scholarly journals Occurrences, Distribution and Composition of Microplastics in the Surface Seawater and Beach Sediments of the Southern Shandong Peninsula, China

Author(s):  
Rashid Pervez ◽  
Yonghong Wang ◽  
Zhongpeng Lai

Abstract The current work provides the detailed analysis about microplastics contamination of the beach sediments and surface seawater. Sediment samples were collected from the high tidal zone at 13 beaches, and surface seawaters of seven stations along the southern Shandong Peninsula. The presence of microplastics was recorded on both beaches and surface seawater. The mean quantity of microplastics was approximately 664±80 microplastics/kg of dry weight (dw) with 0.5~0.125 mm in beach sediments, and 5.62±0.4 microplastics/liter (L) of surface seawater. Predominant microplastics were fibers (>97%). While other plastic forms had lower percentage. Microplastics possessed different color with polymer composition including polypropylene, polyethylene, and polystyrene. The accumulation of microplastics on beaches is an alarming issue and provides better understanding about microplastics pollution along the coastal regions of the southern Shandong Peninsula. It would also help to establish better monitoring system for future and evaluate possible risks by microplastics due to rapid economic growth of China.

2021 ◽  
Vol 13 ◽  
pp. 11-22
Author(s):  
B. A. Kalu ◽  
M.G. Njike ◽  
S.A. Ikurior

A quantitative method of specifying the morphological stage of development in Tridax procumbens was used for evaluating the chemi­cal composition of the plant at specified cano­py ages. An eight stage classification system was defined and assigned numerical values from 1 to 8 in a sequential order of increasing maturity. The mean stage of total herbage (MSW) at a specified age of canopy was calcu­lated as the average of the individual stages present and weighted for the dry weight in each stage. For the individual morphological stages present in a herbage samples, quality components measured by. leaf percentage, crude protein (CP), in vitro true digestibility (IVTD), progressively decreased with maturi­ty. From the vegetative to the mature seed stage, decreases were from 90% to 26% for the leaf proportion; 28% to 14% for CP; and from 82% to 53% for IVTD. Corresponding increases in fibre composition were from 26% to 59% for the total cell wall or neutral deter­gent fibre (NDF); 22% to 40% for ligno-cellu­lose or acid detergent fibre (ADF); and from 25% to 9% ilignin. . Older canopies reached siginificantly higher mean stage (MSW) values than younger canopies. Associated with these were lower percentage, CP, and IVTD; higher NDF; ADF, and lignin at higher MSW values. The implications of these findings are fully discussed


Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1766 ◽  
Author(s):  
Alessandro Suardi ◽  
Sergio Saia ◽  
Walter Stefanoni ◽  
Carina Gunnarsson ◽  
Martin Sundberg ◽  
...  

The collection of residues from staple crop may contribute to meet EU regulations in renewable energy production without harming soil quality. At a global scale, chaff may have great potential to be used as a bioenergy source. However, chaff is not usually collected, and its loss can consist of up to one-fifth of the residual biomass harvestable. In the present work, a spreader able to manage the chaff (either spreading [SPR] on the soil aside to the straw swath or admixed [ADM] with the straw) at varying threshing conditions (with either 1 or 2 threshing rotors [1R and 2R, respectively] in the combine, which affects the mean length of the straw pieces). The fractions of the biomass available in field (grain, chaff, straw, and stubble) were measured, along with the performances of both grain harvesting and baling operations. Admixing chaff allowed for a slightly higher amount of straw fresh weight baled compared to SPR (+336 kg straw ha−1), but such result was not evident on a dry weight basis. At the one time, admixing chaff reduced the material capacity of the combine by 12.9%. Using 2R compared to 1R strongly reduced the length of the straw pieces, and increased the bale unit weight; however, it reduced the field efficiency of the grain harvesting operations by 11.9%. On average, the straw loss did not vary by the treatments applied and was 44% of the total residues available (computed excluding the stubble). In conclusion, admixing of chaff with straw is an option to increase the residues collected without compromising grain harvesting and straw baling efficiencies; in addition, it can reduce the energy needs for the bale logistics. According to the present data, improving the chaff collection can allow halving the loss of residues. However, further studies are needed to optimise both the chaff and the straw recoveries.


