A study on the environmental degradation of pesticides azinphos methyl and parathion methyl

The effect of environmental parameters (temperature and relative humidity) on the degradation rate of azinphos methyl and parathion methyl was studied. Proprietary emulsifiable concentrates were diluted and added to each of 90 glass Petri dishes for each pesticide and were left overnight to dry. Petri dishes were placed in 18 air-tight containers (9 for each pesticide) in which were created environments with relative humidity (RH) of 60, 82, and 96%. The containers were stored at 0, 20, and 40 degrees C. From the experimental results best fit curves, kinetic equations, rate constants, and half-lives were calculated. Half-lives of azinphos methyl for the RH studied were, from 124 to 267 days at 0 degrees C, from 89 to 231 days at 20 degrees C, and from 25 to 71 days at 40 degrees C. Corresponding half-lives for parathion methyl were from 48 to 57 days at 0 degrees C, from 9.2 to 10.5 days at 20 degrees C and from 1.3 to 1.5 days at 40 degrees C. The results were correlated with relevant results from the decomposition of the same or similar pesticides on apples both, on the trees and during refrigerated storage. These correlations are suggesting that biological factors strongly affected the decomposition rate of azinphos methyl. On the contrary the decomposition of parathion methyl was mainly affected by environmental rather than biological factors.     

Metals removal from aqueous solution by iron-based bonding agents

GOAL AND SCOPE AND BACKGROUND: The application of a promising method, termed sorptive flotation, for the removal of chromium(VI) and zinc ions was the aim of the present paper. A special case of sorptive flotation is adsorbing colloid flotation. Suitable sorbent preparation techniques have been developed in the laboratory. METHODS: Sorptive flotation, consisting of the sorption and flotation processes combined in series, has proved to give fast and satisfactory treatment of the industrial streams and effluents bearing dilute aqueous solutions of zinc and chromium(VI). RESULTS AND DISCUSSION: Goethite has proved to be effective for the removal of chromium(VI) and zinc ions. Also, adsorbing colloid flotation with ferric hydroxide (as the co-precipitant) could be an alternative method to the above-mentioned separation of metal ions. In both cases, chromium(VI) (pH=4) and zinc (pH=7) removal was about 100%. CONCLUSION: The reasons for selecting the iron-based bonding materials, like goethite and/or in-situ produced ferric hydroxide, are that they are cheap, easily synthesized, suitable both for cation and anion sorption, and, furthermore, that they present low risks for adding a further pollutant to the system. Promising results were obtained. RECOMMENDATION AND OUTLOOK: The application of goethite and in-situ produced ferric hydroxide has demonstrated their effectiveness in the removal of heavy metal ions, such as chromium anions and zinc cations. A proposed continuation of current work is the utilization of similar iron oxides, for instance synthesized akaganeite. The comparison between the results reported in this paper with the results reported in the literature, also deserves attention.     

Evaluation of the pollution of the surface waters of Greece from the priority compounds of list II, 76/464/EEC directive, and other toxic compounds

The pollution of the surface waters of Greece from the priority compounds of 76/464/EEC Directive was evaluated. The occurrence of 92 toxic compounds, 64 of which belong to priority compounds of List II, candidates for List I, of 76/464/EEC Directive, was studied in surface waters and wastewater through the developed network of 62 sampling stations, which covers the whole Greek territory. The analytical determination was performed by Purge and Trap-Gas chromatography-Mass spectrometry for volatile and semivolatile organic compounds (VOCs), Gas Chromatography-Electron Capture Detection for organochlorine insecticides, Gas Chromatography-Nitrogen Phosphorous Detection for organophosphorous insecticides, High Performance Liquid Chromatography-Photodiode Array Detection for herbicides, and Electrothermal Atomic Absorption Spectrophotometry and Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) for metals and the toluene extractable organotin compounds. The concentrations of VOCs and insecticides detected in the surface waters of Greece were very low, whereas the concentrations of herbicides and metals ranged generally at moderate levels. VOCs were detected almost exclusively in the rivers and very rarely in the lakes, while the frequency of occurrence of insecticides, herbicides and metals was similar for rivers and lakes. Water quality objectives (WQO) and emission limit values (ELV) have been laid down in national legal framework for a number of compounds detected in the samples, in order to safeguard the quality of surface waters from any future deterioration.     

