Maximum Total Concentration Research Articles

Experimental study on the effect of water port injection on the combustion and emission characteristics of diesel/methane dual-fuel engines

In this study, the effect of water port injection on the combustion and emission characteristics of diesel/methane dual-fuel combustion was studied experimentally. Conventional dual-fuel engine combustion was extended and explored as tri-fuel combustion by introducing a water port injection. The experiments were conducted on a four-cylinder engine at 1600 r/min and low load with a brake mean effective pressure of 0.42 MPa. Six methane substitution ratios (MSRs) (0%, 10%, 20%, 30%, 40%, and 50%) were programmed. At each MSR point, five water-to-diesel in pure diesel mode mass ratios (WDMRs) (0%, 25%, 45%, 65%, and 85%) were arranged. The experimental results indicated that methane addition decreased the combustion intensity and retarded the combustion process of the diesel engine. In addition, methane addition and water port injection prolonged the ignition delay of the diesel engine. The larger the MSR, the longer was the ignition delay for the corresponding WDMR. Similarly, the larger the WDMR, the longer was the ignition delay for the corresponding MSR. For emissions, the number concentration of particles decreased owing to methane addition, whereas it increased owing to water injection. Notably, for the maximum MSR (50%) and WDMR (0.85) utilization, the maximum total number concentration was 94474 #/cm3, which is much lower than the minimum total number concentration in a pure diesel engine (118549 #/cm3). Furthermore, both methane addition and water injection significantly decreased the nitrogen oxide (NOx) emissions; however, they increased the CO and HC emissions. In summary, adding methane coupled with water injection is an effective method to decrease NOx and particle emissions simultaneously.

Heterologous Expression and Characterization of a High-Efficiency Chitosanase From Bacillus mojavensis SY1 Suitable for Production of Chitosan Oligosaccharides.

Chitosanase plays an important role in enzymatic production of chitosan oligosaccharides (COSs). The present study describes the gene cloning and high-level expression of a high-efficiency chitosanase from Bacillus mojavensis SY1 (CsnBm). The gene encoding CsnBm was obtained by homologous cloning, ligated to pPICZαA, and transformed into Pichia pastoris X33. A recombinant strain designated X33-C3 with the highest activity was isolated from 120 recombinant colonies. The maximum activity and total protein concentration of recombinant strain X33-C3 were 6,052 U/ml and 3.75 g/l, respectively, which were obtained in fed-batch cultivation in a 50-l bioreactor. The optimal temperature and pH of purified CsnBm were 55°C and 5.5, respectively. Meanwhile, CsnBm was stable from pH 4.0 to 9.0 and 40 to 55°C. The purified CsnBm exhibited high activity toward colloidal chitosan with degrees of deacetylation from 85 to 95%. Furthermore, CsnBm exhibited high efficiency to hydrolyze different concentration of colloidal chitosan to produce COSs. The result of this study not only identifies a high-efficiency chitosanase for preparation of COSs, but also casts some insight into the high-level production of chitosanase in heterologous systems.

Speciation and mobility of heavy metals in the Yundang Lagoon catchment surface sediments after 30 years of continuous remediation and management at Xiamen in China

ABSTRACT The present study emphasised the speciation and mobility of heavy metals (Cr, Mn, Ni, Cu, Zn, As, Cd, and Pb) in sediments of the Yundang Lagoon catchment (YLC) at Xiamen in China. The maximum total metals concentrations of Cr, Cu, Zn, Cd, and Pb were higher than the class I pollution level of China Marine Sediment Quality values. Average total metals concentrations of Cu, Zn, Cd, and Pb were greater than world average shale values. The highest average percentages of Cr (68.01%), Mn (39.14%), Ni (61.32%), and As (74.09%) were found in the residual fraction, while Cu (50.69%) was the highest in the oxidisable fraction. Furthermore, the greater percentages of Zn (37.65%), Cd (48.98%), and Pb (47.52%) were bound in the reducible forms in YLC sediment. Total organic carbon (TOC) showed a strong correlation with heavy metal fractions, suggesting that TOC could be a carrier of heavy metals within alkaline urban sediment. The risk assessment code values for Cd, Mn, and Zn indicate that these metals could pose a medium to a high potential risk to the aquatic organisms. However, the present remediation strategy should be continued with more focus on reducing urban runoff and domestic discharge into the lagoon.

