Sustainable land application: an overview

Man has land-applied societal nonhazardous wastes for centuries as a means of disposal and to improve the soil via the recycling of nutrients and the addition of organic matter. Nonhazardous wastes include a vast array of materials, including manures, biosolids, composts, wastewater effluents, food-processing wastes, industrial by-products; these are collectively referred to herein as residuals. Because of economic restraints and environmental concerns about land-filling and incineration, interest in land application continues to grow. A major lesson that has been learned, however, is that the traditional definition of land application that emphasizes applying residuals to land in a manner that protects human and animal health, safeguards soil and water resources, and maintains long-term ecosystem quality is incomplete unless the earning of public trust in the practices is included. This overview provides an introduction to a subset of papers and posters presented at the conference, "Sustainable Land Application," held in Orlando, FL, in January 2004. The USEPA, USDA, and multiple national and state organizations with interest in, and/or responsibilities for, ensuring the sustainability of the practice sponsored the conference. The overriding conference objectives were to highlight significant developments in land treatment theory and practice, and to identify future research needs to address critical gaps in the knowledge base that must be addressed to ensure sustainable land application of residuals.     

Botswana's environmental policy on recycling

Recycling operations have become one of the primary strategies for waste management, worldwide. Especially, recycling operations are viewed as among the most effective techniques for reducing the amount of municipal solid waste disposed at landfill sites. Botswana's environmental policy on recycling stipulates, among others, that all waste management authorities should provide information on the classification and quantities of controlled waste targeted for recycling. This paper, therefore, examines the extent to which recycling operations in Botswana have either been conducted in compliance with or in violation of some major environmental requirements as enunciated on statutory guidelines. Compatibility between environmental policies on recycling and actual practice is evaluated focusing on two companies (Dumatau trading and Botswana Tissue) involved in recycling operation. Data from the two companies is complemented by one collected from the Gaborone landfill site. Finally, this study discusses on the role played by various stakeholders in policy formulation and implementation with particular emphasis being placed on a select number of non-governmental organisations (NGO).     

Residues of endosulfan and other selected organochlorine pesticides in farm areas of the Lower Fraser Valley, British Columbia, Canada

Crop soils, ditch sediments, and water flowing from several farm areas to salmon tributary streams of the Fraser River in the Lower Fraser Valley (LFV) of British Columbia, Canada, were sampled in 2002-2003 to quantify for residues of an organochlorine cyclodiene pesticide, endosulfan (END = alpha-endosulfan + beta-endosulfan + endosulfan sulfate). Residues from historical use of other selected organochlorine pesticides, namely, cyclodienes (aldrin, alpha-chlordane, gamma-chlordane, dieldrin, endrin, endrin aldehyde, heptachlor, and heptachlor epoxide), hexachlorocyclohexanes [alpha-benzene-hexachloride (alpha-BHC), beta-BHC, delta-BHC, and gamma-BHC (lindane)], and DDT-related compounds (p,p-DDT, p,p-DDD, p,p-DDE, and methoxychlor) were also determined. Reference and background levels of these pesticides in ditches leading to fish streams were obtained from pristine watershed areas. Varying amounts of END residues were detected in soils (<0.02-5.60 mg kg(-1) dry wt.) and ditch sediments (<0.02-3.33 mg kg(-1) dry wt.) in mainly three of five farm areas sampled. Likewise, residues (excluding END) of other selected organochlorine compounds such as aldrin, BHC, chlordane, endrin, p,p-DDT, methoxychlor, and their respective major transformation products (endosulfan sulfate, dieldrin, endrin aldehyde, heptachlor, heptachlor epoxide, p,p-DDD, and p,p-DDE) were found in crop soils (<0.02-16.2 mg kg(-1) dry wt.) and sediments (<0.02-9.73 mg kg(-1) dry wt.). Most of these pesticides (END: <0.01-1.86 microg L(-1); other selected organochlorine pesticides: <0.0.1-1.50 microg L(-1)) were also found in ditch water leading to salmon streams in several farms. The END levels of crop soils from the same LFV study farms in 1994 and 2003 indicated an estimated decline of 22% to 1.35 mg kg(-1) dry wt. during that period. This reduction was probably due to the increasing use of alternate pesticides (e.g., organophosphorus compounds). Some possible biological implications of these pesticide residues on nontarget organisms in the LFV are discussed.     

