Spectrophotometric properties of surface water dissolved organic matter in an afforested upland peat catchment

Many upland catchments in the UK have undergone afforestation; their characteristic waterlogged soils require extensive pre‐plantation ground drainage to allow tree establishment. In peatland areas this can result in very highly coloured runoff and enhanced dissolved organic matter (DOM) export in rivers of naturally high concentrations. In 1966, the Coalburn Experimental Catchment, northern England, was established to investigate the impact of afforestation on an upland peat catchment. Here we report the variations in DOM spectrophotometric properties of streamflow in the catchment at canopy closure, especially with respect to potential carbon sources within the artificial drainage ditches. Drainage ditches are characterized by water that has higher absorption coefficients and which is more highly coloured than in the catchment tributaries. Ditched, afforested areas produce more highly‐coloured runoff waters that are more fluorescent and absorbent normalized to carbon concentration compared to ditches in open moorland. Ditches that had been experimentally re‐excavated have organic matter of different spectrophotometric character, with higher dissolved organic carbon concentration and less aromatic or lower molecular weight material. It is hypothesized that this is due to the exposure of bare peat faces within and adjacent to the ditches that are more susceptible to drying compared to vegetated areas. The large extent of this drainage network acts as both a rapid transport network increasing hydrological connectivity and a pool for the storage of DOM, which is of different spectrophotometric character under low flow conditions, depending on management conditions. Copyright © 2007 John Wiley & Sons, Ltd.     

Long term monitoring of photosystem II herbicides--correlation with remotely sensed freshwater extent to monitor changes in the quality of water entering the Great Barrier Reef, Australia

Photosystem II (PSII) herbicides are used in large quantities on agricultural lands adjoining the Great Barrier Reef (GBR). Routine monitoring at 14 sites in inshore waters of the GBR using passive sampling techniques detected diuron (32-94% of sampling periods) at maximum concentrations of 1.7-430ng L(-1) in the relatively pristine Cape York Region to the Mackay Whitsunday Region, respectively. A PSII herbicide equivalent (PSII-HEq) index developed as an indicator for reporting was dominated by diuron (average contribution 89%) and typically increased during the wet season. The maximum PSII-HEq indicates the potential for photosynthetic inhibition of diatoms, seagrass and coral-symbionts. PSII herbicides were significantly positively correlated with remotely sensed coloured dissolved organic matter, a proxy for freshwater extent. Combining these methods provides for the first time the potential to cost-effectively monitor improvements in water quality entering the GBR with respect to exposure to PSII herbicides.     

Bacteria and organic matter dynamics during a bioremediation treatment of organic-rich harbour sediments

We studied the dynamics of bacteria and organic matter in the Ancient Port of Genoa (Italy) during a bioremediation treatment of sediment (during summer-autumn 1998) in an area characterised by continuous sewage discharge. A strong increase in total benthic bacterial density (TBN) was recorded at the end of the study, from 14 x 10(8) to 58-172 x 10(8) cell g(-1) in different parts of the treated area. The TBN increase was linked to organic matter depletion, from more than 40 to less than 20 mg x g(-1). In order to highlight the main ecological mechanisms involved in bioremediation, a laboratory experiment based on both water and sediment from the basin studied was carried out. We observed an increase in TBN during the first 20 days and a decrease in sediment organic matter (up to about 20%). Increases of organic matter (about 2-fold) and TBN (from 21 to 33 x 10(9) cell l(-1)) occurred in the overlying water, suggesting a strong association between the sediments and water column processes. Hydrolytic activities, which double in the sediment and increase up to a 300-fold in the water, are consistent with the decrease in sediment organic matter and with the water fraction dynamics.     

