A comprehensive pollution survey of polychlorinated dibenzo-p-dioxins and dibenzofurans by means of principal component analysis and partial least squares regression

The combined use of principal component analysis and partial least squares regression to the interpretation of polychlorinated dibenzofuran (PCDF) and dibenzo-p-dioxin (PCDD) patterns in crabs are investigated. By exploratory principal component analysis, the PCDFs and the PCDDs are ranked according to their specificity to the emission source. Among the most specific PCDFs to the emission are the 12368/13479-PeCDF and 12478-PeCDF. The 123789-HxCDD isomer is the only specific PCDD to the emission source. Partial least squares regression is used both to explore the determination of sex specific isomers, and in confirmatory analysis by quantitatively relating the pollution waste to the distance from the emission source. 123678-HxCDF is statistically significant for the separation between male and female crabs collected at the same distance from the emission source, while no separation between male and female crabs is evident from 1234789-HpCDF, Octa-CDF, 2,3,7,8-TCDD and Octa-CDD. This observation is somewhat more shaded than what has previously been reported in the literature on differences in male and female crabs. A linear relationship exists between the logtransformed distance and the concentration of PCDFs and PCDDs in male crabs collected between 18 and 33 km from the source. This model underestimates the predicted distance of crabs collected between 33 and 56 km, possible due to a higher sedimentation rate at distances closer to the fjord and the factory.

Although applied to PCDF/PCDD data in this case, the outlined multivariate methods should be applicable to all kind of similar environmental surveys.     

乌梁素海沉积物孔隙水中溶解有机质的荧光及紫外光谱研究

运用紫外可见光吸收光谱与荧光光谱研究乌梁素海沉积物孔隙水中溶解有机质的来源、结构及腐殖化程度。r_(A,C)、HIX、SUVA₂₈₀和SUVA₂₅₄等被用于表征DOM的腐殖化程度和芳香构化程度及结构,f_450/500用于指示DOM的来源。研究结果表明：腐殖化程度最高的点为湖泊东部的W4样点,腐殖化程度最低的为总排干影响区域的W1样点。E_253/203表明湖泊入口处沉积物孔隙水中有机质主要为不可取代的芳香环结构。荧光指数f_450/500为1.57～1.82之间。总体而言,f_450/500的值更接近于1.6,处于2个端源中间,说明乌梁素海DOM中的腐殖质主要来源于陆源输入。相关分析的结果表明, DOM的不同来源对其腐殖化程度产生影响。随着腐殖化值的增大,DOM的来源由生物源向陆源过渡。     

Effect of permanganate oxidation and chlorination on the mutagenic activity and other quality parameters of artificially recharged ground water processed from humus-rich surface water

The effect of oxygen, chlorine, and potassium permanganate oxidation on the quality of drinking water processed from artificially recharged ground water was studied. Artificially recharged ground water contained only 45% of the organic material of the original lake water, but iron and manganese contents were high.Oxygen removed iron but not manganese. Potassium permanganate proved to be more effective than chlorine in removing manganese.The non-chlorinated waters were non-mutagenic but the level of the mutagenicity of all chlorinated artificially recharged ground waters were as high as in chlorinated drinking water processed from lake water. One exception was found, however. The mutagenicity of potassium permanganate oxidized, chlorinated, artificially recharged ground water was very low, only about 5% of the other waters.     

Dioxins,chlorophenols and other chlorinated organic pollutants in colloidal and water fractions of groundwater from a contaminated sawmill site