Temperature affects growth, geosmin/2-methylisoborneol production, and gene expression in two cyanobacterial species.

Cyanobacterial blooms accompanied by taste and odor (T&O) compounds affect the recreational function and safe use of drinking water. Geosmin and 2-methylisoborneol (2-MIB) are the most common T&O compounds. In this study, we investigated the effect of temperature on geosmin and 2-MIB production in Dolichospermum smithii and Pseudanabaena foetida var. intermedia. More specifically, transcription of one geosmin synthase gene (geoA) and two 2-MIB synthase genes (mtf and mtc) was explored. Of the three temperatures (15, 25, and 35 °C) tested, the maximum Chl-a content was determined at 25 °C in both D. smithii and P. foetida var. intermedia. The maximum total geosmin concentration (19.82 μg/L) produced by D. smithii was detected at 25 °C. The total 2-MIB concentration (82.5 μg/L) produced by P. foetida var. intermedia was the highest at 35 °C. Besides, the lowest Chl-a content and minimum geosmin/2-MIB concentration were observed at 15 °C. There was a good positive correlation between geosmin/2-MIB concentration and Chl-a content. The expression levels of the geoA, mtf, and mtc genes at 15 °C were significantly higher than those at 25 and 35 °C. The transcription of the mtf and mtc genes in P. foetida var. intermedia was higher at 35 °C than at 25 °C. The results highlight unfavorable temperature can increase the potential of geosmin/2-MIB synthesis from the gene expression level in cyanobacteria. This study could provide basic knowledge of geosmin/2-MIB production by cyanobacteria for better understanding and management of T&O problems in drinking water.

USING HISTORIC SITES IN DETERMINING PLANT-SOIL INTERACTIONS UNDER LONG TERM CONTAMINATED SOILS

The relationships between heavy metals in soils and crop tissues are critical in understanding the potential risk to crop yields from Zn, Cu and Ni (the principal phytotoxic elements of concern in sludge), and the possible effects on dietary Cd (the critical zootoxic element that is labile in sludge-treated soil and readily absorbed by plants. These relationships cannot be derived from the agronomic trials because the quantities of heavy metals applied to the soil in sludge are small. These are field sites have been treated with sludge for many years in operational practice and where the oncentrations of heavy metals have been significantly raised above background values, representing potentially a worse-case of soil contamination. The purpose of the study was to provide a surrogate for long-term sludge-treated agricultural soil by examining the effects on crops of heavy metals in soil irrigated with raw sewage effluent for periods of more than 80 years and containing significantly elevated concentrations of heavy metals. Methodology: Two surveys of the Gabal El Asfar Old Farm were undertaken to assess the long-term effects of heavy metals in sludge-treated soil on crop quality. In the first survey, the relationships between total and DTPA extractable heavy metals in soil and concentrations in citrus fruit were examined. Concentrations of heavy metals in leaves of citrus were measured in the second survey and related to total and DTPA extractable metals in soil. The heavy metal contents of citrus leaves and fruit (orange - eleven sampling sites; mandarin - four sampling sites), and total and DTPA extractable concentrations in soils were measured in samples collected from different areas of the Farm during two site surveys. Total and DTPA concentrations of heavy metals in the surveyed soils showed significant enrichment by long-term irrigation with sewage effluent. For example, the maximum total concentrations of Zn and Cu were 530 and 366 mg kg-1, respectively, representing a potential risk to crop yields The maximum Cd concentration detected was 9 mg kg-1 and may be a potential risk to the human food chain from uptake into staple crops grown at the farm. DTPA extractable metals were significantly (P<0.001) correlated with the total contents of Zn (r=0.91***), Cu (r=0.83***), Ni (r=0.63***) and Pb (r=0.85***) in soil when data from both surveys were pooled for statistical evaluation. There was also evidence of a weak relationship between DTPA extractable Cd and the total soil Cadmium is the only element of concern in terms of the risk to human health from uptake into food crops grown on sludge-treated soil. The total Cd concentration in soil was raised to a value 3 times the maximum EU limit for this element in sludge-treated agricultural soil. Despite the marked increase in soil Cd content, there was no detectable transfer into citrus leaves or fruit (Figure 1). The absence of Cd uptake into citrus fruit is to be expected because fruits are amongst the least sensitive plant parts to Cd accumulation. These data emphasise the minimal risk to the human diet from Cd in fruit crops grown on sludge-treated soil. . In all cases, leaf tissue concentrations were low and in some cases Cu status was below the deficiency threshold. The Cd content in leaves was small and generally <0.02 mg kg-1 DM.

