Simulation of the influence of industrial wastewater on a municipal sewage treatment plant—a case study

Purpose  

Industrial wastewater flow caused operational difficulties in the wastewater treatment plant in Debrecen, Hungary. Bioaugmentation was successfully applied to maintain effluent quality in the periods when wastewater of high starch content was accepted, but, at the end of 2008, the nitrification capacity of the plant decreased considerably due to improperly pre-treated pharmaceutical wastewater.     

Influence of regional climatic on the hydrogeochemistry of a tropical river basin—a study from the Walawe river basin of Sri Lanka

Environmental Science and Pollution Research - The Walawe river basin is one of the important watersheds in Sri Lanka subjected to water scarcity due to intensive exploitation for irrigation and...     

Impact of energy carriers’ price distortions on energy allocative efficiency: the case study of Iranian provinces

Environmental Science and Pollution Research - Government control distorts energy prices which leads to loss of optimal factor combination and, as a result, affects efficiency. Previous researches...     

Environmental and socioeconomic assessment of impacts by mining activities—a case study in the Certej River catchment,Western Carpathians,Romania

Background, aim and scope

In the region of the Apuseni Mountains, part of the Western Carpathians in Romania, metal mining activities have a long-standing tradition. These mining industries created a clearly beneficial economic development in the region. But their activities also caused impairments to the environment, such as acid mine drainage (AMD) resulting in long-lasting heavy metal pollution of waters and sediments. The study, established in the context of the ESTROM programme, investigated the impact of metal mining activities both from environmental and socioeconomic perspectives and tried to incorporate the results of the two approaches into an integrated proposition for mitigation of mining-related issues.

Study site

The small Certej catchment, situated in the Southern Apuseni Mountains, covers an area of 78 km². About 4,500 inhabitants are living in the basin, in which metal mining was the main economic sector. An open pit and several abandoned underground mines are producing heavy metal-loaded acidic water that is discharged untreated into the main river. The solid wastes of mineral processing plants were deposited in several dumps and tailings impoundment embodying the acidic water-producing mineral pyrite.

Methods

The natural science team collected samples from surface waters, drinking water from dug wells and from groundwater. Filtered and total heavy metals, both after enrichment, and major cations were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES). Major anions in waters, measured by ion chromatography, alkalinity and acidity were determined by titration. Solid samples were taken from river sediments and from the largest tailings dam. The latter were characterised by X-ray fluorescence and X-ray diffraction. Heavy metals in sediments were analysed after digestion. Simultaneously, the socioeconomic team performed a household survey to evaluate the perception of people related to the river and drinking water pollution by way of a logistic regression analysis.

Results and discussion

The inputs of acid mine waters drastically increased filtered heavy metal concentrations in the Certej River, e.g. Zn up to 130 mg L⁻¹, Fe 100 mg L⁻¹, Cu 2.9 mg L⁻¹, Cd 1.4 mgL⁻¹ as well as those of SO₄ up to 2.2 g L⁻¹. In addition, river water became acidic with pH values of pH 3. Concentrations of pollutant decreased slightly downstream due to dilution by waters from tributaries. Metal concentrations measured at headwater stations reflect background values. They fell in the range of the environmental quality standards proposed in the EU Water Framework Directive for dissolved heavy metals. The outflow of the large tailing impoundment and the groundwater downstream from two tailings dams exhibited the first sign of AMD, but they still had alkalinity.

Most dug wells analysed delivered a drinking water that exhibited no sign of AMD pollution, although these wells were a distance of 7 to 25 m from the contaminated river. It seems that the Certej River does not infiltrate significantly into the groundwater.

Pyrite was identified as the main sulphide mineral in the tailings dam that produces acidity and with calcite representing the AMD-neutralising mineral. The acid–base accounting proved that the potential acid-neutralising capacity in the solid phases would not be sufficient to prevent the production of acidic water in the future. Therefore, the open pits and mine waste deposits have to be seen as the sources for AMD at the present time, with a high long-term potential to produce even more AMD in the future.

