functional nanoparticle-stabilized surfactant foam in petroleum-contaminated soil remediation.

Surfactant foam (SF) can be used to remediate petroleum-contaminated soil because of its easy transfer to inhomogeneous and low-permeability formations. Nanoparticles (NPs) not only stabilize SF under extreme conditions but also impart various functions, aiding the removal of petroleum contaminants. This review discusses the stabilization mechanisms of nanoparticle-stabilized SF (NP-SF) as well as the effects of NP size, chargeability, wettability, and NP-to-surfactant ratio on foam stability.

Coupling surfactants with ISCO for remediating of NAPLs: Recent progress and application challenges.

Non-aqueous phase liquids (NAPLs) pose a serious risk to the soil-groundwater environment. Coupling surfactants with in situ chemical oxidation (ISCO) technology is a promising strategy, which is attributed to the enhanced desorption and solubilization efficiency of NAPL contaminants. However, the complex interactions among surfactants, oxidation systems, and NAPL contaminants have not been fully revealed.

The combined effect of Diversispora versiformis and sodium bentonite contributes on the colonization of Phragmites in cadmium-contaminated soil.

To promote the colonization of Phragmites in Cd polluted, nutrient deprived and structural damaged soil, the combined remediation using chemical and microbial modifiers were carried out in potting experiments. The co-application of Diversispora versiformis and sodium bentonite significantly improved the soil structure and phosphorus utilization of the plant, while decreasing the content of cadmium bound by diethylenetriaminepentaacetic acid by 77.72%.

The effects of biochar and dredged sediments on soil structure and fertility promote the growth, photosynthetic and rhizosphere microbial diversity of Phragmites communis (Cav.) Trin. ex Steud.

The improvement of urban river revetment soil is conducive to promote the growth of pioneer plants which can accelerate the restoration of ecosystems. How to effectively amend soil structure and composition to provide a suitable soil rhizosphere for rapid plant expansion is essential to be solved in the study. Biochar and lake dredged sediments were used to amend an urban river bank soil, where compaction and lack of mineral nutrition hindered the growth of Phragmites.

Using non-ionic surfactant as an accelerator to increase extracellular lipid production by oleaginous yeast Cryptococcus curvatus MUCL 29819.

The aim of this work was to study the effects of non-ionic surfactant on the accumulation of total microbial lipids and extracellular lipid by Cryptococcus curvatus MUCL 29819 with acetic acid as carbon source. Compared with Brij 58 and Triton X-100, Brij 58 most increased the total lipids, with a yield up to 2.84 g/L (extracellular lipid up to 47%).

Enhancement of extracellular lipid production by oleaginous yeast through preculture and sequencing batch culture strategy with acetic acid.

Oleaginous yeast Cryptococcus curvatus MUCL 29819, an acid-tolerant lipid producer, was tested to spill lipids extracellularly using different concentrations of acetic acid as carbon source. Extracellular lipids were released when the yeast was cultured with acetic acid exceeding 20g/L. The highest production of lipid (5.

Bioconversion of mixed volatile fatty acids into microbial lipids by Cryptococcus curvatus ATCC 20509.

The oleaginous yeast Cryptococcus curvatus ATCC 20509 can use 5-40g/L of acetic, propionic, or butyric acid as sole carbon source to produce lipids. High concentrations (30g/L) of mixed volatile fatty acids (VFAs) were used to cultivate C. curvatus to explore the effects of different ratios of mixed VFAs on lipid production and composition.

Microbial conversion of mixed volatile fatty acids into microbial lipids by sequencing batch culture strategy.

Four mixed volatile fatty acids (VFAs) were used as sole carbon source to culture oleaginous yeast Cryptococcus curvatus by sequencing batch culture strategy. The highest lipid content (42.7%) and concentration (1.

[Effect of Constructed Wetland Configuration on the Removal of Nitrogen Pollutants and Antibiotics in Aquaculture Wastewater].

Horizontal subsurface flow constructed wetland (HSSFCW) and integrated vertical flow constructed wetland (IVFCW) consisted of down-flow and up-flow were built to treat aquaculture wastewater under different conditions. The water treatment performance, especially the nitrogen pollutants and antibiotics removal efficiencies, were compared, and the effects of flow patterns and hydraulic retention time (HRT) on the efficiencies were studied. The results showed that IVFCW had a better removal efficiency on nitrogen pollutants, and the removal rates of TN and NH-N were 58% and 80% (HRT=3 d), respectively.

Bioconversion of volatile fatty acids derived from waste activated sludge into lipids by Cryptococcus curvatus.

Pure volatile fatty acid (VFA) solution derived from waste activated sludge (WAS) was used to produce microbial lipids as culture medium in this study, which aimed to realize the resource recovery of WAS and provide low-cost feedstock for biodiesel production simultaneously. Cryptococcus curvatus was selected among three oleaginous yeast to produce lipids with VFAs derived from WAS. In batch cultivation, lipid contents increased from 10.

Culture strategies for lipid production using acetic acid as sole carbon source by Rhodosporidium toruloides.

Rhodosporidium toruloides AS 2.1389 was tested using different concentrations of acetic acid as a low-cost carbon source for the production of microbial lipids, which are good raw materials for biodiesel production. It grew and had higher lipid contents in media containing 4-20 g/L acetic acid as the sole carbon source, compared with that in glucose-containing media under the same culture conditions.

Characteristics of ammonia emission during thermal drying of lime sludge for co-combustion in cement kilns.