BACKGROUND, AIM, AND SCOPE: The distribution of chlorinated organic contaminants in groundwater and the importance of colloids were studied in groundwater from a sawmill site contaminated by chlorophenol preservatives. MATERIALS AND METHODS: The groundwater was fractionated into three different size ranges: (1) >0.7 mum, (2) 0.4-0.7 mum and (3) 0.2-0.4 mum and the filtered water phase. The concentrations of chlorophenols (CP), chlorinated phenoxy phenols (PCPP), chlorinated diphenyl ethers (PCDE), chlorinated dibenzofurans (PCDF) and chlorinated dibenzo-p-dioxins (PCDD) were determined in each fraction. The colloids were characterised regarding the chemical composition using X-ray photoelectron spectroscopy (XPS). RESULTS: Chlorophenols were mostly found in the water fraction and PCDD/Fs were found almost exclusively in the particulate fractions. For example, the filtered water phase contained 2,100 mug l(-1) and 0.72 ng l(-1) for CPs and PCDD/Fs, respectively, and the particulate fractions contained 27 mug l(-1) and 32 ng l(-1) for CPs and PCDD/Fs, respectively. XPS evaluation of the particulate phases showed no correlation between the surface chemistry of the particle properties and the distribution of chlorinated compounds. DISCUSSION: The results suggest that groundwater transport of CPs, PCPPs, PCDEs and PCDD/Fs may occur from contaminated sawmill sites and that the colloid-facilitated transport, especially of PCDD/Fs, is substantial. The results correlated well with previous studies of compounds sorbed to dissolved organic carbon, which indicate that dissolved and colloidal organic carbon facilitated the transport of PCDEs, PCDFs and PCDDs particularly. CONCLUSIONS: Several classes of chlorinated compounds were readily detected in the groundwater samples. Due to the differences in their physicochemical properties, CPs, PCPPs, PCDEs and PCDD/Fs vary in their partitioning between colloidal fractions and the filtered groundwater. The proportion of the bound fraction increased with an increasing hydrophobicity of the chlorinated compounds. The groundwater transport of colloid-associated pollutants from the site may be significant. RECOMMENDATIONS AND PERSPECTIVES: The results imply that colloidal particles <0.7 mum are freely mobile in groundwater from this site. The groundwater transport of colloid-associated pollutants may be significant. However, the extent of the problem is not yet known and, thus, further research is needed to evaluate the impact of colloidal transport of hydrophobic organic contaminants. In Sweden alone, 400 to 500 sawmill sites are estimated to be contaminated with PCDD/Fs as a result of the former use of CP-based wood preservatives. The widespread use of CP mixtures for a variety of applications, including wood preservation, indicates that potential colloidal transport will be an issue of concern in many countries.     

Effects of macrophytes and external carbon sources on nitrate removal from groundwater in constructed wetlands

Several microcosm wetlands unplanted and planted with five macrophytes (Phragmites australis, Commelina communis, Penniserum purpureum, Ipomoea aquatica, and Pistia stratiotes) were employed to remove nitrate from groundwater at a concentration of 21-47 mg NO3-N/l. In the absence of external carbon, nitrate removal rates ranged from 0.63 to 1.26 g NO3-N/m2/day for planted wetlands. Planted wetlands exhibited significantly greater nitrate removal than unplanted wetlands (P<0.01), indicating that macrophytes are essential to efficient nitrate removal. Additionally, a wetland planted with Penniserum showed consistently higher nitrate removal than those planted with the other four macrophytes, suggesting that macrophytes present species-specific nitrate removal efficiency possibly depending on their ability to produce carbon for denitrification. Although adding external carbon to the influent improved nitrate removal, a significant fraction of the added carbon was lost via microbial oxidation in the wetlands. Planting a wetland with macrophytes with high productivity may be an economic way for removing nitrate from groundwater. According to the harvest result, 4-11% of nitrogen removed by the planted wetland was due to vegetation uptake, and 89-96% was due to denitrification.     

Numerical modeling of changes in groundwater storage and nitrate load in the unconfined aquifer near a river receiving reclaimed water

Environmental Science and Pollution Research - Reclaimed water (RW) has been widely used as an alternative water resource to recharge rivers in mega-city Beijing. At the same time, the RW also...     

Coastal water quality in the Kihei and Lahaina districts of the island of Maui, Hawaiian Islands. Impacts from physical habitat and groundwater seepage: implications for water quality standards

Water quality in terms of nutrient concentrations, turbidity, suspended solids, and chlorophyll a, was studied during 2000–2001 at a total of 27 beaches in the Kihei and West Maui–Lahaina districts of Maui, Hawaiian Islands. Nitrate concentrations varied widely and averaged as much as 15–20 μM at some beaches. Most turbidities fell in the range 1–10 nephelometric turbidity units. Resuspension of bottom sediments on shallow reef flats appeared to be a cause of some of the highest turbidity. Onshore-offshore transect studies showed that turbidity and concentrations of nitrate and chlorophyll a declined dramatically with distance from the shoreline. The dramatic gradients in water quality within the first 100 m from the shoreline and the fact that some violations of water quality criteria within that zone appear to be the result of natural phenomena, underscore the difficulty of assessing the quality of coastal waters based on traditional parameters.     