Freeze-Dried Mesenchymal Stem Cell-Secretome Pharmaceuticalization: Optimization of Formulation and Manufacturing Process Robustness.

Producing mesenchymal stem cell (MSC)-secretome for dose escalation studies and clinical practice requires scalable and good manufacturing practice (GMP)-compliant production procedures and formulation into a standardized medicinal product. Starting from a method that combines ultrafiltration and freeze-drying to transform MSC-secretome into a pharmaceutical product, the lyosecretome, this work aims to: (i) optimize the lyosecretome formulation; (ii) investigate sources of variability that can affect the robustness of the manufacturing process; (iii) modify the ultrafiltration step to obtain a more standardized final product. Design of experiments and principal component analysis of the data were used to study the influence of batch production, lyophilization, mannitol (M)/sucrose (S) binary mixture, selected as cryoprotectant excipients, and the total amount of excipients on the extracellular vesicles (EV) particle size, the protein and lipid content and the in vitro anti-elastase. The different excipients ratios did not affect residual moisture or EV particle size; simultaneously, proteins and lipids were better preserved in the freeze-dried product using the maximum total concentration of excipients (1.5% w/v) with a M:S ratio of about 60% w/w. The anti-elastase activity was instead better preserved using 0.5% w/w of M as excipient. The secretome batch showed to be the primary source of variability; therefore, the manufacturing process has been modified and then validated: the final product is now concentrated to reach a specific protein (and lipid) concentration instead of cell equivalent concentration. The new standardization approach led to a final product with more reproducible quali-quantitative composition and higher biological activity.

Low-dose thiamine supplementation of lactating Cambodian mothers improves human milk thiamine concentrations: a randomized controlled trial

ABSTRACTBackgroundInfantile beriberi–related mortality is still common in South and Southeast Asia. Interventions to increase maternal thiamine intakes, and thus human milk thiamine, are warranted; however, the required dose remains unknown.ObjectivesWe sought to estimate the dose at which additional maternal intake of oral thiamine no longer meaningfully increased milk thiamine concentrations in infants at 24 wk postpartum, and to investigate the impact of 4 thiamine supplementation doses on milk and blood thiamine status biomarkers.MethodsIn this double-blind, 4–parallel arm randomized controlled dose–response trial, healthy mothers were recruited in Kampong Thom, Cambodia. At 2 wk postpartum, women were randomly assigned to consume 1 capsule, containing 0, 1.2 (estimated average requirement), 2.4, or 10 mg of thiamine daily from 2 through 24 weeks postpartum. Human milk total thiamine concentrations were measured using HPLC. An Emax curve was plotted, which was estimated using a nonlinear least squares model in an intention-to-treat analysis. Linear mixed-effects models were used to test for differences between treatment groups. Maternal and infant blood thiamine biomarkers were also assessed.ResultsIn total, each of 335 women was randomly assigned to1 of the following thiamine-dose groups: placebo (n = 83), 1.2 mg (n = 86), 2.4 mg (n = 81), and 10 mg (n = 85). The estimated dose required to reach 90% of the maximum average total thiamine concentration in human milk (191 µg/L) is 2.35 (95% CI: 0.58, 7.01) mg/d. The mean ± SD milk thiamine concentrations were significantly higher in all intervention groups (183 ± 91, 190 ± 105, and 206 ± 89 µg/L for 1.2, 2.4, and 10 mg, respectively) compared with the placebo group (153 ± 85 µg/L; P < 0.0001) and did not significantly differ from each other.ConclusionsA supplemental thiamine dose of 2.35 mg/d was required to achieve a milk total thiamine concentration of 191 µg/L. However, 1.2 mg/d for 22 wk was sufficient to increase milk thiamine concentrations to similar levels achieved by higher supplementation doses (2.4 and 10 mg/d), and comparable to those of healthy mothers in regions without beriberi. This trial was registered at clinicaltrials.gov as NCT03616288.

