Occurrence Of Micropollutants Research Articles

Special Issue on Wastewater Treatment and Reuse Technologies

Wastewater treatment allows for the safe disposal of municipal and industrial wastewater to protect public health and the ecosystem[...]

Micropollutants in wastewater and their degradation by ferrates (VI)

Abstract In recent years, the occurrence of micropollutants (MPs) in sewage-, surface-, ground- and drinking water, and their removal processes are widely discussed. The content of various chemical organic/inorganic pollutants (pharmaceuticals, drugs, pesticides, hormones, heavy metals etc.) has increased over the years. Most of these compounds are not eliminated or biotransformed in traditional wastewater treatment plants. Several advanced oxidation processes (AOPs) for the removal of resistant micropollutants from water sources have been studied. Ferrate (VI) has aroused interest as an alternative oxidizing agent in drinking water preoxidation treatment. Electrochemically prepared potassium ferrate was used to remove the studied organic micropollutants. The effect of ferrate on two widely occurring organic micropollutants in water sources, carbamazepine and caffeine, was investigated. High performance liquid chromatography (HPLC) was used for sample analysis.

Dissipation of Micropollutants in a Rewetted Fen Peatland: A Field Study Using Treated Wastewater

In the present study, a mixture of treated wastewater and surface water was used to rewet a degraded fen peatland site during a three-year rewetting experiment. We studied the behavior and effects of micropollutants by means of hydrological, physico-chemical, microbiological and ecotoxicological monitoring. The highest concentrations of micropollutants in the treated wastewater were found for the pharmaceuticals carbamazepine and diclofenac, some metabolites, the sweetener acesulfame, tolyl- and benzotriazole and diatrizoate. In the underlying, shallow groundwater where treated wastewater application for rewetting had been expected to have the greatest impact due to seeping and evapotranspiration processes, only a sporadic occurrence of micropollutants was found. The influence of dilution by groundwater movements was examined by applying a geohydrological model. The sorption of micropollutants onto the peaty soil also played a role, as found for carbamazepine. Further processes such as photolysis, microbial decay under low redox conditions and plant uptake can be assumed to be relevant for the removal of many substances. Ecotoxicity tests with the soil before and after rewetting did not indicate any negative impact on the soil habitat quality by wastewater application, but clearly pointed at ecotoxicologically relevant geogenic arsenic concentrations at the study site. Although a positive effect on receiving surface water systems is expected if wastewater is applied on land instead of discharged to water bodies, the rewetted soil may turn into a sink for micropollutants in the long term. Hence, the findings of the present field study encourage further investigations in order to identify the governing processes in the elimination of micropollutants in rewetted peatlands flooded with treated wastewater.

Occurrence of micropollutants in the wastewater streams of cruise ships

Abstract Nowadays the protection of the marine environment raises increasing academic and public attention. The issue of organic micropollutants is of equally high importance for the marine ecosystems. Maritime vessels are considered to significant sources of micropollutants especially if the ship carries many passengers, which is often true for cruise ships which frequent attractive and sensitive sea areas. The emission pathways for micropollutants include wastewater discharges and sewage sludge disposal. The findings of the German research and development project NAUTEK contribute to bridging the knowledge gap about micropollutant emissions from cruise ships. As expected, micropollutants were detected in both the blackwater and greywater on board, emitted from either the passengers or certain ship operations. In total, 16 out of 21 target substances were detected. Peak concentrations of pharmaceuticals could be found mainly in blackwater (peak conc. Carbamazepine 3.9 μg/L, Ibuprofen 29 μg/L, Diclofenac 0.04 μg/L), while greywater is mainly characterized by substances such as ointment residues, UV-filters and flame retardants (peak conc. Diclofenac 0.65 μg/L, Bisphenol A 8 μg/L, Tris(1-chloro-2-propyl)phosphate 136 μg/L). Further analyses suggest a gradual removal of the micropollutants by the onboard MBR plant (MBR effluent peak conc. Carbamazepine 0.47 μg/L, Ibuprofen 6.8 μg/L, Diclofenac 0.3 μg/L). Findings of this research provide a critical stepstone for shaping technical solutions for onboard micropollutants removal and water resource recycling.

