LAND CONTAMINATION AND REMEDIATION<\/p>\n
CHEMICAL FATE AND BEHAVIOUR ASSIGNMENT 2021<\/p>\n
In environmental risk assessment it is often important to predict the likely environmental fate and behaviour of chemicals of interest. Table 1 lists a number of chemical properties for a real, but anonymised, chemical that we will call \u2018chemical Q\u2019. The chemical properties can be used to determine many aspects of the likely fate and behaviour of chemical Q in the environment. <\/p>\n
Table 1 Selected chemical properties of chemical Q<\/p>\n
Chemical property<\/p>\n
Value<\/p>\n
Units<\/p>\n
Octanol-water partition coefficient (log Kow)<\/p>\n
6.29<\/p>\n
–<\/p>\n
Water Solubility<\/p>\n
1.55 x 10-8<\/p>\n
g\/cm3<\/p>\n
Melting Point<\/p>\n
109<\/p>\n
\u00b0C<\/p>\n
Henry’s Law Constant (H)<\/p>\n
8.32 x 10-6<\/p>\n
(atm m3)\/mole<\/p>\n
Density<\/p>\n
1.48<\/p>\n
g\/cm3<\/p>\n
Soil Adsorption Coefficient (Kd)<\/p>\n
204,000<\/p>\n
L\/kg<\/p>\n
Half-life (water) (t1\/2water)<\/p>\n
85.1<\/p>\n
days<\/p>\n
Bioconcentration Factor (soil)<\/p>\n
19,500<\/p>\n
–<\/p>\n
Use the information in Table 1 and your knowledge of chemical fate and behaviour (from lectures and from the literature) to answer the questions below in relation to chemical Q. For each question explain how you determined your answer including which chemical property or properties were relevant and why. Include references (original source not lecture notes) as part of your answer where it is important to provide attribution for information you have sourced from elsewhere.<\/p>\n
Questions<\/p>\n
1. Is chemical X likely to biomagnify in situations where organisms are exposed to chemical X via the food chain? (2 marks)<\/p>\n
2. Based on NICNAS\u2019s criteria for chemical persistance (NICNAS, ND), would you consider chemical X to be persistent in the soil environment? (2 marks) <\/p>\n
3. A site has a shallow plume of chemical X contamination below the soil surface. Would you be concerned about chemical X volatilizing from the soil into the air with the potential for people on the site to be exposed to chemical X via inhalation? (2 marks) <\/p>\n
4. The Quantitative Structure Activity Relation (QSAR) for determining lettuce EC50 for a group of chemicals similar to chemical X is: log EC50 (mg\/kg) = -0.59*1og Kow + 3.68 (r2 = 0.50) Use the QSAR above to determine an estimated lettuce EC50 for chemical X. Include your working out in your answer. (2 marks) <\/p>\n
5. A half-life for chemical X in surface waters (e.g. rivers, streams, lakes) is provided in Table 1. Explain why using a half-life developed for surface water can be problematic in risk assessments of groundwater (2 marks)<\/p>\n
Reference<\/p>\n
NICNAS (ND). Persistent Organic Pollutants Criteria. National Industrial Chemical Notification and Assessment Scheme, Sydney. https:\/\/www.nicnas.gov.au\/notify-your-chemical\/types-of-assessments\/permit-categories\/controlled-use-permit\/controlled-use-eligibility-criteria\/Persistent-organic-pollutants-criteria (last viewed 28 July 2019)<\/p>\n
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LAND CONTAMINATION AND REMEDIATION CHEMICAL FATE AND BEHAVIOUR ASSIGNMENT 2021 In environmental risk assessment it is often important to predict the likely environmental fate and behaviour of chemicals of interest. Table 1 lists a number of chemical properties for a real, but anonymised, chemical that we will call \u2018chemical Q\u2019. The chemical properties can be […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[10],"class_list":["post-78287","post","type-post","status-publish","format-standard","hentry","category-research-paper-writing","tag-writing"],"_links":{"self":[{"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/posts\/78287","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/comments?post=78287"}],"version-history":[{"count":0,"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/posts\/78287\/revisions"}],"wp:attachment":[{"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/media?parent=78287"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/categories?post=78287"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/tags?post=78287"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}