Microbial degradation of a single branched isomer of nonylphenol by Sphingomonas TTNP3.

The endocrine disrupting chemical nonylphenol (NP) is a technical product which consists of a complex mixture of nonylphenols with different alkyl side-chain isomers. Since the bio-degradation of each NP isomer may lead to its own range of metabolites, the isolation and identification of transformation products is very difficult. In order to overcome this difficulty, the nonylphenol isomer 4(3',5'-dimethyl-3'-heptyl)-phenol (p353NP) was synthesized, and its degradation by an axenic culture of Sphingomonas TTNP3 was investigated with [ring-U-14C]-labelled and non-labelled p353NP including a time-course study. Radioactive mass balancing resulted in different polar soluble fractions, in insoluble radioactivity associated with biomass, and volatile radioactivity in the form of the mineralization product 14CO2. In the extracellular media, the presence of nonanol corresponding to the nonyl chain of the NP isomer was confirmed and its concentration was determined during the course of fermentation. No other radioactive compounds were detected beside the parent isomer. Radioactive metabolites were only found in the intracellular fraction of S. TTNP3.     

Occurrence of nonylphenol, nonylphenol ethoxylate surfactants and nonylphenol carboxylic acids in wastewater in Japan.

Nonylphenol (NP) is known to be a byproduct of nonylphenol ethoxylates (NPnEO) which are used as detergents in industry. It is important that not only NP but also NPnEO and their related substances are analysed when behaviour of NP in the wastewater treatment process is surveyed. NPnEO are biodegraded to shorter ethoxylate (EO) chain NPnEO or nonylphenol carboxylates (NPnEC) under aerobic conditions, and then biodegraded to NP under anaerobic conditions. NP is one of the suspected endocrine disruptors (ED). Moreover, shorter EO chain NPnEO has greater toxicity than longer EO chain NPnEO. We conducted a field survey of NP and its related substances in 20 wastewater treatment plants (WWTP). The concentrations (median) of NP and its related substances in the WWTPs' influent ranged from 0.1 to 8.3 microg/L, showing NP concentration as the same level as those previously reported. The reduction of the long EO chain NPnEO in the WWTPs was almost complete, while the removal efficiency for the short EO chain NPnEO was less significant than the long EO chain NPnEO, suggesting that the degradation rate of the short EO chain NPnEO was lower than that of the long EO chain NPnEO in the wastewater treatment     

The characteristics and measuring technique of refractory dissolved organic substances in urban runoff.

It is considered that refractory dissolved organic substances have caused an increase in the COD concentration in Lake Biwa in recent years. We investigated the organic matter in the first flush of stormwater runoff from a road in the watershed area of the lake, and studied the possibility of improvement in the water environment from that aspect. After percolating the stormwater through soil, we analyzed organic substances fractionated by using GPC-TC. And we examined the effect of removal of organic substances by comparing the peak height before and after percolation. In the result of the experiments, we found that soil infiltration reduced the refractory dissolved organic substance and we successfully designed a system for a simple and easy experimental facility to treat urban runoff.     

The effects of polymer characteristics on nano particle separation in humic substances removal by cationic polymer coagulation.

Removal of humic substances by coagulation involves nano- and microparticle transport processes. The objective of this paper has been to describe the effects of polymer characteristics on the initial coagulation of nano-sized humic substances and on the aggregates' ability to form larger flocs. The study offers a direct comparison of four different low molecular weight polycations, with charge densities ranging from 4.0 to 7.0 meq/g, as well as of a low and medium molecular weight cationic polyacrylamide with practically equal charge densities. The extent of coagulation of humic substances, determined as the percentage removal of humic substances after filtration through 0.1 microm, could, regardless of the polymer type, be explained by the amount of cationic charge equivalents added per mg TOC of humic substances. The optimal polymer dosage with respect to the extent of flocculation, determined as the percentage removal after filtration through 11 microm could not be explained by this, but the maximum extent of flocculation obtained with each polymer type increased with increasing polyelectrolyte charge density. However, the weak polycation chitosan showed a significantly higher maximum extent of flocculation than would be predicted from its charge density. Polyelectrolyte molecular weight did not show any significant effect on the coagulation of humic substances, nor did it increase the extent of floc separability at 11 microm.     