Chemical Characterization of Biosolids from Three Spanish WWTPs: Transfer of Organics and Metallic Pollution from Urban Wastewater to Biosolids

The production of biosolids in three Spanish wastewater treatment plants (WWTPs) has been investigated. Biosolids produced from the treatment of urban wastewater in Spain are usually intended for agricultural use. The reliable production of biosolids mainly depends on both the quantity of suspended solids and the organic load influent to the treatment systems. The quality of the generated biosolids was independent of both the amount of treated water and the treatment process applied, with 20 to 25% dried matter, and 60 to 75%, 7% and 4% of organic matter, N and P, respectively, of the total matter. The biosolids contained ca. 11 to 19 g/kg of total metals in the dry matter, with Fe, Zn, Cu and Mn representing 97% of all of the metals present, and Hg being the minority metal. Such biosolids had the ability to concentrate the organic matter and metals from the wastewater up to 417 and 869 times, respectively, and thus, can be used in agricultural practice.     

周村水库汛期暴雨中溶解有机物(DOM)的光谱特征及来源解析

运用三维荧光光谱（EEMs）技术结合平行因子分析法（PARAFAC）,对周村水库夏季两场暴雨不同降雨历时以及分子量的溶解有机物光谱特征和来源进行分析.结果表明：周村水库不同暴雨荧光光谱中出现了5种组分,分别为类腐殖质（C1、C2）、可见区富里酸（C3）和类蛋白（C4、C5）;相关性分析显示C1与C2、C3、C4以及C5具有显著的相关性,C2与C3具有显著的相关性,C3与C4以及C5具有显著的相关性;同一分子量下的雨水有机质总荧光强度以及各组分荧光强度随着降雨历时的增加均呈下降趋势,并且在各个历时和分子量间差异明显;同一降雨历时下,第一场暴雨总荧光强度随着分子量的减少而增加,第二场暴雨总荧光强度随着分子量的减少而减少;两场暴雨都呈现自生源的特征,其中第一场暴雨具有以陆源输入为主的特征;组分C1和C3与水质参数硝态氮、氨氮、总氮以及有机碳呈显著相关性.通过对暴雨在不同降雨历时以及分子量DOM光谱特征研究,可以进一步分析水库外源输入的天然有机质特征,为水库水质管理提供技术支持.     

Dynamics and fluxes of organic carbon and nitrogen in two Guiana Shield river basins impacted by deforestation and mining activities

Deforestation and mining activities have proven to be very damaging to rivers because these activities disturb the environmental characteristics of rivers. Thus, the concentrations of dissolved organic carbon (DOC), particulate organic carbon (POC), particulate nitrogen (PN), and Chlorophyll‐a (Chl‐a) were measured monthly during 2 hydrological years in the Maroni and Oyapock Rivers to assess the dynamics and fluxes of organic carbon and nitrogen in these 2 Guiana Shield basins, which have been strongly (Maroni) and weakly (Oyapock) impacted by deforestation and mining activities. The 2‐year time series show that DOC, POC, PN, and Chl‐a concentrations vary seasonally with discharge in both rivers, indicating a hydrologically dominated control. Temporal patterns of DOC, POC, and PN indicate that these variables show maximum concentrations in rising waters due to the yield of organic matter and nitrogen accumulated in soils, which are incorporated into the rivers during rainfall. However, the Chl‐a concentrations were at a maximum during low‐water stages. The C/N and C/Chl‐a ratios also showed a seasonal trend, with lower values during the low water periods due to an increase in algal biomass. During high water, the POC in both rivers is the result of terrestrial organic matter, whereas during low‐water autochthonous organic matter can reach up to 34% of the POC. The mean annual fluxes of TOC and PN were higher (4.56 × 10⁵ tonC year^?1 and 1.77 × 10⁴ tonN year^?1, respectively) in the Maroni River than those (1.84 × 10⁵ tonC year^?1 and 0.54 × 10⁴ tonN year^?1, respectively) in the Oyapock River. However, the specific fluxes of DOC, POC, and PN from both basins were nearly the same. Although gold mining activities are performed in both basins, there is no conclusive evidence regarding the impact of these activities on the dynamics of organic matter and particulate nitrogen in the Maroni and Oyapock Rivers.     