New iodine-based electrochemical advanced oxidation system for water disinfection: Are disinfection by-products a concern?

A novel electrochemical Advanced Oxidation System (AOS) has been recently developed for water disinfection where iodide is used to generate active iodine species in-situ. However, the presence of iodide during water disinfection can lead to the formation of iodinated disinfection byproducts (I-DBPs), which have been shown to be more cyto- and genotoxic than their chlorinated and brominated analogs. In this study, the formation of DBPs was assessed in ultrapure water, river water and secondary wastewater effluents treated by the AOS. A comprehensive total organic halogen and target DBP analysis was used that included 25 unregulated DBPs, and the total organic halogen (TOX) quantified as total organic chlorine (TOCl), total organic bromine (TOBr), and total organic iodine (TOI). Ultrapure water disinfection only quantified iodoform (TIM) at a maximum concentration of 0.90 ± 0.05 µg/L. River water results show that TOI increase from 1.3 ± 0.3 µg/L before disinfection (t = 0) to a maximum of 3.5 ± 1.1 µg/L. TIM and bromodiiodomethane (BDIM) were the only targeted iodo-trihalomethanes (I-THMs) that were quantified with a maximum total I-THM concentration of 0.44 µg/L. Secondary wastewater effluent disinfection results show that TOI increased from 1.8 ± 0.3 µg/L (t = 0) to a maximum concentration of 35.3 ± 0.3 µg/L. Iodide and iodate were the main iodinated species exiting the AOS system with a iodine recovery of 94–101%. The results from this study show that the AOS formed low levels of iodinated DBPs in treated water sources that are comparable to the levels found in disinfected drinking water and wastewater.

Thiamine Status of Supplemented, Lactating Mothers in Rural Cambodia: A Randomized Controlled Trial

ObjectivesThiamine deficiency is a cause of infant morbidity and mortality throughout Southeast and South Asia. Maternal intake influences human milk thiamine concentrations, thus mother’s intake must be improved to combat infant deficiency. However, the dose of supplemental thiamine required by lactating mothers is unknown. We aimed to estimate the maternal oral thiamine dose required to optimize milk thiamine concentrations, and to investigate the impact of various doses on thiamine status biomarkers. MethodsThis was a double-blind, four-parallel arm randomized controlled dose-response trial. At 2 weeks postpartum, healthy mothers were randomized to consume one capsule daily for 22 weeks, containing either 0 mg (placebo, n = 83), 1.2 mg (estimated average requirement, n = 86), 2.4 mg (n = 81), or 10 mg (n = 85) thiamine. Human milk total thiamine, whole blood thiamine diphosphate, and erythrocyte transketolase activity coefficient (ETKac) were assessed. An Emax curve, estimated using a non-linear least squares model, was plotted for human milk. Linear mixed-effects models were used to test for differences between treatment groups for milk and blood biomarkers. ResultsA maternal supplemental dose of 2.35 (95% CI 0.58, 7.01) mg/d was estimated to reach 90% of the maximum average human milk total thiamine concentration of 191 μg/L. The mean (SD) milk thiamine concentration was significantly higher in all intervention groups (183 (91), 190 (105), and 206 (89) μg/L, for 1.2, 2.4, and 10 mg, respectively) compared to placebo (153 (85) μg/L; p < 0.0001), and did not differ from each other. Blood biomarkers followed similar group trends, except for infant ETKac, where only the 10 mg (mean [SD]: 1.18 [0.10]) and placebo (1.12 [0.06]) groups differed significantly (p = 0.003). ConclusionsWhile an estimated maternal dose of 2.35 (0.58, 7.01) mg/d was required to reach a milk thiamine concentration of 191 μg/L in Emax dose analyses, group comparisons suggest a daily dose of 1.2 mg/d is sufficient to improve maternal biomarkers to levels similar to higher doses (2.4 and 10 mg/d) and consistent with thiamine-replete populations. However, a higher maternal dose of 10 mg/d was required to improve infant ETKac status compared to other dose groups. Funding SourcesBill & Melinda Gates Foundation, The New York Academy of Sciences.

