Water Organic Matter Research Articles

Potassium dichromate method of coal gasification the study of the typical organic compounds in water

The national standard method is adopted in this paper the water - digestion spectrophotometry for determination of the chemical oxygen demand (COD), after ultrasonic processing of coal gasification water for CODCr measurement. Using the control variable method, measured in different solution pH, ultrasonic frequency, ultrasonic power, reaction conditions of different initial solution concentration, the change of coal gasification water CODCr value under the action of ultrasonic, the experimental results shows that appear when measurement is allowed to fluctuate, data, in order to explain the phenomenon we adopt the combination of the high performance liquid chromatography and mass spectrometry before and after ultrasonic coal gasification qualitative analysis on composition of organic matter in water. To raw water sample chromatography - mass spectrometry (GC/MS) analysis, combined with the spectra analysis of each peak stands for material, select coal gasification typical organic substances in water, with the method of single digestion, the equivalent CODCr values measured after digestion. Order to produce, coal gasification water contained high concentration organic wastewater, such as the national standard method is adopted to eliminate the organic material, therefore to measure the CODCr value is lower than actual CODCr value of the emergence of the phenomenon, the experiment of the effect of ultrasound [9-13] is promote the complex organic chain rupture, also explains the actual measurement data fluctuation phenomenon in the experiment.

Water purification from organic contaminants by avalanche streamer discharge

The paper deals with the influence of avalanche streamer discharges on aqueous solutions of organic substances such as phenols, methyl-orange and simulating amino acid and protein compounds. Studies have shown the possibility of universal water purification when using gas-discharge decontamination technologies. Complex impact of discharge phenomena, physical and chemical factors, radiation at different frequencies of avalanche streamer discharge lead to degradation of organic and inorganic substances in water impurities. The most frequently used discharges for water purification are electrolyte (discharge in liquid), glow, corona, microwave-frequency discharge excitation in several GHz, barrier discharge and avalanche streamer discharge. It is shown that application of avalanche streamer discharges allows to undertake the decomposition of organic matter in water with decomposition in carbon compounds, gaseous components and water more efficiently and with low cost energy. Applying of a discharge technology is a promising direction of water treatment and industrial wastewater disposal technology development. Energy electric shock changes chemical characteristics of the treated water, affects its Ionic composition, structure of dissolved organic matter, viability of the microorganisms in water without additional chemical reagents.

Spatial variations in the molecular diversity of dissolved organic matter in water moving through a boreal forest in eastern Finland

Dissolved organic matter (DOM) strongly affects water quality within boreal forest ecosystems. However, how the quality of DOM itself changes spatially is not well understood. In this study, to examine how the diversity of DOM molecules varies in water moving through a boreal forest, the number of DOM molecules in different water samples, i.e., rainwater, throughfall, soil water, groundwater, and stream water was determined using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) in Norway spruce and Scots pine stands in eastern Finland during May and June 2010. The number of molecular compounds identified by FT-ICR MS (molecular diversity) ranged from 865 to 2,194, revealing large DOM molecular diversity in the water samples. Additionally, some of the molecular compounds were shared between different water samples. The DOM molecular diversity linearly correlated with the number of low-biodegradable molecules, such as, lignin-like molecules (lignins), but not with dissolved organic carbon concentration. The number of lignins shared between different sampling locations was larger than that of any other biomolecular class. Our results suggest that low-biodegradable molecules, especially lignins, regulate spatial variations in DOM molecular diversity in boreal forests.

Probing the redox process of p-benzoquinone in dimethyl sulphoxide by using fluorescence spectroelectrochemistry

Quinones are common organic compounds frequently used as model dissolved organic matters in water, and their redox properties are usually characterized by either electrochemical or spectroscopic methods separately. In this work, electrochemical methodology was combined with two fluorescence spectroelectrochemical techniques, cyclic volta- fluorescence spectrometry (CVF) and derivative cyclic volta- fluorescence spectrometry (DCVF), to determine the electrochemical properties of p-benzoquinone in dimethyl sulfoxide, an aprotic solution. The CVF results show that the electrochemical reduction of p-benzoquinone resulted in the formation of radical anion and dianion, which exhibited a lower fluorescence intensity and red-shift of the emission spectra compared to that of p-benzoquinone. The fluorescence intensity was found to vary along with the electrochemical oxidation and reduction of p-benzoquinone. The CVF and DCVF results were in good consistence. Thus, the combined method offers a powerful tool to investigate the electrochemical process of p-benzoquinone and other natural organic compounds. Open image in new window

