Contamination and remediation of soil Assignment

Contamination and remediation of soil - Assignment Example Thermal desorption system The basic process of DHTD system has been illustrated in the figure 1 given below. The soil is dried through heating it directly with the help of a rotary dryer made up from a high temperature alloy. The rotary dryer comprises of a natural-gas-fired burner that has the capability to heat the feed material up to a temperature of about 550oC or 1,022oF. The rate of heating the feed soil by using the rotary dryer is primarily based upon the moisture present in the soil, the size distribution of the soil particles, and the discharge temperature of the soil. The processed-gas is conveyed to the emission control system from the discharge hood that receives the gas from the rotary dryer. The emission control system consists of the dual cyclones, evaporative cooler, thermal oxidizer, bag house, quench, draft fans with dual induction, supply system of sodium hydroxide, acid gas scrubber, stack, and continuous emissions monitoring system. The natural-gas-fired burner of the rotary dryer is basically fitted with the thermal oxidizer that functions between the temperature ranges of 930oC to 1000oC. The gas is cooled down by spraying an air atomized water stream at the top portion of the evaporative cooler. The bag house conveys the gas to a quench chamber and a packed scrubber through the induced draft fans. Then, in order to remove acid gases from the gas, a pH controlled water stream passes again through the scrubber before the stack discharges the gas to the atmosphere. A double tipping valve, steam hood, pug-mill, steam duct, stacking conveyor and shuttle conveyor are used in the construction of a cooling and handling system for the treated soil. The double tipping valve is used to discharge the soil from the rotary dryer to the pug-mill. The pug-mill also, receives the combined dust streams, through a series of screw conveyors, from the bag house and the dual cyclones. Then the soil is cooled and moisturized through spraying water in to the p ug-mill. Subsequently, the shuttle conveyor passes the cooled and moisturized soil discharged from the pug-mill to a stacking conveyor that, in turn, passes it to the stockpile of the treated soil. The steam-duct transfers the stream discharged from the pug-mill in to the evaporative cooler. The stockpiles of 500 ton each hold the treated soil until they are analyzed for complying with the treatment criteria. Figure 1: The Overview of the DHTD System (Troxler et al. 2010)2. Project Schedule The table 1 given below presents the major milestones related to the implementation and licensing of the thermal treatment plant project. Table 1: Project Schedule (Troxler et al. 2010)2. Commissioning Trials The testing sequence proposed for the selected approach at the site included a process comprising of two stages. In the first stage, the plant processes the non-contaminated soil in order to ascertain that all of the electrical, mechanical, and control equipments are working properly. Then, in the second stage, the plant processes the above-average concentration of the contaminated material which takes about 6 to 7 hours. EPA observed, in the preliminary review of the EIS, that the testing sequence should not include a one-step change from ‘0’ to above average concentration of the contaminant material. Demonstrated performance is required by EPA throughout the range of soil contamination. EPA also, suggests that the

Satyam Computer Service Accounting Scam Essay Example | Topics and Well Written Essays - 1000 words

Satyam Computer Service Accounting Scam - Essay Example After resignation of Srinivas Vadlamani as chief financial officer Ram Mynampati was appointed as the interim CEO of the Satyam computer services and this turned to be the worst scam in the company history. After an audit that was done the report stated that the company cash was not encouraging since the company was in a state of collapsing. After the scam, the aim of Satyam computer services is to ensure that the business continues. After the fraud was noticed, the government of India disbanded Satyam board and the government was not providing funds to the company. A team of auditors from the Securities and Exchange Board of India (SEBI) was appointed to investigate the fraud which is well known to regulate all Indian public companies (Winkler 2010). Satyam computer services is one of the companies that are under Bombay Stock Exchange and still under the New York Stock Exchange, meaning that the company is under the United States international regulators of capital market. The company will face legal process since United States believes that the company has broken the rules of stock exchange. Two of United States law firms are filling lawsuits against the company since the fraud has been in the history as the worst ever scam in India under the New York Stock Exchange and the aim is to recover some of the funds. The scam will have negative effects on the company and the Indian people in coming years since the company was the largest IT service provider and outsourcing giant in India Information Technology. This means Satyam computer service will either be sold but the auditors must recover the funds first if the company will go to that position of being sold. The competitors again will benefit from the company being sold. Its riv als like HCL, Wipro and TCS will pick the best employees and clients thus completely outdoing Satyam