Adsorption of non-ionic surfactants on activated carbon and mineral clay

A series of non-ionic surfactants of nonyl-phenol ethoxylates, with n = 4?23;0 ethylene oxide groups and dinonyl-phenol ethoxylate were studied in dilute aqueous solution. Their removal efficiencies and mechanisms by adsorption on powdered and granular activated carbon and on Na-montmorillonite clay were investigated. The powdered activated carbon proved to be the most efficient with 94–100% non-ionic surfactants removal by addition of 40–80 mg activated carbon.Various models of adsorption isotherms such as Langmuir, BET and S-type were used to determine Q⁴, the limiting adsorption capacity. The relationships between Q^o and parameters affecting the adsorption of non-ionic surfactants such as n, HLB and CMC were determined. The cross-sectional area σ₀ occupied by surfactant molecules on the adsorbent was calculated. Adsorption has been proven to be a potential advanced physicochemical treatment method for the effective removal of non-ionic surfactants present in effluents intended for reuse.     

Universelle Energiekennzahlen für Deutschland – Teil 1: Differenzierte Kennzahlverteilungen nach Energieträger und wärmetechnischem Sanierungsstand

Universelle Energiekennzahlen für Deutschland bezeichnen eine innovative Datenbank, in der aktuell 1/4 Million Gebäude‐Energieverbrauchskennzahlen der BRUNATA‐METRONA‐Gruppe aus den vergangenen Jahren normiert zusammengefasst sind. Die Datenaufbereitung umfasst (1) eine rückwirkende Revision aller meteorologischen Klimakorrekturen mithilfe neuer ortsgenauer Klimafaktoren des Deutschen Wetterdienstes, (2) eine Teil mengenbildung von 18 Kennzahlvergleichsgruppen nach drei Hauptenergie‐ trägern und sechs wärmetechnischen Sanierungsständen sowie (3) eine kontinuierliche Abbildung der Kennzahlverteilungen als Funktion der Gebäudegröße. Die Mediane der Energiekennzahlverteilungen bewegen sich über alle Gebäudegrößen und Vergleichsgruppen etwa zwischen 80 und 175 kWh·m^–2·a^–1. Die absoluten Unterschiede der Mediane der Energiekennzahlverteilungen machen zwischen Neubauten und Gebäuden mit nominell wärmetechnisch unsanierter Gebäudehülle absolut zwischen 40 und 60 kWh·m^–2·a^–1 aus, relativ für alle Größenklassen und Energieträger generell weniger als 30 %. Beim direkten Vergleich zwischen wärmetechnisch sanierten und unsanierten Gebäuden sinkt dieser Relativanteil unter 20 % für gas‐ und ölbeheizte, auf etwa 25 % für fernwärmebeheizte Objekte. Andererseits betragen die statistischen Verteilungsbreiten der Kennzahlverteilungen selbst schon je ±σ = ±25 bis ±55 kWh·m^–2·a^–1. Die Energiekennzahl‐Mediane für Neubauten nach 1995 liegen für die Energieträger Gas und Öl über 100 kWh·m^–2·a^–1, für Fernwärmeobjekte über 80 kWh·m^–2·a^–1. Ein Ansatz zur Einschätzung möglicher Sanierungspotentiale in absoluten Energiebeträgen sowie eine Hochrechnung des wohnflächengewichteten und am aktuellen Klima orientierten Mittelwertes des spezifischen Energieverbrauchs für den nationalen Mietwohnungsbestand auf ca. 120 kWh·m^–2·a^–1 werden vorgestellt. Universal energy ratings for Germany – (Part 1): Differentiated rating distributions according to energy source and energy efficiency standard. Universal energy ratings for Germany represent an innovative database in which a quarter of a million energy consumption ratings for buildings recorded in past years by the BRUNATA METRONA Group are currently summarised in a standardised form. Data preparation includes (1) a retrospective review of all the meteorological corrections with the aid of new, localised climate factors from the German Weather Service, (2) a subset of 18 rating comparison groups according to three main energy sources and six levels of energy efficiency standard and (3) a continuous illustration of the rating distributions as a function of building size. The medians of the energy rating distributions range between about 80 and 175 kWh·m^–2·a^–1across all building sizes and comparison groups. Generally, the absolute differences between the medians of the energy rating distributions of new buildings and unrenovated, existing buildings are between 40 and 60 kWh·m^–2·a^–1. The relative differences for all sizes and energy sources are generally less than 30 %. If one compares renovated and unrenovated buildings directly, the relative figure drops to below 20 % for gas‐heated and oil‐heated and to about 25 % for buildings with district heating. On the other hand, the statistical distribution ranges of the rating distributions themselves are as wide as ±σ = ±25 to ±55 kWh·m^–2·a^–1 respectively. The energy rating medians for new buildings built after 1995 and using gas and oil as energy sources are above 100 kWh·m^–2·a^–1. They are above 80 kWh·m^–2·a^–1for buildings with district heating. An approach for gauging the possible renovation potential in terms of absolute energy and an extrapolation of the mean value of specific energy consumption for the country's existing rented apartments, weighted in terms of living area and based on the current climate, to approx. 120 kWh·m^–2·a^–1 are presented.     

