Environmental Remediation - Science topic

Dear Ipsita Priyadarshini, the question should be more specific in order to get clear and precise answers. In general, the most promising and attracting in BM-NPs is the synergy in properties that arises after such combination. The morphological form of the built structure also has its influence. My Regards

Microbes frequently interact with each other within or upon their animal host, and a rapidly increasing number of studies now shows that these interactions can have substantial effects on host. The following link includes the diversity of microbial interactions, and the variation in their nature and impact on the animal host that have been determined by differences in symbiont diversity.

Kindly check the following review link in which the results of cutting-edge research about the interactions between a range of aquatic species and microplastics, including effects on biota physiology and secondary ingestion have been summarized:

Also, kindly check the attached pdf that may be useful:

@francisco thanks for your valuable answer.

Thank you Dariusz Prokopowicz

The above statement is like this:

I agree with Panagiotis Kirmizakis. You can check the paper below for more details:

Regards,

K

Walter Ojok interesting question and even i would love to see the right answer

Most probably degenerate parametric amplification circuits are what you are looking for.

Unfortunally for you, USA and Soviet applications are secreted, and control of energy produced by these as well.

Silver nano-particles are toxic to varieties of organisms. Silver-based biocidal material is used for commercial & healthcare textiles.They have exhibited 99% efficacy against the spread of bacteria. They also showed a broad spectrum.fungicidal activity. As far as the mechanism of action is considered Silver nano-particles release silver ions, which act as the biocidal species .

Climate change, water and social justice are critical issues. However, I am uneasy about suggesting a focus. Instead, I encourage you to explore these questions to determine your research question:

This is the toughest question to answer, because we often don’t know what we want until we see it. On the other hand, if you don’t know where you are going, any road will do. How could your research help prepare you for what you want to do with your life after graduation?

Do you want to work for a private, public, or NGO organization? Do you already have a wish list of two or three? Might one of them be prepared to sponsor your research on a particular topic that they need to explore? That conversation would help you to get to know them, and help them to get to know you, so you can test your mutual comfort with a longer term relationship. Plus, they might help cover the cost of your studies.

A masters is a lot of work. You need to be energized to learn the findings of your research because you want to know — not me, or your supervisor, or a prospective employer. You. Why do you want to know the answer to your research badly enough to invest the time and money to find out? Don’t do the masters for the credential; do it for the increased knowledge about something that you care about.

Sustainability issues are huge. What needs to be added to the body of knowledge about them that people don’t already know about? For example, what would it take to have governments use sustainable public procurement to only allow suppliers who disclose their contributions to the SDGs to bid on tenders? Is it lack of knowledge or lack of action, or both? Think of your thesis as a draft of a guidebook. Ideally, who would you like to read it so that they can be more effective? One of my books was my master’s thesis, another was my doctoral thesis. I wasn’t doing the research to get another certificate on my wall; I was doing it so that the book would be a more effective instrument for change.

These questions reinforce that a masters should be a means to an end, not the end itself. You want to do the research so that ….(what)? Have fun with the questions, take your time, and I know you will enjoy exploring ways to leverage your research.

I hope this helps a bit. All the best.

hi,

Are you directly irradiating the water sample with the available light sources? If it is so, the process is not going to give you any hydrated electrons. The generation of hydrated electrons require an exact electron energy match/transfer from the excitation energy source to the matter (fluid) under study. In case of water, i guess it is in the range of 2-3eV per electron. The lifetimes of these electrons are extremely short of the order of picoseconds. So unless you have some substrate material submerged in the fluid or very high electric fields (pulsed laser sources), you will barely see any practically cognizable results. The power of the source will be useful when the excitation energy is available to form the hydrated electrons. The power (intensity) of the source will decide the amount of hydrated electrons to be generated.

For the case of using Xenon lamp only, use (this does not guarantee the generation) some kind of nanoparticle suspension in the water which can absorb the incident radiation and provide the hydrated electrons. To visually confirm the formation has taken place, use some sort of organic dye which will undergo degradation (changing its colour) over a certain period of exposure to the incident light. Try to use minimum volume of the fluid and expose its maximum area/volume to the incident radiation,. All these parameters are to be optimised (Trial and error approach) as you go along with the experiments if you have to stick with the available infrastructure. Make sure you know the specs of the lamp or laser and are someway compatible to be use in this experiment!!!

