Effect of surfactants on the determination of soluble iron in waters

The effects of pure cationic, anionic and non-ionic detergents, industrially prepared detergents, sodium tripolyphosphate, sodium pyrophosphate, soap and NTA, in quantities up to 1000 mg l^?1, on the analysis of soluble iron in water using the phenanthroline, tripyridine and biquinoline methods were investigated. The tripyridine method is superior to the other two methods for the determination of iron in the presence of up to 1000 mg l^?1 of various surfactants but not for up to 100 mg l^?1 of non-ionic detergents. The phenanthroline method can be used to determine iron in the presence of up to 1000 mg l^?1 of cationic, anionic and non-ionic detergents, but sodium tripolyphosphate interfered above 2 mg l^?1. The biquinoline method can be used for the determination of iron in the presence of up to 1000 mg l^?1 of cationic, 100 mg l^?1 of anionic and 70 mg l^?1 of non-ionic detergents, and 50 mg l^?1 of sodium tripolyphosphate.     

Effect of surfactants on the determination of aluminium in waters

Eleven surfactants representing pure cationic, anionic and nonionic detergents, four commercial detergents, sodium pyrophosphate, sodium tripolyphosphate, a soap and nitrilotriacetic acid (NTA) were investigated for their effect on the determination of aluminium in water using the eriochrome cyanine R, ferron-orthophenanthroline and chrome azurol S methods. Cationic, anionic and nonionic detergents at concentrations up to 2, 100 and 1000 mg l⁻¹, respectively, did not interfere. Sodium tripolyphosphate interfered badly above 1.0 mg l⁻¹, and therefore the interference by formulated detergents containing tripolyphosphate was serious. Concentrations of NTA, soap and sodium pyrophosphate had to be below 0.5, 10 and 20 mg l⁻¹, respectively, to limit the error to 5%.     

The effect of surfactants on the extraction-atomic absorption spectrophotometric determination of copper, iron, manganese, lead, nickel, zinc cadmium and cobalt

Nine surfactants representing pure cationic, anionic and non-ionic detergents, three industrially prepared detergents. sodium pyrophosphate. sodium tripolyphosphate, and a soap were investigated for their effect on the extraction-atomic absorption spectrophotometric determination of copper. iron, manganese and lead. Some results are also given for nickel, zinc, cadmium and cobalt. Cations were extracted into 10 ml of MIBK as APDC chelates. To Avoid emulsion formation, maximum concentration of LAS was 1 mg 1⁻¹, and for formulated and non-ionic detergents and washing powders it was 5 mg 1⁻¹.A standard addition procedure was used to obtain correct results for copper and nickel. Two extractions of iron, cobalt and lead, and one extraction of manganese, zinc and cadmium gave a recovery of 100 ± 5%. Soap gave high recoveries for iron and copper. NTA in concentrations up to 25 mg l⁻¹ did not interfere. EDTA in concentrations up to 25 mg l⁻¹ interfered with iron and nickel determinations, but the addition of 3 mg of aluminium removed the EDTA interference in the determination of copper, manganese, lead, zinc, cadmium and cobalt.For the determination of trace metals in polluted natural waters the amount of 4% APDC was increased to 10 ml and for manganese to 25 ml. An addition of 3 mg aluminium as nitrate after the addition of buffer with subsequent 20 min reaction time is required for the determination of all eight metals by the recommended procedures. The effect of humic acid was also investigated.     

The effect of surfactants on the mixed chelate extraction-atomic absorption spectrophotometric determination of copper, nickel, iron, cobalt, cadmium, zinc and lead

Twelve surfactants representing pure cationic, anionic and non-ionic detergents, three commercial detergents, sodium pyrophosphate, sodium tripolyphosphate, a soap, nitrilotriacetic acid (NTA), EDTA, and humic acid were investigated for their effect on the extraction-atomic absorption spectrophotometric determination of copper, nickel, iron, cobalt, cadmium, zinc and lead. Cations were extracted into 10 ml of a solution containing diphenylthiocarbazone, 8-quinolinol and acetyl acetone in ethyl propionate. To avoid emulsion formation, the maximum concentration of linear alkylate sulphonate (LAS) was 10 mg l⁻¹ and for solid industrial LAS-type detergent was 50 mg l⁻¹, but washing powder did not interfere at 100 mg l⁻¹. Cationic and non-ionic detergents gave low recoveries for cobalt. Condensed phosphates at a concentration of 20 mg l⁻¹ did not cause significant interference. NTA interfered with nickel extraction and EDTA with all metals. Humic acid, however, gave no interference. A standard addition procedure can be used to correct the results.A comparison is made between the APDC-MIBK and the mixed chelate-ethyl propionate methods for the determination of trace metals in the presence of various surfactants in natural waters; the latter is preferable.     