Direct measurements of the tile drain and groundwater flow route contributions to surface water contamination: From field-scale concentration patterns in groundwater to catchment-scale surface water quality

Enhanced knowledge of water and solute pathways in catchments would improve the understanding of dynamics in water quality and would support the selection of appropriate water pollution mitigation options. For this study, we physically separated tile drain effluent and groundwater discharge from an agricultural field before it entered a 43.5-m ditch transect. Through continuous discharge measurements and weekly water quality sampling, we directly quantified the flow route contributions to surface water discharge and solute loading. Our multi-scale experimental approach allowed us to relate these measurements to field-scale NO₃ concentration patterns in shallow groundwater and to continuous NO₃ records at the catchment outlet. Our results show that the tile drains contributed 90-92% of the annual NO₃ and heavy metal loads. Considering their crucial role in water and solute transport, enhanced monitoring and modeling of tile drainage are important for adequate water quality management.     

Photochemical degradation of ciprofloxacin in UV and UV/H2O2 process: kinetics, parameters, and products

Photochemical degradation of fluoroquinolone ciprofloxacin (CIP) in water by UV and UV/H₂O₂ were investigated. The degradation rate of CIP was affected by pH, H₂O₂ dosage, as well as the presence of other inorganic components. The optimized pH value and H₂O₂ concentration were 7.0 and 5 mM. Carbonate and nitrate both impeded CIP degradation. According to liquid chromatography–tandem mass spectrometry analysis, four and 16 products were identified in UV and UV/H₂O₂ system, respectively. Proposed degradation pathways suggest that reactions including the piperazinyl substituent, quinolone moiety, and cyclopropyl group lead to the photochemical degradation of CIP. Toxicity of products assessed by Vibrio qinghaiensis demonstrated that UV/H₂O₂ process was more capable on controlling the toxicity of intermediates in CIP degradation than UV process.     

紫外活化过硫酸盐工艺降解水中磺胺二甲氧嘧啶动力学特征与机理

采用紫外活化过硫酸盐(UV/PS)工艺降解典型磺胺类抗生素磺胺二甲氧嘧啶(SDM),比较单一紫外(UV)、单一过硫酸盐(PS)和UV/PS对SDM的去除效果,考察各因素对降解动力学的影响,并探究其降解机理,对SDM及其中间产物进行毒性测定和风险评价.结果显示,UV/PS可以加速SDM降解,反应速率常数分别是单一UV和单...     

Occurrence of boscalid and other selected fungicides in surface water and groundwater in three targeted use areas in the United States

Although the use of the insecticide γ-hexachlorocyclohexane (HCH) is now prohibited in many countries because of its hazardousness, stockpiles of γ-HCH still exist. In this study, we subjected γ-HCH to mechanochemical (MC) treatment with a planetary ball mill in the presence of CaO to investigate the feasibility of using this method for the treatment of γ-HCH stockpiles. We confirmed the degradation of γ-HCH and investigated the degradation mechanism. The major intermediates were identified to be 1,3,4,5,6-pentachlorocyclohexene (γ-PCCH) and chlorobenzenes (CBzs). Analysis of the steric structure of γ-HCH and identification of the degradation intermediates suggested that successive dehydrochlorination led to the formation of trichlorobenzenes. Products of further degradation (dichlorobenzenes, monochlorobenzene, and benzene) were also detected. Surprisingly, methane and ethane were also detected, which suggests cleavage of the C-C bonds of the cyclohexane ring and hydrogenation. All of the chlorine atoms in the γ-HCH could be transformed into inorganic chloride compounds by the MC treatment with CaO. Our results indicate that γ-HCH can be completely dechlorinated by MC treatment.     

Altered toxicity of organic pollutants in water originated from simultaneous exposure to UV photolysis and CdSe/ZnS quantum dots

The paper reports unforeseen results of increased toxicity of water, subsequent to interactions between CdSe/ZnS quantum dots (QDs), phenol and toluene under UV irradiation. The consistent pattern of changes in measured toxicity (TU) was observed and correlated with degradation of phenol and/or toluene. Spearman rank coefficients (SRCs) for data pairs sum-parameters vs. TU were calculated. The highest correlation between toxicity and degradation by-products was observed for hydroquinone (0.86) and catechol (0.89). The presence of QDs in tested concentration range in the absence of UV has shown low toxicity and no interactions with phenol and/or toluene. The leak of constituent core and shell metal ions was observed. The minor differences in physical characteristics of tested QDs of the same chemical composition led to rather different degradation patterns of phenol and toluene, and the amount of leak of the metal ions as well.     

