Prof. TA Alasadi, 

Thank you for your resource. However, my questions are yet to be answered. I will find some resources in the pdf attached very useful. Once again, thank you. 

Dear John,

I'm not sure if I understood your question but I'll try to answer.

A - Either if you are aiming to do toxicity tests with plants or use the effluent as fertilizer I would use the same sampling mode for all of them. It is important to collect the effluent on the terminal phase of treatment (the effluent reaching the local stream), which represents the most fit scenario for risk assessment of effluents and usage of wastewater for irrigation (for instance). The bottles you store them shall be dark and made of glass (especially for petrochemical, which is volatile rich). Textile, alloy and mechanical are rich in copper and so, it is important to avoid cross contamination with metal parts from samplers.  Food industries are rich in surfactants and organic matter (from washing) and due to that (depending on your usage) it might be smart to keep them on the fridge... If what you want goes for this direction, let me know. Then I can give you more detailed information.

B- Those segments you showed are in general metal rich effluent, and so mutagenic compounds are unlikely to appear for plants. Teratogenic effects may occur in animal after complexation of metals and there is quite some literature on it. Furthermore, from your samples I would strongly bet on petrochemical industries. They are rich in PCB's and PAH's, that are famous for their mutagenic effect (look for ames test with organic compounds).

On the environment, unfortunately, mutagenic are often found in river sediment and retention basins (wetlands, for instance). To give you an idea, much of the domestic WWTP are not able to cope with pharmaceuticals and other trace organic compounds, discharging them with the final effluent. Another place, very easy to find mutagenic compounds, is on the surrounding areas of gas stations (underground water). Due to leakage, they ofter contaminate the soil and adjacent groundwater in developing countries like ours. Still on the line of organic compounds, much of the mutagenic effect can only be observed if no acute toxicity is present (once toxicity don't allow cells to live enough to show a mutagenic effect) and so you should avoid ultra-toxic samples. Search for the ones showing chronic toxicity. From the metals . . . soils and water contaminated with arsenic can represent mutagenic potential (arsenic surrogates phosphorus and so it can be bind to DNA helix). To finalize, two hotspots for mutagenic compounds depending the amount of sample needed. Urban puddles after light rainfall are a hotspot for all the leachate from roads and trash, a promising mutagenic cocktail for you. If you mind to be more rural, just seek for small streams beneath farming. Hotspots for mutagenic pesticides. 

Hope that info will help you to have some steering. Let me know if you need more proper answer about it.

Cheers.

Environmental Research: Best practices for collection of Industrial Effluent. Available from: https://www.researchgate.net/post/Environmental_Research_Best_practices_for_collection_of_Industrial_Effluent [accessed May 5, 2017].

https://www.epa.gov/sites/production/files/2015-10/documents/steam-electric-envir_10-20-15.pdf

Dear Julio, 

I can't thank you enough for your time and resourcefulness. You have not only answered my questions but widen my horizon. Now I have broader view and more methodical approach to tackling my research questions.

I will digest the resources as you have advised and revert for further clarity if any. 

Noteworthy to commend your broad understanding and generosity in knowledge transference. Once again, thank you. 

Regards, 

John