Montse Meneses

Environmental assessment of urban wastewater reuse: treatment alternatives and applications.

The main function of a Wastewater Treatment Plant is to minimize the environmental impact of discharging untreated water into natural water systems. Also a Wastewater Treatment Plant may get a resource from wastewater carrying out a tertiary treatment on the treated wastewater which can be reused in non-potable applications. Water reuse strategies are intended to address the problem of water scarcity without aggravating other environmental problems, thus reflecting the need of their environmental assessment. In this paper we used Life Cycle Assessment to evaluate different disinfection treatments (chlorination plus ultraviolet treatment, ozonation and ozonation plus hydrogen peroxide) and to assess the environmental advantages and drawbacks of urban wastewater reuse in non-potable applications. To do so, we compared the environmental impacts of producing 1m(3) of water for non-potable uses from reclaimed water, potable water and desalinated water sources. The calculation has used current operating data from a Wastewater Treatment Plant located in the Mediterranean area, although the results can be applied to any other plant with similar technology. The ozonation and ozonation plus hydrogen peroxide disinfection treatment technologies have similar environmental profiles. However most of the indicators are about 50% higher than the ultraviolet disinfection except for the acidification (100% higher) and photochemical oxidation (less than 5%). Non-potable uses (both agricultural and urban uses) of reclaimed water have environmental and economical advantages. Reuse of treated wastewater is particularly beneficial when it can replace desalinated water. Consequently, reclaimed water should be promoted for non-potable uses, when there is scarcity of freshwater.

Polybrominated diphenyl ethers detected in human adipose tissue from Spain.

Polybrominated diphenyl ethers (PBDEs) were detected in 13 human adipose tissue samples from Spain, 3 women and 10 men. Tetra-, penta- and hexabrominated diphenyl ethers were determined at ng/g lipid (ppb) level in all the samples. The average TeBDE level was 1.36 ng/g, the average PeBDE was 0.93 ng/g and the HxBDE 1.83 ng/g. Human adipose tissue levels of PBDE obtained in the current samples from Spain are comparable with the tissue levels reported in recent Swedish investigations.

The use of Monte-Carlo simulation techniques for risk assessment: study of a municipal waste incinerator

The incremental lifetime risks due to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) for the residents living in the surroundings of a municipal solid waste incinerator (MSWI) have been assessed. Two different pathways of exposure to PCDD/Fs, ingestion through the diet and exposure from MSWI emissions, were compared. Monte-Carlo simulations were carried out to obtain variability and uncertainty propagation The joint analysis of uncertainty and variability included a sensitivity analysis that identified the contribution to variance by different inputs. In general terms, PCDD/F ingestion through the diet contributed with more than 99% of the total risk, whereas direct exposition to PCDD/F emissions from the MSWI was less than 1% The results show that the median (50% percentile) of non-carcinogenic risk due to PCDD/Fs in the population living in the surroundings of the MSWI was 0.72 and the ratio of the 95th percentile and fifth percentile was about 2. With respect to the total carcinogenic risk, the median increment in individual lifetime was 7.90 x 10(-5) while the ratio between the 95th percentile and the fifth percentile was about 1.5. In this analysis, a sequential structural decomposition of the relationships between the input variables has been used to partition the variance in the output (risk) in order to identify the most influential contributors to overall variance among them.

Monitoring metals in the vicinity of a municipal waste incinerator: temporal variation in soils and vegetation.

The aim of this study was to determine the temporal variation in the concentrations of arsenic (As), beryllium (Be), cadmium (Cd), chromium (Cr), manganese (Mn), mercury (Hg), nickel (Ni), lead (Pb), tin (Sn), thallium (Tl), vanadium (V) and zinc (Zn) in soil and vegetation near an old municipal solid waste incinerator (MSWI). In October 1997, 24 soil and 24 herbage samples were collected at the same sampling points in which samples were also taken in October 1996. With the exception of an increase in the levels of Be and Ni, no significant differences in soils between both surveys were found; only Cr and V (decreases) and Hg (increase) showed significant variations in herbage samples during the last year. The concentrations of most elements in soil and vegetation samples collected near the MSWI are within the ranges previously reported for soil and vegetation in the vicinity of MSWIs.

Environmental assessment of the milk life cycle: The effect of packaging selection and the variability of milk production data

Milk is a very important part of our diet, which is why there is a wide variety of packaging alternatives with considerable local variants on the market. This study assesses the environmental impact of the commonest packaging options on the Spanish market and evaluates (from the point of view of global warming and acidification) the production of the various packaging materials and sizes and their final disposal (landfilling, incineration and recycling). For the two indicators studied (global warming and acidification) larger aseptic carton packages and recycling disposal have the best environmental impact. The global warming and acidification potential of the milk life cycle were also studied: milk production, transport (local conditions), packaging production and packaging disposal. Of the two indicators studied, the milk production stage has the largest impact on the milk life cycle. It should be taken into account that the impact of the milk production stage can vary considerably and has a significant influence on the global warming and acidification potential of the milk life cycle.

Alternatives for Reducing the Environmental Impact of the Main Residue from a Desalination Plant

One of the most important problems today is the scarcity of fresh water safe enough for human, industrial, and agricultural use. Desalination is an alternative source of fresh water supply in areas with severe problems of water availability. Desalination plants generate a huge amount of brine as the main residual from the plant (about 55% of collected seawater). Because of that, it is important to determine the best environmental option for the brine disposal. This article makes a global environmental analysis, under Spanish conditions, of a desalination plant and an environmental assessment of different final brine disposals, representing a range of the most common alternatives: direct disposal, wastewater treatment plant (WWTP) outflow dilution, and dilution with seawater. The environmental profile of the plant operation and a comparison of the brine final disposal alternatives were established by means of the life cycle assessment (LCA) methodology. From an analysis of the whole plant we observed that the highest environmental impact was caused by energy consumption, especially at the reverse osmosis stage, while the most relevant waste was brine. From an analysis of brine final disposal we have elaborated a comparison of the advantages and detriments of the three alternatives. As all of them might be suitable in different specific situations, the results might be useful in decisions about final brine disposal.

