Multi-biochemical responses of benthic macroinvertebrate species as a complementary tool to diagnose the cause of community impairment in polluted rivers

Biological indexes, based on benthic macroinvertebrate taxa, are currently used worldwide to measure river ecological quality. These indexes assign a global ecological status of the biotic community, but not necessarily may detect specific effects of water pollutants. Conversely a large set of biochemical markers measured in macroinvertebrate benthic species can detect sublethal effects and inform us about additional environmental factors that are impairing benthic communities. This is especially interesting in moderately polluted sites, where other stressors are already affecting communities but not too strongly to be detected by biotic indexes. Up to ten different markers belonging to distinct metabolic paths and 42 contaminants measured in sample collections of the caddis fly Hydropsyche exocellata were assessed across a polluted gradient in the industrialized Mediterranean River basins of Besós and Llobregat (NE, Spain). Twenty four sample collections were selected to include macroinvertebrate communities representing the five impairment degrees defined by the Spanish Environmental authorities using the biotic metrics. Results evidenced a clear deterioration of the ecological water quality parameters and benthic communities towards downstream reaches. Biochemical responses varied significantly across the studied samples and were able to differentiate samples within communities having a good and deteriorated ecological stage. Principal Component Analyses indicated that salinity was one of the major stresses affecting macroinvertebrate assemblages, whereas antioxidant and metabolizing enzymes responded differently and were closely related to high and presumably toxic levels of accumulated organic pollutants. Therefore these results indicate that the use of multiple -markers sensitive to water pollution may provide complementary information to diagnose environmental factors that are impairing macroinvertebrate communities.     

Measurement of protein-like fluorescence in river and waste water using a handheld spectrophotometer

Protein-like fluorescence intensity in rivers increases with increasing anthropogenic DOM inputs from sewerage and farm wastes. Here, a portable luminescence spectrophotometer was used to investigate if this technology could be used to provide both field scientists with a rapid pollution monitoring tool and process control engineers with a portable waste water monitoring device, through the measurement of river and waste water tryptophan-like fluorescence from a range of rivers in NE England and from effluents from within two waste water treatment plants. The portable spectrophotometer determined that waste waters and sewerage effluents had the highest tryptophan-like fluorescence intensity, urban streams had an intermediate tryptophan-like fluorescence intensity, and the upstream river samples of good water quality the lowest tryptophan-like fluorescence intensity. Replicate samples demonstrated that fluorescence intensity is reproducible to +/- 20% for low fluorescence, 'clean' river water samples and +/- 5% for urban water and waste waters. Correlations between fluorescence measured by the portable spectrophotometer with a conventional bench machine were 0.91; (Spearman's rho, n = 143), demonstrating that the portable spectrophotometer does correlate with tryptophan-like fluorescence intensity measured using the bench spectrophotometer.     

Effect of Antarctic solar radiation on sewage bacteria viability

The majority of coastal Antarctic research stations discard untreated sewage waste into the near-shore marine environment. However, Antarctic solar conditions are unique, with ozone depletion increasing the proportion of potentially damaging ultraviolet-B (UV-B) radiation reaching the marine environment. This study assessed the influence of Antarctic solar radiation on the viability of Escherichia coli and sewage microorganisms at Rothera Research Station, Adelaide Island, Antarctic Peninsula. Cell viability decreased with increased exposure time and with exposure to shorter wavelengths of solar radiation. Cell survival also declined with decreasing cloud cover, solar zenith angle and ozone column depth. However, particulates in sewage increased the persistence of viable bacteria. Ultraviolet radiation doses over Rothera Point were highest during the austral summer. During this time, solar radiation may act to partially reduce the number of viable sewage-derived microorganisms in the surface seawater around Antarctic outfalls. Nevertheless, this effect is not reliable and every effort should be made to fully treat sewage before release into the Antarctic marine environment.     

