Treatment of chromium plating process effluents with ion exchange resins.

The surface treatment industry deals with various heavy metals, including the elements Cr, Zn, Ni, Cd, and Cu. Conventional treatments of effluents generate class I solid residue. The aim of this investigation was to study the viability of ion exchange as an alternative process for treatment of rinse water and to determine the efficacy of two ion exchange systems, System 1: "strong" cationic resin-"strong" anionic resin and System 2: "strong" cationic resin-"weak" anionic resin. Commercial resins and solutions taken from rinse tanks of chromium plating companies were used in this investigation. A two-column system, one for the cationic resin and another for the anionic resin, both with 150 ml capacity was mounted. The solution was percolated at a rate of 10 ml/min. The following solutions were used for regeneration of the resins: 2% H2SO4 for the cationic and 4% NaOH for the anionic. The percolated solutions revealed chromium contents of less than 0.25 mg/l, independent of the system used. The "strong" cationic resin-"weak" anionic resin gave excellent regeneration results. The "strong" cationic-"strong" anionic resin presented problems during regeneration, and did not release the retained ions after percolation of 2000 ml of 4% NaOH solution. It is concluded that for this type of treatment, the system composed of "strong" cationic resin and "weak" anionic resin is more appropriate.     

Effects of Acidification and its Mitigation with Lime and Wood Ash on Forest Soil Processes: A Review

Anthropogenic acid deposition causes forest soil acidification and perturbation of the soil forming processes. The impact of soil acidification on tree growth is discussed in view of the role of mycorrhizal fungi in weathering and nutrient uptake. A review has been carried out of experiments involving treatments of forest soil by lime and wood ash, where soil properties and soil solution composition have been investigated. Results from these experiments in Europe and North America are summarized. In general, the content of C in the mor layer decreased as a result of treatment due to higher microbial activity and soil respiration as well as increased leakage of DOC. In addition, the content of N in the mor layer, in general, decreased after treatment and there are occasional peaks of high NO₃concentrations in soil solution. In nearly all reviewed investigations the pH of the deep mineral soil solution decreased and Al, SO₄and NO₃concentrations increased after treatment. These effects are probably due to the high ionic strength and increased microbial activity as a consequence of the treatments. In the soil, pH, CEC and base saturation increased in the upper horizons, but decreases in the upper mineral soil are also reported. In general, there was no increase in tree growth as a result of these treatments. The positive effects of the treatments on soil processes and tree growth are therefore questionable. In view of these conclusions, an investigation was carried out on the soil and soil solution chemistry and the role of mycorrhizal fungi in a spruce stand treated with two doses of lime and another treated with lime/ash in southern Sweden. The results of this investigation is reported in this volume.     

Swine manure composting by means of experimental turning equipment

The purpose of research was to test the effectiveness of a prototype of a turning machine and to evaluate the feasability of a farm-scale composting process of the solid fraction of swine manure. A qualitative evaluation of the process and final product was made by monitoring the following parameters: process temperature, oxygen concentration inside the biomass, gaseous emissions (CH4, CO2, NH3, N2O), respiration index, humification index, total and volatile solids, carbon and nitrogen, pH and microbial load. The prototype proved to be very effective from a technical-operational point of view. The composting process exhibited a typical time-history, characterised by a thermophilic phase followed by a curing phase [Chiumenti, A., Chiumenti, R., Diaz, L.F., Savage, G.M., Eggerth, L.L., Goldstein, N., 2005. Modern Composting Technologies. BioCycle-JG Press, Emmaus, PA, USA]. Gas emissions from compost the windrow were more intense during the active phase of the process and showed a decreasing trend from the thermophilic to the curing phase. The final compost was characterized by good qualitative characteristics, a significant level of humification [Rossi, L., Piccinini, S., 1999. La qualità agronomica dei compost derivanti da liquami suinicoli. (Agronomic quality of swine manure compost). L'informatore Agrario 38, 29-31] and no odor emissions. This method of managing manure represents an effective, low cost approach that could be an interesting opportunity for swine farms.     

Environmental Technology Verification (ETV) test of dioxin emission monitors

The performance of four dioxin emission monitors, including two long-term sampling devices, the Dioxin-MonitoringSystem (DMS) and AMESA (the adsorption method for sampling dioxins and furans), and two semireal-time continuous monitors, the resonance ionization with multimirror photon accumulation time-of-flight mass spectrometer (RIMMPA-TOFMS) and the jet resonance-enhanced multiphoton ionization (jet-REMPI) system were tested. A package boiler burning a simulated chlorinated hazardous waste was used for a total of nine tests. Reference samples were collected during each test and analyzed for polychlorinated dibenzodioxins and dibenzofurans (PCDDs/Fs) using gas chromatography mass spectrometry. The PCDD/F concentrations of the reference samples measured by EPA Method 23 ranged from 0.9 to 6.0 ng toxic equivalence (TEQ)/dry standard cubic meter. The relative accuracies achieved by DMS, AMESA, and jet-REMPI varied from 22.6% to 78.2%, with 100% data completeness. The RIMMPA-TOFMS produced no quantifiable results due to various difficulties associated with the instrument during the testing. The two long-term samplers were easy to install and operate and provided a cumulative, averaged emission for the sampling period. The operations of the two semi-real-time continuous monitors were relatively complex, but one of them provided on-site, real-time data for PCDD/F emissions from measurement of a TEQ correlative indicator compound. This article summarizes results from the individual Environmental Technology Verification reports for the four dioxin monitors. This work was presented, in part, at the Fourth International Conference on Combustion, Incineration/Pyrolysis and Emission Control (i-CIPEC)     

