Environmental Risk Analysis Based on Characterization of Ground Oily Sludge

Oily sludge is recognized as hazardous waste. To reduce the potential danger and harmful factors of oily sludge, it is very important to analyze its environmental risk. In this paper, the characterization of oily sludge from Shengli Oilfield in China was tested experimentally, including the composition content, particle size, microscopic morphology, heavy metal content, organic composition, inorganic composition, and thermogravimetric analysis, which were used to analyze environmental risks. The results show that the oil content of oily sludge is as high as 10.3%, which will cause serious pollution. It is calculated that China can recover 772.5 million liters of oil and reduce 553.9 million kg of carbon emissions compared with incineration in one year, if the oily sludge can be managed effectively. The content of heavy metals such as Ba, Zn, Cr, As, Ni, Se, Be, and Hg in oily sludge exceeds the standard. It will restrain the self-healing ability of soil, pollute groundwater, and endanger animals and plants. The organic matter of oily sludge is concentrated in C₁₁ to C₂₉. It contains a large amount of benzene series and polycyclic benzene hydrocarbons, which can lead to cancer in the human body. Inorganic substances in oily sludge are mixed with some additives, which can not only reduce the toxicity of heavy metals, but also be used as building materials. The median particle size D₅₀ of oily sludge is 0.91 μm, and it spreads all over the narrow pores. Generally, it needs to be treated under high temperature conditions, which will cause secondary pollution to the environment. The research content of this paper provides a theoretical reference for the management of oily sludge.

Multidimensional Urban Exposure Analysis of Industrial Chemical Risk Scenarios in Mexican Metropolitan Areas

Risk scenarios are caused by the convergence of a hazard with a potentially affected system in a specific place and time. One urban planning goal is to prevent environmental hazards, such as those generated by chemical accidents, from reaching human settlements, as they can cause public health issues. However, in many developing countries, due to their strategic positioning in global value chains, the quick and easy access to labor pools, and competitive production costs, urban sprawls have engulfed industrial areas, exposing residential conurbations to environmental hazards. This case study analyzes the spatial configuration of accidental chemical risk scenarios in three major Mexican metropolitan areas: Mexico City, Guadalajara, and Monterrey. Spatial analyses use an areal locations of hazardous atmosphere (ALOHA) dispersion model to represent the spatial effects of high-risk industrial activities in conurbations and the potentially affected populations vulnerable to chemical hazards. Complementary geostatistical correlation analyses use population data, marginalization indexes, and industrial clustering sectors to identify trends that can lead to comprehensive environmental justice approaches. In addition, the marginalization degree of inhabitants evaluates social inequalities concerning chemical risk scenarios.

Quantification of pesticide residues in the topsoil of Belgian fruit orchards: terrestrial environmental risk assessment

BACKGROUND

Pesticides are widely used in fruit orchards. In the context of integrated pest management (IPM) Flemish farmers are advised to restrict the use of pesticides. However, pesticide residues could still pose a threat to beneficial organisms. To date, it is not well known which residues are present in IPM orchards. This study focuses on the pesticide concentration in the topsoil and the implications for soil-dwelling organisms.

RESULTS

Topsoil was sampled in ten sweet cherry (Prunus avium (L.) L.) and eight apple (Malus domestica Borkh.) orchards in Flanders (Belgium), to quantify the concentration of pesticide residues. Topsoil was selected because it is a major exposure route for beneficials. Both pesticides from both current spraying schedules and those used previously were found. In addition, an environmental risk assessment was performed using species sensitivity distribution (SSD) and toxicity/exposure ratio (TER) approaches. The SSD approach led to a more conservative outcome. None of the pesticides in the spraying schedule revealed a risk, although some of the persistent and banned pesticides may continue to do so.

CONCLUSION

Spraying schedules are good predictors of environmental contamination. Monitoring of residues remains essential to determine the real residue concentration in the topsoil. SSDs proved valuable. It was inferred that in addition to the standard test with the earthworm Eisenia fetida (Savigny, 1826), an arthropod test organism such as Folsomia candida (Willem, 1902) should be used in future risk assessments because it displays higher sensitivity towards insecticides.