Regards

Brassica juncea is the most suitable plant for phytoremediation of heavy metals.

Well,

It is very difficult to conduct one method for treating different pollutants at once, as the type of pollutants is determined, for the purpose of determining the effective field remediation method.

Regards

If redox potential would be 100 mV, it is rather questionable if any dissolved oxygen would be present in water. For Biodegradation of MTBE much more important is presence of dissolved oxygen (aerobic conditions) in the environment than redox potential value.

Try google to find more information on MTBE biodegradation. There is planty of information there.

Good Luck

Vit

Please see the following links:

https://www.jstor.org/stable/25045719?seq=1#page_scan_tab_contents

and attached papers.

Regards

Vit

Please take a look at these useful PDF attachment.

Dear Aarthy,

Based on my chemistry knowledge, Potassium dichromate VI (K2Cr2O7) is an oxidizing agent that oxidizes in aqueous solution to produce potassium cation (K+) and chromium anion (Cr2O72−). It has Molar mass of 294.185 g/mol

From your question, 50mg/ml (i.e. 0.05g in 1 ml) is equivalent to 50g/litre

As such, the Molar conc. of your preparation = 50/294.185 = 0.170 M

For 1L preparation, measure 50g of Potassium dichromate VI and dissolve in 1000ml of distilled water.

For other preparation you can use this formula (M1/M2=V1/V2). Where M1 (50g) and V1 (1000ml) is the mass and volume of known; M2 (mass of unknown) and V2 (volume of your preparation)

e.g. For 100ml preparation, measure 5g and dissolve in 100ml of distilled water

Finally for 50ml preparation, measure 2.5g of Potassium dichromate VI and dissolve in 50ml of distilled water.

Hope it helps. Best regards

Good information

Thank you for the suggestion!

The most important consequence of the quantum confinement effect is the size dependence of the band gap for nanocrystalline semiconductors. By confining the exciton of a semiconductor, the band gap may be tuned to a precise energy depending on the dimensionality and degree of confinement .

Some others to consider are found in the attached papers.

Best,

KC

in the specific case of heavy metals, the macrophytes play a fundamental role in the process of complexing these metals, thus absorbing them without showing its toxic effect. The rhizobacteria in the other hand contribute in the bioremediation by changing the state of oxidation of the metals to less toxic species and by achieving the precipitation and immobilization in the soi.

Good answer prof. Bachir.

I am sure if you google you will find many papers about biosorption.

Regards

The case of bacterial multimetal resistance  is a bit different from resistance to single metal but is more worthy as a tool for bioremediation. I am particularly interested to tolerance and resistance strategy and the cellular, biochemical and molecular mechanism involved there. How does escape mechanism and tolerance in course of time evolves as an adaptive  strategy and means of detoxification and/or removal?

We should know the current state of the site chemically and biologically and pathologically, by conducting scientific study, such as chemical biological analyses, and relevant experiments, among many others.  Based on regulatory science and engineering approaches, utilizing available data and newly found facts and data, we would be able to establish tentative measures to minimize harms and best available, new regulations, which will be effective in years to come.    

Interesting discussion...

 

Abstract : Oxidative stress inducing potential of fly ash leachate (FAL) was studied in a freshwater fish, Channa punctata (Bloch). Fish were exposed to fly ash leachate for 24 h and lipid peroxidation (LPO) was studied as a marker of oxidative stress. Catalase (CAT), glutathione S-transferase (GST) activities and levels of reduced glutathione (GSH) were also estimated in the exposed fish. FAL (1 ml/l) induced LPO in all the organs and most prominent response was in the gill. It also caused induction of enzymes and glutathione. Liver showed highest level of induction of enzyme activities. The results of this study demonstrate that fly ash constituents have potential to induce oxidative stress in fish and gills are the most vulnerable organs. It is also suggested that in case of exposure to FAL, along with LPO antioxidant defense is also activated to counteract the reactive oxygen species (ROS) at least partly in the initial stages of exposure.

