Heavy metal distribution in soil and plant in municipal solid waste compost amended plots

A field study was carried out to evaluate long-term heavy metal accumulation in the top 20 cm of a Tunisian clayey loam soil amended for four consecutive years with municipal solid waste compost at three levels (0, 40 and 80 t/ha/y). Heavy metals uptake and translocation within wheat plants grown on these soils were also investigated. Compared to untreated soils, compost-amended soils showed significant increases in the content of all measured metals: cadmium, chromium, copper, nickel, lead and zinc in the last three years, especially for plots amended with municipal solid waste compost at 80 t/ha/y. Wheat plants grown on compost-amended soils showed a general increase in metal uptake and translocation, especially for chromium and nickel. This heavy metal uptake was about three folds greater in plots amended at 80 t/ha/y as compared to plots amended at 40 t/ha/y. At the end of the experimental period, the diluting effect resulting from enhanced growth rates of wheat plants due to successive compost applications resulted in lower concentrations in the plants (grain part) grown on treated plots. On the other hand, chromium and nickel were less mobile in the aerial part of wheat plants and were accumulated essentially in root tissues. Plant/soil transfer coefficients for compost-amended treatments were higher than threshold range reported in the literature, indicating that there was an important load/transfer of metal ions from soils to wheat plants.     

Environmental management of coastal regions in the Caspian Sea

Considering rapid population growth and migration, higher accumulation of communities is noticed in coastal areas. This is especially true with the coastal areas of the Caspian Sea. In the present investigation coastal areas between Jouybar to Behshahr region is selected for their special geographical and ecological locations. Further, adverse impacts of human, agriculture and industrial activities was examined along side the above mentioned coasts. It should be pointed out that protected Miankaleh Wildlife zone which is an internationally recognized wetland, falls within area of study. In the present study strengths, weaknesses, opportunities and threats method is used for the evaluation of environmental management status. In this regard, internal and external factors gained 2.28 and 2.58 scores. This is indicative of the abundance of weaknesses over strengths and it also shows that opportunities are more than threats. Subsequently 27 strategies were developed and quantitative strategic planning matrix method was also used to score each strategies. The results of quantitative strategic planning matrix method analysis was programmed in strategic position and action evaluation matrix. The present situation falls within “competitive” classification. This is indicative of weakness in coordinating development and environmental strategic plans. The result of present investigation strongly emphasis on compilation of strategic environmental plans for the control of population, pollution emission and land use planning changes. The most important strategies include development of environmental regulations and better supervision on enforcement of laws.     

Performance of irrigation projects and their impacts on poverty reduction and its empowerment in arid environment

Biophysical and socioeconomic conditions of pre and post dam construction were assessed in one of the arid regions of Iran commanded by Minab dam. The methodology used in this study was drawn from the international organizations especially the World Commission on Dams and the United Nations for selection of the indicators for sustainable development relating to water resources projects. Commissioning of the dam in 1986 led to progressive expansion of the irrigated agriculture, which was almost doubled in year 2006. Results of the study revealed that there is significant positive impact of the irrigation infrastructures of the dam; for example literacy rate has increased from 41 % (pre project) to 74 % in 2006. Similarly, significant improvements were observed in health care, sanitation, education and other scopes. Nevertheless, for some of the targets only 50–60 % progress were made, whereas no significant achievements had been made in the others. Therefore, development did not match with the planned goals of the project. Deficiency in achieving the primary objectives, especially after many years of project completion, may be attributed to the management and implementation of the project. For effective project performance, a new institutional framework and guide lines are proposed in this article.     

Rapid analysis of risk assessment using developed simulation of chemical industrial accidents software package

The environmental consequences are defined as consequences of accidental release of hazardous substances to the natural environment. This release can lead to many hazards depending on the material stored. The consequences of these hazards to the environment are widespread and have significant importance to human communities living in the surroundings. The mathematical models are extremely useful tools to predict the impacts of chemical process accidents. The objective of this paper is to develop a software package for accident simulation and damage potential estimation. The software is coded in visual basic and is compatible with windows working environments. The software is called Simulation of chemical industrial accident. This application is a comprehensive software package which can be integrated with geographical information system to predict and display the consequence of chemical hazards. The software is a user-friendly and effective tool for evaluating the consequences of major chemical accidents, process decision making for land-use planning, namely locating suitable hazardous installations, hazardous waste disposal areas and emergency response plan.     

Impact of fertilizer plant effluent on water quality

The impact of National Fertilizer Company of Nigeria outfall effluent on the physicochemistry and bacteriology of Okrika creek was investigated during the sampling period from May to December, 1998. The National Fertilizer Company of Nigeria outfall effluent, the Okrika creek water and the Ikpukulubie creek (control) water samples were collected. The physico-chemical parameters analyzed for all the samples included temperature, pH, total chloride, total dissolved solids, dissolved oxygen, conductivity, free ammonia, total phosphate, urea, zinc and iron, while the bacteriological determinations were total culturable aerobic heterotrophic bacteria count and identification of representative isolates. The Okrika creek recorded higher concentrations for all the physico-chemical parameters and bacteria load than the control creek. The higher values of pH, Free NH₃, urea, TDS and the conductivity of the National Fertilizer Company of Nigeria outfall effluent above the FEPA standards reflect the poor effluent quality generated by National Fertilizer Company of Nigeria. The bacteria species isolated from the samples include Aerococcus viridans, Alcaligenes faecalis, Bacillus cereus, Citrobacter freundii, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas aeruginosa, Serratia marcescens and Staphylococcus aureus. In general, the investigation revealed that there was an extremely adverse impact on the physico-chemical and bacteriological water quality characteristics of the Okrika creek as a result of the discharge of poor quality effluent from National Fertilizer Company of Nigeria operations.     