Occurrence and removal of six pharmaceuticals and personal care products in a wastewater treatment plant employing anaerobic/anoxic/aerobic and UV processes in Shanghai,China

The occurrence and removal of six pharmaceuticals and personal care products (PPCPs) including caffeine (CF), N, N-diethyl-meta-toluamide (DEET), carbamazepine, metoprolol, trimethoprim (TMP), and sulpiride in a municipal wastewater treatment plant (WWTP) in Shanghai, China were studied in January 2013; besides, grab samples of the influent were also taken every 6 h, to investigate the daily fluctuation of the wastewater influent. The results showed the concentrations of the investigated PPCPs ranged from 17 to 11,400 ng/L in the WWTP. A low variability of the PPCP concentrations in the wastewater influent throughout the day was observed, with the relative standard deviations less than 25 % for most samples. However, for TMP and CF, the slight daily fluctuation still reflected their consumption patterns. All the target compounds except CF and DEET, exhibited poor removal efficiencies (<40 %) by biological treatment process, probably due to the low temperature in the bioreactor, which was unfavorable for activated sludge. While for the two biodegradable PPCPs, CF, and DEET, the anaerobic and oxic tank made contributions to their removal while the anoxic tank had a negative effect to their elimination. The tertiary UV treatment removed the investigated PPCPs by 5–38 %, representing a crucial polishing step to compensate for the poor removal by the biologic treatment process in winter.     

污水处理对黑水/灰水中溶解性有机物紫外光谱及荧光光谱特性的影响

为了考察黑水/灰水中溶解性有机物(DOM)光谱特征在污水处理过程中的变化规律以及生物处理前后黑水/灰水中DOM特性上的异同,对污水处理过程中黑水/灰水DOM的紫外光谱及荧光光谱特征进行了测定分析。结果表明,黑水原水中DOM的含量远高于灰水,且含有较多难降解有机物。生物处理可实现对黑水与灰水中易降解DOM的有效去除,MBR系统中的膜分离过程也可以起到截留溶解性有机物的作用。经MBR处理后,同黑水出水相比,灰水出水中的DOM含量更低,且主要为饱和有机物,苯环C骨架的聚合程度较高,THMs生成活性更低。生物处理过程可有效去除黑水/灰水中蛋白质类物质与易降解腐殖质类物质。生物处理后,黑水与灰水的蛋白峰均消失,黑水出水类腐殖酸峰F荧光强度高于灰水出水。与黑水出水相比,灰水出水更适用作再生水加以回收利用。     

Removal of pollutants from surface water and groundwater by nanofiltration: overview of possible applications in the drinking water industry

During the last decade, nanofiltration (NF) made a breakthrough in drinking water production for the removal of pollutants. The combination of new standards for drinking water quality and the steady improvement of the nanofiltration process have led to new insights, possible applications and new projects on lab-scale, pilot scale and industrial scale. This paper offers an overview of the applications in the drinking water industry that have already been realised or that are suggested on the basis of lab-scale research. Applications can be found in the treatment of surface water as well as groundwater. The possibility of using NF for the removal of hardness, natural organic material (NOM), micropollutants such as pesticides and VOCs, viruses and bacteria, salinity, nitrates, and arsenic will be discussed. Some of these applications have proven to be reliable and can be considered as known techniques; other applications are still studied on laboratory scale. Modelling is difficult due to effects of fouling and interaction between different components. The current insight in the separation mechanisms will be briefly discussed.     

六氯苯的O3及UV/O3高级氧化降解试验研究

采用O3、UV/O3高级氧化法对水中六氯苯（HCB）的降解效果及机理进行了研究,并对结果进行了比较,结果表明,UV本身对HCB的去除率贡献不大,HCB可被O3、UV/O3快速降解,即UV＜O3＜UV/O3;O3、UV/O3作用时,提高体系的初始pH值不利于HCB的降解,在pH＝3,HCB=0.2 mg/L,反应40 min时,HCB的去除可达50%左右,酸性条件下有利于降解反应的进行;无论是O3单独作用还是UV/O3联合作用,HCB的降解基本上满足准一级反应动力学规律,如果体系的pH值基本保持恒定,这种规律就更为明显。根据离子色谱(IC)、GC对六氯苯降解中间产物进行了测定,探讨了O3、UV/O3降解六氯苯的途径和机理。     