Estimation of odor emission rate from landfill areas using the sniffing team method

The monitoring of the odor annoyance generated by a landfill area is difficult, since it is a multi-area-sources problem, with a discontinuous odor emission. This paper proposes an adaptation of the method of sniffing team campaigns to the particular case of fresh waste odors. The method is based on the field determination of odor perception points, followed by data processing with a bi-Gaussian-type model, adapted to handle the odors. In a first step, field observers delineate the region in which odor impact is experienced and then the emission rate is manipulated in a dispersion model until the predicted size of the impact zone matches that observed in the field. In a second step the adjusted emission rate is entered into the model to calculate the percentiles corresponding to the average annoyance zone. The originality of the proposed method is the introduction of all observation points and of all recorded meteorological data into the model. The paper discusses the method limitations and the errors induced on the results, i.e. the odor emission rate and the percentile lines (or iso-concentration lines) which are used to describe the odor concentrations on a map of the surroundings of the plant. The proposed method proves to be reliable for diffuse sources, such as landfill areas. The obtained results are coherent with other results found in the literature with other techniques.     

Structure-biodegradation relationships of polymeric materials. 1. Effect of degree of oxidation on biodegradability of carbohydrate polymers

The biodegradability of oxidized starch and inulin has been studied in relation to the degree of periodate oxidation to dialdehyde derivatives, by measuring oxygen consumption and mineralization to carbon dioxide. A higher degree of oxidation of dialdehyde starch and dialdchyde inulin results in a lower rate at which the polymers are biodegraded. It is demonstrated that the biodegradation rate of dialdehyde inulin derivatives decreases more than that of equivalent starch derivatives. The differences in biodegradation behavior between dialdehyde starch and dialdehyde inulin, resulting from comparable modifications, are discussed in terms of conformational structure.     

Zinc processing in the USA : An analysis of a declining industry

The purpose of this paper is to analyse the recent behaviour of the US zinc processing industry and the impact of US government policies on it. The first section of the paper is a discussion on the basic structure and conditions of the US zinc processing industry since 1950 and how they have changed. The discussion contains a general presentation of the US zinc market, a detailed look at the behaviour of individual primary zinc processing plants in the USA, Canada, Japan and Western Europe and an analysis of US government policies and their impacts on the US zinc industry. The second section of the paper is a discussion of the factors that have contributed to the decline in US zinc processing capacity and the type of government policy that should be followed in response.     

Ecological impacts of early 21st century agricultural change in Europe – A review

The impacts of agricultural land use are far-reaching and extend to areas outside production. This paper provides an overview of the ecological status of agricultural systems across the European Union in the light of recent policy changes. It builds on the previous review of 2001 devoted to the impacts of agricultural intensification in Western Europe. The focus countries are the UK, The Netherlands, Boreal and Baltic countries, Portugal, Hungary and Romania, representing a geographical spread across Europe, but additional reference is made to other countries. Despite many adjustments to agricultural policy, intensification of production in some regions and concurrent abandonment in others remain the major threat to the ecology of agro-ecosystems impairing the state of soil, water and air and reducing biological diversity in agricultural landscapes. The impacts also extend to surrounding terrestrial and aquatic systems through water and aerial contamination and development of agricultural infrastructures (e.g. dams and irrigation channels). Improvements are also documented regionally, such as successful support of farmland species, and improved condition of watercourses and landscapes. This was attributed to agricultural policy targeted at the environment, improved environmental legislation, and new market opportunities. Research into ecosystem services associated with agriculture may provide further pressure to develop policy that is targeted at their continuous provisioning, fostering motivation of land managers to continue to protect and enhance them.     

Assessing farming eco-efficiency: a Data Envelopment Analysis approach

This paper assesses farming eco-efficiency using Data Envelopment Analysis (DEA) techniques. Eco-efficiency scores at both farm and environmental pressure-specific levels are computed for a sample of Spanish farmers operating in the rain-fed agricultural system of Campos County. The determinants of eco-efficiency are then studied using truncated regression and bootstrapping techniques. We contribute to previous literature in this field of research by including information on slacks in the assessment of the potential environmental pressure reductions in a DEA framework. Our results reveal that farmers are quite eco-inefficient, with very few differences emerging among specific environmental pressures. Moreover, eco-inefficiency is closely related to technical inefficiencies in the management of inputs. Regarding the determinants of eco-efficiency, farmers benefiting from agri-environmental programs as well as those with university education are found to be more eco-efficient. Concerning the policy implications of these results, public expenditure in agricultural extension and farmer training could be of some help to promote integration between farming and the environment. Furthermore, Common Agricultural Policy agri-environmental programs are an effective policy to improve eco-efficiency, although some doubts arise regarding their cost-benefit balance.