Uptake of phosphorus from sediment by aquatic plants, Myriophyllum spicatum and Hydrilla verticillata

Eurasian water milfoil(Myriophyllum spicatum L.) and hydrilla (Hydrilla verticillata Royle) took up most or all of their P from the hydrosoil (sediment) when the water contained 0.015 μg P ml⁻¹Myriophyllum continued to utilize largely hydrosoil-P with 0.5 μg P ml⁻¹ in the water; however, when 2.0 μg P ml^-1 was present in the water, the uptake of hydrosoil-P decreased and the of uptake of water-P increased.Stems of Myriophyllum cut off 2 cm above the crown transferred only 4–20 μg P/plant of hydrosoil-P into the water in the first 18 h after decapitation; thereafter, no further P release occurred. A harvesting operation would thus result in the direct transfer of only a small amount of hydrosoil-P into the water; however, the organically bound-P removed in the harvested Eurasian water milfoil plants would be derived largely from the hydrosoil, not the water body. The procedure would not be effective in reducing the P content of the lake unless its P content was higher than 0.5 μg ml⁻¹.The specific activity of the P taken up by hydrilla was similar to that of the water extracted from the hydrosoil. It differed greatly from the specific activity of the P adsorbed on the sediment that was extracted from the hydrosoil by a weak NH₄F---HCI extract. This adsorbed-P fraction, believed to be important in non-aquatic soils, was not supplying the P to the solution feeding the aquatic plant roots or was not in equilibrium with the hydrosoil solution-P.     

Chlorophenols in surface waters of the Netherlands (1976–1977)

In this paper an analytical method is described for the capillary gas chromatographic determination, after derivatization, of 19 individual chlorophenols in surface water. The minimum detectable amounts are for monochlorophenols 2 μg l⁻¹, for dichlorophenols 0.05 μg l⁻¹, for trichlorophenols 0.02 μg l⁻¹ and for tetra- and pentachlorophenols 0.01 μg l⁻¹. The results of a monitoring program in the river Rhine and other Dutch surface waters with respect to these compounds are presented. The results cover the period January 1976–December 1977. 2,6-Dichlorophenol, 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol and pentachlorophenol had the highest frequencies of occurrence in the river Rhine and its tributaries. Pentachlorophenol was found in the highest concentrations (up to 11 μg l⁻¹).     

Rate constants of reactions of ozone with organic and inorganic compounds in water—III. Inorganic compounds and radicals

Second-order rate constants for reactions of ozone with 40 inorganic aqueous solutes are reported. Included are compounds of sulfur (e.g. H₂S, H₂SO₃, HOCH₂SO₃H), chlorine (e.g. Cl⁻, HOCl, NH₂Cl, HClO₂, ClO₂), bromine (e.g. Br⁻, HOBr), nitrogen (e.g. NH₃, NH₂OH, N₂O, HNO₂) and oxygen (e.g. H₂O₂), as well as free radicals (e.g. O₂⁻, OH^•). Most of these compounds exhibit an increase in rate constant with increasing pH corresponding to their degree of dissociation. Rate constants are based on ozone consumption rates measured by conventional batch-type or continuous-flow methods (10⁻³-10⁺⁶ M⁻¹ s⁻¹ range) and determinations of stoichiometric factors. Also listed are data determined by pulse-irradiation techniques using kinetic spectroscopy (10¹⁰ M⁻¹ s⁻¹ range). Additional literature data are reviewed for completeness. Results are discussed with respect to water treatment and environmental processes.     

Chlorophenols in river sediment in The Netherlands

In this paper an analytical method is described for the capillary gas chromatographic determination, after derivitization, of 19 individual chlorophenols in river sediment. The minimum detectable amounts are for monochlorophenols 10 μg kg⁻¹, dichlorophenols 0.5 μg kg⁻¹, trichlorophenols 0.2 μg kg⁻¹ and for tetra- and pentachlorophenols 0.1 μg kg⁻¹. The results of a monitoring program in the Rhine River and its tributaries and other Dutch surface waters with respect to these compounds are presented. 2,5-Dichlorophenol, 2,3,5- and 2,4,5-trichlorophenol, 2,3,4,5- and 2,3,4,6-tetrachlorophenol and pentachlorophenol had a frequency of occurrence of 100% in sediment samples from Lake Ketelmeer, which is a deposition area for Rhine River sediment. The highest concentrations of chlorophenols were found in the Nieuwe Maas River near Rotterdam, a heavily industrialized area.     

