Impact of polyhexamethylene guanidine on filtering of Pb(II) and Cd(II) hydroxides from aqueous solutions

The paper presents results of investigations aimed at optimizing the process of Pb(II) and Cd(II) removal using polyhexamethylene guanidine (PHMG) from aqueous solutions. The formation of compounds of chemisorption-type ions of the above metals with PHMG was established by using the methods of polarography, infrared spectroscopy, and pH-metry. The investigations revealed a positive impact of PHMG on the sedimentation and filtering of the precipitation of Pb(II) and Cd(II) hydroxides.     

Impact of montmorillonate on the process of purification of waters containing uranium by ultra- and nanofiltration

The article has investigated the impact of montmorillonite (natural and modified) for purification of waters containing uranium by ultraand nanofiltration. It has been shown that maximally possible uranium retention coefficient by a nanofiltration membrane was obtained when a modifier with the molecular weight 2 kDa was used. Whereas for an ultrafiltration membrane a high index of purification is achieved when using a modifier with the molecular weight 10 kDa.     

Impact of complexing agents on the processes of sorption treatment of waters containing cobalt

We have investigated the impact on the Co(II) sorption by montmorrilonite of complexing agents: ethylenediaminetetraacetic acid disodium salts (EDTA) and nitrilotriacetic acids (NTA), and fulvic acids (FA). By the impact value of the latter on the Co(II) sorption process by montmorrilonite they can be arranged into a series: EDTA > NTA > FA.     

强化混凝工艺处理滦河低温低浊水的试验研究

结合现有的中试试验系统,开展了强化混凝工艺的试验研究,结果表明,在该水质期,混凝剂PAC对浊度和CODMn的去除效果较优于混凝剂FeCl3;然而在满足出水浊度和CODMn要求的情况下,每处理单位水体PAC混凝药剂费用远高于FeCl3;使用NaSiO3与FeCl3混合液作为混凝剂时,适当增大混合液中NaSiO3的比例有利于提高常规工艺处理效率。     

The effect of centrifugation on the suspended particles of river waters

Samples of river water have been analyzed for their particle size distribution using the Coulter Counter. The feasibility of the application of the centrifugal method for particle size analysis on river water samples has been investigated. The efficiency of centrifugation for separating the colloidal and suspended particles from river water samples has been determined.     

HYBAS工艺处理城市河道污水

通过HYBAS工艺处理生产、生活混合污水实验，研究了该工艺对几种主要污染物质的去除效果，实验发现，在水力停留时间为11h，C／N为5.6的条件下，反应器出水稳定且处理效果好，出水COD稳定在50mg／L左右，对氨氮去瞟率大干90％，对总氮去除率为38.5％。     

Life cycle assessment of wastewater treatment technologies treating petroleum process waters

This paper describes the implementation of life cycle assessment to investigate the environmental impact of 20 technologies suitable for treating extensive volumes of water produced during the oil and gas extraction processes. Data on the physical and operational attributes of technologies under consideration were assembled and their life cycle environmental impacts estimated over 15 year time period. The results were then incorporated in a decision support system which allows identification and prioritisation of potential technology combinations capable of producing water for nine designated industrial and agricultural end uses. In total, more than 618 technology combinations were investigated for their environmental impacts. The identification and prioritisation of technologies were done on the basis of their environmental and technical performance. This analysis showed that dissolved air flotation, absorbents, dual media filtration and reverse osmosis technologies offer relatively low environmental impact parts of systems for cleaning such process waters. Furthermore, the environmental assessment combined within the decision support system has revealed potentially valuable indirect downstream "benefits" from effects such as evaporative losses from wetlands in terms of the overall environmental impact of a treatment system.     