Occurrence of pesticides and their transformation products in headwater streams: Contamination status and effect of ponds on contaminant concentrations

In France, more than 90% of monitored watercourses are contaminated with pesticides. This high contamination level increases at the head of agricultural watersheds, where dilution capacities are low and transport from treated lands is direct. Ponds, numerous around headwater streams, could provide additional protection against pesticide pollution. Because of their long hydraulic residence time and large water volumes, they mitigate pesticide concentrations between upstream and downstream rivers. However, pesticide transformation products may also be responsible for the degradation of environments, owing to their presence at high concentrations and their persistence, but related data are scarce, particularly because of their high level of molecular diversity. We first reported on the state of water contamination in agricultural headwater streams, based on high frequency water sampling. Analysis of 67 molecules (HPLC-ESI-MS/MS) showed pesticides and pesticide transformation product mixtures of up to 29 different compounds in one sample. Regardless of the sampling location, transformation products represented at least 50% of the detected compounds. Then, we demonstrated the capacity of a pond to reduce contaminant concentrations in downstream rivers for 90% of the detected compounds. Upstream from this pond, environmental quality or ecotoxicological standards were exceeded during sampling, with pesticide and transformation product sum concentrations of up to 27 μg/L. Downstream from the study pond, few exceedances were observed, with a maximum total concentration of 2.2 μg/L, reflecting significant water quality improvement.

Early Assessment Window for Predicting Breast Cancer Neoadjuvant Therapy using Biomarkers, Ultrasound, and Diffuse Optical Tomography.

The purpose of the study was to assess the utility of tumor biomarkers, ultrasound (US) and US-guided diffuse optical tomography (DOT) in early prediction of breast cancer responseto neoadjuvant therapy (NAT). This prospective HIPAA compliant study was approved by the institutional review board. Forty one patients were imaged with US and US-guided DOT prior to NAT, at completion of the first three treatment cycles, and prior to definitive surgery from February 2017 to January 2020. Miller-Payne grading was used to assess pathologic response. Receiver operating characteristic curves (ROCs) were derived from logistic regression using independent variables, including: tumor biomarkers, US maximum diameter, percentage reduction of the diameter (%US), pretreatment maximum total hemoglobin concentration (HbT) and percentage reduction in HbT (%HbT) at different treatment time points. Resulting ROCs were compared using area under the curve (AUC). Statistical significance was tested using two-sided two-sample student t-test with P < 0.05 considered statistically significant. Logistic regression was used for ROC analysis. Thirty-eight patients (mean age = 47, range 24-71years) successfully completed the study, including 15 HER2 + of which 11 were ER + ; 12 ER + or PR + /HER2-, and 11 triple negative. The combination of HER2 and ER biomarkers, %HbT at the end of cycle 1 (EOC1) and %US (EOC1) provided the best early prediction, AUC = 0.941 (95% CI 0.869-1.0). Similarly an AUC of 0.910 (95% CI 0.810-1.0) with %US (EOC1) and %HbT (EOC1) can be achieved independent of HER2 and ER status. The most accurate prediction, AUC = 0.974 (95% CI 0.933-1.0), was achieved with %US at EOC1 and %HbT (EOC3) independent of biomarker status. The combined use of tumor HER2 and ER status, US, and US-guided DOT may provide accurate prediction of NAT response as early as the completion of the first treatment cycle. NCT02891681. https://clinicaltrials.gov/ct2/show/NCT02891681 , Registration time: September 7, 2016.

Efficient Saccharification of the Microalga Chlorella vulgaris and its Conversion into Ethanol by Fermentation