Characterization and origin of dissolved organic carbon in Yegua ground water in Brazos County, Texas

Dissolved organic carbon (DOC) concentrations in five shallow (< 20 m) and three deeper wells (27 to 30 m) in the Eocene Yegua Formation (Brazos County in east-central Texas) ranged from 92 to 500 microns. Characterization of high, intermediate, and low molecular weight DOC fractions (HMW > 3000 amu, IMW 1000 to 3000 amu, and LMW 500 to 1000 amu) and combined neutral sugar analyses provide information on organic matter sources in the Yegua aquifers. Combined neutral sugars ranged in concentration from 0.6 to 2.7 mumol/L and comprised 0.8% to 6.7% of DOC in ground water. Glucose was the most abundant neutral sugar, followed by xylose and galactose, arabinose, mannose, rhamnose, and fucose. These combined neutral sugars were more diagenetically altered in shallow, oxic ground water as indicated by high mole % fucose + rhamnose and low neutral sugar yield. The precursors for neutral sugars are most probably angiosperm leaves, which show a similar distribution pattern of neutral sugars. Ground water DOC was depleted in 13C relative to soil-zone organic matter (OM) (-16@1000 to -19@1000). The delta 13C values of bulk DOC and HMW DOC ranged from -24@1000 to -32@1000, whereas LMW and IMW DOC ranged from -32@1000 to -34@1000 and -16@1000 to -28@1000, respectively. This variability in delta 13C values is probably related to microbial processes and selective preservation of OM. Carbon isotope analyses in bulk and different molecular weight DOC fractions imply a predominantly C3 OM source and a low contribution of soil-zone OM to DOC.     

Allochthonous and autochthonous organic matter in surface waters in Karelia

A relationship between indirect chemical indices of organic matter content of surface waters and light absorption in the visible and ultraviolet ranges is discussed. The allochthonous and autochthonous types of organic matter are found to essentially differ in the rate of light absorption. Techniques are proposed for the calculation of the concentrations of allochthonous and autochthonous organic matter by the integral rate of light consumption in the visible region and the bichromate oxidability of water, as well as by three indirect indices: chemical oxygen demand, permanganate oxidability, and water color index. The mean concentrations of allochthonous and autochthonous organic matter in large lakes (Ladoga, Onega, and Baikal) and in rivers and smaller water bodies in Karelia (>300 water objects) are analyzed. Allochthonous organic matter was found to predominate in most surface waters of Karelia (>80%), while allochthonous organic matter predominates only in lakes with a small specific catchment area (supposedly, <5) and in highly eutrophic lakes.     

Land–ocean distribution of allochthonous organic matter in surface sediments of the Chiloé and Aysén interior seas (Chilean Northern Patagonia)

We investigated the relative distribution of allochthonous (i.e., terrigenous) organic matter in the complex, continuous, river–fjord–sound–channel–gulf system of Chile’s North Patagonia (41.5–46.5°S) in order to establish whether this organic matter can reach the open ocean or whether it is largely retained near its fluvial sources. Grain size distribution, total organic carbon and total nitrogen contents, and carbon stable isotope contents (δ¹³C) were quantified in 53 surface sediment samples collected during the CIMAR Fiordos cruises 1, 4, 8, and 10, as were salinity and silicic acid concentrations in the surface waters. A principal component analysis segregated the Chiloé and Aysén interior seas into two zones: (i) the continental fjords, with sediment enriched in allochthonous organic matter, having higher C:N molar ratios (10–14) and lower δ¹³C composition (?23‰ to ?27‰); and (ii) the channels and gulfs, with a prevalent autochthonous marine source, having lower C:N values (6–10) and higher δ¹³C composition (?20‰ to ?23‰). Estuarine waters with low salinity (2–30) and high silicic acid (10–90 μM) were associated with high C:N ratios and low δ¹³C in surface sediments, meaning that terrestrial organic matter was transported up to the mouth of the continental fjords. A two-source mixing model confirmed that allochthonous (terrestrial) organic matter contents (50–90%) associated with local river discharges were present within the continental fjords. On the contrary, autochthonous (marine) organic matter was prevalent (50–90%) at the sites in the marine influenced channels, sounds, and gulfs.     