Prediction of the temperature dependence of electrical conductance for river waters

The application of mixed electrolyte theories to the prediction of the electrical conductivity of 14 river-water samples covering a range of ionic strength and temperatures between 5 and 25°C has been evaluated using a new program, CONCAL. Both the Fuoss-Onsager, FO, and Lee-Wheaton, LW, theories produce better agreement between the measured and predicted conductivities for the majority of the samples than the simple product equation. For river waters with a charge imbalance of less than 10%, the prediction of the simple product, FO and LW equations are on average within 11.1, 3.4 and 3.7%, respectively, of the experimental values over the range of temperatures considered. The major error in the predictions of the FO and LW models is associated with the reliability of the chemical analytical data input to CONCAL. The accuracy of the predictions of the models is also discussed in terms of the magnitude and sign of the charge imbalance calculated for each of the samples from the analytical data.Five equations that are available to apply a temperature compensation to conductivity data to predict values at 25°C have been tested over a temperature range of 5–25°C. The best performance is achieved using the modified Walden's product.The relationship between the measured conductivity at 25°C, κ(25), and ionic strength, I, has been calculated to be I = 0.0021 + 0.0148 κ(25) with I in mmol dm⁻³. This observation is discussed by reference to the predicted relationship for simple binary mixtures of NaCl and Ca(HCO₃)₂.     

胍基磷酸盐阻燃处理木材应用研究

利用胍基磷酸盐对杉木试样进行阻燃处理.对处理样品进行氧指数测试、热失重分析、显微观察和力学性能试验.结果表明,胍基磷酸盐对杉木有明显阻燃作用,使杉木样品在高温下形成蜂窝状炭层,且随力学强度无不良影响.     

Intensification of nonlinear separation effects in systems of treatment of oil-containing process waters

The issues of treatment of process waters at petroleum storage depots have been studied. The conditions for intensifying nonlinear separation effects of physicochemical methods applied in the water treatment were investigated and a system of treatment of oil-containing process waters based on the leading-edge nanotechnology was presented.     

Determination of cationic surfactants in waste- and river waters

Three analytical methods were used to determine the concentration of ditallow dimethyl ammonium chloride (DTDMAC), a cationic surfactant in river water, sewage influent and sewage effluent. The methods consist of (a) high performance liquid chromatography (HPLC) coupled with conductimetric detection, (b) a colorimetric procedure commonly referred to as disulfine blue active substance (DBAS) and (c) a combination of DBAS and thin-layer chromatography (TLC).The results from this comparison showed that the DBAS procedure was less specific and sensitive than either DBAS-TLC or HPLC and therefore tended to overestimate the concentration of DTDMAC in environmental samples. It also showed DBAS-TLC and HPLC to be comparable in specificity although HPLC is more sensitive and requires significantly less time to perform than either DBAS or DBAS-TLC. The overall advantages of the HPLC procedure make it an attractive analytical technique to accurately measure the concentration of DTDMAC in the environment.     

Silver complexation in river waters of central New York

The dissolved component of the apparent silver complexation capacity was determined for Susquehanna and Chenango River water samples collected over a 3-month period in the vicinity of Binghamton, New York. Silver ion activities detected by the Ag⁺/S^2? ion selective electrode during potentiometric titration of the river water with AgNO₃ were lower than Ag⁺ activities calculated with an inorganic equilibrium speciation model. The maximum difference in Ag⁺ activity, which ranged from 1.5 × 10^?8 to 8.4 × 10^?8, was attributed to the presence of a constituent or constituents in the river water which strongly bind Ag, perhaps dissolved organic matter and/or colloidal material. Variation in apparent complexation capacity between river water samples was explained by different concentrations of the ligands complexing Ag. A tentative extrapolation of the dissolved Ag speciation to Ag concentrations in natural river water suggested that most of the Ag would be complexed by Cl^? and an unidentified constituent or constituents.     

Particulate forms of radium and barium in uranium mine waste waters and receiving river waters

A method of selective dissolution was used for analysis of particulate forms of radium and barium in a system consisting of uranium mine waste waters purified by coprecipitation with barium sulphate and of adjacent river waters. Four particulate forms of both the elements were distinguished: “loosely bound”, “acid soluble”, Ba(Ra)SO₄ and “in crystalline detritus”. It was found that the distribution of radium and barium between dissolved and particulate forms in waste waters depended on the time interval elapsing between the sampling and membrane filtration of the waters. No such dependence occurred in river water. The main particulate form of radium and barium in the system was Ba(Ra)SO₄. River water upstream of the mine water discharge contained radium mainly in “acid soluble” form or “in crystalline detritus” and barium as BaSO₄ or “crystalline detritus”. In unpurified mine effluents, a large part of radium and barium was present as “crystalline detritus”. Abundance of the “loosely bound” form was very low in all the samples analyzed. The bond of radium in bottom sediments was approximately the same as that in the solids suspended in waste waters. Suitability and accuracy of the selective dissolution method for analysis of surface and waste waters has been demonstrated by the analysis of the results and by radiotracer experiments.     