1957 ◽  
Vol 35 (3) ◽  
pp. 195-202 ◽  
Author(s):  
M. A. A. Vonk ◽  
L. W. McElroy ◽  
R. T. Berg

Four treatments, involving differences in method of feeding and interval between last feed and slaughter, were employed in a study of the effect of dietary chlortetracycline on protease, amylase, and cellulase activity in the intestinal and cecal contents of 16 pairs of weanling pigs. Most consistent results were obtained with six pairs which were limited pair-fed except for the final feeding during which feed was available ad libitum for a 4-hour period ending 18 hours before slaughter. The mean total activities of all three hydrolases in the contents of the small intestines and of the ceca of the antibiotic-fed animals of these six pairs were significantly greater than in those of the control animals. Expressed as activity per gram dry matter of intestinal contents, significantly higher values for protease and amylase, but not for cellulase, were observed in the pigs that had received chlortetracycline. When the combined results obtained from all 16 pairs of the experimental animals were analyzed, the results showed that on a basis of activity per gram dry matter of intestinal contents, ingested chlortetracycline was associated with significant increases in amylase and cellulase but not in protease activity. Protease, amylase, and cellulase activities per gram dry matter of cecal contents were higher for pigs fed the antibiotic than for their controls. The mean wet weight of the empty small intestine and the mean dry weight of the mucosa scraped from the anterior 3-meter section of the small intestine were lower for the chlortetracycline-fed animals, but the differences were not statistically significant.


2015 ◽  
Vol 63 (3) ◽  
pp. 331-336 ◽  
Author(s):  
Marcia Vanacor Barroso ◽  
Breno Barroso Boos ◽  
Rosemar Antoniassi ◽  
Luiz Fernando Loureiro Fernandes

AbstractThe advantages of using copepods in aquaculture include nutritional superiority, high digestibility and broad spectrum of sizes, with the possibility of bioencapsulation of nutrients, probiotics and medicines. This study aimed to compare the effects of feeding copepods with a microalgae diet and two commercial inert diets on the copepod culture performance and their fatty acid profile. Wild copepods were collected in the estuarine system of Piraquê-açu River, Aracruz, Espírito Santo, Brazil, with a conical net of 60 cm in diameter and 200 μm mesh with a blind cup end, towed through the subsurface layer at a speed of 1 knot for 5 minutes. Once collected, the material was sieved in order to select only Oithona hebes. The experiment was conducted in nine cylindrical-conical tanks with a 60 L capacity, salinity of 25.8 ± 1.3, temperature of 25.5 ± 0.5 ºC and weak aeration, stocked with a density of 1.5 copepod/mL. Treatments were made in triplicate and consisted of: Treatment 1 (Control) fed with microalgae Chaetoceros gracilis and Nannochloropsis oculata (1:1) with 50,000 cells.mL-1each; Treatment 2 with S.Parkle® INVE (1g.million-1); and Treatment 3 with freeze-dried spirulina (1g.million-1). The mean final population was compared by a Tukey test (p < 0.05). Results showed higher population growth for copepods treated with S.parkle, which was the only treatment that presented copepodites. S.parkle was a good source of total lipids (9.54 g.100g-1 dry weight), high availability of DHA, EPA and had a good DHA:EPA:ARA ratio of 12.4:3.4:1.0. Copepods that were fed S.parkle had the highest DHA levels and a DHA:EPA:ARA ratio of 15.4:2.2:1.0. This study showed that S.parkle is a good inert food for rearing the copepod O. hebes, demonstrating the ability of copepods to bioencapsulate nutrients, allowing their transfer in the food chain.