Organic matter of the Kiziltashskie Limans

Data on biochemical ecosystem monitoring of Kiziltashskie Limans are given. The limans are the only natural water bodies in the Russian Black Sea where pascual breeding of very valuable commercial fish is implemented. The presented concentrations of dissolved and particulate organic matter are 2–5 times greater than the values typical of the coastal zone of the Black Sea (from 7.9 to 27.7 mg/L and from 0.3 to 1.5 mg/L, respectively). The main biochemical component of the dissolved organic matter is carbohydrates, and that of particulate matter is protein. The share of particulate organic matter in the Kiziltashskie Limans never exceeds 7%. The elemental (C, N, P) and biochemical composition of organic matter is studied (carbohydrates, proteins, lipids). The rates of enzymatic reactions vary from season to season. Thus, processes of hydrolytic splitting of phosphor-organic compounds during primary production are very intensive in the spring, while processes of organic matter oxidation, catalyzed by enzymes of electron-transport system, are intensive in the summer.     

Effect of organic matter on splash detachment and the processes involved

The influence of organic matter on splash detachment was investigated using soils with grass and peat treatments. The relationship between organic matter and aggregate stability to water disruption was positive for soils with grass treatment while it was negative for those with peat treatment. Organic matter from both treatments, however, reduced splash detachment by rainfall. Soils with grass did this by increasing aggregate stability while peat acted as a mulch on the soil surface. This implies that though organic matter always reduces splash detachment, different processes may be involved, depending on the form of the organic material. Because of the different processes involved, both negative and positive relationships between splash detachment and aggregate stability as reported in literature were obtained for the soils with grass and peat respectively.     

Sunlight Degradation of Aquatic Humic Substances Abbau von Huminstoffen unter dem Einfluß von Sonnenlicht

Coloured bog water and an aqueous solution of fulvic acid were exposed to natural sunlight. Up to 67% reduction in colour and 32% reduction in DOC concentration were measured after 12 days exposure. Colour bleaching and reduction in ultraviolet light absorbance were independent of added preservatives. The high molecular weight fraction of dissolved organic matter was most reduced in concentration while substances with low molecular weight increased. The reduction in absorbance (λ = 254 nm) per DOC was most significant for substances with high molecular weight. The final concentration of DOC was highest in samples where microbial activity was suppressed.     

Fenton体系处理黑臭河道沉积物的效果初探

沉积物中有机质的削减是黑臭水体治理的关键.Fenton(Fe^2++H2O2)试剂在有机污染废水和土壤原位修复中的应用广泛且效果良好;Fenton试剂也能很好地去除黑臭水体中的色度和浊度,但其氧化沉积物有机质的研究未见报道.为探究Fenton试剂对黑臭水体沉积物的氧化效果,本研究通过室内模拟实验用Fenton氧化法对黑臭河道沉积物进行处理,考察氧化过程沉积物特征和性质的变化;分析覆水后沉积物中污染物的释放特征,并和H2O2体系(无Fe^2+)进行比较.结果表明:Fenton体系显著提高了沉积物与上覆水的氧化还原电位,对黑臭河道沉积物中的有机质具有很强的氧化效率.在温度为28℃、H2O2为20%Q(Q为体系中沉积物有机质完全矿化的理论H2O2用量)和Fe^2+∶H2O2(摩尔比)为0.5∶1时,反应1 d,酸挥发性硫化物去除率为70.13%,沉积物总有机碳减少了22.14%,总有机氮减少了87.60%,生成了较多的铵态氮和硝态氮;由于铁对磷的钝化,沉积物中溶解性反应磷含量大幅减少.H2O2体系的氧化速度较Fenton体系慢,覆水后对体系中的Eh提高不明显.值得注意的是,Fenton体系会降低上覆水的pH,释放较多的铵态氮.需要联合其他技术(如微生物法),强化水体中有机质和氨氮的降解,以取得理想的修复作用.     