In-pipe water quality monitoring in water supply systems under steady and unsteady state flow conditions: a quantitative assessment

Monitoring the quality of drinking water from the treatment plant to the consumers tap is critical to ensure compliance with national standards and/or WHO guideline levels. There are a number of processes and factors affecting the water quality during transmission and distribution which are little understood. A significant obstacle for gaining a detailed knowledge of various physical and chemical processes and the effect of the hydraulic conditions on the water quality deterioration within water supply systems is the lack of reliable and low-cost (both capital and O & M) water quality sensors for continuous monitoring. This paper has two objectives. The first one is to present a detailed evaluation of the performance of a novel in-pipe multi-parameter sensor probe for reagent- and membrane-free continuous water quality monitoring in water supply systems. The second objective is to describe the results from experimental research which was conducted to acquire continuous water quality and high-frequency hydraulic data for the quantitative assessment of the water quality changes occurring under steady and unsteady-state flow conditions. The laboratory and field evaluation of the multi-parameter sensor probe showed that the sensors have a rapid dynamic response, average repeatability and unreliable accuracy. The uncertainties in the sensor data present significant challenges for the analysis and interpretation of the acquired data and their use for water quality modelling, decision support and control in operational systems. Notwithstanding these uncertainties, the unique data sets acquired from transmission and distribution systems demonstrated the deleterious effect of unsteady state flow conditions on various water quality parameters. These studies demonstrate: (i) the significant impact of the unsteady-state hydraulic conditions on the disinfectant residual, turbidity and colour caused by the re-suspension of sediments, scouring of biofilms and tubercles from the pipe and increased mixing, and the need for further experimental research to investigate these interactions; (ii) important advances in sensor technologies which provide unique opportunities to study both the dynamic hydraulic conditions and water quality changes in operational systems. The research in these two areas is critical to better understand and manage the water quality deterioration in ageing water transmission and distribution systems.     

Evaluation of an attempt to cultivate shrubs and trees on a heap of a potash mine

Starting at the end of November 1993, the Dr. Kahl GmbH has attempted to grow shrubs (Amorpha: Amorpha fructuosa and snow-berry: Symphoricarpos rivularis) and trees (poplar hybrid ‘University of Idaho’ Populus deltoides and Eleagnus angustifolia), on the heap of the potash mine Sondershausen/Harz (Free state of Thuringia). Patented water-saving planting method was used. A flexible planting container made of polyethylene was first filled with 50 g polyacrylamide (also called ‘hydrogel’) and after that with about 40 kg of a mixture of anhydrite (CaSO₄) — the mean soil of the heap — and dried sewage sludge, respectively, composted sewage sludge on top of the hydrogel. After placing the container into the ground, one-year-old seedlings of the shrubs or trees were planted into the containers. Five years after planting investigations on the plants and soil were started. The results until now show that, using the planting method, Amorpha, the poplar ‘University of Idaho’ and the Eleagnus are able to grow under the poor conditions of the heap.     

Evaluation of public health risks at recreational beaches in Lake Michigan via detection of enteric viruses and a human-specific bacteriological marker

Each year the National Resource Defense Council addresses the quality of US beaches by routine bacterial indicators. In the Great Lakes region the indicator used is Escherichia coli and for 2007 more beaches were closed and impacted than ever before. In this study, water quality was addressed at two Lake Michigan Beaches over the 2004 swimming season by monitoring infectious enteric viruses by cell culture and integrated PCR and for a human sewage marker based on the Enterococcal Surface Protein (esp). Our goals for this study were to 1) examine the occurrence and variety of human enteric viruses present during peak usage of the beaches 2) determine key variables for development of predictive models for viruses; and 3) use quantitative risk assessment to estimate the potential health impact. Our results demonstrate that for both beaches predictive models of virus pollution were best described utilizing physical parameters like wind speed, wind direction and water temperature. The esp marker was not predictive of human viruses. The daily risk of acquiring a viral infection at either of the beaches ranged from 0.2 to 2.4/1000 swimmers using a quantitative microbial risk assessment model, with three swims during a day at the beach for children and over the season, the risk was 9-15/1000 swimmers using adenovirus as the model.Conclusions: Lake Michigan recreational beaches are being adversely impacted by human fecal pollution. Monitoring for the traditional indicators of water quality does not address viral risks and models can be developed and potentially used as real-time water quality forecasting tools.     

In situ disinfection of sewage contaminated shallow groundwater: a feasibility study

Sewage-contaminated shallow groundwater is a potential cause of beach closures and water quality impairment in marine coastal communities. In this study we set out to evaluate the feasibility of several strategies for disinfecting sewage-contaminated shallow groundwater before it reaches the coastline. The disinfection rates of Escherichia coli (EC) and enterococci bacteria (ENT) were measured in mixtures of raw sewage and brackish shallow groundwater collected from a coastal community in southern California. Different disinfection strategies were explored, ranging from benign (aeration alone, and aeration with addition of brine) to aggressive (chemical disinfectants peracetic acid (PAA) or peroxymonosulfate (Oxone)). Aeration alone and aeration with brine did not significantly reduce the concentration of EC and ENT after 6 h of exposure, while 4-5 mg L⁻¹ of PAA or Oxone achieved >3 log reduction after 15 min of exposure. Oxone disinfection was more rapid at higher salinities, most likely due to the formation of secondary oxidants (e.g., bromine and chlorine) that make this disinfectant inappropriate for marine applications. Using a Lagrangian modeling framework, we identify several factors that could influence the performance of in-situ disinfection with PAA, including the potential for bacterial regrowth, and the non-linear dependence of disinfection rate upon the residence time of water in the shallow groundwater. The data and analysis presented in this paper provide a framework for evaluating the feasibility of in-situ disinfection of shallow groundwater, and elucidate several topics that warrant further investigation.     