Investigation of Cr(VI) reduction in continuous-flow activated sludge systems

The aim of this research was to investigate hexavalent chromium, Cr(VI), reduction by activated sludge and to evaluate the use of continuous-flow activated sludge systems for the treatment of Cr(VI)-containing wastewater. Three series of experiments were conducted using two parallel lab-scale activated sludge systems. During the first experiment, one system was used as a control, while the other received Cr(VI) concentrations equal to 0.5, 1, 3 and 5mg l(-1). For all concentrations added, approximately 40% of the added Cr(VI) was removed during the activated sludge process. Determination of chromium species in the dissolved and particulate phase revealed that the removed Cr(VI) was sorbed by the activated sludge flocs mainly as trivalent chromium, Cr(III), while the residual chromium in the dissolved phase was mainly detected as Cr(VI). Activated sludge ability to reduce Cr(VI) was independent of the acclimatization of biomass to Cr(VI) and it was not affected by the toxic effect of Cr(VI) on autotrophic and heterotrophic microorganisms. During the second experiment, both systems were operated under two different hydraulic residence time (theta equal to 20 and 28h) and three different initial organic substrate concentration (COD equal to 300, 150 and 0mg l(-1)). Cr(VI) reduction was favored by an increase of theta, while it was limited by influent COD concentration. Finally, at the last experiment the effect of anoxic and anaerobic reactors on Cr(VI) reduction was investigated. It was observed that the use of an anoxic zone or an anaerobic-anoxic zone ahead of the aerobic reactor favored Cr(VI) reduction, increasing mean percentage Cr(VI) reduction to almost 80%.     

Comparative environmental assessment of biocides used in antifouling paints

In response to increasing scientific evidence on the toxicity and persistence of organotin residues from antifouling paints in the aquatic environment, the use of triorganotin antifouling products was banned on boats of less than 25 m length in many countries during 1987. Alternatives to tributyltin (TBT) paint are mainly copper based coatings containing organic booster biocides to improve the efficacy of the formulation, and have been utilised on small boats for the last 10 years. With policies encouraging a total ban on TBT, it is expected that these biocides will be used to a greater extent in the future. Limited data and information are available on the environmental occurrence, fate, toxicity, and persistence of these biocides, and thus any decisions on policies regulating antifoulants cannot be fully informed. In this study, a multicriteria comparison of alternative biocides, based on a general assessment of available information in the literature, provided support for the use of the precautionary principle with respect to policies on antifouling products. This assessment was validated by a more detailed comparison of four selected biocides and TBT. Results indicate that TCMS pyridine and TCMTB demonstrate environmental characteristics similar to TBT and thus detail risk assessments are needed before their use is permitted. The widespread use of the other biocides should be allowed only after research to fill the gaps in knowledge with respect to their toxicity and persistence in aquatic environments.     

Sediment pollution by heavy metals in the Strymonikos and Ierissos Gulfs,North Aegean Sea,Greece

Surface sediment samples from Strymonikos and Ierissos Gulfs wereanalyzed for Cu, Pb, Zn, Cr and Ni. The results showed that the sediment of Ierissos Gulf is more polluted with Cu, Pb, and Zn ascompared to that of Strymonikos Gulf. The benthal area located off the load-out facility of the mining operations in the town of Stratoni, in Ierissos Gulf is established as the most pollutedregion. The distribution of Cr and Ni in both gulfs indicates thenatural origin of these metals with the weathering of Strymon River and of other smaller rivers rocks being responsible for their enrichment.     

Management of nutrient emissions of Axios River catchment: Their effect in the coastal zone of Thermaikos Gulf,Greece

The estimation of nutrient fluxes, the determination of spatial and temporal response and the understanding of biogeochemical changes in the past, present and future in the Axios River catchment, in Greece, as well as the impacts to the coastal zone of Thermaikos Gulf were accomplished by the use of harmonized watershed and coastal zone models. The mathematical model MONERIS was the watershed management model that was used to model the export loads of nutrients in Axios River. MONERIS was developed to estimate the nutrient inputs into river basins by point sources and various diffuse pathways. Watershed hydrologic and water quality data were collected and synthesized to develop input data sets for the simulation of Axios River catchment. The model was modified to better assess organic nitrogen export loads in Mediterranean watersheds. The results showed the importance of agricultural and livestock activities, concerning their nutrients emissions in the River. MONERIS was integrated with the coastal zone model WASP 6.0 to assess the impacts of the nutrient loads to the eutrophication status of the coastal zone. Several management scenarios were assessed. Management scenarios included measures for reduction in the emissions from the fertilizer plant of Veles, removal of phosphorous from the detergents in FYROM, treatment of urban wastes to EU Standards, reduction in N-fertilizer input, reduction in erosion and the green scenario that represented the maximum reduction scenario of all the measures together. The model simulations indicated that the coastal zone of Axios mouth will be eutrophic for nitrate (2.69–3.34 μM) and phosphate (0.2–0.68 μM) and upper mesotrophic for chlorophyll-a (0.74–1.45 μg/l) for the scenarios tested. The results suggest that the impact of the management scenarios will be largely negligible (no change in trophic status) for the Thermaikos Gulf sector nearby the Axios River due to additional sources such as the loads from Thessaloniki's waste water treatment plant which appear to affect the region to a greater extent. The integration of watershed and coastal zone models can be used to assess management scenarios in order to illustrate the significance of various land use practices to the eutrophication of the Gulf.     