Determination of trialkyl and triaryl phosphates in environmental samples

Analytical methods of trialkyl and triaryl phosphate esters in water and sediment were developed. An environmental survey of them was performed using developed methods. The extract with dichloromethane (water sample) or acetone (sediment sample) was analyzed with a gas chromatograph equipped with a flame photometric detector and a gas chromatograph/mass spectrometer after clean-up through Florisil column. The separation of gas chromatography was good with 2% OV-17 + 2% PZ-179 on Uniport HPS. Recoveries fortified with 0.3–3 μg were 71–98% for water sample and 78–95% for sediment sample. In the environmental survey, tributyl phosphate (5–36 ng l^?1), Tris (3-chloropropyl) phosphate (16–176 ng l^?1), Tris (2-chloroethyl) phosphate (TCEP) (14–347 ng l^?1), Tris (2,3-dichloropropyl) phosphate (CRP) (23–136 ng l^?1), triphenyl phosphate (13–31 ng l^?1), and tricresyl phosphate (67–259 ng l^?1) were detected in river water and seawater, and TCEP (13-28 ng g^?1) and CRP (9–17 ng g^?1) were detected in sediment.     

The biodegradability of two primary alcohol ethoxylate nonionic surfactants under practical conditions,and the toxicity of the biodegradation products to rainbow trout

A field trial has been performed to measure the biodegradability of two typical alcohol ethoxylate nonionic surfactants, “Dobanol” 45-7 and “Dobanol” 45-11, by dosing them to biological filters in a mixture with domestic sewage. Influent levels were 10 and 25 mg l^?1 of each surfactant and 96–98% degradation was achieved within a temperature range of 5–10°C. The surfactants had no adverse effects on the filters in terms of the usual sanitary parameters (BOD, COD, TOC and ammoniacal nitrogen). Tests on the effluents indicated no residual acute lethal toxicity to rainbow trout Salmo gairdneri).     

Assessment of wastewater pollution in pig leather industry in China

Pig leather industry contributed significantly to the life of people all over the world, but serious water environmental problems have arisen. Investigation in tanneries with green pig hides in China showed that pollution resulted mainly from beamhouse operations. Assessment indicated that wastewater from pig‐hides processing had: (1) wide variations of pH, (2) high levels of sulfide (S^2?) and chromium, (3) high levels of neutral salts and ammonia nitrogen (NH ₄⁺‐N), (4) high levels of suspended solids (TSS) and oil & grease, and (5) low biodegradability. A tannery processing 10 000 pig hides per day generated chemical oxygen demand (COD) of 3.81–12.31 tonnes and NH ₄⁺‐N 0.27–1.06 tonnes, respectively. The pollution loads were equivalent to those of a city of 60 000–120 000 inhabitants, which has a COD of 3.9–10.56 tonnes/day and NH ₄⁺‐N of 0.462–1.164 tonnes/day, respectively (SEPAC). And nearly 30% of the tanneries discharged their wastewater by screening only or by primary treatment like coagulation–sedimentation, while the rest of them discharged directly into surface waters without any treatment.     