Subjective perceptions,symptom intensity and performance: a comparison of two independent studies,both changing similarly the pollution load in an office

The present paper shows that introducing or removing the same pollution source in an office in two independent investigations, one in Denmark and one in Sweden, using similar experimental methodology, resulted in similar and repeatable effects on subjective assessments of perceived air quality, intensity of sick building syndrome symptoms and performance of office work. Removing the pollution source improved the perceived air quality, decreased the perceived dryness of air and the severity of headaches, and increased typing performance. These effects were observed separately in each experiment and were all significant (P < or = 0.05) after combining the data from both studies, indicating the advantages of pollution source strength control for health, comfort, and productivity.     

Occurrence, molecular characterization and antibiogram of water quality indicator bacteria in river water serving a water treatment plant

Water pollution by microorganisms of fecal origin is a current world-wide public health concern. Total coliforms, fecal coliforms (Escherichia coli) and enterococci are indicators commonly used to assess the microbiological safety of water resources. In this study, influent water samples and treated water were collected seasonally from a water treatment plant and two major water wells in a Black Belt county of Alabama and evaluated for water quality indicator bacteria. Influent river water samples serving the treatment plant were positive for total coliforms, fecal coliforms (E. coli), and enterococci. The highest number of total coliform most probable number (MPN) was observed in the winter (847.5 MPN/100 mL) and the lowest number in the summer (385.6 MPN/100 mL). Similarly E. coli MPN was substantially higher in the winter (62.25 MPN/100 mL). Seasonal variation of E. coli MPN in influent river water samples was strongly correlated with color (R² = 0.998) and turbidity (R² = 0.992). Neither E. coli nor other coliform type bacteria were detected in effluent potable water from the treatment plant. The MPN of enterococci was the highest in the fall and the lowest in the winter. Approximately 99.7 and 51.5 enterococci MPN/100 mL were recorded in fall and winter seasons respectively. One-way ANOVA tests revealed significant differences in seasonal variation of total coliforms (P < 0.05), fecal coliforms (P < 0.01) and enterococci (P < 0.01). Treated effluent river water samples and well water samples revealed no enterococci contamination. Representative coliform bacteria selected by differential screening on Coliscan Easygel were identified by 16S ribosomal RNA gene sequence analysis. E. coli isolates were sensitive to gentamicin, trimethoprim/sulfamethazole, ciprofloxacin, vancomycin, tetracycline, ampicillin, cefixime, and nitrofurantoin. Nonetheless, isolate BO-54 displayed decreased sensitivity compared to other E. coli isolates. Antibiotic sensitivity pattern can be employed in microbial source tracking.     

Influence of bacteria on lanthanide and actinide transfer from specific soil components (humus, soil minerals and vitrified municipal solid waste incinerator bottom ash) to corn plants: Sr-Nd isotope evidence

Experiments have been performed to test the stability of vitrified municipal solid waste (MSW) incinerator bottom ash under the presence of bacteria (Pseudomonas aeruginosa) and plants (corn). The substratum used for the plant growth was a humus-rich soil mixed with vitrified waste. For the first time, information on the stability of waste glasses in the presence of bacteria and plants is given. Results show that inoculated plant samples contained always about two times higher lanthanide and actinide element concentrations. Bacteria support the element transfer since plants growing in inoculated environment developed a smaller root system but have higher trace element concentrations. Compared with the substratum, plants are light rare earth element (LREE) enriched. The vitrified bottom ash has to some extent been corroded by bacteria and plant activities as indicated by the presence of Nd (REE) and Sr from the vitrified waste in the plants. (87)Sr/(86)Sr and (143)Nd/(144)Nd isotope ratios of plants and soil components allow the identification of the corroded soil components and confirm that bacteria accelerate the assimilation of elements from the vitrified bottom ash. These findings are of importance for landfill disposal scenarios, and similar experiments should be performed in order to better constrain the processes of microbially mediated alteration of the MSW glasses in the biosphere.     

