Effect of sewage effluents on germination of three marine brown algal macrophytes

1996 ◽  
Vol 47 (8) ◽  
pp. 1009 ◽  
Author(s):  
TR Burridge ◽  
T Portelli ◽  
P Ashton
Keyword(s):  
Dichlorophenoxyacetic Acid ◽  
Secondary Effluent ◽  
Effluent Quality ◽  
End Point ◽  
Sewage Effluents ◽  
Treated Effluent ◽  
Eastern Australia ◽  
Reference Toxicant ◽  
2,4 Dichlorophenoxyacetic Acid

Inhibition of germination of zygotes of the fucoid macroalgae Hormosira banksii and Phyllospora comosa and zoospores of the laminarian Macrocystis angustifolia was used as an end-point to assess the toxicity of three sewage effluents of differing quality. For each species, between-assay variation was low and results of tests with the reference toxicant 2,4-dichlorophenoxyacetic acid suggested that results are reproducible, especially in R. comosa. Each species showed a greater sensitivity to primary-treated effluent than to secondary-treated effluent, and higher variability in response to the primary effluent. High variation in response for each species when exposed to the primary effluent (compared with that for the secondary effluent) is presumably indicative of variation in quality of the primary effluent. The capacity to reproduce these assays, the sensitivity of species employed, and the ecological relevance of germination as a toxicological end-point suggest that germination tests of this nature may be useful in biological testing of effluent quality at discharge sites in south-eastern Australia.

Test on Microfiltration as a Tertiary Treatment Downstream of Fixed Bacteria Filtration

1992 ◽  
Vol 25 (10) ◽  
pp. 219-230 ◽  
Author(s):  
B. Langlais ◽  
Ph Denis ◽  
S. Triballeau ◽  
M. Faivre ◽  
M. M. Bourbigot
Keyword(s):  
Suspended Solid ◽  
Sewage Water ◽  
Poor Quality ◽  
Operating Conditions ◽  
Secondary Effluent ◽  
Tertiary Treatment ◽  
Effluent Quality ◽  
Filtration Cycle ◽  
Highly Sensitive

Conventional methods of disinfecting sewage water are all highly sensitive to variations in the effluent quality upstream of the disinfection stage. Microfiltration was tested as a tertiary treatment downstream of biofiltration, simulating very poor biofilter efficiency, to test the limits of the microfiltration process. Despite the poor quality of the secondary effluent (COD between 100 and 400 mgO2/l, BOD5 between 30 and 150 mgO2/l and suspended solid concentrations between 15 and 90 mg/l), the microfiltration process (filtration level : 0.2 µm) eliminated all faecal germs and tenia and ascaris eggs. The total elimination of free amoeba cysts still needs to be confirmed. With the COD and BOD5 reduced by an average of 60 and 70% respectively, the effluent quality is equivalent to level e after microfiltration (COD: 90 mgO2/l and BOD5=30 mgO2/l on samples averaged over 24 hours). Turbidity, measured instead of suspended solids at outlet from the microfilter, was 99% eliminated. The colour remained between 50 and 150 mg Pt.Co/l. Under the operating conditions applied, the minimum filtration cycle was 72 hours for a minimum permeate flow of 80 l/h/m2 of membrane.

scholarly journals Effect of 2,4-D and CPPU on Triploid Watermelon Production and Quality

HortScience ◽  
2007 ◽  
Vol 42 (3) ◽  
pp. 559-564 ◽  
Author(s):  
Maria Victoria Huitrón ◽  
Manuel Diaz ◽  
Fernando Diánez ◽  
Francisco Camacho ◽  
Antonio Valverde
Keyword(s):  
Citrullus Lanatus ◽  
Soluble Solids ◽  
Dichlorophenoxyacetic Acid ◽  
Cucurbita Moschata ◽  
Average Production ◽  
Pollinating Insects ◽  
Seedless Watermelon ◽  
Triploid Watermelon ◽  
2,4 Dichlorophenoxyacetic Acid

Pollination is one problem with intensive seedless watermelon (Citrullus lanatus Thunb.) production under unfavorable environmental conditions (low solar radiation and temperature) due to the lowered activity of pollinating insects, such as the bee (Apis mellifera L.). An alternative to overcome these problems is the use of plant growth regulators. For this reason, experiments were conducted for 2 years in plastic greenhouses in the fields of Almeria, southwestern Spain, to evaluate the production and quality of ‘Reina de corazones’ triploid watermelon grafted onto RS841 rootstock (Cucurbita maxima × Cucurbita moschata). Two phytoregulators were used for the development of the ovary: 1-(2-chloro-4-pyridyl)-3-phenylurea (CPPU) and 2,4-dichlorophenoxyacetic acid (2,4-D). Concentrations of CPPU evaluated were 50, 100, 150, and 200 mg·L−1. An application of 0.6 mL was applied to each ovary in addition to 4, 6, 8, or 12 mg·L−1 of 2,4-D to the foliar mass at a proportion of 1000 L·ha−1. Results showed that the production and number of fruit obtained with CPPU treatments were similar to what is obtained by using bees for fruit pollination. Maximum production was reached at concentrations of 100–200 mg·L−1. Average production was 32% to 83% higher than results from 2,4-D at 8 mg·L−1. The number of fruit per plant was 33% to 35% higher as well. In the first assay, a positive correlation was also observed between production and CPPU concentration. CPPU treatments had a lower accumulation of sugars than those with 2,4-D; nevertheless, both treatments showed values of commercially acceptable soluble solids.