Nitrate concentrations in river waters of the upper Thames and its tributaries

The spatial and temporal patterns of in-stream nitrate concentrations for the upper Thames and selected tributaries are described in relation to point and diffuse sources for these rural catchments. The rivers associated with catchments dominated by permeable (Cretaceous Chalk) bedrock show a smaller range in nitrate concentrations than those associated with clay and mixed sedimentary bedrock of lower permeability. The differences reflect the contrasting nature of water storage within the catchments and the influence of point and diffuse sources of nitrate. Nitrate concentrations often increase in a gradual way as a function of flow for the rivers draining the permeable catchments, although there is usually a minor dip in nitrate concentrations at low to intermediate flow due to (1) within-river uptake of nitrate during the spring and the summer when biological activity is particularly high and (2) a seasonal fall in the water table and a change in preferential flow-pathway in the Chalk. There is also a decrease in the average nitrate concentration downstream for the Kennet where average concentrations decrease from around 35 to 25 mg NO(3) l(-1). For the lower permeability catchments, when point source inputs are not of major significance, nitrate concentrations in the rivers increase strongly with increasing flow and level off and in some cases then decline at higher flows. When point source inputs are important, the initial increase in nitrate concentrations do not always occur and there can even be an initial dilution, since the dilution of point sources of nitrate will be lowest under low-flow conditions. For the only two tributaries of the Thames which we have monitored for over 5 years (the Pang and the Kennet), nitrate concentrations have increased over time. For the main stem of the Thames, which was also monitored for over 5 years, there is no clear increase over time. As the Pang and the Kennet river water is mainly supplied from the Chalk, the increasing nitrate concentrations over time clearly reflect increasing nitrate concentrations within the groundwater. It primarily reflects long-term trends for agricultural fertilizer inputs and significant aquifer storage and long water residence times. The results are discussed in terms of hydrogeochemical processes and the Water Framework Directive and are compared with data from other eastern UK rivers. The importance of diffuse sources of nitrate contamination is highlighted. On a flow weighted basis, the average diffuse component of nitrate is around 95% for the Thames Basin rivers draining Chalk and for the corresponding rivers draining less permeable strata, there is a more significant but not major point source component (at least in terms of flux); the average diffuse component is 79% in this case. These data fit well with earlier assessments of agricultural sources to UK surface waters. Under baseflow conditions the diffuse sources remain dominant for the Chalk fed Thames Basin rivers, but point sources can be dominant for the low permeability cases. On a proportionate basis, the Thames Basin rivers are similar to the rural rivers of the Tweed and Humber Basins in terms of percentage diffuse components although the lower intensity agriculture occurring for the rivers monitored means that the average nitrate concentrations are lower for the rural rivers of central and northern England and the borders with Scotland: the Humber and Tweed.     

An improved dianthrimide technique for the determination of boron in river waters

A modified dianthrimide method is described which is capable of detecting as little as 0.01 mg 1⁻¹ boron in river water. The procedure is based upon the use of calcium hydroxide to fix the boron; this also permits rapid evaporation of the water sample without the loss of volatile borates.     

Occurrence of androgens and progestogens in wastewater treatment plants and receiving river waters: Comparison to estrogens