Water quality improvement in a full-scale tertiary constructed wetland: Effects on conventional and specific organic contaminants

The surface flow constructed wetland (SF CW) in Can Cabanyes (Granollers, Catalonia, northeastern Spain) was created as a part of a series of activities aimed at restoring a highly impacted fluvial peri-urban zone. The system is fed with a small part of the secondary effluent, which is not completely nitrified, from an urban wastewater treatment plant. Effluents in the SF CW were sampled between 2003 and 2006 for physical and chemical parameters and faecal bacteria indicators. In addition, 8 pharmaceuticals and personal care products (PPCPs) were measured in June 2005 and February 2006. The system showed a good reliability for ammonium and faecal bacteria removal, with average ammonium efficiencies between 64 and 87% and a removal of approximately 2 logarithmic units of Faecal Coliforms. A clear seasonal trend was observed for ammonium. The results for PPCPs demonstrated that the wetland has a good capacity for removing a large variety of these compounds; the removal efficiencies were higher than 70% for most of them, with the exception of clofibric acid (34%) and carbamazepine (39%). Although the chemical oxygen demand and total suspended solid removal rates were either low or zero because of the permanent eutrophic conditions of the system and the low incoming concentrations, the effluent quality is generally considered to be quite good.     

Effects of local climate and hydrological conditions on the thermal regime of a reservoir at Tropic of Cancer, in southern China

Thermal regime is strongly associated with hydrodynamics in water, and it plays an important role in the dynamics of water quality and ecosystem succession of stratified reservoirs. Changes in both climate and hydrological conditions can modify thermal regimes. Liuxihe Reservoir (23°45′50″N; 113°46′52″E) is a large, stratified and deep reservoir in Guangdong Province, located at the Tropic of Cancer of southern China. The reservoir is a warm monomictic water body with a long period of summer stratification and a short period of mixing in winter. The vertical distribution of suspended particulate material and nutrients are influenced strongly by the thermal structure and the associated flow fields. The hypolimnion becomes anoxic in the stratified period, increasing the release of nutrients from the bottom sediments. Fifty-one years of climate and reservoir operational observations are used here to show the marked changes in local climate and reservoir operational schemes. The data show increasing air temperature and more violent oscillations in inflow volumes in the last decade, while the inter-annual water level fluctuations tend to be more moderate. To quantify the effects of changes in climate and hydrological conditions on thermal structure, we used a numerical simulation model to create scenarios incorporating different air temperatures, inflow volumes, and water levels. The simulations indicate that water column stability, the duration of the mixing period, and surface and outflow temperatures are influenced by both natural factors and by anthropogenic factors such as climate change and reservoir operation schemes. Under continuous warming and more stable storage in recent years, the simulations indicate greater water column stability and increased duration of stratification, while irregular large discharge events may reduce stability and lead to early mixing in autumn. Our results strongly suggest that more attention should be focused on water quality in years of extreme climate variation and hydrological conditions, and selective withdrawal of deep water may provide an efficient means to reduce internal loading in warm years.     

Confirmation of putative stormwater impact on water quality at a Florida beach by microbial source tracking methods and structure of indicator organism populations

The effect of a stormwater conveyance system on indicator bacteria levels at a Florida beach was assessed using microbial source tracking methods, and by investigating indicator bacteria population structure in water and sediments. During a rain event, regulatory standards for both fecal coliforms and Enterococcus spp. were exceeded, contrasting with significantly lower levels under dry conditions. Indicator bacteria levels were high in sediments under all conditions. The involvement of human sewage in the contamination was investigated using polymerase chain reaction (PCR) assays for the esp gene of Enterococcus faecium and for the conserved T antigen of human polyomaviruses, all of which were negative. BOX-PCR subtyping of Escherichia coli and Enterococcus showed higher population diversity during the rain event; and higher population similarity during dry conditions, suggesting that without fresh inputs, only a subset of the population survives the selective pressure of the secondary habitat. These data indicate that high indicator bacteria levels were attributable to a stormwater system that acted as a reservoir and conduit, flushing high levels of indicator bacteria to the beach during a rain event. Such environmental reservoirs of indicator bacteria further complicate the already questionable relationship between indicator organisms and human pathogens, and call for a better understanding of the ecology, fate and persistence of indicator bacteria.     

