Effects of lignin and chlorolignin in pulp mill effluents on the binding and bioavailability of hydrophobic organic pollutants

The partition coefficients (K_p) of benzo(a)pyrene (BaP), 3,3′,4,4′-tetrachlorobiphenyl (TCB) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to dissolved kraft lignin (Indulin AT), chlorolignin isolated from a bleached kraft mill effluent (BKME) and dissolved organic matter (DOM) in a lake receiving BKME were measured by equilibrium dialysis. The K_p values of kraft lignin were 28.2 × 10⁵, 6.5 × 10⁵ and 15.9 × 10⁵ and those of chlorolignin were 8.3 × 10⁵, 2.9 × 10⁵ and 2.2 × 10⁵ for BaP, TCB and TCDD, respectively. In addition, DOM in a series of lake water samples collected from the southern part of Lake Saimaa, SE Finland, receiving BKME revealed higher binding capacities to all of the three model compounds than natural DOM in water upstream from the pulp mill. An important phenomenon related to the environmental transport and fate of xenobiotics was almost the full reversibility of the binding between chlorolignin and model compounds. The obtained K_p values of chlorolignin after a 4 day dissociation period were 12.6 × 10⁵ and 4.6 × 10⁵ for BaP and TCDD, respectively.In short-term (24 h) accumulation experiments with Daphnia magna the effects of kraft lignin and chlorolignin on the bioavailability of three model compounds was very clear. The bioconcentration factors of the xenobiotics in the chlorolignin containing water (DOC = 10 mg C/l) were 20–30 and 25–35% of those organic-free control and upstream reference waters (DOC = 7.2 mg C/l), respectively. The effect of chlorolignin of BKME on the bioavailability of model compounds was also seen in the lake water series of Lake Saimaa.     

Quantitative evaluation of enterococci and Bacteroidales released by adults and toddlers in marine water

Traditionally, the use of enterococci has been recommended as the fecal indicator bacteria of choice for testing marine recreational water quality, and prior studies have shown that bathers shed large numbers of enterococci into the water. The current study expands upon prior research by evaluating shedding from both toddlers and adults, and by the expansion of measurements to include enterococci shedding via three different methods (membrane filter (MF), chromogenic substrate (CS), and quantitative polymerase chain reaction (qPCR)) and shedding of alternative fecal indicator bacteria (Bacteroidales human markers UCD and HF8 via qPCR). Two sets of experiments were conducted. The first experiment consisted of two groups of 10 adults who bathed together in a large pool. The second study consisted of 14 toddlers who bathed individually in a small pool which allowed for sand recovery. Sand recovery was used to estimate the amount of sand transported on the bodies of toddlers and to estimate the number of fecal indicator bacteria released from this sand. The numbers of estimated enterococci shed per adult ranged from 1.8 × 10⁴ to 2.8 × 10⁶ CFU, from 1.9 × 10³ to 4.5 × 10⁶ MPN, and from 3.8 × 10⁵ to 5.5 × 10⁶ GEU based on the MF, CS, and qPCR methods, respectively. The estimated numbers of Bacteroidales human markers ranged from 1.8 × 10⁴ to 1.3 × 10⁶ for UCD, and ranged from the below detection limit to 1.6 × 10⁵ for HF8. The estimated amount of sand transported per toddler (n = 14) into the water column after sand exposure was 8 ± 6 g on average. When normalizing the numbers of enterococci shed from toddlers via sand by the 3.9 body surface area ratio, the differences between toddlers and adults were insignificant. Contributions of sands to the total enterococci (MF) shed per toddler was 3.7 ± 4.4% on average. Although shedding via beach sand may contribute a small fraction of the microbial load during initial bathing, it may have a significant role if bathers go to water repetitively after sand exposure.     

Heavy metals in animals of Lake Balaton

Hg, Cd, Cu, Pb, Zn, Fe and Mn concentrations were measured in Chironomidae larvae, Crustacea plankton, as well as in various organs of mussels and fishes collected from the open water area of Lake Balaton. The values were comparatively low. However, there were significant differences in the metal concentrations of species and tissue.Most Cd was found in the gill of Unio pictorum L., most Pb, Zn and Mn in the gill of Anodonta cygnea L., most Cu in Crustacea plankton and in the liver of Abramis brama L., and most Hg and Fe in Chironomidae larvae. Low concentrations occurred in fishes, the lowest in the flesh of Stizostedion lucioperca L.Accumulation of metals in organs as compared with their concentration in the lake water was in the range of 3.4 × 10²−2.6 × 10³ for Hg; 7.0 × 10²−6.8 × 10³ for Cd; 3.3 × 10²−9.7 × 10³ for Cu; 6.9 × 10²−8.1 × 10³ for Zn; 1.5 × 10³−2.4 × 10⁴ for Pb; 3.5 × 10²−3.1 × 10⁴ for Fe; and 5.0 × 10¹−3.5 × 10⁵ for Mn.     