Thermal drying was used to reduce sludge moisture content before co-combustion in cement kilns. The characteristics of ammonia (NH3) emission during thermal drying of lime sludge (LS) were investigated in a laboratory-scale tubular dry furnace under different temperature and time conditions. As the temperature increased, the NH3 concentration increased in the temperature range 100-130°C, decreased in the temperature range 130-220°C and increased rapidly at >220°C.

[Extraction of surface active substance and analysis of demulsifying characteristics for the demulsifying strain Alcaligenes sp. S-XJ-1].

Extraction and identification of surface active substance of Alcaligenes sp. S-XJ-1, as well as description of its emulsion breaking process were conducted to reveal the demulsifying characteristics of this demulsifying strain. Alkali solvent was adopted in the extraction process with conditions optimized as 35 degrees C, 0.

[Influence of yeast extract on the fermentation of glucose by the demulsifying strain Alcaligenes sp. S-XJ-1].

The demulsifying strain Alcaligenes sp. S-XJ-1, isolated from oil contaminated soil, was cultivated with glucose as the carbon source. The influences of yeast extract on the growth, demulsifying ability and the element composition of the strain were investigated.

Pretreatment methods for aquatic plant biomass as carbon sources for potential use in treating eutrophic water in subsurface-flow constructed wetlands.

Plant biomass is usually added to constructed wetlands (CW) to enhance denitrification. In this study, we investigated effects of different pretreatments on two common external plant carbon sources, cattail and reed litter. We determined the average ratio of chemical oxygen demand (COD) to total nitrogen (TN), designated as C/N, in water samples after addition of litter subjected to various pretreatments.

Relationship of cell-wall bound fatty acids and the demulsification efficiency of demulsifying bacteria Alcaligenes sp. S-XJ-1 cultured with vegetable oils.

Considering that the surface properties of demulsifying cells correlate with their demulsification efficiency, the demulsifying bacteria Alcaligenes sp. S-XJ-1 with various surface properties were obtained using different vegetable oils as carbon sources. The results show that better performance was achieved with demulsifying bacteria S-XJ-1 possessing a relatively high cell surface hydrophobicity (CSH) and total unsaturated degree for the cell-wall bound fatty acids.

Turbiscan Lab ® Expert analysis of the biological demulsification of a water-in-oil emulsion by two biodemulsifiers.

The long-term destabilization process of a water-in-oil emulsion was investigated with two different biodemulsifiers produced under different culture conditions by Alcaligenes sp. S-XJ-1. Biodemulsifier I was obtained by using paraffin as substrate at initial culture pH of 10 and biodemulsifier II was produced with waste frying oils at pH of 7.

[Production of biodemulsifier by Alcaligenes sp. S-XJ-1 using waste diesel oil].

Biodemulsifier is a new type of demulsifiers for breaking oil-water emulsion. One demulsifier-producing strain, Alcaligenes sp. S-XJ-1 could grow on waste diesel oil (WDO), dry weight of the strain was up to 2.

Optimization of biodemulsifier production from Alcaligenes sp. S-XJ-1 and its application in breaking crude oil emulsion.

A biodemulsifier-producing strain of Alcaligenes sp. S-XJ-1, isolated from petroleum-contaminated soil of the Karamay Oilfield, exhibited excellent demulsifying ability. The application of this biodemulsifier significantly improved the quality of separated water compared with the chemical demulsifier, polyether, which clearly indicates that it has potential applications in the crude oil extraction industry.

Analysis of biological demulsification process of water-in-oil emulsion by Alcaligenes sp. S-XJ-1.

A demulsifying strain (S-XJ-1) was isolated from petroleum-polluted soil and identified as Alcaligenes sp. It showed emulsion breaking ratio of 81.3% for W/O emulsion within 24h when the cell concentration was 500mg/L.

[Treatment of oilfield produced water by biological methods-constructed wetland process and degradation characteristics of organic substances].

Hydrolysis acidification-aerobic-constructed wetland process and hydrolysis acidification-constructed wetland were used to treat oilfield produced water after the pretreatment of oil separation-coagulation. Gas chromatography-mass spectrometry was used to study the degradation characteristics of organic substances during the treatment process. The results showed that COD and ammonia nitrogen of both the two process effluents were below 80 mg/L and 15 mg/L, respectively, when HRT was 20 h for hydrolysis acidification, 10 h for aeration and 2 d for constructed wetlands or when HRT was 20 h for hydrolysis acidification and 4 d for constructed wetland.

Characterization and phylogenetic analysis of biodemulsifier-producing bacteria.

Based on demulsification performance, twenty biodemulsifier-producing strains were isolated from various environmental sources. Five of them achieved nearly or over 90% of emulsion breaking ratio within 24 h. With the aid of biochemical and physiological tests and 16S rDNA analysis, these isolates were classified into eleven genera, in which six genera (Brevibacillus sp.

[Production of biodemulsifier by Alcaligenes sp. XJ-T-1 with waste frying oil].

As a new member of demulsifier family, biodemulsifier is applied in oil-water emulsion breaking. A strain, XJ-T-1, was isolated from petroleum-contaminated soil and identified as Alcaligenes sp..

Comparison between waste frying oil and paraffin as carbon source in the production of biodemulsifier by Dietzia sp. S-JS-1.

In order to lower the production cost, waste frying oils were used in the biosynthesis of demulsifier by Dietzia sp. S-JS-1, which was isolated from petroleum contaminated soil. After 7 days of cultivation, the biomass concentration of the most suitable waste frying oil (WFO II) culture reached 3.