The Effects of a Timber Preservative Spillage on the Ecology of the River Lossie

This study examines the effects of timber preservative spillages on the ecology of the River Lossie whilst the river's quality was recovering following the removal of an unsatisfactory discharge of sewage effluent. The effects of spillages on a minor tributary of the River Lossie are also presented.     

Non-linear effects on solute transfer between flowing water and a sediment bed

A previously developed model of periodic pore water flow in space and time, and associated solute transport in a stream bed of fine sand is extended to coarse sand and fine gravel. The pore water flow immediately below the sediment/water interface becomes intermittently a non-Darcy flow. The periodic pressure and velocity fluctuations considered are induced by near-bed coherent turbulent motions in the stream flow; they penetrate from the sediment/water interface into the sediment pore system and are described by a wave number (χ) and a period (T) that are given as functions of the shear velocity (U_∗) between the flowing water and the sediment bed. The stream bed has a flat surface without bed forms. The flow field in the sediment pore system is described by the continuity equation and a resistance law that includes both viscous (Darcy) and non-linear (inertial) effects. Simulation results show that non-linear (inertial) effects near the sediment/water interface increase flow resistance and reduce mean flow velocities. Compared to pure Darcy flow, non-linear (inertial) effects reduce solute exchange rates between overlying water and the sediment bed but only by a moderate amount (less than 50%). Turbulent coherent flow structures in the stream flow enhance solute transfer in the pore system of a stream bed compared to pure molecular diffusion, but by much less than standing surface waves or bed forms.     

Rapid effects of diverse toxic water pollutants on chlorophyll a fluorescence: variable responses among freshwater microalgae

Chlorophyll a fluorescence of microalgae is a compelling indicator of toxicity of dissolved water contaminants, because it is easily measured and responds rapidly. While different chl a fluorescence parameters have been examined, most studies have focused on single species and/or a narrow range of toxins. We assessed the utility of one chl a fluorescence parameter, the maximum quantum yield of PSII (F_v/F_m), for detecting effects of nine environmental pollutants from a range of toxin classes on 5 commonly found freshwater algal species, as well as the USEPA model species, Pseudokirchneriella subcapitata. F_v/F_m declined rapidly over <20 min in response to low concentrations of photosynthesis-specific herbicides Diuron^® and metribuzin (both <40 nM), atrazine (<460 nM) and terbuthylazine (<400 nM). However, F_v/F_m also responded rapidly and in a dose-dependent way to toxins glyphosate (<90 μM), and KCN (<1 mM) which have modes of action not specific to photosynthesis. F_v/F_m was insensitive to 30-40 μM insecticides methyl parathion, carbofuran and malathion. Algal species varied in their sensitivity to toxins. No single species was the most sensitive to all nine toxins, but for six toxins to which algal F_v/F_m responded significantly, the model species P. subcapitata was less sensitive than other taxa. In terms of suppression of F_v/F_m within 80 min, patterns of concentration-dependence differed among toxins; most showed Michaelis-Menten saturation kinetics, with half-saturation constant (K_m) values for the PSII inhibitors ranging from 0.14 μM for Diuron^® to 6.6 μM for terbuthylazine, compared with a K_m of 330 μM for KCN. Percent suppression of F_v/F_m by glyphosate increased exponentially with concentration. F_v/F_m provides a sensitive and easily-measured parameter for rapid and cost-effective detection of effects of many dissolved toxins. Field-portable fluorometers will facilitate field testing, however distinct responses between different species may complicate net F_v/F_m signal from a community.     

Sustainability: A Clarion Call for a New Approach

Looking beyond the tickbox approach of green-rating systems that apply North American climatic criteria to a Brazilian context, Joana Carla Soares Gonçalves , a professor of environmental design at the Faculty of Architecture and Urbanism of the University of Sâo Paulo, advocates a more far-reaching way forward for sustainability in Brazil.     

Progress on sustainable development goal 6 in refugee camps in the Middle East: a comparative study

This paper examines the water and sanitation procedures taken in refugee camps to provide inclusive services, preserve the environment, and design out waste, based on empirical data collected using a questionnaire distributed in Iraq, Jordan, and Lebanon. Our study finds that refugees in Lebanon were the furthest left behind compared to refugees in Jordan and Iraq. Moreover, considering the culture of refugees, installing quality WASH services, and shifting from the traditional linear approach to the circular economy approach is an advantage in refugee camps that creates more resilience opportunities for refugees and their hosts. Without the concrete Partnership between governmental institutions, NGOs, and stakeholders, SDG6 and other related ones, including SDG3, SDG4 SDG5 and SDG8 will not be accomplished by 2030.