Environmental concerns pollution control

Cement plants in the United States are now carehiUy monitored for compliance with Environmental Protection Agency (EPA) standards for emissions of particulates, SO, NO, and hydrocarbons. AH plants incorporate particulate collection devices such as baghouses and electrostatic precipitators (see Air POLLUTION CONTROL methods). The particulates removed from stack emissions are called cement kiln dust (CKD). It has been shown that CKD is characterized by low concentrations of metals which leach from the CKD at levels far below regulatory limits (63,64). Environmental issues continue to be of concern as the use of waste fuel in cement kilns becomes more widespread. 

It is obvious that such an assessment is formidable, technically difficult, and extremely expensive. Since an environmental source assessment study is required to characterize the total pollution potential of all waste streams, the sampling program must be more extensive than those conducted for the acquisition of process or control engineering data. Assessment sampling is more complete in that all waste streams are sampled and no attempt is made to limit sampling to a preselected number of process streams. The sampling is also more comprehensive in that all substances of potential environmental concern must be detectable above some minimum level of concern. These requiements of completeness and comprehensiveness call for a strategy of approach in which the philosophy and structure ensure maximum utilization of available resources. 

Sulfur chemistry is important both in combustion and in the petrochemical industry. Most fossil fuels contain sulfur, and also biofuels and household waste have a sulfur content. As a consequence sulfur species are often present in combustion processes. Knowledge of gas-phase sulfur chemistry occurring in combustion has bearing on pollutant emissions and on system corrosion. Air pollution by SO2 still constitutes a major environmental concern and search for control techniques has motivated research also on high-temperature homogeneous sulfur chemistry. However, more recent work on sulfur chemistry has been concerned mainly with the effect of sulfur on other pollutant emissions, such as NO and CO, and with the SO3/SO2 ratio, which is important for the corrosive potential of the flue gas and for formation of sulfur containing aerosols. 

Notes B1 = survey on the actual condition of chemical substances in the environment (until 2001) B2 = survey on the actual condition of chemical substances in the environment (after 2002) D = survey under the Law concerning Special Measures against Dioxins E = survey on the environmental endocrine disrupters W = survey under the Water Pollution Control Law A = the air pollutants monitoring O = other survey. Details of the survey on the actual condition of chemical substances in the environment refer to Ministry of the Environment web site http // www.env.go.jp/chemi/kurchen/index.html (also refer to annual reports before FY1996). 

Furthermore, from around 1996 onward Japanese public became increasingly concerned about environmental contamination caused by releases from waste incinerator facilities. In 1997 dioxins were designated as hazardous air pollutants and measures were introduced to control their emission into the atmosphere in terms of the preventive actions taken to reduce risks of health hazards under the Air Pollution Control Law (Law No. 97 of 1968). Furthermore, in July 1999, the law concerning special... 

Not noted above is the profound effect that environmental concerns have on new products and processes. It was mentioned earlier that the chemical manufacturing industry spends about five billion dollars annually on pollution and environmental control. Thus, the entire staff of an organization must be aware of these costs and have concerns for the environment when new products and processes are created. 

Environmental concerns of lime kiln operation chiefly relate to exhaust gas dust control and are usually solved by water scrubbing. The slaked lime (calcium hydroxide) produced by the scrubber can be employed as a base in the operations of a chemical complex, or sold. Electrostatic precipitation of precooled gases is also used, sometimes in series with water scrubbing. The dissociated carbon dioxide discharged is not ordinarily regarded as a pollutant. The amount discharged from this source is far less than the carbon dioxide produced by fossil fuel combustion. Lime kilns associated with Solvay ammonia-soda plants may be able to recycle a part of the dissociated carbon dioxide, particularly if the concentrations are raised by the use of oxygen-enriched combustion air. Recently, interest has been shown... 

The need for such sensors is unquestioned whether one is concerned with environmental pollution control, general air management, e.g., in airplanes or other closed rooms, or with the detection of bio-hazards, the food industry, the cosmetic industry - the list of potential customers is endless. 

In the process involving hydrogen cyanide, treatment of process waste water becomes an issue of environmental concern in addition to the air pollution control. 

The Clean Air Act Amendments of 1970 along with the National Environmental Policy Act, which created the Environmental Protection Agency (EPA), put some strong measures into air pollution control enforcement. The U.S. Environmental Protection Agency is responsible for implementation of the statutes of this law. The first air pollutants covered by this law of concern to the fuels industry were SOx and NOx. Since the passage of the Clean Air Act Amendments of 1970, a series of additional U.S. Federal environmental laws affecting various industries have been passed ... 

---