Rapid regional recovery from sulfate and nitrate pollution in streams of the western Czech Republic--comparison to other recovering areas

Hydrochemical changes between 1991 and 2001 were assessed based on two synoptic stream surveys from the 820-km2 region of the Slavkov Forest and surrounding area, western Czech Republic. Marked declines of sulfate, nitrate, chloride, calcium and magnesium in surface waters were compared with other areas of Europe and North America recovering from acidification. Declines of sulfate concentration in the Slavkov Forest (-30 microeq L(-1) yr(-1)) were more dramatic than declines reported from other sites. However, these dramatic declines of strong acid anions did not generate a widespread increase of stream water pH in the Slavkov Forest. Only the most acidic streams experienced a slight increase of pH by 0.5 unit. An unexpected decline of stream water pH occurred in slightly alkaline streams.     

Influence of water quality parameters on occurrence of polybrominated diphenyl ether in sediment and sediment to biota accumulation

Polybrominated diphenyl ether (PBDE) concentrations in sediment and fish from 12 principal rivers in Taiwan were investigated to determine their association with water quality parameters as well as the biota-sediment accumulation factor (BSAF) in fish with different living patterns. The highest PBDE concentration in sediment was found in the Bajhang River (261 ng g^?1 dry weight (d.w.)) and the lowest in the Beinan River and the Da-an River (0.17 ng g^?1 d.w.). The PBDE concentrations in fish samples ranged from 1.28 ng g^?1 d.w. (Oreochromis niloticus niloticus) in the Yanshuei River to 33.7 ng g^?1 d.w. (Varico rhinos barbatulus) in the Da-an River. We conclude that PBDEs contamination in sediment was significantly affected by NH₃–N, pH, and DO. The BSAF results showed a parabolic trend from low- to high-brominated BDEs. Fish easily accumulated the congeners BDE-47, -100, -119, -126, and -154 from sediment. The BSAF decreased in the following order: PeBDE > HxBDE > TeBDE > other BDEs. Principle component analysis showed that demersal fish have different PBDE sources than do pelagic fish. We conclude that living and feeding habits are critical factors affecting PBDE accumulation in fish.     

六氯苯的O3及UV/O3高级氧化降解试验研究

采用O₃、UV/O₃高级氧化法对水中六氯苯（HCB）的降解效果及机理进行了研究，并对结果进行了比较，结果表明，UV本身对HCB的去除率贡献不大，HCB可被O₃、UV/O₃快速降解，即UV＜O₃＜UV/O₃；O₃、UV/O₃作用时，提高体系的初始pH值不利于HCB的降解，在pH＝3，HCB=0.2 mg/L，反应40 min时，HCB的去除可达50%左右，酸性条件下有利于降解反应的进行；无论是O₃单独作用还是UV/O₃联合作用，HCB的降解基本上满足准一级反应动力学规律，如果体系的pH值基本保持恒定，这种规律就更为明显。根据离子色谱(IC)、GC对六氯苯降解中间产物进行了测定，探讨了O₃、UV/O₃降解六氯苯的途径和机理。     

大型溞投放密度对湖库水体水质改善及底泥污染物影响

向北京市沙河水库投放大型溞(Daphnia magna),利用其摄食藻类、促进悬浮颗粒态污染物沉降的特性,以提升水体的透明度,为后续沉水植物群落的恢复创造条件,并探索大型溞的投放密度,以及投放后对水质及底泥主要污染物的影响。结果表明：向沙河水库投加大型溞的最佳密度为5~15 ind·L⁻¹;在该条件下,水体透明度可在3~5 d由40 cm提升至100 cm,浊度由19.7 NTU降至3 NTU,藻密度由2.4×10⁶ cell·mL⁻¹降至(4~6)×10⁴ cell·mL⁻¹;大型溞可在沙河水库长期存活,并可长期抑制藻类、维持水体的透明度;水体COD并未发生明显改变;大型溞的分泌物促进了悬浮颗粒态氮、磷的沉降,使TN和TP的去除率分别达到70.2%和54.9%;由于投溞后藻类浓度迅速下降,藻对NH₃-N的吸收量降低,使水体NH₃-N升高了32.2%;底泥中有机质、TN、TP均出现了一定程度的升高。针对于湖库水体透明度低的问题,应投放适宜密度的大型溞,调整水质状态,并结合水中藻类、底泥污染物等条件,综合考虑有效改善水质的方法。