Studies on the Corrosion Performance for Steel Embedded in Fly Ash Blended Concrete

The present investigation it to study the corrosion performance of fly ash blended cement concrete in chloride-contaminated environments by various electrochemical and non-electrochemical techniques. The chloride binding ability at the optimum replacement level of fly ash was also studied

Comparative studies on the corrosion performance of steel in concrete in natural, polluted and marine environments

Performance studies of two different cements were carried out by electrochemical and non electrochemical techniques on concrete specimens exposed to natural, polluted and marine environments. It was observed that ordinary Portland cement (OPC), showed better performance than Portland pozzolona cement (PPC). Microbiological examination was conducted and found that 10 micro-organisms were present in the sewage. Out of these, sulphate reducing bacteria (SRB) mainly led to deterioration in the concret

Electrical and electronic waste: A global environmental problem

The production of electrical and electronic equipment (EEE) is one of the fastest growing global manufacturing activities. This development has resulted in an increase of waste electric and electronic equipment (WEEE). Rapid economic growth,coupled with urbanization and growing demand for consumer goods, has increased both the consumption of EEE and the production of WEEE, which can be a source of hazardous wastes that pose a risk to the environment and to sustainable economic growth. To address potential environmental problems that could stem from improper management of WEEE, many countries and organizations have drafted national legislation to improve the reuse, recycling and other forms of material recovery from WEEE to reduce the amount and types of materials disposed in landfills. Recycling of waste electric and electronic equipment is important not only to reduce the amount of waste requiring treatment, but also to promote the recovery of valuable materials. EEE is diverse and complex with respect to the materials and components used and waste streams from the manufacturing processes. Characterization of these wastes is of paramount importance for developing a cost-effective and environmentally sound recycling system. This paper offers an overview of electrical and e-waste recycling, including a description of how it is generated and classified, strategies and technologies for recovering materials, and new scientific developments related to these activities. Finally, the e-waste recycling industry in India is also discussed

Performance evaluation of low cost adsorbents in reduction of COD in sugar industrial effluent

Studies on reduction of chemical oxygen demand (COD) in effluent from sugar industry have been carried out by employing different absorbents optimizing various parameters, such as initial concentration of adsorbate, pH, adsorbent dosage and contact time. Experimental studies were carried out in batches using metakaolin, tamarind nut carbon and dates nut carbon as adsorbents by keeping initial adsorbent dosage at 1 g l−1, agitation time over a range of 30–240 min, adsorbent dosage at 100–800mg l−1 by varying the pH range from 4 to 10. Characterization of there adsorbents were done using techniques such as Fourier transforms infra red spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). The experimental adsorption data fitted well to Langmuir and Freundlich adsorption isotherms. The isotherms of the adsorbents indicate appreciable adsorption capacity. Higher CODremoval was observed at neutral pH conditions. Studies reveal that maximum reduction efficiency of COD takes place using metakaolin as an absorbent at a dosage of 500mgl−1 in a contact time of 180 min at pH 7 and it could be used as an efficient absorbent for treating sugar industrial effluent

Textile technology

This review discusses cotton textile processing and methods of treating effluent in the textile industry. Several countries, including India, have introduced strict ecological standards for textile industries. With more stringent controls expected in the future, it is essential that control measures be implemented to minimize effluent problems. Industrial textile processing comprises pretreatment, dyeing, printing, and finishing operations. These production processes not only consume large amounts of energy and water, but they also produce substantial waste products. This manuscript combines a discussion of waste production from textile processes, such as desizing, mercerizing, bleaching, dyeing, finishing, and printing, with a discussion of advanced methods of effluent treatment, such as electro-oxidation, bio-treatment, photochemical, and membrane processes

Study on strength and corrosion performance for steel embedded in metakaolin blended concrete/mortar

It is an undeniable fact that concrete is the most widely used man-made construction material in the world today, and will remain so for decades to come. The popularity of concrete is largely due to the abundance of raw material, low manufacturing and maintenance cost, excellence in compression, and corrosion aspects, durability to weathering and fire hazards, versatility in forming various shapes and its unlimited structural applications in combination with steel reinforcement. However, the cement industry is also highly energy intensive, and the emission of carbon dioxide during cement manufacturing has created enormous environmental concerns. There has also been an increase in the number of incidents where concrete structures experienced severe deterioration in extreme environments. All these factors have contributed pressures from various quarters to reduce cement consumption, and to intensify research in exploring the possibilities of enhancing strength, durability and corrosion reduction through the use of pozzolans as supplementary cementing materials. The utilization of calcined clay in the form of metakaolin as a pozzolan for concrete has received considerable interest in recent years. The use of metakaolin as a mineral admixture for concrete is a well documented practice. Metakaolin is a quality enhancing pozzolan for concrete. It is manufactured from kaolin which is abundance in India and other parts of the country. In the present investigation mechanical property and corrosion behavior of carbon steel using metakaolin (5–20%) as partial replacement in ordinary Portland cement (OPC). Compressive strength, resistivity, ultra pulse velocity, open circuit potential, studies on water absorption, weight loss were studied. It was found that up to 15% replacement of metakaolin in OPC improves the mechanical properties of concrete. Corrosion of carbon steel improved by the addition of metakaolin up to 15%

Environmental effects on concrete using ordinary and pozzolana portland cement

Wastewater treatment plant consists of pipe lines and lift stations. These plants consist of concrete pipes, manholes, pump stations, interceptors and wet wells. Entire wastewater (WW) system is forced to chemical attack due to the presence of sulphate and acid available in WW. It leads to the damage in the interior wall or structure of a sewer pipe and lift station. A concrete structure when exposed to different environments, the life of the structure is drastically reduced. Main cause of the deterioration is corrosion or erosion. The defective structures are replaced periodically which leads to indirect loss in the national growth. In other words, the failure of these structures may lead to invest more on the repair and rehabilitation. In this study, the strength of the concrete in various environments has been investigated using different techniques such as compressive strength, flexural test, rapid chloride permeability, weight loss measurements, linear polarization and open circuit potential. Microbiological examinations were also analyzed. Two types of cement namely Ordinary Portland Cement (OPC) and Portland Pozzolana Cement (PPC) with one mix ratio were used for complete study. Concrete specimens exposed in three environments namely: normal water (NW Potable water), domestic sewage water (DSW) and textile wastewater (TWW). From the results, it is observed that PPC exposed in different media shows better performance than OPC in both mechanical and electrochemical studie

Management of Biomedical Waste in India and Other Countries: A Review

The objective of this study is (i) to summarize the rules for management and handling of biomedical wastes, (ii) to give the definition, categories of biomedical wastes, suggested storage containers including colour-coding and treatment options, (iii) mainly to highlight the effects of biomedical waste in the environment such as air, land, radioactive pollution and (iv) disposal of wastes, regulation and recommendations. Health-care waste management in several countries including India is receiving greater attention due to stringent regulations. The waste generation rate ranges between 0.5 and 2.0 kg bed-1day-1. The solid waste from the hospitals consists of bandages, linen and other infectious waste (30-35%), plastics (7- 10%), disposable syringes (0.3-0.5%), glass (3-5%) and other general wastes including food (40-45%). Several survey works carried out by various research organizations by (Government and Non government and private sectors) have been discussed and reviewed in this paper