2010 ◽  
Vol 62 (3) ◽  
pp. 731-738 ◽  
Author(s):  
D. Yildiz ◽  
I. Kula ◽  
G. Ay ◽  
S. Baslar ◽  
Y. Dogan

The aim of this study was to determine the current level of atmospheric heavy metal content on the Bozdag Mountain of the Aegean Region, Turkey. Twenty nine different plants were selected to study their potential as biomonitors of trace elements such as Ni, Zn, Fe, Pb, Mn and Cd (?g g-1, dry weight). The samples were collected from two different altitudes of Mt. Bozdag. The concentrations of trace elements were determined by atomic absorption spectrometry. The mean concentrations determined at 1000 m altitude ranged from 0.025 to 1.609, 0.232 to 0.731, 0.578 to 5.983, 0.287 to 0.565 and 0.176 to 2.659 (?g g-1, dry weight), for Ni, Zn, Fe, Pb and Mn, respectively. At the altitude of 1600 m, the values ranged from 0.023 to 0.939, 0.258 to 1.254, 0.839 to 5.176, 0.301 to 1.341 and 0.405 to 3.351 (?g g-1, dry weight) for Ni, Zn, Fe, Pb and Mn, respectively. No Cd was detected at either altitude. Statistical significance was determined by the independent sample t-test and comparisons were made in order to determine if there were any differences between the averages of herbaceous and woody plants. .


1960 ◽  
Vol 40 (2) ◽  
pp. 335-344 ◽  
Author(s):  
Henri P. Therrien ◽  
Dale Smith

The percentage of plants that flowered in the seedling year in spaced populations of red and alsike clovers at Madison and Arlington, Wisconsin, was highest in the earliest seedings (May 15) and decreased with later seeding dates. No plants flowered in the July 15th seedings. The percentage of winterkilling during the first winter was higher in the flowering plants of each clover than in the non-flowering plants. Differences in flowering and winter survival were noted among clover strains and in winter survival among plant types within strains.Prevention of flowering in medium red clover by removing flower buds, flowering stems and/or elongating tillers resulted in greater vegetative vigour and winter survival. Plants that were allowed to flower freely in the seedling year in spaced populations had a smaller number of non-flowering crown tillers, a smaller width of crown, a lower dry weight of crown, root and total available carbohydrates in the roots, less root branching, a slightly lower percentage of total available carbohydrates in the roots, and more winterkilling during the first winter than plants that were prevented from flowering. These responses may help in part to explain the benefits attributed to clipping red clover in the seedling year.


2011 ◽  
Vol 8 (1) ◽  
pp. 552-560
Author(s):  
Baghdad Science Journal

The heavy metals Cd, Cu, Fe, pb, and Zn were determined in dissolved and particulate phases of the water,in addition to exchangeable and residual phases of the sediment and in the selected organs of the fish Cyprinus carpio collected from the Euphrates River near Al-Nassiriya city center south of Iraq during the summer period / 2009 .Also sediment texture and total organic carbon(TOC) were measured. Analysis emploing a flam Atomic Absorption Spectrophotometers . The mean regional concentrations of the heavy metals in dissolved (µg/l) and particulate phases (µg/gm) dry weight were Cd (0.15,16.13) ,Cu (0.59,24.48) ,Fe (726,909.4) ,Pb (0.20, 49.95) and Zn (2.5,35.62) respectively,and those for exchangeable and residual phases of the Sediment were Cd (0.2,0.1) ,Cu (13.75,16.65) ,Fe (683 , 1351 ) ,Pb (10.1,1.07) and Zn (7.3,16.75)µg/gm dry weight respectively. The heavy metals concentrations in C. carpio organs followed the trend gill > liver > kidney> muscles . The mean concentration in the muscles were Cd (ND) , Cu (0.07) , Fe (4.7) , pb (0.06) and Zn (6.4) (µg/gm) dry weight . The statistical analysis proved a significant correlation between metal concentration in the sediment and total organic carbon, also a positive correlation was proved between its concentrations in the liver organ and the water (particulate phase) . In conclusion the trace metals concentration in particulate phase were higher than its concentration in the dissolved phase . The fish organs showed variations in the metals concentration and the muscle organs showed less concentration than the other organs .