Researchers Take a look at Govindarajan, B, and V. Prabaharan. 2014. Gut microflora of earthworm a review.  It is a very understandable review and stresses the importance of fungi for a nutritional role for earthworms. They suggest the proliferation of bacteria in the gut results from soil substrate and fungal material being decayed. Fungal material is higher in soil and is reduced in the later parts of the earthworm gut. After fungal digestion the bacterial components increase feeding on the decay products as such bacteria increase during the same passage results for fungal and protozoa used for the nutrition process. Diversity of bacterial flora include 7 species of Bacillus genus which are noted for their ability to serve probiotic roles in plants and animals Bacillus species are noted for copious ability for extra cellular polysaccharide substances which are very important for soil macro and micro aggregation process in soil. The casting generally has a much more diverse microbial composition than the soil ingested.  In terms of bioremediation the earthworm casting is famous for ability to provide humic fractions which are capable of sequestering toxic materials such as heavy metals preventing toxicity for earthworm and in the environment. This humic fraction is probably the result of the microbial action also.  In terms of bioremediation the ability of fungi to degrade phenolic chemicals of notorious role as contaminants in soils especially those that become contaminated by petroleum based materials that are rich in toxic phenolics which are not readily degraded by many soil organisms. 

Check EPA website

Most of the studies have been done with regard to biochar originated from plant biomass. Application of biochar , especially in acid soils has proven more beneficial than alkaline soils.  hoever , there are  pressing documents to prove that biochars are equally effective in alkaline soils as well . Application of biochar invariably improves the adsorptive capacity of soils through enhancement of CEC of soils, therefore , better NUE can very well be anticipated. If it is acidic soils , it brings an improvement of soil pH , thereby ,  brings  conspicuous imprvoments in soil fertility plus biological soil properties as well. but , the most distinctive advantage of biochar as an physical amendment is the  provision of carbon contributing handsomely towards the non-labile fraction of soil SOC, as the carbon from biochar has maximum residence time compared to ant other form of organic residues including the organic manures... 

Thank you sir.  is ZVI available on market? laboratory synthesis to it have only minimal yield.

thanks you so much Sir Kanhaiya  

The only significant way to demonstrate that a transformation product (TP) derive from a specific parent compound is the use of labelled parent compound. But this is expensive and unpractical, becuase there are few commercially available labelled compounds. So the most of the degradation pathways are inductive and founded on the knowledge of the chemical reactivity

With metal, but because of the protonation, as said before, the groups where they can attach are very limited.

I had this written somewhere else, but it may help to understand the concepts.

Q and removal % are calculated from the same data. But the sorption capacity is given by the Q not by the removal. They measure metal removal: Q from the point of view of the sorbent and the % from the point of view of the solution.

We can say that the Q is sort of a measurement for how many functional groups are occupied or can be occupied in the sorbent, but the removal refers to the metal that is missing from solution after incubation.

e.g. 1 g biochar incubated in 100 mL solution of 10 g/L metal. After 1 h of incubation, the concentration is 9 g/L.

Based on that, the removal would be 10% and the Q would be 100 mg/g. It would be possible to say that in those conditions the sorbent is saturated, given that most of the metal remains in solution.

Hypothetically if you would increase the volume used,e.g using 1 L solution instead of 100 mL and leaving all the other parameters intact, the removal would drop to a 1% but the Q would still be 100 mg/g. Off course this would be debatable, as the ratio of sorbent/solution would be 10 times lower.

Its really a very interesting question. Chlorella sp, can be used for bio-remediation purpose as there are several works suggesting it's bio-accumulation potential (El-Sheekh et al. 2000; Franklin et al. 2002). Work on metal uptake on Chlorella sp is going on since a long time (eg. Ting et al. 1989, 1991). The previous answers already have shed light into the toxicity effect of Chlorella sp on fishes. But I would like to introduce another angle of thought; that what would be the condition of the native algal species when a external species is introduced into a river system. It can competitively exclude the natural phytoplankton diversity and algal community composition (Reynolds 2003;Zettler 2002). Its my thought that ecological effect of introduction of a species on local community structure could also be investigated before consideration of introduction of a bio-remediating species.

Thank you Dr. Vallero for the beautiful and extensive explanation. The anaerobic microenvironments are actually quite prevalent in sponges. Though it hasn't been published, scientists from Isreal have found that in some sponges, the anoxic zones could last for hours (even in their water canals) and sometimes the pumping activities were completely interrupted. I couldn't figure out the possible sources of aromatic compounds in sponges till now. The metabolism of phototrophic bacteria as you suggested, the PBDEs from marine heterotrophic bacteria, the aromatic carboxylic acids derived from plants and animals, as well as human activities could all contribute to the existence of aromatic compounds in sponges. In my study, I also found there was a negative correlation between the aromatics removal and starch utilization, which implied aromatics were utilized by microbes as nutrition. Additionally, the aromatics degrading gene diversity correlated positively with the bacterial microdiversity. 