Note on a rapid and sensitive method for the determination of anionic detergents in natural waters at the ppb level

A rapid and sensitive method for the determination of anionic detergents in natural waters is developed using atomic absorption spectrophotometry and his (ethylenediamine) copper(II) ion. The method is suitable for a concentration range of 0–50 μg1⁻¹ (ppb), but its applicability can be extended up to 15 μg ml⁻¹. The limit of detection is 0.3 μg l⁻¹.     

Distribution of halomethanes in potable waters of Kuwait

The distribution of bromine containing trihalomethanes in the water distribution system of Kuwait has been studied. Total halomethanes in the drinking water averaged 25.6 ± 9.1 μg l⁻¹ with a maximum of 50.5 μg l⁻¹. Average concentrations (μg l⁻¹) of individual compounds were: CHBr₃, 13.6 ± 4.6; CHBr₂Cl, 8.8 ± 3.7; CHCl₂Br, 3.3 ± 1.5. Water from roof top storage tanks contained significantly less halomethanes than that from underground reservoirs.     

Investigation of the Folin-Ciocalteau phenol reagent for the determination of polyphenolic substances in natural waters

The methodology associated with the Folin-Ciocalteau phenol reagent was investigated and the performance characteristics of a method using sodium carbonate as the supporting medium were determined. Calibration curves using phenol, tannic acid, or l-tyrosine were linear up to at least 1000 μg l⁻¹. The limit of detection was 6 μg phenol l⁻¹ and the relative standard deviation at 100 μg phenol l⁻¹ was 5.2% and at 1000 μg phenol l⁻¹ was 4.1%. The absorbances obtained with equal amounts of a range of potential standards showed variations when compared with that of phenol: phenol (100%), l-tyrosine (62%), oak gall tannin (58%), tannic acid (48%), chestnut tannin (26%), oak tannin (24%), fulvic acid (5%). The method was applicable to a wide range of monohydric and polyhydric phenolic substances and interferences from inorganic and non-phenolic organic compounds were examined. Interference would be expected above 30 μg S²⁻ l⁻¹, 300 μg Mn(II) l⁻¹, or 400 μg SO₃²⁻ l⁻¹. Concentrations of iron >2 mg l⁻¹ as Fe(II) or Fe(III) formed the insoluble iron(III) hydroxide which increased the absorbance, but centrifugation could be used to remove this source of interference. Other potential sources of intereference (e.g. reducing agents and certain metabolic products) would be expected to have a negligible effect in unpolluted waters. Methods using diazotised sulphanilic acid or 4-aminoantipyrine (4-AAP) were found to be inferior when applied to natural water samples.     

Utilisation de la clinoptilolite en potabilisation des eaux—elimination de l'ion NH4

