Dissemination of Phytophthora cactorum, cause of crown rot in strawberry, in open and closed soilless growing systems and the potential for control using slow sand filtration

2010 ◽  
Vol 125 (4) ◽  
pp. 756-760 ◽  
Author(s):  
F. Martínez ◽  
S. Castillo ◽  
E. Carmona ◽  
M. Avilés
Keyword(s):  
Crown Rot ◽  
Phytophthora Cactorum ◽  
Sand Filtration ◽  
Slow Sand Filtration

Treatment of Groundwater with Slow Sand Filtration

1988 ◽  
Vol 20 (3) ◽  
pp. 141-147 ◽  
Author(s):  
T. Hatva
Keyword(s):  
Biological Activities ◽  
Treatment Phase ◽  
Purification Process ◽  
Sand Filtration ◽  
Sand Filters ◽  
Slow Sand Filtration ◽  
Filtration Method ◽  
Pre Treatment ◽  
Full Scale Tests ◽  
Iron Manganese

The purification process and techniques of the slow sand filtration method for treatment of groundwater was studied on the basis of pilot plant and full scale tests and studies of waterworks, to obtain guidelines for construction and maintenance. The purification process consists in general of two principal phases which are pre-treatment and slow sand filtration. Both are biological filters. The main purpose of the pre-treatment is to reduce the iron content of raw water, in order to slow down the clogging of the slow sand filters. Different types of biofilters have proved very effective in the pre-treatment phase, with reduction of total iron from 50 % to over 80 %. During the treatment, the oxidation reduction conditions gradually change becoming suitable for chemical and biological precipitation of iron, manganese and for oxidation of ammonium. Suitable environmental conditions are crucial in the oxidation of manganese and ammonium which, according to these studies, mainly occurs in slow sand filters, at the end of the process. Low water temperature in winter does not seem to prevent the biological activities connected with the removal of iron, manganese and ammonium, the chief properties necessitating treatment of groundwater in Finland.

scholarly journals Natural organic matter removal by ion exchange at different positions in the drinking water treatment lane

2013 ◽  
Vol 6 (1) ◽  
pp. 1-10 ◽  
Author(s):  
A. Grefte ◽  
M. Dignum ◽  
E. R. Cornelissen ◽  
L. C. Rietveld
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Organic Matter ◽  
Water Treatment ◽  
Organic Carbon ◽  
Natural Organic Matter ◽  
Drinking Water Treatment ◽  
Biological Stability ◽  
Sand Filtration ◽  
Slow Sand Filtration

Abstract. To guarantee a good water quality at the customers tap, natural organic matter (NOM) should be (partly) removed during drinking water treatment. The objective of this research was to improve the biological stability of the produced water by incorporating anion exchange (IEX) for NOM removal. Different placement positions of IEX in the treatment lane (IEX positioned before coagulation, before ozonation or after slow sand filtration) and two IEX configurations (MIEX® and fluidized IEX (FIX)) were compared on water quality as well as costs. For this purpose the pre-treatment plant at Loenderveen and production plant Weesperkarspel of Waternet were used as a case study. Both, MIEX® and FIX were able to remove NOM (mainly the HS fraction) to a high extent. NOM removal can be done efficiently before ozonation and after slow sand filtration. The biological stability, in terms of assimilable organic carbon, biofilm formation rate and dissolved organic carbon, was improved by incorporating IEX for NOM removal. The operational costs were assumed to be directly dependent of the NOM removal rate and determined the difference between the IEX positions. The total costs for IEX for the three positions were approximately equal (0.0631 € m−3), however the savings on following treatment processes caused a cost reduction for the IEX positions before coagulation and before ozonation compared to IEX positioned after slow sand filtration. IEX positioned before ozonation was most cost effective and improved the biological stability of the treated water.

scholarly journals First report of crown rot of Photinia fraseri caused by Phytophthora cactorum

2006 ◽  
Vol 55 (4) ◽  
pp. 573-573 ◽  
Author(s):  
A. M. Vettraino ◽  
L. Antonacci ◽  
L. Flamini ◽  
P. Nipoti ◽  
E. Rossini ◽  
...  
Keyword(s):  
Crown Rot ◽  
Phytophthora Cactorum ◽  
First Report

Deterministic-Based Model of Slow Sand Filtration. I: Model Development

2006 ◽  
Vol 132 (8) ◽  
pp. 872-886 ◽  
Author(s):  
Luiza C. Campos ◽  
Stephen R. Smith ◽  
Nigel J. D. Graham
Keyword(s):  
Model Development ◽  
Sand Filtration ◽  
Slow Sand Filtration

Rainwater treatment in airports using slow sand filtration followed by chlorination: Efficiency and costs

2012 ◽  
Vol 65 ◽  
pp. 124-129 ◽  
Author(s):  
Ronan Fernandes Moreira Neto ◽  
Maria Lúcia Calijuri ◽  
Isabella de Castro Carvalho ◽  
Aníbal da Fonseca Santiago
Keyword(s):  
Sand Filtration ◽  
Slow Sand Filtration

scholarly journals Influence of Ripening State of Filters on Microbe Removal Efficiency of Slow Sand Filtration Used to Disinfect a Closed Soilless Culture System

2003 ◽  
Vol 72 (3) ◽  
pp. 190-196 ◽  
Author(s):  
Yoko Mine ◽  
Ryozo Sakiyama ◽  
Yoshikazu Yamaki ◽  
Masaru Suematsu ◽  
Hitoshi Saka
Keyword(s):  
Removal Efficiency ◽  
Culture System ◽  
Soilless Culture ◽  
Sand Filtration ◽  
Slow Sand Filtration

STUDIES OF CROWN ROT OF APPLE TREES

1942 ◽  
Vol 20c (9) ◽  
pp. 457-490 ◽  
Author(s):  
Maurice F. Welsh
Keyword(s):  
Soil Moisture ◽  
Apple Tree ◽  
Disease Incidence ◽  
Antagonistic Effect ◽  
Crown Rot ◽  
Phytophthora Cactorum ◽  
Additional Information ◽  
Two Factors ◽  
Below Ground ◽  
Old Trees

The form of apple tree crown rot that occurs in the irrigated orchards of British Columbia is confined to the below-ground bark tissues of the tree. It has been encountered in trees of all ages and of all the commercial varieties.Proof is given that this crown rot is caused by the fungus Phytophthora cactorum (L. & C.) Schroet. Typical symptoms of the disease have been reproduced in over 200 trees of various ages as a result of their inoculation with this fungus. Isolation has been possible only from the margins of active lesions, and has proved difficult even from these tissues. There is evidence that the activity of P. cactorum is inhibited in rotted tissues by the antagonistic effect of one or more secondary organisms.The influence of soil moisture and temperature on disease incidence has been studied by field observations and by the inoculation of two-year—old trees under controlled conditions in Wisconsin tank equipment in the greenhouse. The effects of these two factors seem to be interrelated, with the highest incidence of disease in an almost saturated soil at the highest temperature imposed, 32 °C. The influence of soil moisture is exerted particularly in the subsoil, rather than in the locus of crown rot attack.Certain varieties of apple have been found to vary in their resistance to crown rot. Deep wounds have proved necessary to allow entry of the fungus into bark tissues.The additional information now available is being utilized in a search for improved means of combating the disease.

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