Complete Solid State Dissolved Oxygen Sensor Using Hemin Electrocatalyst and Palladium-Reusable Reference Electrode

Dissolved oxygen (DO) is essential for aquatic life, but is consumed during the decomposition process of the organic matter in water. It is used as a primary indicator of water quality, and is also crucial for the efficiency of the waste water treatment process. Hence, a sensitive, long term reliable, in-line DO sensor is essential for sustainability of water ecosystems and management of water resources. This paper introduces a low-cost, all-solid state DO sensing device by the integration of polyhemin-based DO sensitive electrode and Pd/H reference electrode. Low cost electrodeposition techniques are applied in both the DO sensitive electrode and the Pd/H reference electrode synthesis. First, the operation parameters of the Pd/H reference electrode was characterized to obtain the adequate lifetime and response time of reference for DO sensing application. The regeneration procedure of the reference electrode is also investigated to achieve multi-usage of this Pd/H electrode. Consequently, this DO sensing device has a sensitivity of 1.3 ( $\mu \text{A}$ /cm2)/(mg/L) over a DO concentration range of 1.5 – 20 mg/L. The DO sensing applications in various water samples including tap water, simulated surface water and wastewater are also demonstrated. The all solid-state feature allows this sensing device to be applied as a long-term DO sensor for continuous, in-situ water monitoring.

Prediction of the adsorption capacities for four typical organic pollutants on activated carbons in natural waters

A new model is developed to predict the competitive adsorption isotherms of atrazine, methyl tertiary butyl ether (MTBE), 2-methylisoborneol (2-MIB) and 2,4,6-trichlorophenol onto activated carbons (ACs) in natural water. Based on the Polanyi-Dubinin (PD) equation, with the limiting pore volume of adsorbent estimated from the pore size distribution data, and the Ideal adsorbed solution theory - equivalent background compound (IAST-EBC) model approximation, the model takes into account both the properties of ACs and the impact of natural organic matters in water. Only one set of isotherm in deionized water and one set in natural water are needed to obtain the parameters for the prediction of adsorption isotherms onto different ACs in natural water. The model was employed for the predictions of adsorption capacities for atrazine, MTBE, 2-MIB and 2,4,6-trichlorophenol onto 14 ACs in 22 synthetic and natural waters reported in 9 references, with errors between 14.9% and 44.5% SDEV only. The results suggest that in the proposed PD-IAST-EBC approach, prediction of adsorption capacity for organic compounds onto different ACs in the same natural water is feasible, if the ACs are thermally activated with known pore size information. The model may provide a simple approach for the prediction of adsorption of organic compounds in natural water, and thus greatly reduces the effort required for water utilities when change of AC is needed.

A method for determining and exploring the distribution of organic matters and hardness salts in natural waters

A question regarding how organic matters in water are associated with hardness salts hasn’t been completely studied. For partially clarifying this question, a water fractional separation and investigation method has been recommended. The experiments carried out by the recommended method showed that the dynamics of the distribution of total hardness and permanganate oxidation values in the fractions of frozen and melted water samples coincided completely based on which it has been concluded that organic matters in natural waters are associated with hardness salts and always distributed in this form. All these findings are useful information for the deep study of macro- and microelements in water.

