Environmental Risk Assessment Of Wastewater With Carbinol In Natural Gas Field

With the development of our society and industrialization, each country of theworld blindly pursuing the growth of GDP at the same time, for the destruction of theenvironment to the containment is the point. Some grave environmental pollutionincidents have occurred that brought great damage to human health and environmentand ecological environment. Environment risk assessment is a necessary work thatcould prevent environmental pollution accident and provide effective measures. Atpresent, there is no emission standard concerning the carbinol wastewater by processingof distillation column in natural gas field. Our study introduced the results of the healthrisk assessment and ecological risk assessment about the carbinol wastewater.We determined the concentration of methanol steam in the air, and we got thehealth risk value through exposure dose and exposure dose from human body contactdirectly and the inhaled of the carbinol. Combined with methanol content logarithmnormal distribution functions, through probability statistics and Monte-Carlo methods,we evaluated the results by the figures of probability distribution and risk accumulation.The result showed that methanol wastewater to the human body health hazard mainlycame from the methanol steam in the air (more than80%of the total risk), in order toavoid the harm to human body from the carbinol wastewater, the limitation of themethanol steam concentration in the air is307.07mg/m~3.By selected several typical aquatic animals and mycorrhizal fungi as riskreceptors, as well as determined the concentration of half to death, we determined theconcentration of methanol steam in the air and calculated risk attribute coefficient bymeans of the commercial value method, thus, we valued the carbinol wastewater for the potential risk of ecological assessment in two ways, wastewater discharge directly viaditch and soil infiltration. It turned out that when the carbinol maximum concentrationin the wastewater is26670mg/L actually, there would be harmful to green alga, waterflea, duckweed, protozoa and mycorrhizal fungi, while it would cause low ecologicalrisk to fish and Rotifera. By calculating the threshold of the carbinol concentration inthe wastewater, we found that when the carbinol concentration in the wastewater ismore than10000mg/L, the ecological risks will be caused to the aquatic animals andmycorrhizal fungi. Therefore, it is essential to process carbinol wastewater properly,and purify the air of work environment. The research results have a significant guidelinevalue for producing in changqing natural gas field.