Response of pre-harvest drop of grapefruit on two rootstocks to 2,4-D, MCPA and gibberellic acid

1982 ◽  
Vol 22 (117) ◽  
pp. 337 ◽  
Author(s):  
RA Sarooshi
Keyword(s):  
Gibberellic Acid ◽  
Poncirus Trifoliata ◽  
Dichlorophenoxyacetic Acid ◽  
Phenoxyacetic Acid ◽  
Rough Lemon ◽  
Fruit Drop ◽  
South Wales ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Better Than

Several formulations, concentrations and timings of sprays of 2,4-D (2,4-dichlorophenoxyacetic acid) and MCPA (4-chloro-2-methyl phenoxyacetic acid) were tested for their ability to reduce pre-harvest drop of late hanging Marsh grapefruit growing on rough lemon (Citrus jambheri) and trifoliata (Poncirus trifoliata) rootstocks at Dareton in south-western New South Wales. Gibberellic acid was also tested in several timing combinations with 2,4-D for its ability to improve the quality of late hanging fruit. On rough lemon the established standard treatment of 2,4-D at 20 ppm applied in mid-May was as good or better than all other treatments. On trifoliata this standard spray was again as effective as all others in preventing drop up to mid-November, but a similar spray applied in midJune was more effective from mid-November to mid-December. MCPA applied at 10 or 20 ppm in mid-May was not as effective as the standard spray. The best treatments reduced the average cumulative fruit drop, of 39% on trifoliata and 70% on rough lemon, by at least a half. When gibberellic acid at 10 ppm was added to the standard mid-May spray of 2,4-D, or when it followed it in mid June, it improved the colour and appearance and reduced the rind thickness and puffiness of late hanging fruit.

Ontogeny of somatic embryos of Pennisetum americanum. II. In cultured immature inflorescences

1984 ◽  
Vol 62 (8) ◽  
pp. 1629-1635 ◽  
Author(s):  
Claudia Botti ◽  
Indra K. Vasil
Keyword(s):  
Cell Wall ◽  
Embryogenic Callus ◽  
Somatic Embryos ◽  
Cell Separation ◽  
Dichlorophenoxyacetic Acid ◽  
Pennisetum Americanum ◽  
Embryogenic Cells ◽  
Floral Primordia ◽  
2,4 Dichlorophenoxyacetic Acid

Embryogenic callus was induced from young, unemerged inflorescences of Pennisetum americanum cultured on Murashige and Skoog's medium supplemented with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D). The amount and quality of the embryogénie callus and the rapidity with which it was formed depended on the age of the explant and the concentration of 2,4-D. Best results were obtained from explants with floral primordia at the earliest stages of development and with 2.5 mg/L 2,4-D. The compact, embryogenic callus originated from the floral primordia. Subsequent differentiation of the callus led to the formation of subepidermal layers of embryogenic cells. These richly cytoplasmic cells contained numerous starch grains. Increase in cell wall thickness, cell separation, and a sequence of internal segmenting divisions in single embryogenic cells led to the formation of embryoids.

Microfiltration Used as a Means of Disinfection Downstream: A Bacterial Treatment Stage on Fixed-Bed Bacteria

1993 ◽  
Vol 27 (7-8) ◽  
pp. 19-27 ◽  
Author(s):  
B. Langlais ◽  
Ph. Denis ◽  
S. Triballeau ◽  
M. Faivre ◽  
M. M. Bourbigot
Keyword(s):  
Fixed Bed ◽  
Suspended Solid ◽  
Poor Quality ◽  
Operating Conditions ◽  
Secondary Effluent ◽  
Effluent Quality ◽  
Filtration Cycle ◽  
Highly Sensitive ◽  
Bacterial Treatment

