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Heavy metals in untreated/treated urban effluent and sludge from a biological wastewater treatment plant Full text
2007
da Silva Oliveira, Aline | Bocio, Ana | Beltramini Trevilato, Tânia M. | Magosso Takayanagui, Angela M. | Domingo, José L. | Segura-Muñoz, Susana I.
BACKGROUND, AIM AND SCOPE: The presence of heavy metals in wastewater is one of the main causes of water and soil pollution. The aim of the present study was to investigate the removal of Cd, Cu, Pb, Hg, Mn, Cr and Zn in urban effluent by a biological wastewater treatment, as well as to quantify the levels of As, Be, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sn, Tl, V and Zn in dewatering sludge from the Biological Wastewater Treatment Plant to Ribeirão Preto (RP-BWTP), Brazil. MATERIALS AND METHODS: Concentrations of Cd, Cr, Cu, Mn and Pb in wastewater and those of Ni in sludge were determined by atomic absorption spectrophotometry with graphite furnace atomization. Mercury concentrations in wastewater were measured by hydride generation atomic spectrophotometry, and Zn levels were determined by atomic absorption spectrophotometry using acetylene flame. In sludge, the levels of As, Be, Cd, Cr, Cu, Fe, Hg, Mn, Pb, Sn, Tl, V and Zn were determined by inductively coupled plasma-mass spectrometry. RESULTS: The percentages of removal efficiency (RE) were the following: Hg 61.5%, Cd 60.0%, Zn 44.9%, Cu 44.2%, PB 39.7%, Cr 16,5% and Mn 10.4%. In turn, the mean concentrations (mg/kg) of metals in dewatering sludge followed this increasing order: Tl (<0.03), Hg (0.31), Be (0.43), As (1.14), Cd (1.34), V (59.2), Pb (132.1), Sn (166.1), Cr (195.0), Mn (208.1), Ni (239.4), Cu (391.7), Zn (864.4) and Fe (20537). DISCUSSION: The relationship between metal levels in untreated wastewater, as well as the removal efficiency are in agreement with previous data from various investigators, It is important to note that metal removal efficiency is not only affected by metal ion species and concentration, but also by other conditions such as operating parameters, physical, chemical, and biological factors. CONCLUSIONS: Metal values recorded for treated wastewater and sludge were within the maximum permitted levels established by the Environmental Sanitation Company (CETESB), São Paulo, Brazil. RECOMMENDATIONS: There is an urgent need for the authorities who are responsible for legislation on sludge uses in agriculture of establishing safety levels for As, Be, Hg, Sn, Tl and V. PERSPECTIVES: According to the current metal levels, RP-BWTP sludge might be used for agriculture purposes. However, for an environmentally safe use of sewage sludge, further studies including systematic monitoring are recommended. Annual metal concentrations and predicted variations of those elements in the sludge should be monitored.