The socioeconomic study showed that mining provided the major source of income. Over 45% of the households were partly or completely reliant on financial compensations as a result of mine closure. Unemployment was considered by the majority of the interviewed persons as the main cause of social problems in the area. The estimation of the explanatory factors by the logistic regression analysis revealed that education, household income, pollution conditions during the last years and familiarity with environmental problems were the main predictors influencing peoples’ opinion concerning whether the main river is strongly polluted. This model enabled one to predict correctly 77% of the observations reported. For the drinking water quality model, three predictors were relevant and they explained 66% of the observations.

Conclusions

Coupling the findings from the natural science and socioeconomic approaches, we may conclude that the impact of mining on the Certej River water is high, while drinking water in wells is not significantly affected. The perceptions of the respondents to pollution were to a large extent consistent with the measured results.

Recommendations and perspectives

The results of the study can be used by various stakeholders, mainly the mining company and local municipalities, in order to integrate them in their post-mining measures, thereby making them aware of the potential long-term impact of mining on the environment and on human health as well as on the local economy.

     

Study on habitat suitability of overwintering cranes based on landscape pattern change—a case study of typical lake wetlands in the middle and lower reaches of the Yangtze River

Shengjin Lake wetland is located in the middle and lower reaches of the Yangtze River in China. It is a typical lake-type wetland and is also an ideal place for rare cranes to overwintering. The changes of wetland landscape are closely related to the habitat quality of wintering cranes. It is of great significance to study the habitat change of wintering cranes in wetland for wetland ecological restoration and restoration. In this paper, we analyze four kinds of winter cranes and wetland landscape pattern types from the years 1986 to 2015. Also, we adopted the Pearson correlation analysis method to analyze the relationship between wetland landscape types and crane population, and the main landscape types of cranes habitat were obtained. We selected disturbance degree, food richness, vegetation cover, and hydrological condition as the main factors affecting wintering habitat of cranes. We established a habitat suitability index model for wintering cranes and generated habitat suitability assessment maps by ArcGIS. The results show that the change of landscape pattern in Shengjin Lake protected area was obvious, the number of wetland patches increased, the fragmentation degree of landscape increased, the landscape patch difference became smaller, and the diversity index and evenness index increased gradually. From 1986 to 2015, the number of wintering cranes decreased and the habitat suitability index of wintering cranes decreased from 0.845 to 0.465, and the habitat suitability of wintering cranes fell from 13,577.11 to 7424.42 ha, which showed the overall habitat deteriorated significantly and had a positive correlation between the crane population and habitat suitability.

     

Effluent characterization and different modes of reuse in agriculture—a model case study

Background, aim, and scope  

High-quality waters are steadily retreating worldwide. Discharge of industrial effluent in the environment again declines soil/water quality to a great extent. On the other hand, effluent reuse in agriculture could be a means to conserve natural resources by providing assured water supply for growing crops. But industrial effluents are highly variable in nature, containing a variety of substances, and all are not favorable for farming. Appraisal and developing modes of effluent reuse is therefore a prerequisite to enable its proper use in agriculture. Effluents of various industries were assessed and approaches for their use in farming were developed for a particular region in this study. As per availability of effluents, the same could be implemented in other water-scarce areas.     

Economic assessment of the negative impacts of ozone on crop yields and forest production. A case study of the estate Ostads Säteri in southwestern Sweden

Ground level ozone concentrations, in combination with the prevailing climate, at the estate Ostads S?teri in southwestern Sweden were estimated to reduce the yield of wheat and potato ranging between 5% and 10%. Occasionally, in years with the highest ozone concentrations and/or climatic conditions favoring high rates of ozone uptake to the leaves, yield loss levels above 10% may occur. Based on simple extrapolation, these ozone-induced reductions of crop yields at Ostads S?teri represent a potential total annual yield loss in Sweden in the range of 24.5 million Euro for wheat and 7.3 million Euro for potato, respectively. A simulation of forest growth at Ostad S?teri predicted that prevailing mean ozone exposure during 1993-2003 had the potential to reduce forest growth by 2.2% and the economic return of forest production by 2.6%. Using this value for extrapolation to the national level, the potential annual economic loss for Sweden due to negative impacts of ozone on forest production would be in the range of 56 million Euro (2004 prices).     