Re-evaluation and reconstruction of water purification system using soil. I. Assessment of soil as a sorbent of humic substances and phosphate ion.

The purpose of our study is to develop a treatment procedure for humic substances (HS hereafter) and phosphate ion in wastewater and environmental water by percolation of the water through a constructed soil layer at the hydraulic loading of a few metres per day. In the present work, batch sorption tests were conducted for more than 80 samples of soil, sludge, mineral and organic materials in order to find good sorbents for fulvic acid (FA hereafter) and phosphate ion. The results showed that the sorption of FA was high for some charcoal, and apatite and goethite minerals. Comparatively high sorption of FA was found for some Andosols and volcanic ash soil. Significant sorption of phosphate ion, on the other hand, was found for various types of soil, sludge from water treatment plants and some waste materials. The linear isotherm was obtained for the sorption of FA to a charcoal, apatite and goethite minerals, and Andosols.     

Limnological aspects of humic substances in Chubut River (Patagonia‐Argentina)

Humic Substances (HSs) of the Chubut River (Patagonia‐Argentina) have been investigated, during two consecutive years and different climatic seasons, in order to obtain a first approach at their spatial and temporal distribution, as well as their origin and relation with environmental characteristics. Absorbance at 250 nm and limnological variables were measured and the data processed by different statistical tools. We found that the processes developed in the lower sections of Chubut River are dominated by those produced in the Florentino Ameghino Reservoir. The riverine HSs are present in very low concentrations, have mainly autochthonous origin, exhibit spatial homogeneity and temporal variability similar to nutrients (nitrates and soluble reactive phosphorus). Copyright © 2010 John Wiley & Sons, Ltd.     

Distribution of estrogen, nonylphenol and its derivatives in the sediments of a shallow lake.

To determine the distribution of endocrine disruptors (EDs) in lake water and sediments, field investigation was conducted in Lake Teganuma, which is a shallow eutrophic lake, highly affected by human activities. Concentration profiles with sediment depths were obtained for estrogens, nonylphenol (NP), nonylphenol ethoxylates (NPnEO), and nonylphenoxy acetic acids (NPnEC). 17beta-Estradiol (E2) was rarely detected, and 17alpha-ethynylestradiol (EE2) and estriol (E3) were undetected at all depths (0-98 cm) in any of the sediment core samples. The sediment concentrations of estrone (E1) ranging from <0.05 to 3.5 microg/kg-dry wt. and NP from 11.8 microg/kg-dry wt. to 21 mg/kg-dry wt. were obtained. The maximum concentrations of NPnEO and NPnEC in the core sediments were 2.5 mg/kg-dry wt. and 1.4 mg/kg-dry wt., respectively. The EDs concentrations are higher at the inlet than at the outlet (except for NP) in the sediments near the surface. The longitudinal distributions of E1, NPnEO and NPnEC in the benthic sediments show that the concentrations are highest at the inlet, and are fairly constant at lower levels towards the downstream. The obtained results also indicate that NP tends to be adsorbed to the organic particulates produced by algae, followed by sedimentation near the outlet of the lake.     

Examining the biodegradation of endocrine disrupting bisphenol A and nonylphenol in WWTPs.

The aim of this work was to examine biodegradation of the endocrine disrupting chemicals bisphenol A (BPA) and nonylphenol (NP) in activated sludge. Experiments were performed in a pilot wastewater treatment plant (WWTP) in Copenhagen, Denmark. During standard operation the BPA concentration was halved whereas the NP concentration was unchanged. Step-addition experiments showed that biomass adaptation to increased BPA and NP concentrations took 10 to more than 40 days depending on temperature, hydraulic retention time, and pre-exposure of the biomass. Mass-balance experiments showed that above 99% of the dosed BPA and 90% of the dosed NP is removed by biodegradation at steady-state. Batch experiments showed that BPA biodegradation occur solely under aerobic conditions. The work is believed to add vital knowledge to our understanding of parameters and processes governing biodegradation of EDCs in WWTPs.     