Show more [+] Less [-]The OECD Validation Program of the H295R Steroidogenesis Assay for the Identification of In Vitro Inhibitors and Inducers of Testosterone and Estradiol Production. Phase 2: Inter-Laboratory Pre-Validation Studies (8 pp) Full text
2007
Hecker, Markus | Hollert, Henner | Cooper, R. (Ralph) | Vinggaard, Anne-Marie | Akahori, Yumi | Murphy, Margaret | Nellemann, Christine | Higley, Eric | Newsted, John | Wu, Rudolph | Lam, Paul | Laskey, John | Buckalew, Angela | Grund, Stefanie | Nakai, Makoto | Timm, Gary | Giesy, John
BACKGROUND: Goals and Scope. In response to concerns that have been raised about chemical substances that may alter the function of endocrine systems and result in adverse effects on human health, an OECD initiative was undertaken to develop and validate in vitro and in vivo assays to identify chemicals that may interfere with endocrine systems of vertebrates. Here we report on studies that were conducted to develop and standardize a cell-based screening assay using the H295R cell line to prioritize chemicals that may act on steroidogenic processes in humans and wildlife. These studies are currently ongoing as part of the 'Special Activity on the Testing and Assessment of Endocrine Disruptors' within the OECD Test Guidelines Program to review, develop, standardize, and validate a number of in vitro and in vivo toxicological assays for testing and assessment of chemicals concerning their potential to interact with the endocrine system of vertebrates. -: Study Design. Six laboratories from five countries participated in the pre-validation studies. Each laboratory tested the effects of three model chemicals on the production of testosterone (T) and estradiol (E2) using the H295R Steroidogenesis Assay. Chemicals tested were well described inducers or inhibitors of steroidogenic pathways (forskolin, prochloraz and fadrozole). All experiments were conducted in 24 well plates following standard protocols. Six different doses per compound were analyzed in triplicate per plate. A quality control (QC) plate was run in conjunction with the chemical exposure plate to account for inter-assay variation. Each chemical exposure was conducted two or three times. RESULTS: All laboratories successfully detected increases and/or decreases in hormone production by H295R cells after exposure to the different model compounds and there was good agreement in the pattern of response for all groups. Forskolin increased both T and E2 while fadrozole and prochloraz decreased production of both hormones. All chemicals affected hormone production in a dose-response manner with the exception of fadrozole which caused maximum inhibition of E2 at the two least concentrations tested. Some inter-laboratory differences were noted in the alteration of hormone production measured in chemically exposed cells. However, with the exception of the production of T measured at one laboratory in cells exposed to forskolin, the EC50s calculated were comparable (coefficients of variation 34-49%) for all hormones. DISCUSSION: and Perspectives. The results indicated that the H295R Steroidogenesis Assay protocol was robust, transferable and reproducible across all laboratories. However, in several instances that were primarily related to one laboratory there were unexplained minor uncertainties related to the inter-laboratory hormone production variation. Based on the findings from this Phase 2 pre-validation study, the H295R Steroidogenesis Assay protocol is currently being refined. The next phase of the OECD validation program will test the refined protocol across the same group of laboratories using an extended set of chemicals (~30) that will include positive and negative chemical controls as well as a broad spectrum of different potential inducers and inhibitors of steroidogenic pathways.
Show more [+] Less [-]Organic Contaminants from Sewage Sludge Applied to Agricultural Soils. False Alarm Regarding Possible Problems for Food Safety? (8 pp) Full text
2007
Laturnus, Frank | von Arnold, Karin | Grøn, Christian
GOAL, SCOPE AND BACKGROUND: Sewage sludge produced in wastewater treatment contains large amounts of organic matter and nutrients and could, therefore, be suitable as fertiliser. However, with the sludge, besides heavy metals and pathogenic bacteria, a variety of organic contaminants can be added to agricultural fields. Whether the organic contaminants from the sludge can have adverse effects on human health and wildlife if these compounds enter the food chain or groundwater still remains a point of controversial discussion. MAIN FEATURES: This paper presents an overview on the present situation in Europe and a summary of some recent results on the possible uptake of organic contaminants by crops after addition to agricultural fields by sewage sludge. RESULTS: Greenhouse experiments and field trials were performed to study the degradation and uptake of organic micro-contaminants in sludge-amended agricultural soil in crops, such as barley and carrots grown in agricultural soil amended with anaerobically-treated sewage sludge from a wastewater treatment plant, but studies hitherto have revealed no immediate risks. Common sludge contaminants such as linear alkylbenzene sulphonates (LAS), nonylphenol ethoxylates (NPE), polycyclic aromatic hydrocarbons (PAH), bis(diethylhexyl) phthalate (DEHP), showed neither accumulation in soil nor uptake in plants. DISCUSSION: It is assumed that the annual amount of sewage sludge produced in