Analysis of the influence of urban form and materials on sensible heat flux — a case study of Japan's largest housing development “Tama New Town”

In this study, the relationship between the form and materials of urban blocks and sensible heat flux from total surfaces was analyzed in the case of `Tama New Town', which is one of the largest housing developments in Japan and is under continuing development. First, urban blocks were divided into five categories depending on the building plot types. The characteristics of the form and thermal properties of each building, as well as the land cover condition (area of vegetation, bare soil, asphalt pavement, and built area) of each category was considered. Furthermore, 6 urban blocks were selected for numerical simulation of heat balance of the total surfaces, and sensible heat flux from the total surfaces of each urban block on clear sky summer day was calculated. It was confirmed that the influence of the direction that buildings faced and floor area ratio was as great as that of building materials upon the amount of sensible heat flux in each urban block.     

Correction to: Study on habitat suitability of overwintering cranes based on landscape pattern change—a case study of typical lake wetlands in the middle and lower reaches of the Yangtze River

Environmental Science and Pollution Research - The correct corresponding Author of this paper is Bin Dong.     

Potential of Eucalyptus globulus for the phytoremediation of metals in a Moroccan iron mine soil—a case study

Environmental Science and Pollution Research - The contamination left by abandoned mines demands sustainable mitigation measures. Hence, the aim of this study was to examine the phytoremediator...     

Spatiotemporal distribution of water environmental capacity—a case study on the western areas of Taihu Lake in Jiangsu Province,China

Currently, the poor water quality in Taihu Lake is a major problem in China, so pollution control in the upstream areas has become a government priority. In Jiangsu Province, pollution emissions around the western areas of Taihu Lake, including Changzhou Municipality and Yixing City, need to be highly restricted, and calculating the water environmental capacity is important if pollution is to be reduced. In this study, 19 control units in these areas were established, and a 0-D mathematical model was used to calculate the water environmental capacity. For three important control units with important cross sections, a 1-D model was established to redress the results. Finally, the total maximum monthly loads of each control unit were obtained using temporal allocation principles. The results suggested that (1) the total pollution control of chemical oxygen demand was 58,894.2 tonnes per annum (t a^?1), with ammonia nitrogen, total nitrogen, and total phosphorus amounting to 3,808, 6,054.6, and 386.6 t a^?1, respectively; (2) water environmental capacity per unit water area in the ambient control units was smaller than that in the middle control units; and (3) the largest water environmental capacity was in June, and the smallest capacity was in December. The study provides important information for local governments, which will enable them to implement pollution control strategies that will improve the water quality in Taihu Lake.     

Validation of the species sensitivity distribution in retrospective risk assessment of herbicides at the river basin scale—the Scheldt river basin case study

Species sensitivity distribution (SSD) is commonly used in prospective risk assessment to derive predicted no-effect concentrations, toxicity exposure ratios, and environmental quality standards for individual chemicals such as pesticides. The application of SSD in the retrospective risk assessment of chemical mixtures at the river basin scale (i.e., the estimation of “multiple substance potentially affected fractions” [msPAFs]) has been suggested, but detailed critical assessment of such an application is missing. The present study investigated the impact of different data validation approaches in a retrospective model case study focused on seven herbicides monitored at the Scheldt river basin (Belgium) between 1998 and 2009. The study demonstrated the successful application of the SSD approach. Relatively high impacts of herbicides on aquatic primary producers were predicted. Often, up to 40 % of the primary producer communities were affected, as predicted by chronic msPAF, and in some cases, the predicted impacts were even more pronounced. The risks posed by the studied herbicides decreased during the 1998–2009 period, along with decreasing concentrations of highly toxic pesticides such as simazine or isoproturon. Various data validation approaches (the removal of duplicate values and outliers, the testing of different exposure durations and purities of studied herbicides, etc.) substantially affected SSD at the level of individual studied compounds. However, the time-consuming validation procedures had only a minor impact on the outcomes of the retrospective risk assessment of herbicide mixtures at the river basin scale. Selection of the appropriate taxonomic group for SSD calculation and selection of the species-specific endpoint (i.e., the most sensitive or average value per species) were the most critical steps affecting the final risk values predicted. The present validation study provides a methodological basis for the practical use of SSD in the retrospective risk assessment of chemical mixtures.     

