Heavy metal control in microalgae cultivation with power plant flue gas entering into raceway pond.

The heavy metal sources of large-scale raceway pond microalgae cultivation with flue gas were investigated to reduce heavy metal contents in microalgae during cultivation. The microalgae were cultivated with power plant flue gas (as C source) and circulating cooling seawater (added with N and P nutrients) for 6 days. The Pb, Cd, Hg, and As contents in microalgae were 0.

Effects of acupuncture on breast cancer-related lymphoedema: A systematic review and meta-analysis.

Background: Lymphoedema is a common complication of axillary dissection surgery, especially for breast cancer patients. Approximately 20% of breast cancer survivors develop breast cancer-related lymphoedema (BCRL). Acupuncture (AC) has become an alternative treatment for BCRL.

Improving microalgal growth by strengthening the flashing light effect simulated with computational fluid dynamics in a panel bioreactor with horizontal baffles.

Biological CO elimination by photosynthetic microalgae is a sustainable way to mitigate CO from flue gas and other sources. Computational fluid dynamics was used to simulate algal cell movement with an enhanced flashing light effect in a novel panel bioreactor with horizontal baffles. Calculation results showed that the light/dark (L/D) cycle period decreased by 17.

Microstructure and antioxidative capacity of the microalgae mutant Chlorella PY-ZU1 during tilmicosin removal from wastewater under 15% CO.

The response mechanisms of microalgal mutant Chlorella PY-ZU1 cells were investigated in their removal of antibiotic tilmicosin from wastewater under 15% CO. Low concentrations (0.01-2mgL) of tilmicosin in wastewater stimulated the growth of microalgal cells, whereas high concentrations (5-50mgL) of tilmicosin significantly inhibited cell growth.

Developing a water-circulating column photobioreactor for microalgal growth with low energy consumption.

A water-circulating column photobioreactor (WCC-PBR) was developed to decrease bubble generation time and mixing time for growing microalgal biomass at low energy consumption. Bubble generation time was decreased by 60.4% and mixing time was decreased by 41.

Decrease in light/dark cycle of microalgal cells with computational fluid dynamics simulation to improve microalgal growth in a raceway pond.

In this study, computational fluid dynamics (CFD) was used to systemically analyze the movement of algae in a vortex flow field produced by up-down chute baffles. The average cell light/dark (L/D) cycle period, vertical fluid velocity, fraction of time the algae was resides in light zone and the L/D cycle period were investigated under different paddlewheel speeds and microalgal concentrations. Results showed that the L/D cycle period decreased but the vertical fluid velocity increased when the up-down chute baffles were used.

Gradient domestication of Haematococcus pluvialis mutant with 15% CO2 to promote biomass growth and astaxanthin yield.

In order to increase biomass yield and reduce culture cost of Haematococcus pluvialis with flue gas from coal-fired power plants, a screened mutant by nuclear irradiation was gradually domesticated with 15% CO2 to promote biomass dry weight and astaxanthin yield. The biomass yield of mutant after 10 generations of 15% CO2 domestication increased to 1.3 times as that with air.

Improving pollutants removal by microalgae Chlorella PY-ZU1 with 15% CO2 from undiluted anaerobic digestion effluent of food wastes with ozonation pretreatment.

In order to purify various pollutants (3108mg COD/L, 2120mg NH3-N/L) in the undiluted anaerobic digestion effluent of food wastes (UADEFW), ozonation pretreatment was employed to improve pollutants removal by microalgae mutant Chlorella PY-ZU1 with 15% CO2. Ozonation pretreatment broke CC bonds and benzene rings of refractory organics such as unsaturated fatty acids and phenols in UADEFW and degraded them into low-molecular-weight organics such as methanoic acid and methanal, but excessive ozone induced the accumulation of toxic by-products. The microalgal growth rate and biomass yield markedly increased to the peaks of 456mg/L/d and 4.

Improving microalgal growth with small bubbles in a raceway pond with swing gas aerators.

A novel swing gas aerator was developed to generate small bubbles for improving the mass transfer coefficient and microalgal growth rate in a raceway pond. A high-speed photography system (HSP) was used to measure the bubble diameter and generation time, and online precise dissolved oxygen probes and pH probes were used to measure the mass transfer coefficient and mixing time. Bubble generation time and diameter decreased by 21% and 9%, respectively, when rubber gas aerators were swung in the microalgae solution.

Enhanced energy recovery from cassava ethanol wastewater through sequential dark hydrogen, photo hydrogen and methane fermentation combined with ammonium removal.