The third-generation bioethanol production depends on the utilization of algae as raw material and an excellent source of polysaccharides, which can be fermented to bioethanol. The microalga Chlorella vulgaris is suitable for bioethanol production due to its carbohydrate content. In this study, the chemical pretreatments of acidic and alkaline pretreatments of Chlorella vulgaris biomass showed that the maximum reducing sugars and total carbohydrate concentrations produced from acidic pretreatment of the algal biomass by using 2% sulfuric acid (H2SO4) at 120 °C for 30 min were (24.77 g/100 g dried biomass) and (16.08 g/100 g dried biomass), respectively. The bioethanol released from the biomass was increased gradually until the 5th day (14.32 g/100 g dried biomass). The maximum bioethanol produced after 2% (w/v) of sodium hydroxide (NaOH) at 120 °C for 30 min. alkaline pretreatment was (21.54 g/100 g dried biomass) reducing sugar, (15.72 g/100 g dried biomass) total carbohydrate and the produced bioethanol concentration on the 4th day (7.74 g/100 g dried biomass). At the same time, the physical pretreatments were done by microwaves and ultrasonication. The highest reducing sugars after ultrasonication, (18.97 g/100 g dried biomass) which fermented to (16.19 g/100 g dried biomass) bioethanol at the 4th fermentation day. While microwaves pretreatment reached (11.22 g/ 100 g dried biomass) reducing sugars, that synthesis (2.91 g/100 g dried biomass) at the 5th fermentation day. This work concluded that 2% H2SO4 was the best treatment method, which resulted in the highest concentrations of reducing sugars, total carbohydrate, and bioethanol.

Interval wavelength selection and simultaneous quantification of spectrally overlapping food colorants by multivariate calibration

Variables selection is often necessary to remove redundant data and to reduce the negative influence of spectral overlapping. In the current work, two interval variable selection methods were applied to quantify five coloring agents (Tartrazine TAR, Sunset Yellow SY, Allura Red AR, Brilliant Blue BBL, and Brilliant Black BBK) which exhibited intense spectral overlapping in powdered soft drinks. Interval partial least squares iPLS and net analyte signal NAS methodology were used to pick up the most informative variables for dyes quantification in powdered soft drinks. Based on NAS calculations, the optimum sensitivity and selectivity for dyes measurement were found to be (1.23–5.56) and (0.30–0.72), respectively and at pH 3.0. Moreover, the minimum spectral overlapping (28–70%) among dyes was observed at pH 3.0 while the maximum overlapping (38–74%) was at pH 10.0. Interval partial least squares iPLS was more capable to handle the overlapping between SY and AR dyes. On the other hand, net analyte signal method was effective to capturing the informative regions for dyes of lower spectral overlapping, TAR, BBL, and BBK. In the case of AR, the best prediction (REP% 2.4) was achieved at 350–530 nm using iPLS. However, the best prediction of BBL (REP% 3.4%) was achieved at 655–680 nm (i.e., 6 variables) using NAS/PLS regression. The ability NAS/PLS regression, which uses fewer number of variables, was attributed to NAS mechanism which extracts the net signal of the analyte, thus; preventing overlapping with the rest of compounds signals and this will elegantly leads to fewer number of variables. The superiority of iPLS to calibrate intensely overlapping dyes is attributed to its inherent mechanism of selecting the spectral data that include all possible variables leading to better prediction. At the optimum calibration conditions, the dyes were detected in powdered soft drinks with adequate accuracy (%recoveries 97.3–107.5) and precision (RSD 3.1–9.30). The maximum total concentration of dyes was reported in orange drink samples reaching to 567 mg/kg. The result highlights and emphasizes the highly required further monitoring of this type of food, considering the damages of such popular synthetic dyes to human health. Analysis of results by ANOVA indicated that the total content of dyes was statistically comparable in the samples while the total content of each single dye was statistically different in tested samples.

Thermal hydrolyzed food waste liquor as liquid organic fertilizer

Thermal hydrolysis (TH) is an efficient technology for food waste (FW) management. This study investigated the nutrients released from FW under various TH temperature (140, 160, 180, 200 and 220 °C) and evaluated the feasibility of the hydrolyzed liquor (HL) as liquid organic fertilizer. The phytotoxicity and biotoxicity of HL was analyzed using wheat seed and Pseudomonas putida. Results revealed that TH could effectively solubilize FW and release nutrients (N, P and K) and organic substances. The highest content of total nitrogen (TN, 1685 mgN/L) and phosphorus (TP, 235 mgP/L) in the HL was obtained under 180 °C. The K+ was 278–293 mg/L regardless of treatment temperature. Secondary nutrients (Ca and Mg) and micro metals (Fe, Cu, Zn, Al, Co and Mn) were all detected at relatively high level, while heavy metals (As and Cd) were generally lower than 0.5 mg/L. Twenty types of free amino acid were identified and the maximum total concentration was 4965.13 mg/L. 2% HL displayed higher germination index (>80%) and enhanced root and shoot lengths. No biotoxicity was observed as confirmed by the bioassay. This study proposes a feasible method to solubilize food waste and produce liquid organic fertilizer.