I wish the attached files will help for your reference

Both chemical preoxidation and addition of surfactants maybe an option in special cases, especially for the components refractory to biodegradation.

Adding the same time is counterproductive because both will eat each other. For labscale experiments we experienced beneficial effect of adding first oxidant than surfactant (case of PAH contaminated fine fraction). For application of surfactants for recalcitrant PAH contamination in our experience one has to avoid preferential biodegradation of surfactants. See http://appliedcolloidssurfactants.blogspot.com/2005/07/open-source-surfactant-combinations.html

It is common practice on some plants to periodically inject formic acid into the air pipes to maintain the diffusers. However every few years they will need replacement anyway.

Do you want to take samples  for analysis or use the dust as a source for reusing the (heavy) metals?

The other answers were very good.  Be sure to capture your off gas generated.  This is both to protect you and your colleagues and provide additional data.  If you capture the off gas, for instance on activated carbon, you can then 'desorb' the captured material for analysis by GC or GC/MS.  This will give you information on your mass balance, any degradation, efficiencies, etc.

Hi Joyti,

Having worked in RBLM for hydrocarbons, Arsenic in real field soils, my recommendation is -implementing RBLM should be underpinned by site specific scientific evidences. 

Personally I would avoid using the term "ecosystem health".  It's one of those phrases that is used without any real thought as to what it means, and once you start pulling it apart means nothing at all.  Any ecosystem that supports its component species could be considered "healthy". but that would include ecosystems that appear very degraded from a human perspective, e.g. a highly eutrophic lake.  It's much better to think in terms of ecosystem functions, flows of energy and nutrients, presence of native species and their interactions, etc.  

Cyclodextrins have a hydrophobic core where low polarity organic contaminants will partition into from the water phase. This can be used to increase the solubility of many organic contaminants to increase contaminant extraction from soil and groundwater using cyclodextrin with water flushing or washing. Some cyclodextrins can also be used to complex and enhance the extraction of metals at the same time as organic contaminants.

Please see my attached paper:

Carroll, K.C., and M.L. Brusseau (2009) Dissolution, Cyclodextrin-Enhanced Solubilization, and Mass Removal of an Ideal Multicomponent Organic Liquid. Journal of Contaminant Hydrology, 106(1-2): 62-72.

In my humble opinion:

1) The BCA will give a quantitative benchmark whether the project is go or no go. But in the project concerning ecological aspect, the community participation is an essential factor for its success. This factor is quite difficult to include in the analysis.

2 & 3) The debate between quantitative and qualitative method is always a big issue and it is never ending debate. They have different approach. However, nowadays researchers and scientist encourage multidisciplinary approach to solve the problem, I think a good methodology will develop soon.

As you know, tert butyl mercaptan is volatile with relatively low Kow and aqueous solubility around 2000 mg/L. One would expect it to be susceptible to oxidation. You could determine the amount of oxidant needed by doing a total oxidant demand test of the soil as outlined in 2003 paper by Haselow et al. (Remediation,Autumn, 2003, pp 5-16).  

To remove it from soil, the most effective (and least costly method) would likely be air sparge and soil vapor extraction and I would start by doing that since it will reduce the oxidant demand of the soil (if you later wanted to amend with a chemical oxidant for example). Although the theoretical analysis of potential reactions is important, bench tests of soil samples from the site (using different oxidants) and a field pilot test will be the most effective way to solve your problem and will also provide insight into the theoretical reaction pathways.

To treat the off gas of an air sparge SVE you may want to consider a flame oxidation unit,  UV /ozone or other activated radical-based process. Researchers have also had success with sorption to activated carbon.

Interest in the microbial biodegradation of pollutants has intensified in recent years as mankind strives to find sustainable ways to cleanup contaminated environments. These bioremediation and biotransformation methods endeavour to harness the astonishing, naturally occurring, microbial catabolic diversity to degrade, transform or accumulate a huge range of compounds including hydrocarbons (e.g. oil), polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), pharmaceutical substances, radionuclides and metals. Major methodological breakthroughs in recent years have enabled detailed genomic, metagenomic, proteomic, bioinformatic and other high-throughput analyses of environmentally relevant microorganisms providing unprecedented insights into key biodegradative pathways and the ability of organisms to adapt to changing environmental conditions. Source: http://www.highveld.com/microbiology/biodegradation.html

Perhaps you can separate it with magnetism. 

