Rapid treatment of vessels fouled with an invasive polychaete, Sabella spallanzanii, using a floating dock and chlorine as a biocide.

Chlorine solution was added to the water encapsulated within a proprietary 'floating dock' to treat a vessel infested with the invasive polychaete Sabella spallanzanii. The chlorine was added as sodium dichloroisocyanurate ('dichlor') at an initial concentration of 200 mg l(-1) of free available chlorine (FAC). This concentration killed 99% of S.

A source mixing model to apportion PAHs from coal tar and asphalt binders in street pavements and urban aquatic sediments.

Present-day and more than 30 years old road and footpath pavements from Auckland, New Zealand were analysed for PAHs to test the hypothesis that coal tar based pavement binders contribute to unusually high PAH concentrations in adjacent stream and estuarine sediments. Total PAH (∑(28)PAH) concentrations in the dichloromethane-soluble fraction ("binder"), comprising 5-10% of pavement mass, were as high as 200,000 mgkg(-1) (10,000 mgkg(-1) in binder+aggregate). Older and deeper pavement layers were strongly pyrogenic, whereas pavement layers from recently sealed roads had a more petrogenic composition and more than 1000 times lower ∑(28)PAH concentrations.

Heavy metal stabilization in contaminated road-derived sediments.

There is increasing interest in the stabilization of heavy metals in road-derived sediments (RDS), to enable environmentally responsible reuse applications and circumvent the need for costly landfill disposal. To reduce the mobility of heavy metals (i.e.

Polymer building blocks: self-assembly of silver(I) cyclotriphosphazene cationic columns.

The multimodal ligand hexakis(2-pyridyloxy)cyclotriphosphazene (L) and its 4-methyl-2-pyridyloxy analogue (MeL) react with Ag(I) to afford {[AgL]+}infinity supramolecular cationic columns via self-assembly, with the anions occupying the intercolumnar channels. In contrast, the reaction of MeL with Cu(I) yields a dimetallic Cu(II) complex containing mu-OH and mu-4-methyl-2-pyridyloxylato bridges.

Copper(II) chloride complexes with multimodal ligands based on the cyclotriphosphazene platform.

The reaction of hexakis(2-pyridyloxy)cyclotriphosphazene (L) and hexakis(4-methyl-2-pyridyloxy)cyclotriphosphazene (MeL) with copper(ii) chloride afford the complexes [CuLCl(2)], [(CuCl(2))(2)(MeL)], [CuLCl]PF(6) and [Cu(MeL)Cl]PF(6). The single-crystal X-ray structure of [CuLCl(2)] shows the copper ion to be in a square based pyramidal distorted trigonal bipyramidal (SBPDTBP) environment (tau= 0.47) with L acting as a kappa(3)N donor, coordinating via the nitrogen atoms from two non-geminal pyridyloxy pendant arms, a nitrogen atom in the phosphazene ring and two chloride ions.

Inhomogeneous distribution of polycyclic aromatic hydrocarbons in different size and density fractions of contaminated sediment from Auckland Harbour, New Zealand: an opportunity for mitigation.

Polycyclic aromatic hydrocarbons (PAHs) in sediment from Auckland Harbour (New Zealand) are not distributed evenly throughout bulk sediment, but highly concentrated in coarser, low-density fractions. Concentrations of 24 PAHs, measured in sediment that was separated into six size fractions that were furthermore separated into two density sub-fractions by flotation in sodium-polytungstate solution (rho = 2.15 g cm(-3)), varied between 4-103 microg g(-1)dw among grain size fractions and 2-998 microg g(-1)dw for density sub-fractions.