1977 ◽  
Vol 28 (4) ◽  
pp. 417 ◽  
Author(s):  
R Marchant ◽  
WD Williams

Quantitative samples of P. zietziana were taken monthly for two years from Pink Lake and Lake Cundare. Shrimps were usually contagiously distributed. To reduce error, samples were stratified resulting in confidence limits of 40-50% for the mean population density. Despite this variability, stable trends emerged, and variation was not so great as to mask significant differences. Length-frequency analyses distinguished cohorts; a regression was established between length and dry weight, enabling growth to be estimated from samples. By combining growth with population densities in Allen curves, production was computed. In Pink Lake and Lake Cundare mean pro- duction was 11.3 and 1.0 g dry weight m-2 year-1 respectively. Generally there were two or three generations per year, but time and extent of recruitment were not predictable. Each generation suffered continuous mortality, the death of young shrimps accounting for most of the production. This mortality remains unexplained; there are no significant predators and salinity and temperature stress would occur only during summer.


2012 ◽  
Vol 109 (5) ◽  
pp. 944-952 ◽  
Author(s):  
M. Fernanda Bernal-Orozco ◽  
Barbara Vizmanos-Lamotte ◽  
Norma P. Rodríguez-Rocha ◽  
Gabriela Macedo-Ojeda ◽  
María Orozco-Valerio ◽  
...  

The aim of the present study was to validate a food photograph album (FPA) as a tool to visually estimate food amounts, and to compare this estimation with that attained through the use of measuring cups (MC) and food models (FM). We tested 163 foods over fifteen sessions (thirty subjects/session; 10–12 foods presented in two portion sizes, 20–24 plates/session). In each session, subjects estimated food amounts with the assistance of FPA, MC and FM. We compared (by portion and method) the mean estimated weight and the mean real weight. We also compared the percentage error estimation for each portion, and the mean food percentage error estimation between methods. In addition, we determined the percentage error estimation of each method. We included 463 adolescents from three public high schools (mean age 17·1 (sd1·2) years, 61·8 % females). All foods were assessed using FPA, 53·4 % of foods were assessed using MC, and FM was used for 18·4 % of foods. The mean estimated weight with all methods was statistically different compared with the mean real weight for almost all foods. However, a lower percentage error estimation was observed using FPA (2·3v. 56·9 % for MC and 325 % for FM,P< 0·001). Also, when analysing error rate ranges between methods, there were more observations (P< 0·001) with estimation errors higher than 40 % with the MC (56·1 %), than with the FPA (27·5 %) and FM (44·9 %). In conclusion, although differences between estimated and real weight were statistically significant for almost all foods, comparisons between methods showed FPA to be the most accurate tool for estimating food amounts.


1984 ◽  
Vol 39 (9-10) ◽  
pp. 863-866 ◽  
Author(s):  
T. Stijve

Abstract A total of 138 samples of higher fungi, representing 35 species (15 belonging to the genus Amanita), were analysed for the trace element bromine using spectrophotometric and gas chromatographic methods. High concentrations of bromine, up to 100 mg/kg on dry weight, were encountered in Amanitaceae, especially in members of the subsections Phalloideae and Eu-Amanita, whereas in other fungi the mean value for this element was only 3,3 m g/kg. Some bromine-accumulating Amanitas also contained unusually high chlorine levels. Am axi­mum concentration of 3 percent on dry weight was measured in A. phalloides. It could be demonstrated that most, if not all of bromine and chlorine was present in the fungi as ionisable inorganic salts. Two organochlorine metabolites, previously reported in some mushrooms, were absent in A. phalloides and A. muscaria.


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