New light on mechanism of air-water oxygen exchange in quiescent systems

Experiments employing novel apparatus which permits measurement of the rate of oxygen transport across liquid strata indicate that the diffusivity of oxygen through water immediately adjacent to the free air-water interface of a quiescent system is the same as its molecular diffusivity in bulk water remote from an interface. A molecular diffusivity of 2.07 × 10⁻⁵cm²s⁻¹ is reported. Water strata of thickness ranging from 0.3 to 3.6 mm are shown to be effectively isotropic with respect to their resistance to oxygen transport. Thicker strata were found to exhibit a reduced but significant resistance consistent with the spontaneous development of a mechanically disturbed bulk zone between the boundary layers.     

Sorption of polychlorinated biphenyls (PCB) to clay particulates and effects of desorption on phytoplankton

The sorption of polychlorinated biphenyls (PCB) on illite and chlorite, two minerals of defined composition, was investigated. Illite particles adsorbed higher [¹⁴C]PCB (Aroclor 1254) concentrations than did chlorite particles, with equilibrium concentration factors between particles and water being 1.4 × 10⁴ for illite and 1.0 × 10⁴ for chlorite. Desorbed PCB inhibited photosynthesis and reduced chlorophyll-a content of natural phytoplankton assemblages within dialysis membrane bags suspended in the water of a tidal marsh. There was no significant difference in effects on the phytoplankton of PCB desorbed from the two minerals. The rate of [¹⁴C]PCB desorption was dependent on the initial concentration on the clay particles. The rate of [¹⁴C]PCB loss from bags with particles was slower than that from bags without particles.     

Septage disposal in waste recycling ponds

Experiments were carried out to investigate the feasibility of septic tank sludge (septage) disposal into pilot-scale waste recycling ponds for the production of algae and fish. A septage loading of 100 kg COD ha⁻¹ day⁻¹ to four 4-m² single-stage ponds resulted in the production of algal biomass and dissolved oxygen in the pond water, suitable for Tilapia growth. Some microbiological investigations of this waste recycling scheme were undertaken using ten earth ponds (each with the dimensions of 20 × 10 × 1.3 m: length × width × depth). It was found that the densities of coliform bacteria and bacteriophages in the pond water and sediment tended to increase with increased septage loadings and loading periods. The ponds fed with septage at the loading of 100 kg COD ha⁻¹ day⁻¹ were found to contain higher densities of these microorganisms than those of the control pond without septage feeding. The possible public health impact resulting from this practice was assessed.     

Purification and characterization of extracellular polysaccharide from activated sludges

A three stage purification process has been developed for soluble, activated-sludge exocellular polymers which results in a polysaccharide fraction substantially free of nucleic acids and protein, with the residual protein probably bound as a glycoprotein. Characterization and comparison of purified exopolysaccharide fractions from five different effluent treatment works revealed many similarities both in terms of monomer composition and molecular weight distribution. Only five monomers were detected, namely: glucose, galactose, mannose, glucuronic acid and galacturonic acid, and all the polysaccharide fractions were of high molecular weight, ranging from 3 × 10⁵ to 2 × 10⁶.     

The dynamics of suspended algal populations in the lower Wye catchment

The algae of the R. Wye and its tributary the R. Lugg were described principally from samples collected from 7 sites in the lower Wye catchment during 1980 and 1981. The density of algae in the Wye was found to be correlated with river flow and solar radiation, highest numbers (12.5 × 10⁵ cells ml⁻¹), principally of Scenedesmus and Cyclotella, occurring at low stable flows and relatively high solar radiation. Algal populations in the Lugg were much smaller ( 1.3 × 10³cells ml⁻¹) than those of the Wye and were principally composed of species derived from the periphyton. Downstream increases in load (cell density × flow) of both Scenedesmus and Cyclotella in the Wye were generally equivalent to about 0.3 division d⁻¹; these rates were lower than those obtained in laboratory culture and this was probably largely related to underestimates arising from algal removal by filter feeders (principally simuliid larvae). Potential problems arising from the treatment of Wye water supporting substantial algal growths are considered: these include haloform production, deoxygenation in a transfer pipeline, algal penetration into potable supply and taste and odour.     