Cassava ethanol wastewater (CEW) was subjected to sequential dark H2, photo H2 and CH4 fermentation to maximize H2 production and energy yield. A relatively low H2 yield of 23.6mL/g soluble chemical oxygen demand (CODs) was obtained in dark fermentation.

Optimizing gas transfer to improve growth rate of Haematococcus pluvialis in a raceway pond with chute and oscillating baffles.

Up-down chute and oscillating (UCO) baffles were used to generate vortex and oscillating flow field to improve growth rate of Haematococcus pluvialis in a raceway pond. Effects of gas flow rate, solution velocity, and solution depth on solution mass transfer coefficient and mixing time were evaluated using online pH and dissolved oxygen probes. Mass transfer coefficient increased by 1.

Enhanced solution velocity between dark and light areas with horizontal tubes and triangular prism baffles to improve microalgal growth in a flat-panel photo-bioreactor.

Novel horizontal tubes and triangular prism (HTTP) baffles that generate flow vortices were developed to increase solution velocity between dark and light areas and thus improve microalgal growth in a flat-panel photo-bioreactor. Solution velocity, mass-transfer coefficient, and mixing time were measured with a particle-imaging velocimeter, dissolved oxygen probes, and pH probes. The solution mass-transfer coefficient increased by 30% and mixing time decreased by 21% when the HTTP baffles were used.

Improving microalgal growth with reduced diameters of aeration bubbles and enhanced mass transfer of solution in an oscillating flow field.

A novel oscillating gas aerator combined with an oscillating baffle was proposed to generate smaller aeration bubbles and enhance solution mass transfer, which can improve microalgal growth in a raceway pond. A high-speed photography system (HSP) was used to measure bubble diameter and generation time, and online precise dissolved oxygen probes and pH probes were used to measure mass-transfer coefficient and mixing time. Bubble diameter and generation time decreased with decreased aeration gas rate, decreased orifice diameter, and increased water velocity in the oscillating gas aerator.

Enhancing the growth rate and astaxanthin yield of Haematococcus pluvialis by nuclear irradiation and high concentration of carbon dioxide stress.

Unicellular green microalgae Haematococcus pluvialis was mutated with (60)Co-γ irradiation to promote growth rate and increase astaxanthin yield under high concentration of CO2 stress. The average specific growth rate of H. pluvialis mutated with 4000 Gy γ-ray irradiation was increased by 15% compared with the original strain with air aeration.

Improving CO2 fixation with microalgae by bubble breakage in raceway ponds with up-down chute baffles.

The aeration gas was broken into smaller bubbles with enhanced local solution velocity to improve CO2 fixation with microalgae in raceway ponds with up-down chute baffles. A high-speed photography system and online precise pH probes were used to measure bubble generation and residence times, which were affected by paddlewheel speed, aerator orifice diameter, gas flow rate, and solution depth. Bubble generation time (from gas reaching aerator orifice surface to completely escaping from the aerator) decreased because of the enhanced local solution velocity, whereas bubble residence time increased because of the vortex flow field produced by up-down chute baffles.

Microstructures and functional groups of Nannochloropsis sp. cells with arsenic adsorption and lipid accumulation.

The pore structures and surface morphological characteristics of Nannochloropsis sp. cells with arsenic adsorption were initially investigated by N2-adsorption analysis and scanning electronic microscopy. Functional groups of cells were analysed by Fourier-transform infrared spectrometry and X-ray photoelectron spectroscopy.

Improving growth rate of microalgae in a 1191m(2) raceway pond to fix CO2 from flue gas in a coal-fired power plant.

CO2 fixation between microalgal biomass and culture solution and the weight ratio of biomass consumption at nighttime to biomass growth at daytime were compared in an open raceway pond aerated with flue gas from a coal-fired power plant. Average daytime sunlight intensity and solution temperature were optimized to improve microalgal growth rate and to enhance the efficiency of CO2 fixation. When the average daytime solution temperature increased from 12 to 26°C, the rate of biomass consumption due to microalgal respiration at nighttime increased from 6.

Enhanced flashing light effect with up-down chute baffles to improve microalgal growth in a raceway pond.

Novel up-down chute baffles that sequentially generate clockwise and anticlockwise liquid vortexes were developed to increase vertical liquid velocity between the bottom dark area and the top light area in a raceway pond. The vertical liquid velocity, mixing time, and mass transfer coefficient were measured as functions of paddlewheel speed and air aeration rate by using a particle imaging velocimeter, pH probes, and dissolved oxygen probes. The up-down chute baffles decreased the liquid mixing time and increased the mass transfer coefficient by 41% and 25%, respectively.