The origin of organic matter in the Martian meteorite ALH84001.

Stable carbon isotope measurements of the organic matter associated with the carbonate globules and the bulk matrix material in the ALH84001 Martian meteorite indicate that two distinct sources are present in the sample. The delta 13C values for the organic matter associated with the carbonate globules averaged -26% and is attributed to terrestrial contamination. In contrast, the delta 13C values for the organic matter associated with the bulk matrix material yielded a value of -15%. The only common sources of carbon on the Earth that yield similar delta 13C values, other then some diagenetically altered marine carbonates, are C4 plants. A delta 13C value of -15%, on the other hand, is consistent with a kerogen-like component, the most ubiquitous form of organic matter found in carbonaceous chondrites such as the Murchison meteorite. Examination of the carbonate globules and bulk matrix material using laser desorption mass spectrometry (LDMS) indicates the presence of a high molecular weight organic component which appears to be extraterrestrial in origin, possibly derived from the exogenous delivery, of meteoritic or cometary debris to the surface of Mars.     

Comparison of Fe-based and Al-based coagulants in the removal of organic and disinfection by-product precursors

Surface water is renowned for its natural organic matter, constituting approximately 45% of total dissolved organic carbon (DOC) which can be removed in water treatment plants. However, residual DOC in water can react with chlorine to form several carcinogenic disinfectant by-products (DBPs). This study aimed to examine the molecular weight of organic fractions dissolved in three different water sources that act as precursors to the formation of DBPs species. The coagulants used were Al- and Fe-based, frequently used in water treatment plants to remove organic fractions. Characterization of DOC in source water served as the first step in determining the performance of both coagulants in terms of organic properties. The results showed that the selected surface waters had similar DOC characteristics, including biopolymers, humic substances, building blocks, and a low molecular weight. These fractions contributed to the formation of trihalomethanes (THMs) and haloacetic acids (HAAs). The Fe-based coagulant was more effective than the Al-based coagulant in removing all organic fractions and reducing THMs compared to HAAs. Furthermore, one-way ANOVA analysis showed a significant difference in the average removal of organic fractions and DBP species between the Fe-based and Al-based coagulants. The Fe-based coagulant showed higher efficiency in removing biopolymers, dibromochloromethane, and chlorodibromoacetic acid than the Al-based coagulant. In contrast, the Al-based coagulant had better performance in reducing dibromo HAA and tribromo HAA. Both coagulants had no significant difference in extracting other organic fractions or DBPs species.     

Current State of Water Resources of Gusinoe Lake (Western Transbaikalia)

Seasonal and spatial dynamics of the concentrations of major ions, biogenic elements, organic matter, and microelements in Gusinoe Lake water are studied. The economic activity on lake coast has caused an increase in the concentrations of sulfate, sodium, and biogenic and organic matter in areas subject to direct technogenic impact. Lake areas subject to different technogenic impacts were found to differ in water mineralization and pH and the concentrations of microelements. The concentrations of Mo and Sr in lake water are 12–14 and 2–4 times greater than Russian MACs for water bodies used for fishery, respectively.     

Studies on the Pollution of the Kalinadi by Industrial Wastes Near Mansurpur Part 1: Hydrometric and Physico-Chemical Characteristics of the Wastes and River Water