In Search of Cheap, Fast Ways To Detect Water Troubles

In Search of Cheap, Fast Ways To Detect Water Troubles Trent Jacobs and Stephen Rassenfoss, JPT Writers Treating produced water to control bacteria is like weeding a garden. It addresses the problem that is not going away. Regular field testing shows water quality is highly variable. The biological and chemical makeup of a tank of produced water is complex and can quickly change as water from other sources is added and microbes rapidly multiply. “In the Permian Basin, I went out to wells that have been recently fractured and within 2 months they are already soured. It was back-traced to poor water quality. That happens more often than you think it does,” said David Burnett, a research scientist at the Texas A&M Engineering Experiment Station (TEES). One of the TEES projects is seeking practical, cheap, reliable, and quick testing options for microbes and chemicals, and seeing if those tests also work in the hands of a worker in the field. The goal is to convince operators that they need to test often and can rely on those results to manage their operations because performing a test that costs USD 10 or less could save USD 500,000 on a workover. TEES’ interest coincides with a spate of new options on the market for biological and chemical monitoring of oilfield water. New Field Testing Device for Water Competes With Laboratory Methods Trent Jacobs, JPT Senior Technology Writer Analyzing the properties of produced water is a difficult process because of the extreme levels of suspended and dissolved particulates contained in it, and a chemistry profile that is in constant flux. But the transition from using fresh water to recycling produced and flowback water for hydraulic fracturing in North America has driven the need to improve how oilfield water sources are analyzed. Industry research shows that water chemistry can affect production behavior, and compared with fresh water, produced and flowback fluids introduce many more chemical constituents to the equation. TOC Analysis Gains Acceptance as a Standard for Organics Testing Stephen Whitfield, Staff Writer The presence of excessive levels of organic components in produced water can lead to costly problems for operators ranging from clogged membranes in treatment facilities to environmental issues and compliance with government permits. Having adequate technologies and processes for measuring organics may be a solid economic strategy for operators. Johnny Robinson, an organics monitoring process sales manager at GE, spoke about the importance of analyzing and controlling the levels of total organic carbon (TOC) in waste water during a short course on water management held by the Global Petroleum Research Institute at Texas A&M University. Robinson outlined three metrics for monitoring organics in water: biological oxygen demand (BOD), the quantity of oxygen used by microorganisms in the oxidation of organic matter; chemical oxygen demand (COD), the amount of oxygen required to oxidize soluble and particulate organic matter in water; and TOC, the amount of carbon found in an organic compound.

Dissolved Organic Matter or Salts Change the Bioavailability Processes and Toxicity of the Nanoscale Tetravalent Lead Corrosion Product PbO2 to Medaka Fish.

Nanoscale lead dioxide (nPbO2(s)) is a corrosion product formed from the chlorination of lead-containing plumbing materials. This metal oxide nanoparticle (NP) plays a key role in determining lead pollution in drinking water and receiving water bodies. This study uses nPbO2(s) and medaka fish (Oryzias latipes) as surrogates to investigate the aqueous fate and toxicological risk of metal oxide NPs associated with water matrices. The larvae of medaka were treated with solutions containing nPbO2(s) or Pb(II)aq in different water matrices for 7-14 days to investigate the in vivo toxic effects of NPs. Ionic strength enhanced aggregation and sedimentation of nPbO2(s) in water, leading to increased lead contents in fish bodies. However, the presence of dissolved organic matter in water enhanced particle stability and accelerated the lead dissolution, thus changing the bioavailability processes (bioaccessibility) of particles. Oxidative stress response and neurotoxicity in exposed fish was greater for nPbO2(s) solution with increased salinity than dissolved organic matter. We predict the bioavailability processes and toxicity of nPbO2(s) in medaka from the aqueous particle behavior under environmentally relevant exposure conditions. Our investigation suggests a toxicological risk of metal oxide NP pollution in the aquatic environment.

Humic substances alter the uptake and toxicity of nanodiamonds in wheat seedlings