Identification of the effect of extracellular polymeric substances on bacterial adhesion to the membrane surface in a membrane bioreactor using Pseudomonas fluorescens.

In a membrane bioreactor (MBR) process containing a variety of bacteria, the bacterial adhesion to the membrane surface, prior to cake formation, causes an increased filtration resistance. In this study, Pseudomonas fluorescens, commonly found in the municipal wastewater treatment process with activated sludge, was used to show the effects of extracellular polymeric substances (EPS) on bacterial adhesion to the membrane surface in the MBR. Of the various roles of EPS in promoting membrane fouling, the adhesion of bacteria to the membrane surface was calculated using the specific cake resistance (alpha, m/kg). Although the amount of EPS binding with bacteria was increased by the addition of Ca2+, there was no significant effect on the bacterial growth. The results of the particle size distribution showed that the addition of Ca2+ increased flocculation, allowing the formation of a complex with the bacteria and EPS. In order to identify the effects of the addition of Ca2+ on the hydrophobicity, the contact angle was also measured. The result showed that the addition of Ca2+ showed no significant differences in the hydrophobicity, even though there was an increase in flocculation. With the bacteria containing a higher EPS concentration, a higher specific cake resistance was observed. From the results of the adhesion experiment, which was conducted with various EPS levels, displayed as the COD and TOC concentration, an increased EPS concentration was shown to promote bacterial adhesion to the membrane surface.     

The role of sludge conditioning and dewatering in the fate of nonylphenol in sludge-amended soils.

One of the main concerns associated with the recycling of biosolids to arable land is their contamination by organic pollutants, like endocrine disruptors. Conditioning and dewatering are usually the last steps of the sewage sludge treatment, before its further utilization. The choice of the specific conditioning/dewatering method may have an effect, not only on the amount of residues in the biosolids, but also on the fate of these compounds in amended soils. Anaerobically digested wastewater sludge was conditioned at lab-scale by means of physical and chemical methods and subsequently dewatered by centrifugation. The produced biosolids plus non-conditioned and non-dewatered sludges were amended separately to soil and spiked with 14C radiolabelled single isomer of nonylphenol. The persistence and leaching potential of nonylphenol after an incubation period of three months were correlated to the sludge treatment method. In comparison to non-conditioned sludge, 54% and 72% higher amount of pollutant residues were extractable when freeze-thawed and limed sludge, respectively, were used. Conditioning of sludge with cationic polymer decreased the leaching potential of nonylphenol in sludge-amended soils, while liming increased it. Fractions of the model compound recovered as extractable and bound residues were analyzed in order to interpret nonylphenol fate.     

Management of chemical substances in a water environment communicating among stakeholders.

With the implementation of Pollutant Discharge and Transfer Register (PRTR) in fiscal 2003, information on the quantity of chemical substances discharged annually from each business is released in Japan. Such information is expected to lead to heightened public concern about the presence of chemical substances in environment. This paper showed the effects of using PRTR data for managing chemical risk in a water environment communicating among stakeholders based on the results of the case study held in Japan. First, it was possible to identify the discharge sources using PRTR and related data for the chemicals such as Zn and NPs which were shown that they had relatively high risks based on the survey in a model area. Second, it was suggested that the chemical risk communication among the stakeholders including people using PRTR and related data would be a good way to encourage environmental activities of businesses, and to build a good relationship among stakeholders including people who have anxiety about chemical risk.     

Influence of dissolved oxygen on nitrification kinetics in a circulating bed reactor

The influence of dissolved oxygen concentration in nitrification kinetics was studied in a new biofilm reactor, the circulating bed reactor (CBR). The study was carried out partly at laboratory scale with synthetic water containing inorganic carbon and nitrogen compounds, and partly at pilot scale for secondary and tertiary nitrification of municipal wastewater.The experimental results showed that either the ammonia or the oxygen concentration could be limiting for the nitrification rate. The transition from ammonia to oxygen limiting conditions occurred for an oxygen to ammonia concentration ratio of about 1.5 - 2 gO₂/gN-NH₄⁺ for both laboratory- and pilot-scale reactors. The nitrification kinetics of the laboratory-scale reactor was close to a half order function of the oxygen concentration, when oxygen was the rate limiting substrate.     