Effect of surfactants on the determination of fluoride in waters

Eleven surfactants representing pure cationic anionic and nonionic detergents, four commercial detergents, sodium pyrophosphate, sodium tripolyphosphate, a soap and nitrilotriacetic acid were investigated for their effect on the spectrophotometric and specific ion electrode determinations of fluoride in water. Cationic, anionic and nonionic detergents at concentrations up to 50, 400 and 1000 mg l⁻¹, respectively, gave 5% error or less in the determination of fluoride. Sodium tripolyphosphate interfered badly above 1.5 mg l⁻¹, and therefore the interference by formulated detergents containing tripolyphosphate was large. The fluoride ion activity electrode method is the most suitable procedure for the determination of fluoride in polluted waters containing surfactants.     

Effect of surfactants on the spectrophotometric determination of silica

The effects of up to 2500 mg 1⁻¹ of pure cationic, anionic and nonionic detergents, industrially prepared detergents, sodium tripolyphosphate, sodium pyrophosphate and a soap on the analysis of silica in water using the amino-naphthol-sulphonic acid, sodium sulphite and ascorbic acid methods were investigated. Interferences were very large for the cationic and nonionic detergents, but negligible for the biodegradable (LAS-type) detergents. The amino-naphthol-sulphonic acid method is recommended.     

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.     

An automated method for the determination of non-ionic surfactants in water

An automated colourimetric procedure using ammonium cobaltothiocyanate as the colour-producing reagent was shown to be suitable for the determination of non-ionic surfactants in water. The complex formed by this reagent and non-ionic surfactants is extracted into chloroform and its concentration is measured absorptiometrically at 620 nm. Samples were analysed at a rate of 3 h⁻¹ by a modified AutoAnalyzer system. The limit of detection was approximately 0.5 mg l⁻¹, and the standard deviation at the 10 mg l⁻¹ level was 0.2 mg l⁻¹. The technique has limitations but forms a basis for further investigation.     

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.     

The effects of phenol and some alkyl phenolics on batch anaerobic methanogenesis

Phenol and seven alkylphenols (o-, m- and p-cresol, 2.5-, 2.6-, 3.4- and 3,5-dimethylphenol) were added at various concentrations to aliquots of domestic anaerobic sludge in Hungate serum bottles and these were incubated at 37°C. The concentration of methane in the headspace gas was monitored to determine if the phenolics were fermented to methane or if they inhibited the anaerobic process. Only phenol and p-cresol were fermented to methane. At 500 mg l⁻¹ (but not at 300 mg l⁻¹) 2,5-, 3,4- and 3,5-dimethylphenol reduced the rate and the amount of methane produced. The cresols were inhibitory at 1000 mg l⁻¹ but not at 400 mg l⁻¹.In cultures supplemented with acetate and propionate (VOA), and in unsupplemented cultures, phenol at concentrations up to 500 mg l⁻¹ was fermented to methane. Between 800 and 1200 mg l⁻¹ phenol, methane production was neither enhanced nor inhibited relative to control cultures containing no phenol. Inhibition of methane production was evident when phenol was present at 2000 mg l⁻¹. Thus the methanogens are less susceptible to phenol inhibition than are the phenol-degrading acid formers. In similar experiments with p-cresol: enhanced methane production was observed at concentrations of 400 mg l⁻¹; no enhancement or inhibition was observed at 600 mg l⁻¹; and inhibition was noted when p-cresol was present at 1000 mg l⁻¹.     

The toxicity of various mining flotation reagents to rainbow trout (Salmo gairdneri)

Preliminary testing of eight collectors (xanthates) and four frothers in 96-h static and 28-day flow-through bioassays using rainbow trout as the test organism show a great disparity in the toxicity of the chemicals administered in these two ways.For the short-term tests, the relative toxicity of the compounds is expressed as an lc₅₀ or as a range of concentration in mg l⁻¹ in which the lc₅₀ is expected to fall. Of the collectors tested in this way sodium ethyl and potassium amyl xanthate were the most toxic, with lc₅₀'s in the range of 30–50 mg l⁻¹. Among the frothers, xylenol (cresylic acid) was found to be the most toxic (5.6 mg l⁻¹ >lc₅₀ > 3.2 mg l⁻¹) while polypropylene glycol was least toxic (lc₅₀ > 1000 mg l⁻¹).The long-term tests using potassium ethyl, sodium isopropyl, sodium ethyl, and potassium amyl xanthate indicated that in the flow-through system, the toxicity of the chemicals was in the order of 100 fold greater compared with the static bioassay results.     