Electrochemical determination and characterization of surface active substances in freshwaters

Surface active material has been analyzed in samples of different freshwater systems: river water, groundwater and tap water, by electrochemical methods based on the measurement of the adsorption effects at the mercury electrode. Two electrochemical methods were used: the measurement of the suppression of the polarographic maxima and a.c. polarography. A rough characterization of predominant surface active compounds was performed through a comparison of the shape and the intensity of the electrochemical responses with those obtained with different model surfactants. It was found that humic substances represent predominant surface active substances in freshwater systems. The total surfactant activity corresponds to approx. 0.5–20 mg dm^?3 of humic substances.Anionic detergents were analyzed by the spectrophotometric methylene blue method. The highest values (100–300 μg dm^?3) were found in river water samples which were taken downstream from the city location. The total surfactant activity values of river water samples as measured by the electrochemical methods were only exceptionally influenced by the presence of detergents.     

Use of 222radon as a simple tool for surface water–groundwater connectivity assessment: a case study in the arid Limarí basin,north‐central Chile

We report the results from a pilot study on the use of ²²²Rn (²²²radon) for river–aquifer interaction assessment in the Limarí watershed, north‐central Chile. Previous studies on this tool for such applications are not abundant at international level, and no records exist for Chile. The lowest ²²²Rn levels (less than 1000 Bq/m³) were found in water reservoirs, thus indicating that this isotope is easily lost (and therefore usually absent) in surface waters. Conversely, the highest levels of ²²²Rn were found in groundwater, with maxima activities around 20 000 Bq/m³. This remarkable contrast allowed clear identification of zones of surface water–groundwater connectivity in the searched watershed domain.     

The stabilization of “dissolved” iron in freshwaters

Laboratory experiments have been conducted to see what substances are capable of holding iron at a concentration of about 1 ppm in a “dissolved” form (i.e. will pass through a 0.45 μm pore size filter) in oxygenated water. The results show that reagents capable of doing this include humic and tannic acids, surfactants such as sodium dodecyl sulphate and sodium dodecylbenzene sulphonate, and the inorganic ions silicate and phosphate. In contrast, the synthetic polymer polyvinylpyrrollidone and the simple ions Cl⁻, HCO₃⁻, SO₄⁻ and NO₃⁻ showed no ability to stabilise iron. The efficiency of phosphate at keeping iron in the “dissolved” state was found to decrease in the presence of cations, particularly divalent ones, but increased with rise in water pH in the range 6–11.It seems unlikely that much of the stabilization observed for any of the reagents tested is due to their forming complexes with the iron. A much more likely explanation is that the substances for which positive results were obtained are able to stabilize fine colloidal iron particles and inhibit them from forming larger aggregates.     

Separation of diluted fine-disperse water-oil emulsions by ultraflocculation and floatation

Using a fine-disperse emulsion of sunflower oil in water stabilized by sodium dodecyl sulfate it has been shown that ultraflocculation combined with floatation is an effective means of separation of sta- bilized phases of water-oil emulsions whose complete treatment time may constitute < 0.5 min, while the residual concentration of oil in water < 30 mg/dm³; an increase of the medium gradient velocity in the course of flocculation within the range 500–900 s^?1 is accompanied by a monotonic decrease of the residual concentration of oil in the water, which makes it possible to effectively separate diluted water-oil emulsions; an increase of the medium velocity gradient in a flocculator to 10⁴ s^?1 makes it possible to decrease the time of ultraflocculation treatment to several seconds.     

The life history parameters of Moina micrura (Kurz.) grown in different culturing media

Some life history parameters of Moina micrura were derived from culture tube experiments with media comprising mohua oil cake, mustard oil cake, cow dung, poultry waste and rice bran as well as pond water. First reproduction time (A) did not differ from one medium to another (3–4 days). Longevity (W) was maximal (19 days) in mohua oil cake and minimal (9 days) in both mustard oil cake and rice bran media. Total offspring production per lifespan (S), ranging from 0.65 to 51.4, was directly dependent upon the lifespan of the test animal. The reproduction peak (T) in these culture media ranged from 3 to 13 days. The intrinsic (r) and finite rates (e^r) of natural increase were larger for cow dung than for other media.     