Detonation synthesis nanodiamonds (ND) are among the most widely applied nanoparticles due to their low cost of production and broad scope of applications. However, the fate and behavior of NDs in the environment are largely unknown. The behavior of NDs is greatly affected by humic substances (HSs), which comprise 50 to 80 % of natural organic matter in water and soil ecosystems. The uptake of detonation NDs by wheat seedlings and its toxicity were evaluated in the presence of seven HSs of different origins, including humic acids (HA, HS fraction soluble in alkali and insoluble in acid) and fulvic acids (FA, soluble in both alkali and acid). To monitor the uptake of NDs by plants, tritium-labeled NDs were produced. Liquid scintillation spectrometry and autoradiography were used to determine the amount of NDs absorbed by plants. The photosynthetic activity of the plants was measured using light response curves. After a 24-h exposure period, the ND content in the plant roots was 1720 μg g−1. The introduction of HSs decreased the ND contents in the plant roots to 680–1570 μg g−1 (except for peat FA, for which the ND content did not differ from the blank value). The observed phenomenon was probably related mainly to the influence of HSs on the zeta potential of the NDs, which shifted from positive to negative. Based on chlorophyll fluorescence evaluation, the toxicity of NDs did not inhibit photosynthesis during illumination in the physiological range. However, NDs were slightly toxic to wheat plants under excessive light, likely due to the inhibition of electron transport between Q A and Q B and the disruption of the formation of a thylakoid transmembrane potential. The introduction of HA in a suspension of NDs obviously reduced the inhibiting effect of the NDs; however, the mitigating activities of FA were not so apparent. Our results demonstrate the urgent need for further studies of the influences of NDs on plant growth and development.

Substantial Humic Acid Adsorption to Activated Carbon Air Cathodes Produces a Small Reduction in Catalytic Activity.

Long-term operation of microbial fuel cells (MFCs) can result in substantial degradation of activated carbon (AC) air-cathode performance. To examine a possible role in fouling from organic matter in water, cathodes were exposed to high concentrations of humic acids (HA). Cathodes treated with 100 mg L(-1) HA exhibited no significant change in performance. Exposure to 1000 mg L(-1) HA decreased the maximum power density by 14% (from 1310 ± 30 mW m(-2) to 1130 ± 30 mW m(-2)). Pore blocking was the main mechanism as the total surface area of the AC decreased by 12%. Minimization of external mass transfer resistances using a rotating disk electrode exhibited only a 5% reduction in current, indicating about half the impact of HA adsorption was associated with external mass transfer resistance and the remainder was due to internal resistances. Rinsing the cathodes with deionized water did not restore cathode performance. These results demonstrated that HA could contribute to cathode fouling, but the extent of power reduction was relatively small in comparison to large mass of humics adsorbed. Other factors, such as biopolymer attachment, or salt precipitation, are therefore likely more important contributors to long-term fouling of MFC cathodes.

Formation of symbiotic communities of ciliates, algae, and cyanobacteria in a waterbody of the Ptich’ya Gavan nature park (Omsk)

This article deals with the formation of symbiotic communities in a waterbody of the Ptich’ya Gavan nature park (Omsk) at the end of May 2010. The samples were collected by plankton nets, fixed in formalin, and examined with the use of optical microscope. The symbiotic communities consist of ciliates Ophrydium versatile and 35 other species and forms of algae and cyanobacteria inhabiting the pelagic zone of the waterbody. It is found that the species composition of producers in these communities is formed as a result of the higher adaptation of some species to specific conditions regardless of their abundance. The species with high tolerance to abiotic environmental factors (cosmopolitan species), inhabitants of polluted zones, and species with high tolerance to the concentrations of organic matter in water are most abundant.

Water-sediment distribution and behaviour of Polonium (²¹⁰Po) in a shallow coastal area with high concentration of dissolved organic matters in water, North Vietnam

The behaviour and water-sediment distribution of particle-reactive Polonium-210 in the marine environment with high concentration of total suspended particulates (TSP) and dissolved organic matters (DOC) along the coast of the Tonkin Gulf (North Vietnam) were investigated. It was revealed that the water-sediment distribution coefficient, Kd(s), of 210Po varied from 2.39x103 to 1.9x104 (L kg-1) and from 7x103to 2.5x105 (L kg-1), respectively, in the rainy and dry season. This implies that in the aquatic environment 210Po tends to be of high affinity to suspended particulates. The 210Po Kd(s) was positively correlated with salinity in both rainy and dry seasons. With DOC the Kd(s) was positively correlated in the rainy season, but in the dry season the relationship tended to be reverse. This behaviour of 210Po in the coastal region was explained by the variation of pH of seawater and by the complexation of the isotope with DOC. The Kd(s) found in this study was in an order lower compared to that reported by Malaysian researchers for the Thailand Gulf. The most important source of 210Po was suggested to be from in-situ generation by the decay of its grand-parent 210Pb which mainly derived from the atmospheric fall-out.