Open Air Laboratories (OPAL): a community-driven research programme

OPAL is an English national programme that takes scientists into the community to investigate environmental issues. Biological monitoring plays a pivotal role covering topics of: i) soil and earthworms; ii) air, lichens and tar spot on sycamore; iii) water and aquatic invertebrates; iv) biodiversity and hedgerows; v) climate, clouds and thermal comfort. Each survey has been developed by an inter-disciplinary team and tested by voluntary, statutory and community sectors. Data are submitted via the web and instantly mapped. Preliminary results are presented, together with a discussion on data quality and uncertainty. Communities also investigate local pollution issues, ranging from nitrogen deposition on heathlands to traffic emissions on roadside vegetation. Over 200,000 people have participated so far, including over 1000 schools and 1000 voluntary groups. Benefits include a substantial, growing database on biodiversity and habitat condition, much from previously unsampled sites particularly in urban areas, and a more engaged public.     

Alternative soilless media using olive-mill and paper waste for growing ornamental plants

Peat-based growing media are not ecologically sustainable and peat extraction threatens sensitive peatland ecosystem. In this study, olive-stone waste (OSW) and paper waste (PW) were used in different ratios—as growing media—for ornamental crop production, as peat (P) substitutes. Marigold (Calendula officinalis L.), petunia (Petunia x hybrita L.) and matthiola (Matthiola incana L.) plants were grown in (1) P (100%), (2) P:OSW (90%:10%), (3) P:OSW (70%:30%), and (4) P:OSW:PW (60%:20%:20%). The physicochemical properties of these substrates and the effects on plant growth were determined. The addition of 10–30% OSW into the substrate increased marigold height compared to plants grown in 100% peat. No differences in plant size, plant biomass (leaves and flowers), and dry matter content were found. Adding PW, in combination with OSW, maintained marigold height and total number of flowers produced to similar levels as in plants grown in 100% peat. In matthiola, adding 30% OSW into the substrate reduced plant size and fresh weight, but not plant height. No differences were observed when plants grew in lower OSW (i.e., 10%) content. Petunia’s height, its total number of flowers and flower earliness (flower opening) were increased in the presence of OSW compared to the plants grown in 100% peat. The addition of OSW did not affect petunia’s size and fresh weight among treatments. The addition of PW suppressed several plant growth-related parameters for both matthiola and petunia. The insertion of OSW did not change leaf chlorophyll content whereas the presence of PW decreased chlorophylls for marigold, petunia, and matthiola. Both OSW and PW altered the content of total phenolics and antioxidant capacity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) in leaves and flowers for marigold and petunia. Both 30% OSW and PW increased antioxidative enzyme metabolism due to the increased damage index and lipid peroxidation observed in plants. Leaf N and P content decreased in PW-based media, while matthiola displayed visual phytotoxicity symptoms when PW was added into the substrate. The present work indicates that up to 30% of OSW can replace peat for marigold and petunia growing and only up to 10% of OSW for matthiola, while the addition of PW on top of OSW is not recommended, so further research is needed.     

A multi-criteria sustainability assessment framework: development and application in comparing two food waste management options using a UK region as a case study

Preventing food wastage is a key element of sustainable resource management. But as food waste is still generated at high volumes, priority is placed on its proper management as a resource, maximising sustainability benefits. This study, by integrating a multi-criteria decision analysis with a sustainability assessment approach, develops a screening and decision support framework for comparing the sustainability performance of food waste management options. A structured process for selecting criteria based on the consideration of environmental, economic and social aspects related to region-specific food waste system planning, policy and management has been developed. Two food waste management options, namely the use of food waste disposal units, which grind food waste at the household’s kitchen sink and discharge it to the sewer, and the anaerobic co-digestion of separately collected food waste with sewage sludge, were selected for comparison due to their potential to create synergies between local authorities, waste and water companies, with local circumstances determining which of the two options to adopt. A simplified process used for assessing and comparing the two food waste management options in the Anglian region in the UK, indicated that there are benefits in using the framework as a screening tool for identifying which option may be the most sustainable. To support decision-making, a detailed analysis that incorporates stakeholders’ perspectives is required. An additional use of the framework can be in providing recommendations for optimising food waste management options in a specific region, maximising their sustainability performance.