Pyrolysis of wastewater biosolids significantly reduces estrogenicity

Most wastewater treatment processes are not specifically designed to remove micropollutants. Many micropollutants are hydrophobic so they remain in the biosolids and are discharged to the environment through land-application of biosolids. Micropollutants encompass a broad range of organic chemicals, including estrogenic compounds (natural and synthetic) that reside in the environment, a.k.a. environmental estrogens. Public concern over land application of biosolids stemming from the occurrence of micropollutants hampers the value of biosolids which are important to wastewater treatment plants as a valuable by-product. This research evaluated pyrolysis, the partial decomposition of organic material in an oxygen-deprived system under high temperatures, as a biosolids treatment process that could remove estrogenic compounds from solids while producing a less hormonally active biochar for soil amendment. The estrogenicity, measured in estradiol equivalents (EEQ) by the yeast estrogen screen (YES) assay, of pyrolyzed biosolids was compared to primary and anaerobically digested biosolids. The estrogenic responses from primary solids and anaerobically digested solids were not statistically significantly different, but pyrolysis of anaerobically digested solids resulted in a significant reduction in EEQ; increasing pyrolysis temperature from 100°C to 500°C increased the removal of EEQ with greater than 95% removal occurring at or above 400°C. This research demonstrates that biosolids treatment with pyrolysis would substantially decrease (removal>95%) the estrogens associated with this biosolids product. Thus, pyrolysis of biosolids can be used to produce a valuable soil amendment product, biochar, that minimizes discharge of estrogens to the environment.

Communication About Micropollutants in Drinking Water: Effects of the Presentation and Psychological Processes.

This study investigates how people change their risk perception, trust, and behavior as a consequence of being informed about the occurrence of micropollutants in drinking water. Micropollutants are substances present in extremely low concentrations that might be dangerous in higher concentrations. Data were gathered in the city of Zurich, Switzerland in 2013 using a questionnaire in which the information on micropollutants was presented differently to 12 experimental groups. Data of the key constructs were gathered before and after this information, so that causal effects could be quantified by regression analyses. Affective reactions to the information turned out to be the critical mediator of changes in risk perception (operationalized as the perceived change of quality due to pollution), which is an important determinant of changes in behavior and trust. Also, direct effects of affective reactions on behavior and trust were observed. Trust before appraising risks reduces negative affective reactions; however, it also reduces perceived quality (i.e., increases risk perception) and trust after risks are appraised. The different forms of information mainly influenced the participants' affective reactions, but they also influenced perceived quality. The presentation with the least negative effects was a comparison of the intake of the substance by water with intake by food. The experimental design with repeated measurement that considers trust as a determinant and consequence of risk perception uncovered positive and negative effects of trust before appraising risks on changes of risk perception and trust due to appraising risks.

Occurrence of micropollutants in four major rivers in Korea

There has been an increasing concern in recent years over the presence of numerous micropollutants in river water. Simultaneously, risk assessment of micropollutants has become increasingly important due to their high toxicity. Therefore, the aims of this study were to characterize the levels of micropollutants in rivers, to identify the sources of these pollutants, and to evaluate their risk quotients (RQ) to the ecological system. Monitoring data from 159 sites distributed across four major rivers in Korea were collected from the Ministry of the Environment (KME) reports. Tests were performed to check for the presence of 35 pollutants in river waters, from which 29 pollutants were detected. Organochlorine pesticides (OCPs) occurred most frequently, at low concentrations, whereas volatile organic compounds (VOCs) and phthalates were detected at higher concentrations. Based on this study, it was suggested that the factories near the sampling sites where pollutants were found represent one of the main sources of chemicals. After comparing the industrial activities with the measured pollutants, although the released amounts were not reported, representative intermediate chemicals were found in the river water. The RQs of most VOCs were below one, despite their concentration range being higher, compared with other pollutants. Methyl bromide and di-n-octyl phthalate occurred frequently in the Han River Basin and the Nakdong River Basin, respectively, and their RQs were consistently high, so further studies should focus on their exact emission source in order to reduce ecological risk. The results suggest that it will be necessary to develop methods of risk assessment that are more tailored to the various micropollutants present in river water, in addition to the implementation of water treatment systems to reduce ecological risk.