The objective of this study is to develop a technique to remove ammonium ion from water intended for potable purposes. An ion exchange method is used with a selective ion exchanger, a natural cation zeolite, clinoptilolite. Glass columns (Fig. 1) are used for laboratory experiments. These experiments show that the NH₄⁺ exchange capacity is very small compared to its total capacity 2.17 meq g⁻¹; its value depends essentially on the NH₄⁺ initial concentration and less on the Ca²⁺ concentration in the influent water. Figure 3 illustrates the practical exchange capacity relative to the initial concentration of ammonium ion for a soft water (Ca²⁺ = 35–50 mg l⁻¹). We were particularly interested in waters weak in ammonium ion concentration (NH₄⁺ = 1–3 mg l⁻¹). In this case and for 1 and 2 mg l⁻¹ NH₄⁺ concentration in water, the practical capacity is only 0.06 and 0.108 meq g⁻¹ respectively. The leakage is smaller than the ECC limit (European Community Council) for drinking waters (NH₄⁺ 0.5 mg l⁻¹) and the treated volume of water to breakthrough, defined at 0.5 mg l⁻¹ of NH₄⁺, is 720 BV (BV = bed volume) in both cases.In another way Fig. 6 shows that hard waters (due to Ca²⁺ ions) are more difficult to treat than soft waters. The practical capacity is smaller than before and the NH₄⁺-leakage is greater. To lessen NH₄⁺-leakage to less than 0.5 mg l⁻¹ for soft waters down-flow and up-flow, regeneration is used. Figure 7 shows that up-flow regeneration is more attractive than down-flow regeneration.Cycle reproducibility (Figs 4 and 5) shows that the regeneration conditions satisfied our requirements: in this case, the salt consumption is 180 eq of salt per eq of NH₄⁺ eliminated. This prompted us to try to reuse the regenerant (with NH₄⁺ ion). An increase of NH₄⁺-leakage is noticed in the presence of an NH₄⁺-residual in the regenerant. This increase is more significant with down-flow regeneration.After these laboratory experiments, we carried out a semi-industrial pilot-plant. Our objective was first to verify the laboratory results and secondly to study clinoptilolite behaviour relative to the time it was used. Two plexiglass columns comprise the pilot-plant shown in Fig. 9; soft water is used for these experiments. The first column is regenerated with fresh salt solution. The cycles obtained, considering their initial NH₄⁺-concentration, are reproduced in Fig. 10. For 2 mg l⁻¹ NH₄⁺ in the influent water, the leakage is about 0.2 mg l⁻¹ and the treated volume to breakthrough (0.5 mg l⁻¹ of NH₄⁺) is about 750 BV. The second column is regenerated with a recycled solution. The quality of the cycles decreases with the number of reuse of the regenerant as shown in Fig. 11. Nevertheless, it is interesting to note that after 3 reuses, the performance decrease is only 25% and the leakage, although it increases is smaller than 0.5 mg l⁻¹.Pilot results allowed us to propose a treatment of 30,000 m³ day⁻¹; the cost per cubic meter water treated, relative to NH₄⁺-removal, is about 0.165 FF (0.033 US $) for a plant and 0.77 FF (0.014 US $) for the same plant at the seaside. Using two serial columns decreased the cost by about 40–50%.     

Factors affecting nutrient loads in some Iowa streams

The export and concentration of inorganic nitrogen and total phosphorus from 34 watersheds in a northwestern Iowa lake district were measured during March 1971–August 1973. Annual nutrient losses were approximately 0.35 kg ha⁻¹ P. 6.7 kg ha⁻¹ NO₃-N, and 1.0 kg ha⁻¹ NH₃-N. A statistical analysis of the relationship between land-use and plant nutrients was used to determine differences among streams. Animal units in feedlots were significantly correlated with phosphorus and ammonia nitrogen (mg l⁻¹ and kg ha⁻¹ yr⁻¹). Nitrate nitrogen was negatively correlated with the percentage of watershed in marshland. Tile drainage and surface runoff from grasslands, feedlots, cornfields, and soybean fields were analyzed for nitrogen and phosphorus in spring 1974: mean values are given.     

Mercury fluxes in a natural forested Amazonian catchment (Serra do Navio, Amapá State, Brazil)

Mercury (Hg total) fluxes were calculated for rainwater, throughfall and stream water in a small catchment located in the northeastern region of the Brazilian Amazon (Serra do Navio, Amapá State), whose upper part is covered by a natural rainforest and lower part was altered due to deforestation and activities related to manganese mining. The catchment area is 200 km from the nearest gold mining (garimpo). Minimum and maximum Hg concentrations were measured monthly from October 1996 to September 1997 and were 3.5–23.4 ng l⁻¹ for rainwater, 16.5–82.7 ng l⁻¹ for throughfall (March–August 1997) and 1.2–6.1 and 4.2–18.8 ng l⁻¹ for stream water, in natural and disturbed areas, respectively. In the natural area, the inputs were 18.2 μg m⁻² year⁻¹ in rainwater and 72 μg m⁻² year⁻¹ in throughfall. This enrichment was attributed to dry deposition. The stream output of 2.9 μg m⁻² year⁻¹ indicates that Hg is being recycled within the forest as other chemical species or is being retained by the soil system, as confirmed by the cumulative Hg burden in the 0–10 cm surface layer, which was 36 480 μg m⁻². When the disturbed area of the catchment was included, the stream output was 9.3 μg m⁻², clearly indicating the impact of the deforestation of the lower part of the basin on the release of mercury. The Hg burden in the disturbed area was 7560 μg m⁻² for the 0–10 cm surface layer.     