Bioavailability of benzo[a]pyrene during NAPL-enhanced biodegradation in soil and in liquid culture.

The high molecular weight polycyclic aromatic hydrocarbon (HMW PAH) benzo[a]pyrene is generally persistent in the environment and its persistence may be due to bioavailability limitations. However, the presence of degradation-capable microorganisms and a suitable cosubstrate are also necessary. This is especially the case for benzo[a]pyrene because it may only be degraded by fortuitous metabolism. Non-aqueous phase liquid (NAPL)-enhanced benzo[a]pyrene biodegradation and indicators of bioavailability were measured in soil and liquid culture. In soil, 14CO2 from 7-[14C]benzo[a]pyrene mineralisation and overall CO2 production were monitored for 83 d after treatment with different types of NAPLs in biometer flasks. Monitoring was followed by soil extraction and measurement of 14C residues and of the remaining NAPL by gravimetry. In liquid culture, 7-[14C]benzo[a]pyrene mineralisation was monitored after treatment with different NAPLs and followed by a radiocarbon mass balance of 14C residues. Results indicated that although benzo[a]pyrene may have been bioavailable in both media types, benzo[a]pyrene mineralisation only occurred when a suitable NAPL cosubstrate was present to facilitate biodegradation. In soil, rapid increases in the rate and onset of benzo[a]pyrene mineralisation were shown to occur in benzo[a]pyrene-contaminated soils that were treated with mineral oil, which was a relatively non-biodegradable NAPL cosolvent, plus a hexane fraction-NAPL which was biodegradable and contained suitable cosubstrate(s).     

Comprehensive management of chemical substances in a water environment using PRTR data.

The annual quantity of discharge of 354 chemical substances from each business has been released based on PRTR law in Japan since 2003. MLIT and municipalities should be responsible for managing chemical risk in public water bodies through communication with stakeholders, such as the public and businesses. However, it is economically difficult to measure the discharge loads and behaviour of all chemical substances and reveal which substances should be particularly managed in each basin. NILIM has begun studies on survey methods to understand the discharge and behaviour of chemical substances in each basin based on PRTR information, and to conduct risk management of chemical substances in cooperation with stakeholders such as the public and businesses. We selected 30 chemical substances, such as those listed or nominated in environmental criteria and endocrine disrupters, collected the volume of discharge of chemical substances from public and industrial wastewater treatment plants using PRTR information, and surveyed their behaviour in the river in the model area. As a result, the discharge of 12 chemical substances were reported in PRTR, and 17 substances were detected in the river. Some inorganic compounds were detected intensively near discharge sites reported in the PRTR. But some organic compounds and endocrine disrupters, such as oestrone, were detected although their discharge was not reported in the model area in the PRTR. It suggested that PRTR information is useful to identify hot spots, but further study is needed to understand the discharge of chemical substances from small businesses, farmland and houses.     

臭氧对二级出水中溶解性有机物的氧化特性

利用臭氧对二级出水进行深度处理对于缓解北方地区河流污染问题具有重要意义。为了探究臭氧对二级出水中溶解性有机物的氧化特性,在取自北京市砂河污水处理厂二级出水的水样中分别持续通入不同浓度的臭氧,检测60min内各水样中溶解性有机碳(DOC)、紫外吸收光谱、荧光光谱、分子量分布随时间变化情况。结果发现:水样中DOC去除率与臭氧浓度和通入时间呈正相关,在臭氧浓度为1.31mg/L、通入时间为60min时,可达到最大DOC去除率(70%);通入臭氧5min时,水中溶解性有机物的荧光特性基本消失;紫外吸光度值部分减少;分子量为5～6kDa、1～3kDa和400Da的有机物显著减少,部分转化为分子量为60Da的有机物。经过臭氧氧化处理,二级出水中有机物含量显著减少,大分子有机物几乎被全部降解。     

Effects of treated wastewater irrigation on the dissolved and soil organic carbon in Israeli soils.