Europe will increase in the future, mainly due to larger amounts of high quality drinking water needed by an increasing population and due to increasing demands for cleaner sewage water. Application of sewage sludge to agricultural soils is sustainable and economical due to nutrient cycling and disposal of sewage sludge. However, this solution also involves risks with respect to the occurrence of organic contaminants and other potentially harmful contents such as pathogens and heavy metals present in the sludge. There have been concerns that organic contaminants may accumulate in the soil, be taken up by plants and thereby transferred to humans via the food chain. Results obtained so far revealed, however, no immediate risk of accumulation of common organic sludge contaminants in soil or uptake in plants when applying sewage sludge to agricultural soil. With very high dosages of sewage sludge, there may be a risk for accumulation of very apolar contaminants, such as DEHP, to the soil. CONCLUSIONS: Any conclusions on the safe use of sewage sludge in agriculture have to be drawn carefully, as the studies performed until now have been limited. Further studies are required, and before final statements can be drawn, it is imminent to study a larger variety of common crops and the effect sewage sludge application may have on a possible accumulation of organic contaminants in the crops. Furthermore, a larger variety of organic contaminants need to be studied and special focus should be given to contaminants newly introduced into the environment. Besides investigating possible plant uptake of organic contaminants, the fate of these compounds in soil after sludge application need to be monitored too. Here, special attention has to be given to studies on degradation and the formation of degradation products, to weathering and to leaching effects on groundwater, to the application of different crops on the same field (crop rotation), to the use of full-width tillage and strip tillage, and to long term application of sewage sludge on the soil. RECOMMENDATIONS AND PERSPECTIVE: There are environmental, political as well as economical incentives to increase the agricultural application of sludge. However, such usage should be performed with care as there are also ways in which sludge fertilisation could harm the environment and human health. Recently, a new European COST Action (859) has been established covering the field of food safety and improved food quality. Part of the Action is dealing with the application of sewage sludge in agriculture. Before any political and economical measures can be taken, the pros and cons have to be sufficiently investigated on a scientific level first.
Show more [+] Less [-]An Estimate of Biogenic Emissions of Volatile Organic Compounds during Summertime in China (7 pp) Full text
2007
BACKGROUND AND AIM: An accurate estimation of biogenic emissions of VOC (volatile organic compounds) is necessary for better understanding a series of current environmental problems such as summertime smog and global climate change. However, very limited studies have been reported on such emissions in China. The aim of this paper is to present an estimate of biogenic VOC emissions during summertime in China, and discuss its uncertainties and potential areas for further investigations. MATERIALS AND METHODS: This study was mainly based on field data and related research available so far in China and abroad, including distributions of land use and vegetations, biomass densities and emission potentials. VOC were grouped into isoprene, monoterpenes and other VOC (OVOC). Emission potentials of forests were determined for 22 genera or species, and then assigned to 33 forest ecosystems. The NCEP/NCAR reanalysis database was used as standard environmental conditions. A typical summertime of July 1999 was chosen for detailed calculations. RESULTS AND DISCUSSION: The biogenic VOC emissions in China in July were estimated to be 2.3×1012gC, with 42% as isoprene, 19% as monoterpenes and 39% as OVOC. About 77.3% of the emissions are generated from forests and woodlands. The averaged emission intensity was 4.11 mgC m-2 hr-1 for forests and 1.12 mgC m-2 hr-1 for all types of vegetations in China during the summertime. The uncertainty in the results arose from both the data and the assumptions used in the extrapolations. Generally, uncertainty in the field measurements is relatively small. A large part of the uncertainty mainly comes from the taxonomic method to assign emission potentials to unmeasured species, while the ARGR method serves to estimate leaf biomass and the emission algorithms to describe light and temperature dependence. CONCLUSIONS: This study describes a picture of the biogenic VOC emissions during summertime in China. Due to the uneven spatial and temporal distributions, biogenic VOC emissions may play an important role in the tropospheric chemistry during summertime. RECOMMENDATIONS AND PERSPECTIVE: Further investigations are needed to reduce uncertainties involved in the related factors such as emission potentials, leaf biomass, species distribution as well as the mechanisms of the emission activities. Besides ground measurements, attention should also be placed on other techniques such as remote-sensing and dynamic modeling. These new approaches, combined with ground measurements as basic database for calibration and evaluation, can hopefully provide more comprehensive information in the research of this field.