Inactivation des virus dans l'eau sur une filiere de production a ozonation etagee

The removal and inactivation of indigenous viruses for individual water treatment processes were investigated both in a pilot (3 m³ h⁻¹) and a full-scale (4000 m³ h⁻¹) plant, treating water from the Seine and Oise rivers respectively.Viruses were recovered by the previously described methods of adsorption-elution using electronegative Balston filters (Joret and Block, 1981) for the pilot plant study or alternatively using either electronegative or electropositive 1 MDS Cuno filters (Sobsey and Glass, 1981) for the full-scale water supply.Depending on the efficiency of filtration, the volumes of water samples concentrated directly in the field varied from 30 to 100 litres for raw, preozonated, stored river water and decanted water, and from 550 to 1000 litres for treated water downstream from the clarification step. BGM cells were used for virus detection by the plaque assay method.During this study, the initial virus concentration in the Seine river water entering the pilot plant, varied from 190 to 1420 PFU/1000 l. The virus removal observed after coagulation-flocculation with 35–50 g m⁻³ of water aluminum chloride (WAC) (a basic aluminum chloride) and settling, was 31–90% effective (130–390 PFU/1000 l. of decanted water), and did not exceed 1–2 logarithms after sand filtration at a rate of 5 m h⁻¹ (83% of 600–800 samples were positive for viruses, maximum concentration = 80 PFU/1000 l.).The preozonation of river water (0.8 ppm during 2–3 min without residual oxidant) inactivated 64–97% of viruses (maximum viral concentration in preozonated water being 300 PFU/1000 l.). Under these conditions, no viruses could be isolated from samples of 550–1000 litres of sand filtered water.The treatment process for the industrial water supply located at Mery sur Oise was preozonation (0.5–1 ppm for 1 min), storage, coagulation-flocculation, settling, sand filtration, second stage ozonation (1.4–1.6 ppm for 10 min, residual oxidant: traces to 0.3 ppm), activated carbon filtration, postozonation (0.4 ppm free residual for 4 min) and chlorine dioxide (0.1 ppm). Nine series of samples were taken after various stages of treatment and tested for viruses. All samples of raw river water yielded positive results with relatively low numbers (10–146 PFU/1000 l.) compared with the number of enterovirus in the Seine river.The efficiency of preozonation before storage could not be evaluated in this study due to its intermittent operation. Enteroviruses were found in 83% of samples after storage (7–100 PFU/1000 l.), 77% after settling and 55% after sand filtration (3–10 PFU/1000 l.). Enteroviruses were not detected after the second stage ozonation in any of the nine samples. The subsequent postozonation and final treatment with chlorine dioxide serves as an additional barrier to ensure virologically safe drinking water.During studies on pilot and full scale water treatment plants, viral isolates are as follows: ECHO virus (49 and 37% respectively), coxsackie B virus (42 and 49% respectively) and poliomyelitis virus (9 and 14% respectively).     

Tobacco ore of the Kerch iron-ore basin as a sorbent for removing <Superscript>90</Superscript>Sr from water medium

The paper investigates sorption removal of ⁹⁰Sr from water media by the tobacco ore of the Kerch iron-ore basin. It has been found that effective sorption is observed within the pH interval 6–9, the limit value of adsorption of strontium ions calculate by means of the Langmuir equation constitutes 17.95 mg/g. It is shown that sorbent efficiency for the removal of ⁹⁰Sr from water is determined, in the first place, by their salt composition—nature of macrocomponents characteristic for water media (Na⁺, K⁺ and Ca²⁺) and their concentration.     

Oil palm shell as a lightweight aggregate for production high strength lightweight concrete

In Malaysia, oil palm shell (OPS) is an agricultural solid waste originating from the palm oil industry. In this investigation old OPS was used for production of high strength lightweight concrete (HSLC). The density, air content, workability, cube compressive strength and water absorption were measured. The effect of five types of curing conditions on 28-day compressive strength was studied. The test results showed that by incorporating limestone powder and without it, it is possible to produce the OPS concretes with 28-day compressive strength of about 43–48 MPa and dry density of about 1870–1990 kg/m³. The compressive strength of OPS HSLC is sensitive to the lack of curing. The water absorption of these concretes is in the range of good concretes.     

Evaluating a mass transfer model for the dissolution of organics from oil films into water

A mass-transfer model analogous to one used to describe the volatilization of organics from natural waters was used to describe the dissolution of constituent organics from a floating oil film into the underlying water. The mass flux of a material across the oil-water interface was depicted using an oil-phase mass-transfer coefficient, k_o a water-phase mass-transfer coefficient, k_w, a partition coefficient, P, describing the equilibrium partitioning of a substance between oil and water, and the concentrations of the substance in the oil and water, C_o and C_w, in the following expression: Rates of dissoltion were observed to vary with properties of the solute, P, the oil (viscosity, P, oil depth) and the environment (oil and water mixing, water depth). The observed rates of dissolution of chemicals from a low-viscosity oil (heptane) varied by a factor of 10⁴ between the most rapidly and most slowly dissolving materials.     