2020s scenario analysis of nutrient load in the Mekong River Basin using a distributed hydrological model

A distributed hydrological model, YHyM, was integrated with the export coefficient concept and applied to simulate the nutrient load in the Mekong River Basin. In the validation period (1992–1999), Nash–Sutcliffe efficiency was 76.4% for discharge, 65.9% for total nitrogen, and 45.3% for total phosphorus at Khong Chiam. Using the model, scenario analysis was then performed for the 2020s taking into account major anthropogenic factors: climate change, population, land cover, fertilizer use, and industrial waste water. The results show that the load at Kompong Cham in 2020s is 6.3 × 10⁴ tN a^− 1 (+ 13.0% compared to 1990s) and 4.3 × 10³ tP a^− 1 (+ 24.7%). Overall, the noticeable nutrient sources are cropland in the middle region and urban load in the lower region. The installation of waste water treatment plants in urban areas possibly cut 60.6%N and 19.9%P of the estimated increase in the case without any treatment.     

A study of the copper-complexing compounds released by some species of cyanobacteria

The production of copper-complexing extracellular material by cyanobacteria was studied by using ion specific electrodes. The species studied were Plectonema boryanum and Anabaena cylindrica. The values of the conditional stability constants for the copper complexes (K′), for the two species at pH 6.60 (±0.05) were, respectively 2.8 (±0.8) × 10⁶ and 5.9 (±2.0) × 10⁷. A strain of P. boryanum that was made tolerant to a concentration of 1 × 10⁻⁶M copper produced greater amounts of copper-complexing products than the normal strain although the K′ value for the copper complexes was the same. When stressed with copper, P. boryanum and A. cylindrica produced more complexing material than under the usual growth conditions.     

Optimization of PMA‐qPCR for Staphylococcus aureus and determination of viable bacteria in indoor air

Staphylococcus aureus may cause infections in humans from mild skin disorders to lethal pneumonia. Rapid and accurate monitoring of viable S. aureus is essential to characterize human exposure. This study evaluated quantitative PCR (qPCR) with propidium monoazide (PMA) to quantify S. aureus. The results showed comparable S. aureus counts between exclusively live cells and mixtures of live/dead cells by qPCR with 1.5 or 2.3 μg/mL PMA (P>.05), illustrating the ability of PMA‐qPCR to detect DNA exclusively from viable cells. Moreover, qPCR with 1.5 or 2.3 μg/mL PMA performed optimally with linearity over 10³‐10⁸ CFU/mL (R²≥0.9), whereas qPCR with 10, 23 or 46 μg/mL PMA significantly underestimated viable counts. Staphylococcus aureus and total viable bacteria were further determined with PMA‐qPCR (1.5 μg/mL) from 48 samples from a public library and two university dormitories and four from outside. Viable bacteria averaged 1.9×10⁴ cells/m³, and S. aureus were detected in 22 (42%) samples with a mean of 4.4×10³ cells/m³. The number of S. aureus and viable bacteria were positively correlated (r=.61, P<.005), and percentages of S. aureus relative to viable bacteria averaged 12‐44%. The results of field samples suggest that PMA‐qPCR can be used to quantify viable S. aureus cells.     

Field studies on coliphages and coliforms as indicators of airborne animal viral contamination from wastewater treatment facilities

The occurrence of animal viruses in the aerosol emissions of wastewater treatment facilities was evaluated by direct assay and by the use of coliforms and coliphages as indicator organisms. Coliforms and coliphages were compared and evaluated with regard to their suitability as indicators of airborne animal viral contamination from wastewater treatment facilities. Two plants, one with treatment by activated sludge and the other by trickling filtration, were studied. Field air sampling procedures used large-volume air samplers, with recirculation devices, and Andersen samplers. Airborne viruses were enumerated by a most probable number (MPN) procedure. Partially treated liquid sewage contained about 1.0 × 10² pfu l⁻¹ of animal viruses assayed on Buffalo Green Monkey (BGM) cells, 3.6 × 10⁵ and 5.0 × 10⁵ pfu l⁻¹ of coliphages, depending upon the E. coli host strain used for assay, and 2.0 × 10⁹ colonies l⁻¹ of coliform bacteria. No airborne animal viruses were recovered, airborne coliphage levels averaged 2.3 × 10⁻¹ and 3.0 × 10⁻¹ MPN m⁻³, coliforms from aerosol emissions were 2.1 × 10² colonies m⁻³. Ratios of coliphages to animal viruses indicate that wastewater treatment plants may be continuous sources of low level concentrations of animal virus aerosols. Evidence shows coliforms to be much less stable than coliphages in the airborne state. Coliphages may be a more acceptable indicator of airborne animal viral contamination than coliforms.     