Show more [+] Less [-]Production of Ethanol by an Integrated Valorization of Olive Oil Byproducts. The Role of Phenolic Inhibition (2 pp) Full text
2007
Zanichelli, Dario | Carloni, Francesco | Hasanaj, Ermal | D’Andrea, Nausica | Filippini, Alexander | Setti, Leonardo
BACKGROUND, AIM AND SCOPE: Agricultural industrial wastes can frequently be used as raw materials in the production of bio-fuels. Olive-oil milling wastewater is considered as one of the most polluting agro-industrial residues, but fortunately due to its high content of organic matter, it has the potential to be a valuable starting material to obtain bio-ethanol via fermentation with Saccharomyces cerevisiae. The fermentation of olive-oil milling wastewater has been demonstrated with good yield of ethanol (8-12%v/v) once the level of reducing sugars is appropriate and the phenolic fraction, which inhibits the yeast, is removed.Materials and Methods:-Results:-Discussion:-Conclusions:-Recommendations and Perspectives:-
Show more [+] Less [-]Simulated Effects of Acidic Solutions on Element Dynamics in Monsoon Evergreen Broad-leaved Forest at Dinghushan, China - Part 1: Dynamics of K, Na, Ca, Mg and P (7 pp) Full text
2007
Liu, Juxiu
Background, Aim and Scope Acid deposition has become a concern in south China in recent years. This phenomenon has increased to a dramatic extent with the large use of cars and coal- fueled power plants. As a consequence, soils are becoming acidified and their element dynamics will change. A decrease in the nutrient availability will lead to slower plant growth and maybe to a change in the forest type with current species being replaced by new ones with less nutrient requirements. Because of these reasons, it is important to understand how the dynamics of elements will change and what mechanism is part of the process. This knowledge is important for modeling the acidification process and either finding ways to counter it or to predict its consequences. The primary purpose of this study was to provide information about how the dynamics of K, Na, Ca, Mg and P are affected by acid deposition in a typical forest in southern China. Materials and Methods: Experimental soils and saplings were collected directly from the monsoon evergreen broad-leaved forest in Dinghushan. All saplings were transplanted individually into ceramic pots in August 2000 and placed in an open area near their origin site. Pot soils were treated weekly from October, 2000 to July, 2002 with an acidic solution at pH 3.05, pH 3.52, pH 4.00 or pH 4.40, or with tap water as a control. The concentrations of SO42-, NO3-, K+, Na+, Ca2+, Mg2+ and available P and the pH were measured in soil and leachate samples taken at different times. The sapling leaves were collected and their element concentrations were measured at the end of the experiment. Results: Concentrations of soil exchangeable Ca and Mg decreased quickly over time, although only Ca showed changes with the acidic solution treatment and soil exchangeable K was stable because of soil weathering. Leaching of K, Mg and Ca was dependent upon the treatment acidity. Soil available P decreased slowly without any correlation with the acidity of the treatment. All the NO3- added by the treatment was taken up by the plants, but the SO42- added accumulated in the soil. Discussion: Amongst the plant species, Schima superba was little affected by the treatment, the leaf P content was affected in Acmena acuminatissima plants and Cryptocarya concinna was the most susceptible species to soil acidification, with a marked decrease of the leaf K, Ca and Mg concentrations when the treatment acidity increased. Conclusions: Simulated acid deposition affected the dynamics of K, Ca and Mg in the monsoon evergreen broad-leaved forest. The dynamics of Ca in the soil and of K, Mg and Ca in the soil leachates were affected by the acidic solution treatment. If such a soil acidification occurs, Cryptocarya concinna will be amongst the first affected species, but Schima superba will be able to sustain a good growth and mineral nutrition. Recommendations and Perspectives: Acid deposition will lead to imbalance the nutrient elements in the evergreen broad-leaved forest because of accelerated leaching losses of soil exchangeable Ca and Mg. Measures should be developed to slow down soil acidification or nutrient decrease.