Modified curcumin and dianthrimide methods for the determination of boron in the presence of high levels of nitrate and organics

Modifications have been made to the curcumin and 1,1′-dianthrimide methods for boron analysis so that they may be used in the presence of up to 700 mg l⁻¹NO⁻₃ and 500 mg l⁻¹ organic carbon. In the curcumin method, nitrate is removed by alkaline reduction using a slurry of aluminum powder. In the dianthrimide method, nitrate up to 1000 mg l⁻¹NO⁻₃ is removed in the dehydration-with-sulfuric-acid step; organics are most conveniently removed by treatment of the dehydrated sample with solid potassium persulfate. With dianthrimide, an automated procedure is used for the colour formation and measurement steps.     

Modelisation de l'evolution du parathion dans le milieu naturel sur un pilote de laboratoire

The evolution of parathion in a river, and its degradation by the principal natural factors (hydrolysis, photochemical oxidation, biological transformations and retention by sludge and sediments) has been studied on a laboratory pilot plant. The experimental period was 55 days. On the first 34 days, the plant was fed with a solution containing 13 mg l⁻¹ of the pesticide, and during the following 21 days, the effluent was continuously recycled.In the condition in which our experiences were conducted, the main phenomena were biological degradation of the pesticide into non poisonous amino-parathion and its adsorption on the sediments. The quantity of the parathion reduced is proportionated to the quantity of the ATP found in the activated sludge tank.This biological method being the more important, the shock effect of the parathion on a bacterial population was studied by varying the organo-phosphorous concentration (5-10-15 mg l⁻¹) and the quantity of volatile suspended solid (1-2-3 mg l⁻¹).The microorganisms were not affected by the poison and a reduction to aminoparathion was obtained. The quantitative results may be expressed by the following equation On the other hand a very large dose of parathion (1 mg l⁻¹) destroyed the living organism.The presence of anionic or cationic surfactant plays no part in the toxicity of the parathion (15 mg l⁻¹) on the biomass but the degradation of the organo-phosphorous pesticide is totally inhibited.     

Effects of titanium dioxide industry waste dumping on sea water chemistry

An investigation was made to determine the influence of the dumping of a 1000 ton day⁻¹, on the average, of acid-iron waste from the titanium dioxide industry into the shallow but turbulent Southern Bight of the North Sea. This waste contains some 20% sulfuric acid and 2% iron. After the passage of the barge that discharges 10 ton of waste min⁻¹ into its wake, the vertical and horizontal distributions of the pH, iron-concentration and turbidity were measured as a function of time. It appeared that a few seconds after the discharge and for a very brief period, the pH was down to approx. 4 and the Fe-concentration was 13 mg l⁻¹. More than 1 min after the discharge a pH below 6 and an iron-level above 3 mg l⁻¹ could not be detected anywhere. The measured factor for waste dilution by sea water, based on the observed acid and iron concentration in the waste and in the discharge track, were around 5000 after 5 min, 9000 after 10 min and 80,000 after 20 min. Before and long after the dumping, the total iron-concentration in this Southern Bight area was around 100 μg l⁻¹, but this high level might be due to natural causes.     

The growth inhibition of planktonic algae due to surfactants used in washing agents

A survey of inhibitory effects of nonionic and anionic surfactants, including a soap, used in washing agents, on the growth on three species of freshwater phytoplankton, Selenastrum capricornutum, Nitzschia fonticola and Microcystis aeruginosa was conducted. Based on the specific growth rate, μu estimated from a short period (2 or 3 days) cultivation of test algae, the growth inhibition was determined using EC₅₀ values where μu in the culture medium with surfactant decreased 50% of that without surfactant.The EC₅₀ values of nonionic and anionic surfactants tested here for S. capricornutum ranged from 2 to 50 mg l⁻¹ and from 10 to 100 mg l⁻¹, respectively. The tolerances of three species of algae tested with three surfactants, LAS, AE (EO:9) and soap, were different and the inhibitory effects were species specific. EC₅₀ values of LAS, AE (EO:9) and soap for S. capricornutum were 50–100, 4–8 and 10–50 mg l⁻¹, respectively. Those for N. fonticola were 20–50, 5–10 and 20–50 mg l⁻¹, and those for M. aeruginosa were 10–20, 10–50 and 10–20 mg l⁻¹, respectively.     

The reaction of whitefish, Coregonus clupeaformis, to the anionic detergent sodium lauryl sulphate and its effects on their olfactory responses

Whitefish, Coregonus clupeaformis, were attracted to an anionic detergent sodium lauryl sulphate (SLS) at sublethal concentrations, when tested in a trough where a choice between clean and modified water was presented. The olfactory bulbar electrical responses to odourants were depressed when the nares were perfused with SLS and household detergents. The lowest concentration of SLS to cause minimum effects within 15 min was 0.1 mg 1⁻¹. Possible modes of action of detergent are discussed.     