PCB dechlorination enhancement in Anacostia River sediment microcosms

In situ treatment of PCB contaminated sediments via microbial dechlorination is a promising alternative to dredging, which may be reserved for only the most contaminated areas. Reductive dechlorination of low levels of weathered PCB mixtures typical of urban environments may occur at slow rates. Here, we report that biostimulation and bioaugmentation enhanced dechlorination of low concentration (2.1 mg PCBs/kg dry weight) historical PCBs in microcosms prepared with Anacostia River, Washington, DC, sediment. Treatments included electron donors butyrate, lactate, propionate and acetate (1 mM each); alternate halogenated electron acceptors (haloprimers) tetrachlorobenzene (TeCB, 25 μM), pentachloronitrobenzene (PCNB, 25 μM), or 2,3,4,5,6-PCB (PCB116, 2.0 μM); and/or bioaugmentation with a culture containing Dehalococcoides ethenogenes strain 195 (3 × 10⁶ cells/mL). Dechlorination rates were enhanced in microcosms receiving bioaugmentation, PCNB and PCNB plus bioaugmentation, compared to other treatments. Microcosm subcultures generated after 415 days and spiked with PCB116 showed sustained capacity for dechlorination of PCB116 in PCNB, PCNB plus bioaugmentation, and TeCB treatments, relative to other treatments. Analysis of Chloroflexi 16S rRNA genes showed that TeCB and PCNB increased native Dehalococcoides spp. from the Pinellas subgroup; however this increase was correlated to enhanced dechlorination of low concentration weathered PCBs only in PCNB-amended microcosms. D. ethenogenes strain 195 was detected only in bioaugmented microcosms and decreased over 281 days. Bioaugmentation with D. ethenogenes strain 195 increased PCB dechlorination rates initially, but enhanced capacity for dechlorination of a model congener, PCB116, after 415 days occurred only in microcosms with enhanced native Dehalococcoides spp.     

Complexation analysis of fresh waters by equilibrium diafiltration

Equilibrium ultrafiltration has been employed to determine the extent of Cu, Ni, Co, Fe, Mn and Zu chelation in oxic waters from mineralized terrains. Concentrations of Cu, Ni and Co were determined in different organic fractions separated by various Amicon ultrafilters. Titrations of fresh water samples with metal ions were made, and “free” metal concentration measured by equilibrium diafiltration. Experiments were made at concentrations and pH at which metals and ligands occur in natural waters. Conditional stability functions ranged from 10^6.72 at pH 6.5 to 10^7.07 at pH 7.6 for Ni and 10^6.85 at pH 6.8 to 10^6.97 at pH 7.6 for Co. At low metal concentrations (8 × 10⁻⁷ M) only one complexing class of major importance for natural water environments was observed. The order of metal complexing ability was found to be Cu > Ni > Co > Zn > Mn with Cu showing a preference towards the higher MW organic fractions.     

Carbaryl, propham and chlorpropham: A comparison of the rates of hydrolysis and photolysis with the rate of biolysis

Alkaline hydrolysis half-lives, based on second-order alkaline hydrolysis rate constants, for carbaryl, propham (IPC), and chlorpropham (CIPC) at pH 9 (27°C) are 0.15 > 1 × 10⁴, and > 1 × 10⁴ days, respectively. The direct photolysis half-life for carbaryl in sunlight is 6.6 days in distilled water. Calculated minimum half-lives for the direct photolysis of IPC and CIPC in a clear water body near the surface are 254 and 121 days, respectively. Half-lives, based on second-order fungal rate constants, for the IPC and CIPC are calculated under given conditions. Kinetic data on hydrolysis, photolysis, and biolysis are employed as a basis for comparison of the relative importance of these three degradation processes.     