Degradation of common pharmaceuticals and personal care products in mixed solutions by advanced oxidation techniques

Widespread detection of pharmaceutical compounds in water environment has been a serious concern recently, while conventional sewage treatments are ineffective for their elimination. But, advanced oxidation techniques are very promising to remove varieties of organic contaminants in water. This research aims to elucidate oxidation potentials of sixteen commonly used pharmaceutical compounds in mixed solutions by seven advanced oxidation techniques in laboratory batch experiments. The removal profiles exhibited four distinct patterns: a) easily degradable by all seven techniques, b) not easily degradable by all seven techniques, c) easily degradable by ozone-based techniques, but not by ultraviolet radiation-based techniques and d) easily degradable by ultraviolet radiation-based techniques, but not by ozone-based techniques. Ozone-based techniques rather than ultraviolet radiation-based techniques were very powerful for simultaneous removal of the compounds efficiently. Moreover, ozonation combined with ultraviolet radiation was the most appropriate technique for simultaneous removal of the tested compounds efficiently. Increased ozone dissolution and decomposition with ozone-based techniques did not always enhance the compounds’ removal. Physicochemical properties of the compounds and solution pH also presumably played an important role on the removal which merits further attention.     

Geology Along the Line from Yecheng to Shiquanhe and Tectonic Evolution of the Region Involved1

Abstract The geotraverse from Yecheng to Shiquanhe, on the western Qinghai – Tibet Plateau, totalling 1056 km in length, passes the western Kunlun Mountains and the eastern end of the Karakorum Mountains. The Chinese and French scientists made a joint investigation along the line from July to August, 1989. Based on the outcropped ophiolites, palaeontology, sedimentary facies, magmatism, tectonic deformation and metamorphism, the region involved may be divided from north to south into five terranes and four ophiolitic suture zones. The ages of these terranes have a tendency to become increasingly younger from north to south.     

X-ray photoelectron studies of the mechanism of iron silicate dissolution during weathering

Iron silicate minerals (bronzite, fayalite), exposed to aqueous dissolution in the laboratory for up to 60 days at room temperature and pH 1, 1.5, and 6, have been studied for evidence of changes in surface composition, using XPS, and these results compared with those obtained from solution chemical analysis. In the absence of dissolved O₂ or at low pH (1–1.5) dissolution proceeds congruently after the initial formation of a thin (<10 Å) protonated surface layer depleted in Fe relative to Si. This layer is unstable and does not grow with time as attested to by long term congruent dissolution and by the formation of an amorphous silica surficial breakdown product at pH 1 and 1.5. In bronzite the layer is also slightly depleted in Mg but much less than it is in Fe due to the preferential occupation by Fe⁺² of more weakly bonded M₂ sites. The behavior of the layer is similar to that found earlier on iron-free pyroxene (Schottet al., 1981); in other words, because of its thinness and instability it is not diffusion-inhibiting or protective toward dissolution.In the presence of dissolved O₂, as would be the case in most weathering solutions, dissolution of bronzite and fayalite results in the formation of two surface layers whose compositions were deduced by measurements of XPS binding energies. The outer layer, consisting of hydrous ferric oxide, is readily removed by ultrasonic cleaning and, most likely, is not protective toward dissolution. The inner layer consists of Fe⁺³ in a protonated or hydroxylated silicate (Mg-silicate in the case of bronzite) matrix. This layer appears to impede dissolution over the time scale of the experiment as attested to by parabolic dissolution rates. However, the layer does not continue to grow on the time scale of weathering because ultrasonically cleaned soil grains (Berner and Schott, 1982) exhibit surface compositions similar to those found in the present month-long laboratory experiments. In other words, a thick, highly altered, diffusion-inhibiting, protective surface layer does not form at the acidic pH of most soils.     

Removal of bisphenol A from aqueous solution by hydrophobic sorption of hemimicelles

In this work, the hydrophobic sorption of hemimicelles was proposed as an innovative method for removing bisphenol A from aqueous solution with esterified carboxyl cotton as sorbent and cetyl trimethyl ammonium bromide as cationic surfactant. In order to optimize the sorption process, the effect of sorbent dose, initial pH, surfactant dose, sorbate concentration, contact time and temperature was investigated in batch system. The maximum value of bisphenol A removal appeared in the pH range 4–10. The bisphenol A removal ratio came up to the maximum value beyond 12 time of surfactant/bisphenol A. The isothermal data of bisphenol A sorption conformed well to the Langmuir model and the maximum sorption capacity (Q_m) of esterified carboxyl cotton for bisphenol A was 87.72 mg/g. The bisphenol A removal equilibrium was reached within about 4 h and the removal process could be described by the pseudo-second-order kinetic model. The thermodynamic study indicated that the bisphenol A sorption process was spontaneous and exothermic.