Reinforcement of thermoplastic rejects in the production of manhole covers

Thermoplastic rejects are un-recyclable plastics that are either incinerated causing harmful emissions into the air or land-filled. A common problem associated with manhole covers is the theft of the cover made out of cast iron and then selling it on the black market leaving a large empty hole in the road causing many potential safety and health hazards. This paper investigates the reinforcement of un-recyclable thermoplastic rejects to be used in the application of a manhole cover. Foundry sand and steel were used with the thermoplastic rejects as reinforcement of the material. Foundry sand is a hazardous waste that may cause many potential health hazards. It was shown that with 10% foundry sand, 90% thermoplastic rejects, and a steel mesh of diameter size 12 mm reinforcement, the manhole cover could withstand an average load of 112 kN. This value exceeds Grades A, AA, AAA, and B of acclaimed standards BS EN 124 for manhole covers, which ultimately indicates that the manhole cover may be used in pedestrian precincts and areas with occasional vehicular access. This composite material is produced out of waste materials (foundry sand and un-recyclable thermoplastic rejects) thus not utilizing or depleting the earth's natural resources, and eliminating the safety hazards, health hazards, and pollution associated with these waste materials. Not only is this product a benefit to the environment, but also inexpensive due to the fact that the materials are un-recyclable waste materials, and thus do not attain any value or cost.     

Fluoride distribution and the effect of some ions along Alexandria coastal Mediterranean seawater of Egypt

The coastal seawater of Mediterranean of Alexandria receives large amount of discharged waters containing industrial wastes, sewage, and agricultural and domestic drainage. Fluoride and some parameters were( chemical and physical) determined. The data gave indication that the content and the amount of the discharged water largely affect the chemical composition of the coastal water. Stepwise regression analysis was highly significant and the model was very fruitful, where the observed and calculated values were mostly concordant. This may indicated that there was a relation between fluoride content in cosslal seawater and its content in the discharged water.     

Life cycle assessment of a large water treatment plant in Turkey

Environmental Science and Pollution Research - The objective of this study is to assess the environmental sustainability of a large water treatment plant through life cycle assessment (LCA)...     

Potential control of toxic cyanobacteria blooms with Moroccan seaweed extracts

Environmental Science and Pollution Research - Marine macroalgae are a promising source of diverse bioactive compounds with applications in the biocontrol of harmful cyanobacteria blooms...     

Floating aquatic macrophytes for the treatment of aquaculture effluents

Environmental Science and Pollution Research - Aquaculture is an activity with economic and social importance since it generates food, employment, and income. However, like other human activities,...     

Reduction of atmospheric emissions due to switching from fuel oil to natural gas at a power plant in a critical area in Central Mexico

ABSTRACT

A case study was conducted to evaluate the SO₂ emission reduction in a power plant in Central Mexico, as a result of the shifting of fuel oil to natural gas. Emissions of criteria pollutants, greenhouse gases, organic and inorganic toxics were estimated based on a 2010 report of hourly fuel oil consumption at the “Francisco Pérez Ríos” power plant in Tula, Mexico. For SO₂, the dispersion of these emissions was assessed with the CALPUFF dispersion model. Emissions reductions of > 99% for SO₂, PM and Pb, as well as reductions >50% for organic and inorganic toxics were observed when simulating the use of natural gas. Maximum annual (993 µg/m³) and monthly average SO₂ concentrations were simulated during the cold-dry period (152–1063 µg/m³), and warm-dry period (239–432 µg/m³). Dispersion model results and those from Mexico City’s air quality forecasting system showed that SO₂ emissions from the power plant affect the north of Mexico City in the cold-dry period. The evaluation of model estimates with 24 hr SO₂ measured concentrations at Tepeji del Rio suggests that the combination of observations and dispersion models are useful in assessing the reduction of SO₂ emissions due to shifting in fuels. Being SO₂ a major precursor of acid rain, high transported sulfate concentrations are of concern and low pH values have been reported in the south of Mexico City, indicating that secondary SO₂ products emitted in the power plant can be transported to Mexico City under specific atmospheric conditions.

Implications: Although the surroundings of a power plant located north of Mexico City receives most of the direct SO₂ impact from fuel oil emissions, the plume is dispersed and advected to the Mexico City metropolitan area, where its secondary products may cause acid rain. The use of cleaner fuels may assure significant SO₂ reductions in the plant emissions and consequent acid rain presence in nearby populated cities and should be compulsory in critical areas to comply with annual emission limits and health standards.