Occurrence of Micro-pollutants in a Soil–Radish System Irrigated with Several Types of Treated Domestic Wastewater

During this study, the effect of applying several types of treated domestic wastewater on the translocation and accumulation of organic and inorganic micropollutants in soil and radish plants (Raphanus sativus L.) was examined. Primary (PTW), secondary (STW) and tertiary (TTW) treated wastewater as well as tap water (TW) were used for the irrigation of radish plants for a period (transplantating and harvesting) of 67 days. Higher concentrations of polycyclic aromatic hydrocarbons (PAHs) were observed in soils irrigated with PTW. The concentration of PAHs in radish roots ranged between 107.6 ± 12.1 μg/kg for plants irrigated with TTW and 124.1 ± 17.7 μg/kg for plants irrigated with PTW. The root concentration factors (RCFs) expressed as the ratio of PAH concentration in the root mass (dry weight) to the residual concentration in the soil varied from 1.6 to 1.9 indicating a higher accumulation of PAHs in the edible part of radishes than soil. Heavy metals were not detected in the wastewaters utilised and, as a result, no accumulation was found in either the soil or plants in comparison with tap water. RCFs for heavy metals were calculated between 0.91 and 0.99, 0.49 and 0.66, 0.004 and 0.005 for Cu, Zn and Ni, respectively. The results showed that radishes have the ability to concentrate PAHs when they are present in the wastewater and this could have associated health risks.

Environmental impacts of rapid urbanization in China: a showcase of recent research developments

Urbanization is taking an unprecedented rate in China, and it is projected that some 350 million people will be added to the country’s urban population by 2025, and 1 billion people will live in Chinese cities by 2030 (Zhu et al. 2011). For the first time in history, China will have over 50 % of its 1.3 billion population living in cities this year. This is remarkable for China, an ancient and more agriculturebased civilization. In many ways, urbanization will improve the quality of sanitary conditions, better health care systems, the efficiency of public transport, and will provide the population with more access to modern civilization. However, it is also clear that urbanization will, in the same time, bring many negative impacts on the environment and human health, as recently highlighted by Zhu et al. (2011). To overcome the negative environmental impacts of rapid urbanization in China is becoming one of the major themes of environmental studies in China. Urban ecosystem is human-dominated, and the changes in environmental quality and the health of urban ecosystems are largely driven and determined by concentrated human consumption of energy and natural resources. In this special issue, we publish 11 papers to illustrate some of the recent endeavors in investigating the status of urban environmental quality and the impacts of urbanization on environmental changes, as well as technologies to mitigate the negative impacts of urbanization. Two review papers are included in this issue, one by Guo-Ping Sheng provides an overview on wastewater discharge and urbanization in China, and the other one by Chen et al. provides Chinese perspectives of sewage sludge utilization. Four papers examined the current status of environmental quality, such as the occurrence of micropollutants (perfluoroalkyl and estrogenic compounds), sediment quality in urban river systems, particulate matter in urban air, etc. The paper by Jun Yang addresses the issue of aquatic ecosystem health by looking at algal community and trophic state. One paper (by Xinhu Li) looks at the spatial features of the relationship between human health and urbanization. There are also two papers which report some new technological developments that help lessen these environmental problems. In recent years, publications related to “urbanization and China” have increased dramatically, from 21 in 2000 to 337 in 2010 (Web of Science, accessed on 11 March 2012). Therefore, by no means will this special issue provide a full picture of urban environmental studies in China; rather, it serves as a window to showcase the recent developments in urban environmental studies.

The occurrence of micopollutants in the aquatic environment: a new challenge for water management

The occurrence of micropollutants in the aquatic environment has become a crucial topic in the last two decades owing to the innovative development of analytical instrumentation such as LC tandem MS. Using these new techniques it became obvious that pesticides, pharmaceuticals, ingredients of personal care products, biocides, flame retardants, and perfluorinated compounds are entering rivers and streams via treated wastewater. Also contamination of bank filtrates, groundwater and in a few cases even drinking water was identified. Wastewater treatment plants are not designed to remove polar persistent organic pollutants occurring in the sub-mg/L range and hence many of these organic pollutants are passing WWTPs to a high extent. Waterworks with a potential pesticide contamination in their raw water are equipped with advanced techniques such ozonation, activated carbon or nanofiltration enabling the removal of a high variety of other organic compounds. However, waterworks without an expected pesticide contamination are frequently equipped with common treatment processes not enabling the removal of these kinds of organic pollutants. Therefore, comprehensive management activities for protection of aquatic environments and water resources must consider the removal of all micropollutants relevant to water quality and ecology, independent of their usage or origin.