A Study on the Determination Method of TOC Effluent Limitation for Public Sewage Treatment Plants

As the Enforcement Ordinance of Environmental Policy Act was revised in 2013, total organic carbon(TOC) was added as an indicative parameter for organic matter in Water and Aquatic Ecosystem Environmental Criteria. Under these imminent circumstances, a regulatory standard is needed to achieve the proposed TOC limitation control water quality from the public sewage treatment plants(PSTWs). This study purposes to present the determination method for TOC effluent limitation at the PSTWs. Therefore we investigate the TOC effluent limitation of foreign countries such as EU, Germany and USA, and analyse the effluent water qualities of PSTWs. In using these TOC data, we review apprehensively the statistics-based, the technology-based, and the region(water quality)-based determination method of TOC effluent limitation for PSTWs.

Rapid removal of bacterial endotoxin and natural organic matter in water by dielectric barrier discharge plasma: Efficiency and toxicity assessment

Low-temperature plasma was used to control bacteria, endotoxins and natural organic matter (NOM) in water by a dielectric barrier discharge (DBD) device. Results indicate that DBD plasma has an obvious inactivation effect on various bacteria in water. The degree of inactivation from difficult to easy is as follows: Bacillus subtilis>Escherichia coli>Staphylococcus aureus. Activated ultrapure water treated using DBD plasma exhibited a sustained sterilization effect, but this sterilization effect decreased gradually after 1h. The total-endotoxin (free-endotoxin and bound-endotoxin) released by Escherichia coli during inactivation, as well as artificially simulated endotoxin in a control solution, was significantly controlled by DBD plasma. Both the metabolites that appeared after inactivation of microorganisms by plasma treatment, and the NOM in filtration effluent of a water treatment plant were well removed by DBD plasma if the treatment duration was sufficiently long. However, the acute toxicity increased significantly, and persisted for at least 2h, indicating that some long-life active substances were generated during the DBD process. Therefore, the removal of bacteria, endotoxins or NOM does not mean a safe water is produced. It is also important to eliminate the toxicity and byproducts produced during water treatment for the continuous promotion and industrial application of DBD plasma.

Evaluation of the effect of advanced coagulation process to optimize the removal of natural organic matter in water (Case study: drinking water of Mashhad’s Kardeh dam)

Natural Organic Matter (NOM) is a non-uniform mixture of organic compounds that enter water after synthesis of plants, animals, etc. Among the organic matters in natural waters, humic substances which usually exist as solutions have allocated a major portion to themselves and in addition to giving taste, color and odor to the water, they can intervene in the oxidization and removal of heavy metals such as arsenic, iron and manganese. Also, the natural organic precursors of disinfection by-products have been recognized as toxic or carcinogenic substances. The coagulation process is optimized as the most common system of water treatment in Iran for removing turbidity of water. This process is capable of removing the natural organic matter but the conditions for the removal of turbidity are constantly not identical with the optimum conditions for removing the NOM. Therefore, where NOM is the main pollutant, the traetment process should be optimized for removing NOM. Therefore, where NOM is the main pollutant, the traetment process should be optimized for removing NOM. After doing the common treatment, the water of Kardeh dam of Mashhad is used as drinking water of the city of Mashhad. By doing the water analysis experiments, the amounts of natural organic matter in the exiting water from water treatment plant was observed at 5 mg/l which is much higher than the world standards of drinking water. In this research the optimum conditions for the removal of NOM from drinking water of Kardeh dam have been examined. The experiments have been conducted at the laboratory scale and by Jar Test Device by different doses of two coagulants of alum and ferric chloride at various pH of water. It is concluded that these coagulation process by two coagulants remove NOM from drinking water and bring it to standards of US Environmental Protection Agency and World Health Organization. Keywords : advanced coagulation; natural organic matter; drinking water; city of Mashhad.

Monohaloacetic acid drinking water disinfection by-products inhibit follicle growth and steroidogenesis in mouse ovarian antral follicles in vitro.