In many arid and semi-arid regions, the demand for drinking water and other domestic uses is constantly growing due to demographic growth and increasing standard of living. Therefore, less freshwater is available for agricultural irrigation and new water sources are needed. Treated wastewater (TWW) already serves as an important water source in Israel since more than 40 years and its usage will further be extended. Related to its high loads with nutrients, salts and organic materials its use as irrigation water can have major effects on the soil physical, chemical and biological properties, in the worst case leading to soil degradation. Additional organic matter reaches the soil with the effluent water and soil microbial activity is stimulated. Soil organic carbon (SOC) seems to accumulate in the topsoil and tends to decrease after long-term irrigation with secondary TWW in the subsoil. The amount of dissolved organic carbon increased and the aromaticity of the organic compounds in the soil percolates decreased over the irrigation period. Priming effects, occurring after stimulation of microbial activity by the addition of easily degradable substances, could be found in the soils and were stronger for subsoil (1 m depth).     

Development of a monitor to simultaneously measure dissolved ozone and organic matter in ozonated water

A method for measuring both dissolved ozone (DO₃) concentration and UV absorbance was developed adopting ultraviolet (UV) absorption method (Japan Water Works Association (JWWA), 1993a, Japan Water Works Association (JWWA), 1993b) using sodium thiosulfate (Na₂S₂O₃) solution for removing residual ozone in ozonated water. A DO₃ monitor based on this method was tested. This method was proven to be effective from experimental results. The performance of the monitor was examined with continuous ozonated water. As a result, the monitor performed stably during about 2 months, so that both DO₃ concentration and UV absorbance in the ozonated water could be accurately measured. Therefore, the authors have proposed the new aquatic control system with this monitor for ozonation.     

Fate of nonylphenol and 17beta-estradiol contained in composted sewage sludge after land application.

Many environmental problems caused by endocrine disrupters (EDs) have been reported. Because little is known about the fate of EDs accumulated in sewage sludge, we carried out a study to clarify the fate of EDs in composted sludge after its application to soil. Nonylphenol (NP) and 17beta-estradiol (E2) were measured for leachate and soil. High concentrations of NP and E2 were detected in the leachate at the early stage, but they decreased rapidly. Also, the high contents of NP and E2 in soil decreased significantly within 300 days. Because the decrease of NP and E2 in the soil was much larger than that of NP and E2 in the leachate, there must have been a physicochemical or biological decomposition mechanism in the soil layer. We also tried to clarify the transfer of NPs to plants from compost. In the experimental conditions of this study, the transfer of NPs to plants from compost was not observed.     

臭氧氧化对地表水溶解性有机物去除效果的影响研究

针对臭氧氧化作用对受污染地表水中溶解性有机物去除效果的影响进行研究。结果表明:臭氧投加比低于1mgO3/mgDOC时,臭氧对UVA、CODCr和UV410等有机物去除效率较高;臭氧投加比例为0.7mgO3/mgDOC时,BOD/COD由7.4%提高至18.4%,比紫外消光度(SUVA)逐渐降低并趋于平缓;不同臭氧投加比例下水中溶解性有机物的三维荧光指纹光谱变化规律表明,受污染地表水DOM中主要荧光物质为芳香族蛋白质(荧光峰A、B和C)及类腐殖酸(荧光峰D),其中,A峰、B峰和C峰的中心位置分别位于225/300nm、225/338nm和275/342nm;臭氧投加比例为0.7mgO3/mgDOC时峰强削减率为64%～81%,同时部分芳香族蛋白质的结构也发生了变化。     

腐殖酸含量检测及影响因素分析

研究了一种测定腐殖酸纯度的方法即酸碱滴定法,并对影响此方法的浸提剂种类、加热浸提时间和加热氧化时间进行了分析,确定了腐殖酸纯度测定方法的最优操作条件。结果表明,该方法可以简便准确地测定出腐殖酸纯度,精密度和准确度均令人满意。