Research has shown that exposure to androgens and progestogens can cause undesirable biological responses in the environment. To date, however, no detailed or direct study of their presence in wastewater treatment plants has been conducted. In this study, nine androgens, nine progestogens, and five estrogens were analyzed in influent and final effluent wastewaters in seven wastewater treatment plants (WWTPs) of Beijing, China. Over a period of three weeks, the average total hormone concentrations in influent wastewaters were 3562 (Wujiacun WWTP)-5400 ng/L (Fangzhuang WWTP). Androgens contributed 96% of the total hormone concentrations in all WWTP influents, with natural androgen (androsterone: 2977 ± 739 ng/L; epiandrosterone: 640 ± 263 ng/L; and androstenedione: 270 ± 132 ng/L) being the predominant compounds. The concentrations of synthetic progestogens (megestrol acetate: 41 ± 25 ng/L; norethindrone: 6.5 ± 3.3 ng/L; and medroxyprogesterone acetate: 6.0 ± 3.2 ng/L) were comparable to natural ones (progesterone: 66 ± 36 ng/L; 17α,20β-dihydroxy-4-progegnen-3-one: 4.9 ± 1.2 ng/L; 21α-hydroxyprogesterone: 8.5 ± 3.0 ng/L; and 17α-hydroxyprogesterone: 1.5 ± 0.95 ng/L), probably due to the wide and relatively large usage of synthetic progestogens in medical therapy. In WWTP effluents, androgens were still the dominant class accounting for 60% of total hormone concentrations, followed by progestogens (24%), and estrogens (16%). Androstenedione and testosterone were the main androgens detected in all effluents. High removal efficiency (91-100%) was found for androgens and progestogens compared with estrogens (67-80%), with biodegradation the major removal route in WWTPs. Different profiles of progestogens in the receiving rivers and WWTP effluents were observed, which could be explained by the discharge of a mixture of treated and untreated wastewater into the receiving rivers.     

混凝沉淀强化工艺处理低温低浊黄河水的中试研究

针对黄河水的低温低浊水质特点,按照水厂实际工艺设计了中试设备.应用基本涡旋理论的栅条混合、强化絮凝网格反应和低脉动斜板沉淀技术对设备作了改进.通过中试优选了混凝剂和助凝剂,并确定了其最佳投药量和投加点.当水厂PAC稀释液投加量为5.77 mg/L,PAM投加量为0.5 mg/L时,沉后水浊度小于0.5 NTU.     

Partitioning of copper onto suspended particulate matter in river waters

Suspended particles and river water from the Susquehanna River, White Clay Creek and the Delaware River were collected to experimentally study the partitioning of copper. The effects of many factors that may influence the partitioning coefficient (Kd) including pH, total suspended solids (TSS), total copper concentration ([Cu]T), dissolved organic matter (DOM), particulate organic matter (POM), hardness, and ionic strength were investigated by performing batch adsorption experiments. The results implied that organic matter binding sites in both the aqueous and solid phases play the most important role in controlling copper partitioning. Other major factors governing the partitioning are pH and TSS. Kd increases with pH in the pH range 3-8. TSS increases caused decreases in Kd values, which may be attributed to the decrease in the quantity of available binding sites caused by interparticle interactions, rather than by the redistribution of organic matter between solid and solution phases with the variation of TSS. Kd decreases slightly when total Cu concentration increases; however, Kd can be considered to be independent of Cu concentration when TSS is high. The effects of calcium competition and ionic strength on partitioning are small.     

Biodegradation of urea in river waters under controlled laboratory conditions

The biodegradation of urea in river waters has been evaluated under laboratory conditions. Urea will degrade to ammonia at a rate depending on the bacterial state of the river water and on the water temperature. Under normal conditions no breakdown may be expected to occur at temperatures below 8°C for 14 days contact. In river waters with a high suspended solids content, simulating extreme winter river conditions, a maximum breakdown of 3–6 per cent daily of the original urea levels was found for temperatures not exceeding 8°C during the first 7 days contact.     

Solar radiation influence on the decomposition process of diclofenac in surface waters

Diclofenac can be detected in surface water of many rivers with human impacts worldwide. The observed decrease of the diclofenac concentration in waters and the formation of its photochemical transformation products under the impact of natural irradiation during one to 16 days are explained in this article. In semi-natural laboratory tests and in a field experiment it could be shown, that sunlight stimulates the decomposition of diclofenac in surface waters. During one day intensive solar radiation in middle European summer diclofenac decomposes in the surface layer of the water (0 to 5 cm) up to 83%, determined in laboratory exposition experiments. After two weeks in a field experiment, the diclofenac was not detectable anymore in the water surface layer (limit of quantification: 5 ng/L). At a water depth of 50 cm, within two weeks 96% of the initial concentration was degraded, while in 100 cm depth 2/3 of the initial diclofenac concentration remained. With the decomposition, stable and meta-stable photolysis products were formed and observed by UV detection. Beyond that the chemical structure of these products were determined. Three transformation products, that were not described in the literature so far, were identified and quantified with GC-MS.