Microbial lipid production from banana straw hydrolysate and ethanol stillage.

In this study, the feasibility of banana straw (BS) hydrolysate as carbon source and reutilizing the pretreated liquor (PL) of BS in the Rhodosporidium toruloides fermentation was explored for the first time. When BS hydrolysate was used as the carbon source, total biomass concentration, lipid concentration, and lipid content under optimal conditions reached 15.52 g/L, 5.83 g/L, and 37.56% (w/w), respectively, which was similar to the results of pure sugar control. After detoxification, 50% PL can be returned to enzymatic hydrolysis and fermentation, and total biomass concentration, lipid concentration, and lipid content can reach 15.14 g/L, 5.59 g/L, and 36.91% (w/w). Then, ethanol stillage (ES) was used as the nitrogen source. The NaCl and glycerol of ES could promote lipid accumulation, reaching 7.52 g/L under optimized conditions. Finally, microbial lipid production from BS hydrolysate and ES without any additional nutrients was investigated, and the maximum total biomass concentration, lipid concentration, and lipid content were 13.55 g/L, 4.88 g/L, and 36.01% (w/w), respectively. Besides, the main compositions of microbial lipid produced were C16 and C18, and the biodiesel production from the microbial lipid could meet Chinese and US standard through theoretical numerical calculation.

Response of non-point source pollution to landscape pattern: case study in mountain-rural region, China.

Landscape patterns have a substantial effect on non-point source (NPS) pollution in watersheds. Facilitating sustainable development of mountain-rural areas is a major priority for China. Knowledge of the impacts of various landscapes on water quality in these areas is critical to meeting environmental goals. This study applied the Soil and Water Assessment Tool (SWAT) to create a hydrologic and water quality model of the study watershed; then, the relationship between water quality and landscape patterns was investigated using multiple linear regression and redundancy analysis. The results show that the western sub-basins had higher nitrogen pollution loads, and the total nitrogen concentration reached a maximum value of 3.91 mg/L; the eastern sub-basins had a higher pollution load of phosphorous featured by maximum total phosphorous concentration of 2.15 mg/L. The water quality of the entire watershed in all scenarios tended to deteriorate over time. Landscape metrics accounted for 81.7% of the total variation in pollutant indicators. The percentage of forest landscape was negatively correlated with NPS pollution, while other types of landscape showed a positive correlation. The patch density, landscape shape index, and largest patch index of urban and agricultural lands were negatively correlated with pollutant concentrations. Upland landscapes contributed more pollutants than paddy fields. Some measures, e.g., returning grassland and farmland to forest in steep regions and replacing upland crops with paddy fields, were recommended for mitigating NPS pollution in the study watershed.

Indoor use of essential oil-based cleaning products: Emission rate and indoor air quality impact assessment based on a realistic application methodology

Cleaning is performed to increase hygiene, esthetics and material preservation. Despite its benefits, cleaning also poses risks, potentially contributing to nearly 20% of indoor pollution. As indoor air quality has become a major human health concern, “natural-scented” cleaning products, formulated with essential oils, have become market leaders among household products. However, these consumer products have benefitted from skillful marketing strategies based on the ambiguity of the words “green” and “natural”. The characterization of the emission processes studied through 1-m3 chamber experiments under a realistic scenario suggests variable maximum total terpene concentrations from 150 to 300 ppb. The estimated emission rate profiles confirm that the liquid-to-gas transfer of terpenes is driven by (i) the formulation of the product matrix inducing specific chemical affinities, (ii) the liquid content of individual terpenes, and (iii) the intrinsic volatility of terpenes. A unique formaldehyde emission kinetics profile was observed, suggesting the presence of a unique emission source: formaldehyde-releasers. Consequently, the use of essential-oil-based cleaning products might generate a long-term increase in the indoor formaldehyde concentration, and the maximum levels might be sustained for several hours after cleaning. Thus, essential-oil-based cleaners should be seriously considered as versatile and significant sources of fragrance molecules and formaldehyde.