Trace metals: Cd, Cu, Pb and Zn in gelatinous macroplankton from the Northwestern Mediterranean

Gelatinous macroplankton organisms were collected in May 1984 in Villefranche-sur-Mer Bay and analysed for cadmium, copper, lead and zinc. Analyses were carried out by polarography for Cd, Cu and Pb and by flame atomic absorption for Zn. Phosphorus was also measured in the samples as a biomass parameter due to difficulties inherent in measuring dry weight of gelatinous organisms. The samples belong to the Tunicates, the Cnidarians (Hydromedusae, Siphonophores and Scyphomedusae), the Ctenophores and the Molluscs. Crustaceans living on some Tunicates were also sampled.As regards cadmium, copper and lead, mean concentrations did not show significant differences among the phyla studied: especially for Tunicates with mean values of 0.1 ng Cd μg P⁻¹, 2.0 ng Cu μg P⁻¹ and 0.9 ng Pb μg P⁻¹ and for Cnidarians with mean values of 0.5 ng Cd μg P⁻¹, 2.0 ng Cu μg P⁻¹ and 0.9 ng Pb μg P⁻¹ and for Cnidarians with mean values of 0.5 ng Cd μg P⁻¹, 2.0 ng Cu μg P⁻¹, 1.0 ng Pb μg P⁻¹. On the other hand, mean zinc concentrations were significantly lower in Tunicates (7.9 ng Zn μg P⁻¹) than in Cnidarians (36.8 ng Zn μg P⁻¹).Zinc seems to be preferentially concentrated in organisms which are rich in collagen, constituting the mesoglea, such as the Cnidarians, the Ctenophore and the gelatinous Mollusc studied, rather than in organisms rich in tunicin such as the Tunicates.     

Concentrations of heavy metals in small Norwegian lakes

As part of regional surveys of lakes in Norway the concentrations of Zn, Pb, Cu and Cd were measured in surface- and bottom-water samples collected from representative, small, pristine lakes (136 in southern Norway sampled in October 1974, 58 resampled in March 1975, and 77 in northern Norway sampled in March 1975). The lakes, a statistically representative sample of small lakes in Norway, were chosen such that their watersheds are undisturbed. Heavy-metal concentrations in these lakes thus reflect only natural inputs and anthropogenic inputs via the atmosphere.The generally low concentrations (Zn 0.5–12.0 μg l⁻¹; Pb 0–2.0 μg l⁻¹; Cu 0–2.0 μg l⁻¹; Cd 0.1-0.5 μg l⁻¹) measured in lakes in central and northern Norway provide estimates of natural “background” levels. These estimates may be too high because they include the global-scale deposition of heavy metals from the atmosphere which has increased as a result of industrial activities.Concentrations of Zn and Pb in lakes in southernmost and southeastern Norway lie above these “background” levels, apparently because of atmospheric deposition associated with the acidic precipitation that falls over southern Scandinavia. Increased heavy-metal concentrations in acid lakes may also be due to increased mobilization of metals due to acidification of soil- and surface-waters.     