Conventional methods of disinfecting sewage are all highly sensitive to variations in the effluent quality upstream of the disinfection stage. Microfiltration was tested as a tertiary treatment downstream of biofiltration, simulating very poor biofilter efficiency, to test the limits of the microfiltration process. Despite the poor quality of the secondary effluent (COD between 100 and 400 mgO2/l, BOD5 between 30 and 150 mgO2/l and suspended solid concentrations between 15 and 90 mg/l), the microfiltration process (filtration level : 0.2 µm) eliminated all faecal germs and tenia and ascaris eggs. The total elimination of free amoeba cysts still needs to be confirmed. With the COD and BOD5 reduced by an average of 60 and 70% respectively, the effluent quality is equivalent to level e after microfiltration (COD: 90 mgO2/l and BOD5 = 30 mgO2/l on samples averaged over 24 hours). Turbidity, measured instead of suspended solids at outlet from the microfilter, was 99 % eliminated. The colour remained between 50 and 150 mg Pt.Co/l. Under the operating conditions applied, the minimum filtration cycle was 72 hours for a minimum permeate flow of 80 1/h/m2 of membrane. When microfiltration process was used to treat a secondary effluent of good quality (COD between 14 and 40 mg/l; turbidity between 1.4 and 5.1 NTU) the germ elimination remained the same; the COD removal (31 % average elimination) allowed us to get an effluent with an average COD concentration of 24 mgO2/l. The filtration cycle was much longer (300 hours).

In Vitro Shoot Regeneration from Callus Derived from Marubakaido Apple Rootstock under Different Aluminium Concentrations

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 460e-460 ◽  
Author(s):  
Marisa F. de Oliveira ◽  
Gerson R. de L. Fortes ◽  
João B. da Silva
Keyword(s):  
Shoot Regeneration ◽  
Dichlorophenoxyacetic Acid ◽  
Apple Rootstock ◽  
Under Five ◽  
Significant Difference ◽  
Previously Treated ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
In Vitro Shoot Regeneration

The aim of this work was to evaluate the organogenesis of Marubakaido apple rootstock under different aluminium concentratons. The explants were calli derived from apple internodes treated with either 2,4-dichlorophenoxyacetic acid or pichloram at 0.5 and 1.0 μM and under five different aluminium concentrations (0, 5, 10, 15, 20 mg/L). These calli were then treated with aluminium at 0, 5, 10, 15, and 20 mg/L. It was observed shoot regeneration only for those calli previously treated with pichloram. There were no significant difference among the aluminium concentrations.

Characterization of the Reproductive Mode in Guayule In Vitro

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 483a-483
Author(s):  
Roy N. Keys ◽  
Dennis T. Ray ◽  
David A. Dierig
Keyword(s):  
Field Experiments ◽  
Reproductive Mode ◽  
Dichlorophenoxyacetic Acid ◽  
Initial Field ◽  
Breeding Lines ◽  
Reproductive Modes ◽  
Desert Southwest ◽  
2,4 Dichlorophenoxyacetic Acid

Guayule (Parthenium argentatum Gray, Asteraceae) is a latex-producing perennial desert shrub that is potentially of economic importance as an industrial crop for the desert Southwest. It is known to possess complex reproductive modes. Diploids are predominantly sexual and self-incompatible, while polyploids show a range of apomictic potential and self-compatibility. This paper describes the development of a relatively rapid and simple technique for characterizing reproductive modes of breeding lines of P. argentatum. Initial field experiments were based on an auxin test used successfully to characterize reproductive mode in the Poaceae. The application of 2,4-dichlorophenoxyacetic acid inhibited embryo formation in P. argentatum, but this was not the case with other auxins tested. Results of field experiments were ambiguous because: 1) the floral structure of P. argentatum is such that auxins might not have penetrated to the ovules, and 2) there was potential self-fertilization by pollen released within isolation bags. Therefore, in vitro culture of flower heads was tested because it provided much better control of environmental conditions, growth regulator application, and pollen release. Auxin alone, or in combination with gibberellic acid or kinetin, inhibited parthenogenesis in vitro. Embryo production did not vary using two substantially different nutrient media. In vitro flower head culture using a (Nitsch and Nitsch) liquid nutrient medium without growth regulators, enabled characterization of the reproductive mode of seven breeding lines, ranging from predominantly sexual to predominantly apomictic. The results of this technique were substantiated using RAPD analyzes of progeny arrays from controlled crosses.

Continuing the Development of Municipal Effluent Guidelines for the Northwest Territories

1986 ◽  
Vol 18 (2) ◽  
pp. 179-184
Author(s):  
R. J. Kent
Keyword(s):  
Northwest Territories ◽  
Removal Efficiency ◽  
Municipal Wastewater ◽  
Coliform Bacteria ◽  
Flow Ratio ◽  
Dilution Ratio ◽  
Effluent Quality ◽  
Municipal Effluent

The background to and the rationale for the Guidelines for Municipal Type Wastewater Discharges in the Northwest Territories is discussed. Particu1ar attention is given to the development of Table 2.1, Effluent Quality of Municipal Wastewater Discharges, which was based upon expected lagoon performance. Also included is a discussion of the flow ratio and dilution ratio concepts. The viability of these concepts was assessed against the available data. It appears that the guidelines misjudged both the number of coliform bacteria in northern raw sewage and the removal efficiency for these organisms in lagoons. It appears unlikely that lagoons can consistently meet the guideline requirements. More information and research is necessary before a complete assessment can be performed.

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