Comparison of dual stage ultrafiltration and hybrid ultrafiltration-forward osmosis process for harvesting microalgae (Tetraselmis sp.) biomass

In this study, a hybrid ultrafiltration–forward osmosis system was compared with a dual stage ultrafiltration process for the harvesting of marine microalgae. To the best of the author’s knowledge none of the previous studies compared the performance of a dual stage ultrafiltration process with a hybrid UF-FO process for the harvesting of marine microalgae. The application of the hybrid process is expected to reduce the energy consumption for harvesting the microalgae without affecting the concentration factor and final product quality. In forward osmosis, the impact of the feed and draw solutions flowrate and the membrane orientation was investigated. The feed solutions were unfiltered microalgae solution and ultrafiltered concentrated microalgae while the draw solution was brine collected from a thermal desalination plant. A maximum total algal harvesting concentration factor of 37.3 was obtained using the hybrid ultrafiltration-forward osmosis system and the dual stage ultrafiltration process. The flowrate used in the forward osmosis process was 2.5 LPM for the feed solution and 0.8 LPM for the draw solution and the active layer was facing the feed solution (i.e. FO mode). The energy consumption in the hybrid ultrafiltration-forward osmosis system was 24% less than the dual-stage ultrafiltration system.

Caproic Acid Formation by Carbon Chain Elongation During Fermentative Hydrogen Production of Cassava Wastewater

In this work, cassava wastewater was used to evaluate hydrogen production and the subsequent production of caproic acid via acetate carbon chain elongation, adding ethanol as electron donor. Batch reactors were operated with an initial chemical oxygen demand of 10 and 20 g O2/L (A10 and A20, respectively), under self-fermentative operation at 40 ± 1 °C. The initial pH was set to 5.5 to inhibit methanogens growth. Hydrogen production yields were 1.01 and 1.98 mol H2/mol glucose for A10 and A20, respectively. In both cases, the main metabolites were ethanol and acetic, butyric, propionic, and caproic acids during the fermentative step; when adding ethanol for the chain elongation the pH was adjusted to 7.0 using a 2-M NaOH solution. The maximum total caproic acid concentration obtained after ethanol addition was 4.2 and 7.2 g/L for A10 and A20, respectively; of which 84% and 90% resulted from the carbon chain elongation step, respectively.

Effect of boron on growth and yield parameters of sunflower in acid soil

Sunflower (Helianthus annus L.) is an exotic North American plant but its commercialization as a crop started in Russia and now widespread across the globe. Boron has a synergistic effect on nitrogen uptake, which is directly linked with amino acids, RNA, and protein synthesis thereby enhancing the relative growth rate and absolute growth rate. Although numerous studies emphasized the positive effects of boron application on growth, yield and oil content of sunflower, limited information is available on the influence of boron nutrient in sunflower crop cultivated in acid laterite soils. The experiment was laid out in factorial completely randomised block design in Sunflower (Helianthus annus L.) in laterite Soil during Zadi, in 2018 at AICRP on Micronutrients, department Soil science and Agricultural chemistry, OUAT, Bhubaneswar, with two factors (5 Soil types and 5 boron doses of 0kg boron/ha, 0.5kg boron/ha, 1.0kg boron/ha, 1.5kg boron/ha and 2kg boron/ha.) with 25 treatments replicated twice. All the yield parameters showed positive and significant correlation with the soil boron application in all soil types except in soil type 2 and soil type 3 where the growth declined after 1.5 kg/ha and 1 kg/ha respectively. The maximum head diameter (6.33cm at 75 days after sowing) and head dry weight (20.64g) was in Soil type 1 with boron dose 2 kg/ha. Soil type 1 with boron dose 2 kg/ha was also recorded the highest of number of filled seeds per head(183) and seed weight (6.15g),maximum oil content(29.105 %). In Soil type 3 boron dose 2 kg/ha maximum total boron concentration (120.2ppm) and maximum the seed concentration of boron (24.79ppm) was observed. Harvest Index was observed to be maximum in Soil type 1 boron dose 2 kg/ ha it was maximum (16.70%).