ALBERT

Notes: The paper describes the design and construction of a comprehensive drainage scheme which is based on a system of intercepting sewers, headworks, and a long sea outfall. Details are given of the fabrication, discharge arrangements and construction of the outfall, together with measures used for long-term protection of the pipeline. The layout and design of the headworks and the changes made to the original design to meet changing environmental requirements are given. The paper briefly outlines the existing sewerage system and goes on to describe the proposed interceptor sewerage system for the connection of the flow from the existing outfalls to the headworks. Difficulties encountered in construction are highlighted.The authors indicate their view on the suitability of the present design, and recognition is given to the likelihood that additional facilities may be required in future. The difficulties which could arise in the provision of such facilities are also highlighted.

Notes: The degradation of DE-498 (proposed common name flumetsulam) was studied in 21 US soils as a first step in developing a management plan for this new herbicide. Degradation half-lives were shorter in soils that adsorbed the compound less. Adsorption was lower in soils with higher pH and lower organic carbon content. Degradation half-lives were thus influenced by both pH and organic carbon: they were in the range 2–4 weeks in higher pH soils (pH 5 〈inlineGraphic alt="geqslant R: gt-or-equal, slanted" extraInfo="nonStandardEntity" href="urn:x-wiley:00431737:WRE197:ges" location="ges.gif"/〉 7.0) unless the organic carbon content was above 2.5%, at which half-lives were in the range 1–3 months. In medium pH soils (6.4 〈inlineGraphic alt="leqslant R: less-than-or-eq, slant" extraInfo="nonStandardEntity" href="urn:x-wiley:00431737:WRE197:les" location="les.gif"/〉 pH 〈inlineGraphic alt="leqslant R: less-than-or-eq, slant" extraInfo="nonStandardEntity" href="urn:x-wiley:00431737:WRE197:les" location="les.gif"/〉 6.9) half-lives were 1–2 months, while in lower pH soils (5.9 〈inlineGraphic alt="leqslant R: less-than-or-eq, slant" extraInfo="nonStandardEntity" href="urn:x-wiley:00431737:WRE197:les" location="les.gif"/〉 pH 〈inlineGraphic alt="leqslant R: less-than-or-eq, slant" extraInfo="nonStandardEntity" href="urn:x-wiley:00431737:WRE197:les" location="les.gif"/〉 6.3) they were 1–4 months. The laboratory data were supported by the response of sunflowers (Helianthus annuus L.) planted 1 year after application of flumetsulam to different soils. A quantitative model relating half-life to sorption Kd (r2= 0.85) was coupled with an additional equation relating sorption Kd to the proportion of neutral and anionic forms of the compound at different pH values. The study allows estimates of this herbicide's degradation in soil to be made if its pH and organic carbon content are known. Degradation d'un herbicide sulfonamide en fonction de la capacité d'absorption du sol La dégradation du flumetsulam a étéétudiée dans les sols aux Etats Unis comme premier stade dans le développement d'un plan d'utilisation de ce nouvel herbicide. Les demi-vies de dégradation étaient plus courtes dans les sols qui absorbaient moins le produit. L'absorption était plus faible dans les sols à pH élevé et à faible teneur en carbone organique. Les demi-vies étaient ainsi sous l'influence du pH et du carbone organique: elles étaient de 2 à 4 semaines pour les pH de sols élevés (pH 〈inlineGraphic alt="geqslant R: gt-or-equal, slanted" extraInfo="nonStandardEntity" href="urn:x-wiley:00431737:WRE197:ges" location="ges.gif"/〉 7) sauf si le carbone organique était au dessus de 2,5%, dans ce cas, les demi-vies etaient de 1 à 3 mois. Dans les sols à pH moyen (6,4 〈inlineGraphic alt="leqslant R: less-than-or-eq, slant" extraInfo="nonStandardEntity" href="urn:x-wiley:00431737:WRE197:les" location="les.gif"/〉 pH 〈inlineGraphic alt="leqslant R: less-than-or-eq, slant" extraInfo="nonStandardEntity" href="urn:x-wiley:00431737:WRE197:les" location="les.gif"/〉 6,9) les demi-vies étaient de 1 à 2 mois, tandis que dans les sols à pH faible (5,9 〈inlineGraphic alt="leqslant R: less-than-or-eq, slant" extraInfo="nonStandardEntity" href="urn:x-wiley:00431737:WRE197:les" location="les.gif"/〉 pH 〈inlineGraphic alt="leqslant R: less-than-or-eq, slant" extraInfo="nonStandardEntity" href="urn:x-wiley:00431737:WRE197:les" location="les.gif"/〉 6,3) elles étaient de 1 à 4 mois. Les résultats de laboratoire ont été confirmés par le comportement de tournesols plantés un an aprfès l'application de flumetsulam dans différents sols. Un modèle reliant la demi-vie au coefficient d'absorption Kd (r2= 0.85) a été couplé avec une équation additionelle reliant le coefficient d'absorption Kd à la proportion de particules neutres et anioniques de la molécule aux différents pH. L'étude permet de faire des estimations de la dégradation de cet herbicide dans le sol dès que le pH et la teneur en carbone organique sont connus. Abbau eines Sulfonamid-Herbizids als Funktion der Bodensorption Der Abbau von Flumetsulam (DE-498) wurde in 21 Böden untersucht, um eine Grundlage zur Produktentwicklung dieses neuen Herbizids zu gewinnen. Die 50%ige Verlustrate (DT50) war in schwächer sorptiven Böden kürzer. Bei hohem pH-Wert und geringem Gehalt an organischer Substanz war die Adsorption schwächer. Die DT50 wurde durch den pH-Wert und den Gehalt organischer Substanz wie folgt beeinflußt: Sie betrug 2 bis 4 Wochen in Böden mit pH 〉7,0 (wenn der Corg-Gehalt nicht über 2,5% lag; dort dann 1 bis 3 Monate), 1 bis 2 Monate bei 6,4 〈 pH 〈 6,9 und 1 bis 4 Monate bei 5,9 〈 pH 〈 6,3). Die Ergebnisse der Laboruntersuchungen wurden durch Untersuchungen an Sonnenblumen gestützt. die 1 Jahr nach Applikation von Flumetsulam auf verschiedenen Böden angebaut wurden. Ein quantitatives Modell über das Verhältnis der Verlustrate zum Sorptionskoeffizienten Kd (r2= 0,85) wurde mit einer zusätzhchen Gleichung der Beziehung des Sorptionskoeffizienten Kd zum Verhältnis der neutralen und der anionischen Verbindungen des Wirkstoffs bei verschiedenen pH-Werten verknüpft. Aufgrund der Untersuchungen kann der Abbau dieses Herbizids in Böden bekannten pH-Werts und Corg-Gehalts abgeschätzt werden.

Notes: : This paper advances the hypothesis that nitrification exists in shallow streams as a result of surface activity and in estuaries due to growth in the water phase. Between these zones no significant levels of nitrification occur. Field measurements of ammonia, nitrite and nitrate nitrogen, enumerations of Nitrosomonas and Nitrobacter, and respirometry on two small streams and two moderately large rivers are presented. The appropriate mathematical models to describe nitrification must be based on the mechanisms involved - bacterial growth kinetics for estuaries and zero kinetics for the surface activity in shallow streams.