Preliminary studies on the leaching of some trace metals from kitchen faucets

Preliminary studies were carried out on the leaching of copper, zinc, chromium, cadmium and lead from eight kitchen faucets by samples of raw, filtered and distributed Ottawa water, a sample of well water and deionized water containing 2 mg l⁻¹ aqueous fulvic acid. Leaching was effected by allowing the test solutions to stand in the inverted faucets for two successive 24-h periods. Concentrations of the metals found in the leachates were copper: first leaching, 0.12–28.0 mg l⁻¹, second leaching, 0.08-3.54 mg l⁻¹; zinc: first leaching, 0.13-10.25 mg l⁻¹, second leaching, 0.06-2.85 mg l⁻¹; chromium: first leaching, < 1.0 × 10⁻³ − 0.395 mg l⁻¹, second leaching, < 1.0 × 10⁻³−0.032 mg l⁻¹; cadmium: first leaching, < 0.05 × 10⁻³−0.01 mg l⁻¹, second leaching, < 0.05 × 10⁻³−4 × 10⁻³ mg l⁻¹; and lead: first leaching, < 0.2−110.0 mg l⁻¹, second leaching, < 0.2−82.0 mg l⁻¹. The faucets containing lead-soldered copper joints released high concentrations of lead, particularly in the case of leaching with the aqueous fulvic acid solution. Under the conditions of the present investigations it is indicated that in some cases the concentrations of metals leached could lead to intakes in excess of the maximum permissible limits for these metals. However, further investigations will be required to determine the possible contribution of these faucets to metal intake under normal usage.     

The effect of inorganic salts on the activated sludge process performance

The effect of inorganic salts such as sodium chloride and sodium sulfate on the performance of the activated sludge process was examined. When proper acclimation procedures were followed, the adverse effects of salts on the process were minimized. One of the parameters monitored, effluent suspended solids, had very low values (less than 10 mg l⁻¹) up to an inflow sodium chloride concentration of about less than 35 gl⁻¹. The chemical oxygen demand of the effluent increased steadily with increasing sodium chloride concentrations, but biochemical oxygen demand values remained very low (less than 5 mg l⁻¹) which indicated that the increase in chemical oxygen demand was due to the portion that cannot be degrated biologically. The effect of sodium sulfate on the system was even less profound. In addition to the effluent being very clear and low in suspended solids, the chemical oxygen demand removal efficiency remained high.     

A modified version of the sodium salicylate method for analysis of wastewater nitrates

The German sodium salicylate method for nitrate determination has been modified and improved by utilizing flocculating effect of the preservative HgCl₂ (1000 mg 1⁻¹). The method gives highly reproducible results in the range of 0·2–16 mg 1⁻¹ nitrate nitrogen and is applicable for routine analysis of untreated sewage. Interfering substances are chloride ions above 1500 mg 1⁻¹ and nitrite ions above 10 mg 1⁻¹N. The yellow color produced by sodium salicylate with nitrate ions obeys Beer's law and remains stable for several hours.     

Toxic effects of hexavalent chromium on brook trout (Salvelinus fontinalis) and rainbow trout (Salmo gairdneri)

Exposing brook trout to various concentrations of chromium [Cr(VI)] for up to 22 months (including reproduction) significantly increased alevin mortality at 0.35 mg Cr l⁻¹ and retarded growth of young brook trout at the lowest concentration tested (0.01 mg Cr l⁻¹). Eight month exposures of rainbow trout significantly increased alevin mortality at 0.34 mg Cr l⁻¹ and also retarded growth at the lowest concentration tested (0.10 mg Cr l⁻¹). Exposures of brook trout lasting 22 months showed, however, that growth was only temporarily affected, and therefore, it was not used as an end point to measure the affects of chromium on either species. Reproduction, and embryo hatchability of brook trout were unaffected at Cr(VI) concentrations that affected survival of newly hatched alevins. The maximum acceptable toxicant concentration (MATC) for brook and rainbow trout exposed to Cr(VI) in water with a hardness of 45 mg l⁻¹ (as CaCO₃) and a pH range of 7–8 lies between 0.20 and 0.35 mg Cr l⁻¹. The 96-h lc₅₀ for brook and rainbow trout was 59 and 69 mg Cr l⁻¹, respectively: therefore, the application factor (MATC/96-h lc₅₀) for both species lies between 0.003 and 0.006.