Stream pollution by industrial wastes is posing a problem in Uttar Pradesh. In the present investigations an attempt has been made to study the ecological features of a section of the Kalinadi so as to find out the cumulative or detrimental effect of pollution on fish and fisheries by the effluent discharge of sugar factory and distillery wastes near Mansurpur (District Muzaffarnagar), U. P. This paper is part I of the project. The liquid wastes produced by the sugar factory vary from 66 × 10⁶ to 88 × 10⁶ litres/day excluding condenser water and contain variable quantities of cane fibres, cellulose, lime, waxes, fermented sugar juice, mollasses, and some quantities of sulphate, phosphate, and nitrogen, the oxygen being nil with high values of B. O. D. and C. O. D. The liquid waste from the distillery is called spent wash. The spent wash (62 × 10⁴ litres/day) is highly coloured and acidic (pH 4.3 … 2.9). The B. O. D. and C. O. D. values were very high in the order of 28,526 mg/1 … 45,146 mg/1 and 52,516 mg/1 to 66,862 mg/1. Thus total waste of about 17.3 × 10⁶ litres with no oxygen and high B. O. D. (9,600 mg/1 … 10,116 mg/1) is let off into the Kalinadi. Hydrometric observations on the Kalinadi show that the pollutional hazard is appreciable during the low flow period of the river. The wastes affect the river in a number of ways:

• - The deposition of cellulose fibres, organic and inorganic matter affects the substratum adversely. The blackish brown colour of the wastes affects the light penetration by limiting the growth of phytoplankton.
• - There appears to be no potential danger to the river from the electrolyte pollution as the specific conductivity lies below limiting values.
• - Changes in pH in river water due to the acidic nature of the wastes do not affect directly the fauna and flora, but the acidic condition becomes lethal in the presence of low oxygen and high temperature values.
• - The high load of organic matter present in the wastes draws heavily on the oxygen budget of the river and adversely changes the water and bottom quality of the river for a stretch of 10 km, which adversely affects the environmental condition of both fish and fish food.
• - The presence of sulphuric acid in distillery waste and hydrogen sulphide in river water is toxic to fish and fish food.
• - The decomposition of organic matter in an anaerobic condition and in another favourable environment, as with a low redox potential, the presence of sufficient organic matter and a constant supply of sulphur-reducing bacteria, produces more hydrogen sulphide which may be detrimental or sublethal in the presence of a low oxygen saturation and high temperature.
• - The oxygen level increases at each succeeding station through reaeration and dilution with the lowering of B. O. D. and C. O. D. The oxygen-sag curve is like a typical spoon with handle-shape.

     

Molmasseverteilung der organischen Stoffe im Prager Trinkwasser

The water supply of Prague is based upon three different water resources: artesian groundwater and infiltrate of the Jizera river, water of the Vltava and Zelivka rivers. The processing techniques are different; consequently for the purpose of increasing capacity one has to search for the suitable raw water quality as well as for the optimum treatment process. An essential parameter for this is the contents of organic substances whose molar mass distribution is investigated by gel chromatography with the aid of Sephadex G-10, G-25 and G-50. With respect to the total load of organic matter the Jizera shows the lowest values, in the Vltava the C.O.D. values are the highest, in the Zelivka the organic carbon shows the highest values. 80% of the organic substances in water have molar masses below 700. By flocculation 60… 70% of the C.O.D.-Cr can be eliminated, the optimum removal of the high-molecular substances occurring at pH = 6 and with 50… 60 g/m³ aluminium sulphate.     

Effect of Preozonation on the Formation of Chlorinated Disinfection By‐products for River Ruhr

The purpose of the study is to gain a better understanding about the formation of THM (trihalomethanes), HAA (haloacetic acids), and AOX (adsorbable organic halogen) in river water (river Ruhr, Essen) through a chlorination kinetics approach. The effect of chlorination time and preozonation on the formation of THM, HAA, and AOX substances was studied. Preozonation can reduce the chlorine demand and the precursors for AOX and THM. THM generation was reduced further, when the ozone dosage consumed increased from 3.5 to 12.5 mg in the 1.4 L reaction vessel. AOX and TCAA (trichloroacetic acid) concentrations also decreased dramatically when 3.5 mg of ozone had reacted with the river water, but a higher dose of ozone did not further reduce AOX and TCAA formations. Besides, the characteristics of organic matter in raw water, ozonated water, and preozonated/chlorinated water was investigated. The results suggest the formation of low‐molecular‐weight acids with low UV absorbance when high‐molecular refractive matter is oxidized.