Field analysis of PSA O2–ozone production process for water recycling

The use of an oxygen generator based on pressure swing adsorption technology (PSA) has been investigated as an alternative method for supplying oxygen for onsite ozone production. During the investigation period of 1040 h, the oxygen purity from the PSA process fluctuated within a range of 90.5–93 O₂% (v/v). Using the working ratio of 2.8 mol of O₂ to 1 m³ of raw water, the PSA process in series with a corona discharge ozone generator yielded an oxidation–reduction potential of ca. 200 mV and a concentration of 22.8 mg/L dissolved oxygen. The average efficiency of the raw water treatment was as follows: 47% chemical oxygen demand removal, 78% biological oxygen demand removal, 36% sulphide removal and 34% colour removal. The operating cost of the PSA O₂ generation was reduced 3 times compared with the cost of high‐pressure oxygen cylinders.     

Trihalomethanes in the drinking water of Concepción and Talcahuano,Chile

Formation of trihalomethanes (THMs) during water disinfection has been related to several health problems, although the magnitude of these effects is under discussion. This paper quantifies the THMs in drinking water from the Bío‐Bío Region of central Chile, the first since the modification of the national reference value (Nch 409/05) to include maximal values for THMs. THMs were quantified using a solid phase micro‐extraction (SPME) method and GC‐MS. The concentration ranges were 9.7–111.6, 0.1–1.0 and 0.9–25.5 μg/L for chloroform (CHCl₃), and dibromochloromethane (CHClBr₂) and bromodichloromethane (CHCl₂Br), respectively. Bromoform was not detected in any sample. There were good correlations (R²=0.91–0.98, P<0.001) between the THMs and the residence time of the water, the distance from the treatment plant and an inverse correlation to free chlorine in the water. The Additive Toxicity Index Value (0.07–1.00) showed that all samples were within the Chilean reference value for THMs in drinking water. However, several values were close to exceeding the maximum permitted concentration (200, 100, 100 and 60 μg/L for CHCl₃, CHBr₃, CHClBr₂ and CHCl₂Br, respectively), which may occur when the water demand is low and thus residence times are longer.     

Chromatographic determination of pesticide 2,4-D in water bodies

New silica-based adsorbent with covalently immobilized groups of triton X-100 has been proposed for extraction and concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) from water bodies. The recovery of this pesticide into adsorbent phase occurs in the form of its ionic associate with cationic surfactants (CSAS). It was shown that the application of cetyltrimethylammonium bromide made it possible to achieve the pesticide extraction ratio as high as 94%. Elution with acetonitrile allows us to achieve a 50-fold absolute concentration of 2,4-D making it possible to perform its determination by the high performance liquid chromatography method with ultraviolet detection, where the detection level is 0.07 mg/dm³ and the linearity range is from 0.09 to 0.20 mg/dm³.     

Electrochemical treatment of chemical oxygen demand in produced water using flow‐by porous graphite electrode

Produced water is the largest wastewater stream generated in the oil and gas industries. In this study, experiments were carried out using a bench‐scale electrochemical cell using flow‐by porous graphite electrode, for oxidation of organic matter in produced water which was collected from natural gas processing field (real sample). The effect of anodic current density and influent feed flow rate on chemical oxygen demand (COD) removal efficiency, and energy consumption were investigated. The maximum removal efficiency of 66.52% was obtained for a flow rate of 50 mL/min, current density of 1.41 mA/cm² and pH of 7.3 for an influent COD of 2845 mg O₂/L. The energy consumption at these conditions was 2.12 kWh/kg_COD.     

Effect of fats, mineral oils and creosote on the extraction—atomic absorption determination of copper, iron, lead and manganese in water

The effect of five mineral oils, two fats and creosote on the extraction—atomic absorption spectrophotometric determination of copper, iron, lead and manganese in water was investigated. Pure mineral oils, fats and creosote gave 100±15% recovery, but soluble oil gave low results for copper and iron. At a soluble oil concentration of 12.5 mg 1⁻¹, the recoveries of copper and iron were, respectively 41 and 72%.