Acute toxicity and behavioral responses of coho salmon (Oncorhynchus kisutch) and shiner perch (Cymatogaster aggregata) to chlorine in heated sea-water

The acute toxicity and behavioral response to chlorinated and heated sea-water was determined for coho salmon smolts and 1–3 month old shiner perch. LC₅₀'s were determined for 7.5, 15, 30 and 60 min exposure times; 13, 16 and 20°C (Δt = 0, 3, 7°C) temperatures and total residual oxidant (TRO) concentrations ranging from 0.077 to 1.035 mg l⁻¹. The mean 60 min LC₅₀ for shiner perch was significantly reduced (P ≤ 0.05) from 308 μg l⁻¹ TRO at 13°C to 230 μg l⁻¹ TRO at 20°C. The 60 min LC₅₀ for coho salmon decreased from 208 μg l⁻¹ TRO at 13°C to 130 μg l⁻¹ at 20°C. The LC₅₀'s for coho salmon in chlorinated sea-water averaged 55% of those for shiner perch. The relationship between TRO concentration, exposure time, and percent survival in chlorinated sea-water at 13°C is presented for both species.A significant (P ≤ 0.01) avoidance threshold for coho salmon occurred at 2 μg l⁻¹ TRO and was reinforced with increasing temperature. A significant (P ≤ 0.01) avoidance threshold for shiner perch occurred at 175 μg l⁻¹ TRO, while a significant preference (P ≤ 0.05 or 0.01) response at 16°C and 20°C occurred at 10, 25, 50 and 100 μg l⁻¹ TRO. The ecological implications of the toxicity tests and the behavioral responses are discussed.     

A sublethal technique for assessing the effects of contaminants using hydra littoralis

A technique is described for estimating the biological effects of low levels of contaminants using as an index of response the rate of asexual reproduction of Hydra littoralis. Preliminary experiments show the rate of reproduction becomes significantly inhibited by levels of 2–12 μg Cu²⁺ 1⁻¹, although it appears that the rate oscillates for some days after the initial exposure to inhibitory agents. A control mechanism appears to regulate the rate of asexual reproduction and within the range 0.5–2.5 μg Cu²⁺ 1⁻¹ this mechanism enables the organism to counteract the inhibitory effect of copper, restoring growth to that of the controls after about 7 days. The concept of a quantifiable counter response is considered in a toxicological context.     

The effects of organotin on the activated sludge process

Organotin compounds which find increasing use in marine antifouling paints may be present in the discharge from dry dock operations. This investigation was aimed at determining the effect of such wastewater when discharged to a municipal activated sludge treatment plant. Experiments were conducted using a Warburg respirometer and continuous flow bench-scale activated sludge systems. The results showed that unacclimated biological cultures can be inhibited by tributyl tin oxide (TBTO^™) concentrations as low as 25 μgl⁻¹. However, TBTO doses of over 8000 μgl⁻¹ can be tolerated by a well acclimated culture. Continuous loading of up to 1000 μgl⁻¹ TBTO had no effect on organic removal in activated sludge systems. However, an adverse effect on sludge settleability was noticed at 100 μgl⁻¹ TBTO. Shock loadings of 500 and 1000 μgl⁻¹ TBTO had no effect on soluble organic removal but resulted in impaired settling and higher effluent suspended solids. The LC₅₀ of TBTO to the fathead minnow was estimated at 45–200 μgl⁻¹. The toxicity was reduced considerably by activated sludge treatment.     

Acute and chronic toxicity of lead to rainbow trout salmo gairdneri, in hard and soft water

Lead was found to be highly toxic to rainbow trout in both hard water (hardness 353 mg l⁻¹ as CaCO₃) and soft water (hardness 28 mg l⁻¹. Analytical results differ greatly with methods of analysis when measuring concentrations of lead in the two types of water. This is exemplified in LC50's and maximum acceptable toxicant concentrations (MATC's) obtained when reported as dissolved lead vs total lead added in hard water. Two static bioassays in hard water gave 96-h LC50's of 1.32 and 1.47 mg l⁻¹ dissolved lead vs total lead LC50's of 542 and 471 mg l⁻¹, respectively. In a flow-through bioassay in soft water a 96-h LC50 of 1.17 mg l⁻¹, expressed as either dissolved or total lead, was obtained. From chronic bioassays, MATC's of lead for rainbow trout in hard water were between 18.2 and 31.7 μg l⁻¹ dissolved lead vs 120–360 μg l⁻¹ total lead. In soft water, where exposure to lead was initiated at the eyed egg stage of development, the MATC was between 4.1 and 7.6 μg l⁻¹. With exposure to lead beginning after hatching and swim-up of fry, the MATC was between 7.2 and 14.6 μg l⁻¹. Therefore, fish were more sensitive to the effects of lead when exposed as eggs.     