Show more [+] Less [-]Chernobyl -- what have we learned?
2007
Onishi, Yasuo | Voĭt︠s︡ekhovich, O. V. (Oleg V) | Zheleznyak, Mark J.
Groundwater pollution and emerging environmental challenges of industrial effluent irrigation in Mettupalayam Taluk, Tamil Nadu
2007
Mukherjee, S. | Nelliyat, P.
Industrial disposal of effluents on land and the subsequent pollution of groundwater and soil of surrounding farmlands ? is a relatively new area of research. The environmental and socioeconomic aspects of industrial effluent irrigation have not been studied as extensively as domestic sewage based irrigation practices, at least for a developing country like India. The disposal of effluents on land has become a regular practice for some industries. Industries located in Mettupalayam Taluk, Tamil Nadu, dispose their effluents on land, and the farmers of the adjacent farmlands have complained that their shallow open wells get polluted and also the salt content of the soil has started building up slowly. This study attempts to capture the environmental and socioeconomic impacts of industrial effluent irrigation in different industrial locations at Mettupalayam Taluk, Tamil Nadu, through primary surveys and secondary information. This study found that the continuous disposal of industrial effluents on land, which has limited capacity to assimilate the pollution load, has led to groundwater pollution. The quality of groundwater in shallow open wells surrounding the industrial locations has deteriorated, and the application of polluted groundwater for irrigation has resulted in increased salt content of soils. In some locations drinking water wells (deep bore wells) also have a high concentration of salts. Since the farmers had already shifted their cropping pattern to salt-tolerant crops (like jasmine, curry leaf, tobacco, etc.) and substituted their irrigation source from shallow open wells to deep bore wells and/or river water, the impact of pollution on livelihoods was minimized. Since the local administration is supplying drinking water to households, the impact in the domestic sector has been minimized. It has also been noticed that in some locations industries are supplying drinking water to the affected households. However, if the pollution continues unabated it could pose serious problems in the future.
Show more [+] Less [-]Report on water quality survey and pollution in Kurunegala, Sri Lanka
2007
Dissanayake, Priyanka | Clemett, Alexandra | Jayakody, Priyantha | Amerasinghe, Priyanie H.
This project is funded by the European Commission under its Asia Pro Eco II Program. It is undertaken by the International Water Management Institute (IWMI), Sri Lanka; COSI, Sri Lanka; the International Water and Sanitation Centre (IRC), the Netherlands; NGO Forum for Drinking Water Supply and Sanitation, Bangladesh; and the Stockholm Environment Institute (SEI), Sweden. The project pilot cities are Rajshahi City in Bangladesh and Kurunegala City in Sri Lanka.
Show more [+] Less [-]Concentrations of PBDE and BDE congeners in adipose tissue of East Greenland polar bears (Ursus maritimus) Full text
2007
Dietz, Rune | Rigét, Frank F | Sonne, Christian | Letcher, Robert J | Backus, S | Born, Erik W | Kirkegaard, Maja | Muir, Derek C G
Polybrominated diphenyl ethers (PBDEs) were analysed in adipose tissue from 92 East Greenland polar bears (Ursus maritimus) sampled during 1999-2001. Mean SumPBDE concentrations were 70 ng/g lipid weight (lw) (range: 22-192 ng/g lw) and showed no relationship with age or sex. Of the 32 analysed PBDE congeners; BDE47, BDE153, BDE99 and BDE100 dominated, and comprised 99.6% of the SumPBDE concentration. The SumPBDE concentration had a highly significant correlation with SumPCB, SumCHL, dieldrin, HCB and SumHCH concentrations. We found a seasonal pattern of median SumPBDE concentration with 1.2 to 1.8 times higher concentrations in March to July than the rest of the year. The seasonal variation also provides a clue to the seasonal exposure, bio-availability, toxic exposure and degradation. We suggest that future geographical PBDE data comparisons may not need corrections for sex or age, but such data sets should be corrected for seasonal variability, using the presented correctional trigonometric regression.
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