Monitoring dioxins and furans near an old municipal solid waste incinerator: Temporal variation in vegetation

Abstract To determine the temporal variation in the levels of polychlorinated dibenzo‐p‐dioxins (PCDDs) and dibenzofurans (PCDFs) in vegetation grown near an old municipal solid waste incinerator (Montcada, Barcelona, Spain), 24 herbage samples were collected at the same sampling points in which samples had been taken one year before. While in the previous survey PCDD/F concentrations ranged from 1.07 to 3.05 ng I‐TEQ/kg (dry matter) (median value: 1.88 ng I‐TEQ/kg, mean value: 1.92 ng I‐TEQ/kg), in the current samples PCDD/F levels ranged from 0.75 to 1.95 ng I‐TEQ/kg (dry matter) (median value: 1.27 ng I‐TEQ/kg, mean value: 1.30 ng I‐TEQ/kg). An individual comparison between PCDD/F concentrations in samples collected in both studies shows a decrease in all the sampling points with an average reduction of 32.3%. This reduction can be due to general abatement actions for PCDD/F emissions.

Sensitivity analysis in a life cycle assessment of an aged red wine production from Catalonia, Spain

Sustainability in agriculture and food processing is an issue with a clear growing interest; especially in products were consumers have particular awareness regarding its environmental profile. This is the case of wine industry depending on grape production, winemaking and bottling. Also viticulture and generally agricultural production is significantly affected by climate variations. The aim of this article is to determine the environmental load of an aged red wine from a winery in Catalonia, Spain, over its entire life cycle, including sensitivity analysis of the main parameters related to the cultivation, vinification and bottling. The life cycle assessment (LCA) methodology is used for the environmental analysis. In a first step, life cycle inventory (LCI) data were collected by questionnaires and interviews with the winemaker, all data are actual operating data and all the stages involved in the production have been taken into account (viticulture, vinification, bottling and the disposal subsystem). Data were then used to determine the environmental profile by a life cycle impact assessment using the ReCiPe method. Annual variability in environmental performance, stresses the importance of including timeline analysis in the wine sector. Because of that this study is accompanied with a sensitivity analysis carried out by a Monte Carlo simulation that takes into account the uncertainty and variability of the parameters used. In this manner, the results are presented with confidence intervals to provide a wider view of the environmental issues derived from the activities of the studied wine estate regardless of the eventualities of a specific harvesting year. Since the beverage packaging has an important influence in this case, a dataset for the production of green glass was adapted to reflect the actual recycling situation in Spain. Furthermore, a hypothetical variation of the glass-recycling rate in the glass production completes this article, as a key variable of sensitivity analysis, in order… in order to show the potential reduction of total greenhouse gas emissions. It was found that in almost all categories the production of the glass bottles has the highest environmental impact (10%-80% depending on the impact category) followed by the viticulture stage, i.e. the agricultural activities (17%-84% depending on the impact category). The vinification step, i.e. the winemaking itself, has an almost negligible effect on the overall load (1%-5%). The sensitivity analysis showed that the results do not differ by more than ±4% from the expected values except for the water depletion indicator. With the variation of the recycling rate, it could be shown that an increase in the rate from 60% to 85% allows for a reduction of 102gCO2eq. per bottle (-11.1%). The results show that glass production causes the highest environmental load. The key parameters that determine the impact are the recycling rate and the bottle weight. A glass container deposit legislation might be a promising way to enhance the glass recycling. Lightweight bottles and alternative packaging should also be considered.

Environmental evaluation of waste treatment scenarios for the towns Khanty-Mansiysk and Surgut, Russia

Khanty-Mansiysk Autonomous Okrug – Ugra in Siberia has recently started to play a major role in the Russian economy because key oil and gas extraction sites are located in this region. As a result, the extensions of infrastructure and higher incomes have been leading to an accelerated population growth and consequent increase in the generation of solid household waste. The current methods of waste disposal have now reached their limits, especially in the towns Khanty-Mansiysk and Surgut. The key objectives of this study were to identify the influence of waste composition and transport routes on the life cycle assessment (LCA) results and to assess the current waste treatment option for solid household waste and to compare it with proposed scenarios. Furthermore, recommendations for an optimal use of LCA within a decision-making process for a waste management plan are presented. LCA methodology was used to evaluate different waste management scenarios such as landfilling and incineration. One result was that the options ‘incineration with recycling’ and ‘anaerobic mechanical–biological treatment with recycling’ demonstrated lower environmental impact in both Khanty-Mansiysk and Surgut. Another finding was that there were hardly any differences in the ranking of the scenarios for Surgut and Khanty-Mansiysk. However, the special socio-cultural circumstances and location of each town have to be considered seriously in the development of a sustainable waste management plan.

Environmental analysis of Wastewater Treatment Plants Control strategies

In this paper the environmental impacts of 10 control strategies implemented in the Benchmark Simulation Model No. 1 (BSM1) are evaluated by using Life Cycle Analysis (LCA). The aim is to analyze their environmental profiles in order to identify the main flows contributors to those impacts and to find the existing correlations between the control strategies and the selected impact categories. The knowledge of these correlations allows to assess where are located the main environmental impacts product of the plants operation under the control strategies evaluated and to take actions in order to reduce them.