Toxicity of silver to rainbow trout (Salmo gairdneri)

The mean 96-h LC₅₀'s of silver with rainbow trout were 6.5 μg l⁻¹ and 13.0 μg l⁻¹ in soft water (approximately 26 mg l⁻¹ hardness as CaCO₃) and hard water (350 mg l⁻¹ hardness as CaCO₃), respectively. The long-term, “no effect” concentration for silver, added to the water as silver nitrate, was between 0.09 and 0.17 μg l⁻¹ after 18 months exposure in soft water. The “no effect” concentration is that concentration range which defines no observed effect. Based on mortalities different from the control, no mortalities attributable to silver occurred at 0.09 μg Ag l⁻¹, whereas 17.2% mortality occurred to fish exposed to 0.17 μg ll⁻¹. The “no effect” concentration does not reflect possible effects of silver on spawning behavior or reproduction, since female rainbow trout will not generally reach sexual maturity before 3 yr. At silver concentrations of 0.17 μg l⁻¹ or greater, silver caused premature hatching of eggs and reduced growth rate in fry. In one experiment, the eggs were completely hatched within 10 days of exposure; whereas, control eggs completed hatching after 42 days. The prematurely erupted fry were not well developed and frequently died. The growth rate of surviving fry was greatly reduced.     

A rapid manual method for nitrate determination in small volumes by a modification of the cadmium reduction method

Nitrate concentration (2–100 μg NO₃-N1⁻¹) in water samples as small as 5 ml can be determined manually in test tubes by a modification of the standard cadmium reduction method without loss of sensitivity. Once reaction tubes are prepared, 30 samples can be batch-processed in one hour by this technique. Reaction tubes can be used 5–10 times before the reactivation of the cadmium is necessary.     

The use of uric acid as a method of tracing domestic sewage discharges in riverine, estuarine and coastal water environments

The chemical tracking of sewage effluents discharged into fresh and saline waters presents difficulties, especially in estuaries. The main difficulty is caused by the dissolved constituents being used to monitor the effluent also occurring naturally at similar levels. Uric acid is present at significant levels in untreated sewage and is not normally found in unpolluted waters. Until now no suitable routine method has been available for uric acid estimation in fresh and saline waters at levels normally encountered in the environment. In this paper we describe a recently developed technique using high-performance liquid chromatography which estimates uric acid in both fresh and saline waters in the range 1–10,000 μg l⁻¹ with a precision (2σ) of ±20% at 2 μg l⁻¹, ±4% at 40 μg l⁻¹ and ±2% at 10 mg l⁻¹.     

Nitrosamines in tap water after concentration by a carbonaceous adsorbent

Ambersorb XE-340 carbonaceous adsorbent removed trace levels of volatile nitrosamines (NAs) that were added to the influent water. Recovery of seven added NAs was between 58–99% as determined by a gas-liquid chromatograph interfaced with a Thermal Energy Analyzer (GLC-TEA). When municipal (tap) water (10–42 l.) was passed through the Ambersorb XE-340 column. N-nitrosodimethylamine (NDMA; 0.003–0.006 μg 1⁻¹) and -morpholine (NMOR; 0.006–0.018 μg 1⁻¹) were the principal NAs found. All of the NDMA and 18 of 20 NMOR samples were confirmed by high resolution mass spectrometry. Secondary amines added to tap water at levels of 1 mg 1⁻¹ and 10 μg 1⁻¹ formed apparent NAs, suggesting a possible component(s) in the water that caused NA formation. Low levels of volatile NAs were detected by GLC-TEA in commercial, pure, adsorbents (activated carbon). NAs were confirmed by high resolution mass spectrometry except where concentrations were too low. In the latter case, the apparent NAs were found to be photolabile when subjected to u.v. light (365 nm) and were reanalyzed by GLC-TEA thus providing additional evidence that the TEA responsive compounds were NAs.