Identification of soil heavy metal sources from anthropogenic activities and pollution assessment of Fuyang County, China

Understanding regional variations of soil heavy metals and their anthropogenic influence are very important for environmental planning. In this study, 286 surface soil samples were collected in Fuyang county, and the 'total' metals for copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd) and nickel (Ni) were measured in 2005. Statistic analysis showed that Cu, Zn, Pb and Cd had been added by exterior factors, and Ni was mainly controlled by natural factors. The combination of multivariate statistical and geostatistical analysis successfully grouped three groups (Cu, Zn and Pb; Cd; and Ni) of heavy metals from different sources. Through pollution evaluation, it was found that 15.76% of the study area for Cu, Zn and Pb, and 46.14% for Cd suffered from moderate or severe pollution. Further spatial analysis identified the limestone mining activities, paper mills, cement factory and metallurgic activities were the main sources for the concentration of Cu, Zn, Pb and Cd in soils, and soil Ni was mainly determined by the parent materials.     

Application of GC-MS/MS for the analysis of PCDD/Fs in sewage effluents

The application of high resolution gas chromatography in combination with tandem mass spectrometry in an ion trap was tested to substitute the expensive high resolution mass spectrometry in analysing polychlorinated dibenzo-p-dioxins and furans in sewage effluents. In tandem mass spectrometry, a set of parameters has to be optimised in order to attain the required sensitivity. To the best of our knowledge, this is the first time a method development for analysing PCDD/Fs with GC-MS/MS in an ion trap is described in this detail. Nine parameters are varied, including isolation window, collision induced dissociation (CID) amplitude, CID time, acquisition mass range, broadband amplitude, CID bandwidth, modulation range, filament current and ion trap temperature. This technique can be adapted to other analytes. By this optimisation, limits of detection of 0.01-0.05 ng/l are obtained. With its selectivity and sensitivity, tandem mass spectrometry is a powerful tool for the determination of PCDD/Fs in water samples. 55 sewage effluent samples from Germany were analysed.     

Evidence for the "grasshopper" effect and fractionation during long-range atmospheric transport of organic contaminants

Although there is indisputable evidence that long-range atmospheric transport (LRAT) of organic contaminants occurs on a global scale, uncertainties remain about the detailed mechanism and extent of this phenomenon as well as the physical-chemical properties which facilitate LRAT. In this study, we discuss how mass balance models and monitoring data can contribute to a fuller understanding of the mechanism and extent of LRAT. Specifically we address the issues of "grasshopping" or "hopping" (the extent to which molecules are subject to multiple hops as distinct from a single emission-deposition event) and "global fractionation" (the differing behavior of chemicals as they are transported). It is shown that simple mass balance models can be used to assist the interpretation of monitoring data while also providing an instrument that can be used to assess the LRAT potential and the extent of hopping that organic substances may experience. The available evidence supports the notion that many persistent organic pollutants experience varying degrees of "hopping" during their environmental journey and as a consequence become fractionated with distance from source.     

Behavioral aspects of sperm competition in cuttlefish, Sepia officinalis (Sepioidea: Cephalopoda)

Sexual selection studies in cephalopods indicate that sperm competition is a central feature of their mating systems, yet this has not been studied experimentally in any detail. In 1998 we staged 20 matings of the cuttlefish, Sepia officinalis L., in the laboratory. Males rapidly initiated mating in the “head-to-head” position, with no apparent courtship. Mating lasted an average of 10 min (range 7 to 14 min). For the first 6 min (on average 63% of the mating duration), the male flushed strong jets of water directly at the female's buccal membrane, which sometimes resulted in the expulsion of parts of spermatangia placed there in recent matings. Then, in a single discrete movement that lasted an average of only 14 s, the male's modified fourth left arm – the hectocotylus – wrapped around a single large bundle of spermatophores (ca. 150 to 300) and transferred them to the female's buccal membrane. For the remainder of the mating (average 3 min, range 1.5 to 5.0 min), the hectocotylus repeatedly broke the spermatophores open, and manipulated them, so that sperm were released and many spermatangia were attached along the ventral buccal membrane, near the paired seminal receptacles. Approximately 140 spermatangia were attached in rows 3 to 5 deep around the ventral buccal membrane in a single mating; the rest were usually discarded during mating. Histology revealed that each of the seminal receptacles consists of a series of sperm storage bulbs connected by a central duct, which leads to a single pore at the surface of the buccal membrane. Baseline data on sperm motility were obtained, but the mechanism by which sperm enter the seminal receptacle remains unknown. Females seemed to initiate termination of mating, then males guarded their mates temporarily. These results, combined with other recent laboratory experiments, provide evidence that sperm competition may be a major feature of the mating system of S. officinalis. Received: 4 January 1999 / Accepted: 18 May 1999     