Water disinfection greatly reduced the incidence of waterborne diseases, but the reaction between disinfectants and natural organic matter in water leads to the formation of drinking water disinfection by-products (DBPs). DBPs have been shown to be toxic, but their effects on the ovary are not well defined. This study tested the hypothesis that monohalogenated DBPs (chloroacetic acid, CAA; bromoacetic acid, BAA; iodoacetic acid, IAA) inhibit antral follicle growth and steroidogenesis in mouse ovarian follicles. Antral follicles were isolated and cultured with either vehicle or DBPs (0.25-1.00mM of CAA; 2-15μM of BAA or IAA) for 48 and 96h. Follicle growth was measured every 24h and the media were analyzed for estradiol levels at 96h. Exposure to DBPs significantly inhibited antral follicle growth and reduced estradiol levels compared to controls. These data demonstrate that DBP exposure caused ovarian toxicity in vitro.

Laboratory tests of bacterial amendments for accelerating oxidation rates of ammonia, nitrite and organic matter in aquaculture pond water

The effects of 12 bacterial amendments on reducing concentrations of total ammonia nitrogen (TAN), nitrite nitrogen (NO2−N) and organic matter in pond waters were evaluated in the laboratory. Concentrations of TAN, NO2−N and organic matter in untreated water (controls) naturally decreased with time during 16days. No large acceleration in nitrification or organic matter oxidation was observed from using these bacterial amendments. However, minor differences in concentrations of TAN and NO2−N, and rates of dissolved oxygen loss – an indicator of decomposition rate – were found between controls and treatments on some sampling dates. Compared to the controls, the bacterial amendment 5 at the manufacturer's recommended dose resulted in lower TAN concentrations on days 8 and 12, less NO2−N on days 6 and 8 and less oxygen loss on day 1. Water treated with the bacterial amendments 3 and 10 at the recommended doses had slightly lower TAN concentrations on day 0 (soon after initial treatment) and day 16, respectively. The bacterial amendment 11 at the recommended dose lead to lower NO2−N concentration on day 12. Organic matter in water treated with the bacterial amendments 8 and 10 exhibited a greater rate of microbial respiration on day 16. With higher doses or more frequent applications, there was lower (P<0.05) TAN concentrations in water treated with the bacterial amendment 11 on day 0 and day 2. The bacterial amendment 10 at higher dose and the bacterial amendment 7 at more frequent applications than recommended by manufacturers had a small effect on oxygen rate loss on day 1 and days 7, 9 and 13, respectively. The bacterial amendments 1, 2, 4, 6, 9 and 12 were not successful (P>0.05) at lowering concentrations of TAN, and NO2−N or oxygen loss rate on any sampling dates. Statement of relevanceBacterial amendments are widely used in aquaculture in efforts to enhance water quality in ponds. This research showed no benefit of bacterial amendments on water quality in laboratory tests and doubts on the effectiveness of bacterial augmentation.

Characterization of natural organic matter in water for optimizing water treatment and minimizing disinfection by-product formation

Introduction Natural organic matter(NOM)present in source water has significant impact on water treatment processes and on the quality of drinking water.NOM is a complex mixture of diverse groups of organic compounds,humic and fulvic acids,proteins,peptides,carbohydrates,and heterogeneous materials

Characterization of Dissolved Organic Matter with Intermittent Aeration by Fluorescence

ABSTRACTThis work characterized the fluorescence of dissolved organic matter in water under intermittent aeration and the correlation between the fluorescence and ammonia concentration. The fluorescence spectra allowed determination of proteins using two excitation wavelengths for tyrosine and tryptophan. Fulvic acid was determined using visible and ultraviolet excitation. The fluorescence intensities decreased with aeration but increased in the absence of aeration. However, the fluorescence of fulvic acid increased in aerated and nonaerated samples. The fluorescence of the shorter excitation wavelengths for tyrosine and tryptophan was linear with ammonia concentration under intermittent aeration. When the concentration of dissolved oxygen was 6.5 mg l−1, the correlation coefficients were 0.9863 and 0.9822. This study shows that ammonia may be rapidly determined in water by measurement of the fluorescence at the shorter excitation wavelengths of tyrosine and tryptophan.