Sorption and accumulation of cadmium in the sediment of the Tama River

Cadmium contents in the water and the sediment samples collected from the Tama River and several branches were measured. Cadmium (above 0.005mgl⁻¹) was detected in only four of the water samples, while the sediment samples showed cadmium content of 1.0–9.8 μg g⁻¹ dry sediment. Cadmium concentration in the sediments of the main stream was correlated against ignition loss of the samples and it was found that 1 g of ignition loss (organic matter) corresponded to 35 μg of cadmium.The batch adsorption experiment in the laboratory using an aqueous solution of cadmium for 14 sediment samples with a higher concentration of cadmium indicated that the amount adsorbed by the sediment is highly dependent on the ignition loss. The amount adsorbed on unit mass of ignition loss q_IL could be correlated by a Freundlich-type equilibrium relation as where C is the equilibrium concentration in the aqueous phase ranging between 7 × 10⁻³ and 10 mg l⁻¹, while k_IL and n are equilibrium constants.The adsorption rate measurement showed that the intraparticle diffusion coefficient of cadmium in the sediment was about 1.1 × 10⁻⁶ cm²s⁻¹, which is of a reasonable order of magnitude assuming the pore diffusion mechanism inside the particle.The results suggest that suspended solid particles of high organic content in flowing water contribute significantly to the transport of cadmium along the river.     

The use of Bacillus thuringiensis var. israelensis to control the nuisance fly Sylvicola fenestralis (Anisopodidae) in sewage filter beds

The effectiveness of using the microbial insecticide Bacillus thuringiensis var. israelensis (Bti) to control the nuisance fly Sylvicola fenestralis at Rossendale Sewage Works, Lancashire, was investigated. Following a provisional trial in 1987, the whole Works (28 filter beds) was treated with a two-stage application of Bti in 1988; the first application in late April was separated from the second in late May by about half the length of the Sylvicola life-cycle. The Bti treatment was timed to reduce fly nuisance in June, the month when most complaints (71%) had been received. For each application, 0.161. of the Bti preparation, containing nearly 10¹⁰ spores·cm⁻³, was applied per square metre of bed surface. An 80 and 98% kill of Sylvicola larvae was recorded following the first and second applications respectively. The lower kill achieved by the first application was believed to be due to insufficient mixing of the Bti with the settled sewage prior to dosing. Nuisance caused by the flies was considerably reduced; there were no complaints from the public during June, although a few were received in late July, early August. Sewage purification efficiency was not affected by Bti treatment. The maximum concentration of Bti spores in the Works' effluent was 7 × 10⁴ spores·cm⁻³. This concentration did not appear to affect the already impoverished macro-invertebrate fauna of the receiving river.     

Rhizosphere characteristics of two arsenic hyperaccumulating Pteris ferns

Better understanding of the processes controlling arsenic bioavailability in the rhizosphere is important to enhance plant arsenic accumulation by hyperaccumulators. This greenhouse experiment was conducted to evaluate the chemical characteristics of the rhizosphere of two arsenic hyperaccumulators Pterisvittata and Pterisbiaurita. They were grown for 8 weeks in rhizopots containing arsenic-contaminated soils (153 and 266 mg kg^− 1 arsenic). Bulk and rhizosphere soil samples were analyzed for water-soluble As (WS-As) and P (WS-P), pH, and dissolved organic carbon (DOC). Comparing the two plants, P.vittata was more tolerant to arsenic and more efficient in arsenic accumulation than P.biaurita, with the highest frond arsenic being 3222 and 2397 mg kg^− 1. Arsenic-induced root exudates reduced soil pH (by 0.74-0.92 units) and increased DOC concentrations (2-3 times) in the rhizosphere, resulting in higher WS-P (2.6-3.8 times higher) compared to the bulk soil. Where there was no difference in WS-As between the rhizosphere and bulk soil in soil-153 for both plants, WS-As in the rhizosphere was 20-40% higher than those in bulk soil in soil-266, indicating that the rate of As-solubilization was more rapid than that of plant uptake. The ability to solubilize arsenic via root exudation in the rhizosphere and the ability to accumulate more P under arsenic stress may have contributed to the efficiency of hyperaccumulator plants in arsenic accumulation.     

Mode d'action du bioxyde de chlore sur les composes organiques en milieu aqueux: Consommations de bioxyde de chlore et reactions sur les composes phenoliques

The aim of our work was to study the reaction between chlorine dioxide (ClO₂) and organic substances. In the first part of our survey, chlorine dioxide demands were measured in diluted aqueous solutions of various kinds of organic compounds (5 × 10⁻⁵ −10 M) at pH 7. In the second part, the study of the action of chlorine dioxide on phenols (phenol, di and triphenols) was undertaken by observing the change of the organic substance through global parameter controls (COT, u.v. spectrum) and by trying to identify a certain number of oxidation products by means of chromatographic analysis (HPLC and GC), of mass spectrometry and of Nuclear Magnetic Resonance spectrometry (NMR).