Potassium carbonate-based ternary transition temperature mixture (deep eutectic analogues) for CO2 absorption: Characterizations and DFT analysis

•Addition of hindered amine increased thermal stability and viscosity of TTTM. •Addition of hindered amine improved the CO₂ absorption performance of TTTM. •Good the CO₂ absorption of recycled solvents after two regenerations. •Important role of amine group in CO₂ absorption of TTTM confirmed by DFT analysis. Is it possible to improve CO₂ solubility in potassium carbonate (K₂CO₃)-based transition temperature mixtures (TTMs)? To assess this possibility, a ternary transition-temperature mixture (TTTM) was prepared by using a hindered amine, 2-amino-2-methyl-1,3-propanediol (AMPD). Fourier transform infrared spectroscopy (FT-IR) was employed to detect the functional groups including hydroxyl, amine, carbonate ion, and aliphatic functional groups in the prepared solvents. From thermogravimetric analysis (TGA), it was found that the addition of AMPD to the binary mixture can increase the thermal stability of TTTM. The viscosity findings showed that TTTM has a higher viscosity than TTM while their difference was decreased by increasing temperature. In addition, Eyring’s absolute rate theory was used to compute the activation parameters (ΔG*, ΔH*, and ΔS*). The CO₂ solubility in liquids was measured at a temperature of 303.15 K and pressures up to 1.8 MPa. The results disclosed that the CO₂ solubility of TTTM was improved by the addition of AMPD. At the pressure of about 1.8 MPa, the CO₂ mole fractions of TTM and TTTM were 0.1697 and 0.2022, respectively. To confirm the experimental data, density functional theory (DFT) was employed. From the DFT analysis, it was found that the TTTM+ CO₂ system has higher interaction energy (|ΔE |) than the TTM+ CO₂ system indicating the higher CO₂ affinity of the former system. This study might help scientists to better understand and to improve CO₂ solubility in these types of solvents by choosing a suitable amine as HBD and finding the best combination of HBA and HBD.     

Trace metals in the hair of habitants of the Ok Tedi region, Papua New Guinea

It has long been known that mining activity can markedly change the level and distribution of certain heavy metals in the adjacent environment. This pollution can be quite widespread and long lasting and often has deleterious effects on the health of local populations. In the present study scalp hair was used as the biopsy material because of its ease of collection and long history of use in this connection. Hair was collected from all the local villages in the vicinity of the mine site, as well as from Papua New Guinean nationals from other provinces, and European expatriates who were employed by the mining company and who were resident in the area. Hair from local people showed a remarkably high iron content by comparison with previously studied populations. The extreme variations in hair iron levels were reflected in the differential distribution of levels according to location, age and sex. Hair cadmium was also high in the population studied. Hair copper, lead, zinc and mercury all appeared to be within 'normal' limits by comparison with other general populations. These results are discussed in the context of the environmental and social impact of the mining operations on the local people.     

Trees as bioindicator of heavy metal pollution in three European cities

Concentrations of four heavy metals were determined in tree leaves and bark collected from polluted and non-polluted areas of three European cities (Salzburg, Belgrade and Thessaloniki) for a comparative study. Platanus orientalis L. and Pinus nigra Arn., widespread in urban northern and southern Europe, were tested for their suitability for air quality biomonitoring. Leaves and barks were collected uniformly of an initial quantity of about 30 g of each sample. Analysis was accomplished by electrothermal atomic absorption spectrometry after total digestion. Site-dependent variations were found with the highest concentration level measured in Belgrade, followed by Thessaloniki and Salzburg. A higher accumulation of heavy metals was found in bark compared to leaves. Pine tree bark, accumulating higher concentrations of trace metals compared to plane tree bark, shows a higher efficiency as bioindicator for urban pollution. Both indicator species are suitable for comparative studies on bioindication of urban air pollution.