SimPhy: a simulation game to lessen the impact of phytosanitaries on health and the environment—the case of Merja Zerga in Morocco

Diffuse phytosanitary pollution is a complex phenomenon to manage. Reducing this type of pollution is one of today’s key socio-economic and environmental challenges. At the regional level, few approaches enable the actors concerned to implement agricultural management strategies to reduce the use and impact of phytosanitary products. Our research problem focused on the consequences of intensive agriculture and, in particular, how to evaluate the impact of phytosanitary products on human health and the environment. In this article, we present the SimPhy simulation game which places the actors from a given region directly into a situation in which they manage farms whilst under pressure to reduce phytosanitaries (quantity and toxicity). The application focused on the Merja Zerga catchment area in Morocco. The region is dominated by intensive agriculture which is located upstream from a Ramsar-classified wetland area. The SimPhy simulation game is based on a decision support system-type tool. It allows us to anticipate the impact of regulations on farming systems. It also enables us to analyse the consequences of the actors’ strategies on farm economies, human health and the quality of ecosystems. Initial results from the SimPhy simulation game enabled the technicians from Agricultural Development Center (CDA) themselves to learn about managing agricultural production systems in a dynamic and interactive fashion. With the simulation game, it was possible to learn about the farmer's ability to adapt to new regulatory constraints, and the involved consequences for toxicity risks for human health and the environment.     

Solid waste management of small island developing states—the case of the Seychelles: a systemic and collaborative study of Swiss and Seychellois students to support policy

Solid waste management (SWM) is a significant challenge for the Seychelles. Waste generation, fueled by economic development and tourism, increases steadily, while landfilling continues to be the main disposal path, thus exacerbating the island nation’s specific weaknesses. Due to the small scale of the Seychelles economy, there is little capital available to stimulate innovations in SWM and generate the knowledge for setting priorities and guiding SWM action. Students from ETH Zurich and UniSey conducted a transdisciplinary case study (tdCS) to fill this knowledge gap and gain insights into the obstacles and opportunities related to sustainable SWM. The tdCS approach allowed students to gain comprehensive and in-depth knowledge about the SWM system required to set priorities for action and next steps. The government should streamline the different financial frameworks according to a clear principle (e.g., polluter pays principle). Specific biogenic waste streams represent a potential source of energy and fertilizers. Expanding the scope and densifying the network of collection points could help raise recycling rates of other waste fractions. Diverting biogenic waste and recycling more glass, metals, paper, and plastics would also significantly reduce landfilling rates. Regardless of future amounts of waste ending up on landfills, the latter must be reengineered before the surrounding environment suffers major adverse impacts. All these actions imply a government-driven approach which integrates the views of stakeholders and consumers alike.     

Distribution-based effects of disaggregated GDP and environmental quality—a case of quantile on quantile estimates

Environmental Science and Pollution Research - There is a strong association between environmental quality and economic activity. Empirical studies term this relationship as environmental Kuznets...     

Study on the threshold relationship between landscape pattern and water quality considering spatial scale effect—a case study of Dianchi Lake Basin in China

Environmental Science and Pollution Research - It is of great significance to analyze the threshold relationship between landscape pattern and water quality for watershed water environment...     

Impact of financial development and technological innovation on the volatility of green growth—evidence from China

Environmental Science and Pollution Research - China’s green growth has shown a trend of fluctuation year by year. Simultaneously, Chinese local governments have pursued simple economic...     

Impacts of urbanization at city cluster scale on ecosystem services along an urban–rural gradient: a case study of Central Yunnan City Cluster,China

Environmental Science and Pollution Research - Urban agglomeration will be the main mode of future urbanization in China, greatly influencing social and economic development and ecosystem...