I have not worked on numerical modelling as of yet. However, since Cd is non essential and lacks it own transmembrane through which it can be accumulated and translocated to other parts of the plant, it might be useful if you consider interactions with those essential element that are normally displaced by it

Hello! Perhaps the following research articles (or references therein) will be of some assistance to you in your research endeavour:

Metallophytes in Latin America: A Remarkable Biological and Genetic Resource Scarcely Known and Studied in the Region (GINOGNOCCHIO and BAKER, 2004)

Removal Process for Arsenic in Constructed Wetlands (LIZAMA et al., 2011)

Assessment of the Phytoremediation Efficacy of Boron Contaminated Waters by Salvinia natans (HOLSTRA et al., 2010)

Remediation of Heavy Metal Contaminated Soils: Phytoremediation as a Potentially Promising Clean-Up Technology (MARQUES et al., 2009)

Metal Uptake, Transport and Release by Wetland Plants: Implications for Phytoremediation and Restoration (WEIS and WEIS, 2004)

Suppose that we intend to find anomaly. In parametric method, we have mathematical insight about threshold as we have to know the distribution. In Non-parametric method, we need to calculate I.Q.R i.e., inter quartile range and then take 1.5 times I.Q.R, why 1.5 times? So adhoc value, not based on rigorous mathematics.

Dear Gautam

Is IRMS laboratory available over there in Hyderabad?

Thanks all for the very useful thoughts. I deliberately delayed to see more opinions. The test area is to be divided into 'micro plots' each measuring 3m X 6m with about 18 sampling grids present per plot so as to maintain lateral spread of sample collection. The intended/prefarable depth of oil contamination is 1.5-2.0m while the intended concentration of TPH is 30,000ppm for high impact soil and 10,000ppm for low impact soil. At the moment, I am trying to figure out mathematical modelling of tidal flow and velocity, ground water percolation and other field specific parameters of interest. Abraham's suggestion seems tenable using aquarial aerators, I am guessing the technicality of concern there will be how the pumped in water drains out without contaminating other test beds beacuse a good number of products will be tested, and there exists concerns for third party land contamination.

Davidson, the area penned is quite mashy, exacavation will be highly difficult especially if the tides are seasonal and high, but your thoughts seem very sound, I ma thinking along moving to another spot and shrinking the test plots.

Daniel, I will very much appreciate a mesocosm model if you have one handy, if regulatory approvals become tedious we might have to do a laboratory trial and simulate that to field situations as much as possible.

Edward, we are looking at replicating a near-live situation.

Capucci, the baseline soil is chikoko mud, it holds alot of moisture and almost not permeable. except for areas where crab holes can channel contaminants and test products to ground water. There are no physical boundaries hindering prospective test plots from tidal action. However, regulatory constriants might hinder our setup moving too far out into third party plot, Now, if we decide to artificially contaminate, we might not exactly get field situations.

Sukla, any further required information will be availed you.

Regards all and please keep your thoughts coming, they have been quite useful. I eargerly await more.

If you have huge financial resources you may do so.

Biochar is much cheaper.

The report suggested by Greg is of much use for me to monitor river from my area.

I have seen the paper, As biosorption by nutshell & pine.

Many thanks Chen and Kent for your reply! I have just noticed that I didn't give the number for the desired level accidently. It is between 200 and 500 ng I-TEq/kg.The sites you are referring to are obviously far from it. Therfore you are right that shipping will be the most challenging part.

I'll let you know if we will be not sucessful to get material containing the desired level and contact you directly.

Well, based on my experiences working in the field, reducing excessive nitrate requires mutliple solutions ranging from good farm management strategies, innovative farm irrigation schemes, careful design of farms in relation to land geomorphology & geology, to educating the farmers to use biofertilizers instead of synthetic fertilizers. In addition, a selective planting strategy of plant species that can mop up these nutrients will also be useful if constructed wetlands form part of this nitrate reduction strategy: https://www.researchgate.net/publication/235873867_A_SELECTION_OF_PLANTS_FOR_GREENING_OF_WATERWAYS_AND_WATERBODIES_IN_THE_TROPICS?ev=prf_pub