Water Environment Federation (WEF) Discussion Forums / Air Quality / Archives / Archived Forum Topics

RE: chlorination of raw influent

01797809 — Fri, 15 Feb 2008 20:05:45 GMT

Consider using Magnesium Hydroxide in a master lift station before it gets to the plant. There is a plus. pH around 8.5 which locks in the hydrogen sulfide and great alkalinity which will improve treatment in the plant

chlorination of raw influent

J.W.Koch — Tue, 27 Dec 2005 19:32:28 GMT

We have a odor problem at are head works. We have an enclosed wet well at our main pump station. Considered using pre aeration but afraid of corrosion from the release of sulfides. Would likely have to enclose and install some kind of ventallation or scrubber? What are the minus and plus of using cl2?

Calcium Nitrate Odor Control Management

01799068 — Thu, 17 Jan 2008 10:59:26 GMT

I am looking for expertise on the monitoring of collection system H2S concentrations as they relate to the addition of Calcium Nitrate feeding into the pump stations of a countywide collection system. We currently feed and meter the Calcium Nitrate and check the effectiveness of the odor reduction by monitoring the H2S levels downstream of the injection point using portable air quality meters lowered in the sewer line. Is this the best way to monitor the effectiveness of the Calcium Nitrate or are other air quality parameters or wastewater quality parameters more useful and accurate?

Hydrogen sulphide removal using chemical scrubbers

zaffrulla — Wed, 09 Jan 2008 02:31:18 GMT

Members,

We are running a municipal waste water treatment plant in abudhabi, for odor control we use chemical scrubbers ( US FILTERS -Now SIEMENS) up to the primary treatment , the chemicals we use are Sodium hypochlorite , Caustic soda.Our H2S levels inlet to the scrubbers are an avagf 250 ppm , we get 98% removal efficiency It is cocontinuouslow and we use NON potable water for dilution.
Can any one tell me what are standard requirements for the NPW consumption , we think that we are using excess NPW if there are standards for this water consumption we are planning to go for Potable water which has less hardness than our NPW which is very HARD.
Is there any relation ship between the inlet H2S levels and the water consumption
We can see that the scrubbers are performing to its maximum but we face the problem of scaling in the media due to this HARD water hence we are planning to switch over to potable water ( less hardness ).As the potable water is expensive in these regions we would like to know the exact requirement based on the H2S levels ?!!!
regards
zaffrulla

RE: Hydrogen sulphide removal using chemical scrubbers

HForbes — Thu, 10 Jan 2008 08:38:18 GMT

We also add a polyphosphate canister to the water line. This has nothing to do with the buildup, but will make it much easier to clean.

RE: Hydrogen sulphide removal using chemical scrubbers

zaffrulla — Wed, 09 Jan 2008 08:22:05 GMT

hai ,
thanks for the reply pls be informed that we already installed softeners for hardness removal but unfortunately they are all under designed ,as the number of plants are more than 8 the client is not willing to install new softener units ( huge investments) instead go for potable water for which consumption quantity is vital
hence pls give me out other soulution ie cals to find out the design consumption
zaffrulla

RE: Hydrogen sulphide removal using chemical scrubbers

HForbes — Wed, 09 Jan 2008 07:56:43 GMT

In the States, we, Siemens offer service agreements for scrubbers. One of the first things we do is add a water softener to heavily loaded units, to reduce the buildup in the scrubber. Over dosing with bleach will add to the problem of scaling as well.

H2S Controls from Acid-Phase Digesters

Jag — Wed, 09 Jan 2008 00:46:29 GMT

Does anyone know if there is a waste water treatment facility that uses a scrubber, iron sponge, sulfaTreat vessels, biotrickling filters or any other type of emission control technology to control H2S emissions from acid-phase digester? H2S concentrations are about 6,000 ppmv with addition of ferric chloride.

Caustic Hypochlorite scrubber for ATAD Offgas

01780898 — Wed, 31 Oct 2007 22:50:55 GMT

Could you please refer to my question in the Biosolids category. Thanks Grant

RE: Caustic Hypochlorite scrubber for ATAD Offgas

mjwboofer — Mon, 05 Nov 2007 12:13:14 GMT

Link to this discussion:
http://www.wef.org/technicaldiscussions/Topic7332-10-1.aspx

RE: Note to Moderator...

Victor — Tue, 30 Oct 2007 22:20:16 GMT

I will have to second and third this. I see no practical reasons to "filter" comments/responses. I've seen and learned quite a bit without having to log into the forum. I will log in when I have a response to make. There are numerous international as well as Stateside participants that are not WEF members that have many things to say and I welcome their points of view--which at times may be far and ahead of what is being done here in the States. Europe, keep the anaerobic digestion and endocrine disruptor research coming. Asia, keep them frugal and affordable treatment processes in the pipeline. There is never a time when we need to be a bit down to earth, introspective, and humble. Complacency gets you nowhere.

Note to Moderator...

SRB — Wed, 17 Oct 2007 17:06:58 GMT

There doesn't appear to be anywhere to post general comments or questions about this forum, so I'm posting here in the first forum marked as a "moderated forum".

I was assuming that this is a resource for WEF members. Most of folks in the currently online list are accessing this forum from a search engine like google, yahoo, msn, etc. Are these folks required to sign in? Most forums that I've been involved in have restrictions about what forums you can get to without being a member - like I would be fine with students accessing job post area or something, but not technical discussions.

I'm keeping anonymous because I don't feel that this is a very secure forum for asking questions to other WEF members without being read by the whole world, including regulators! (I realize that I'm anonymous except to WEF who can look up my member number, e-mail, etc.)

Anyone else have concerns or a moderator like to jump in and explain WEF's position on hosting a forum that is not secure and open to be viewed by anyone on the web?

RE: Note to Moderator...

Old lag — Tue, 30 Oct 2007 18:52:05 GMT

I'm with Terry on this -- I think there is the correct balance where anyone can read the posts but you have to register to post or reply. Most of the times I stop by to read the posts I don't bother to sign in. If there is something interesting I want to respond to I will log on. I really don't understand SRB's reluctance to use this format -- it's a very civilized place to come; it's quick; most of the posts on the fora I look at are relevant to me and I don't bother with topics I know nothing about or don't care about. I don't worry about regulators reading what I write because (a) they don't know who I am and (b) I suspect they don't care unless I admit to something criminal and (c) I try not to post anything which would be embarrassing to me or my employer if it did get out in the open. Glad to see an administrator (even if he is a newbie -- when did you last see a board admistrator with that title??) with a light hand. But don't make people sign in to just read our words of wisdom/denial/suffering etc. as may be. Sometmes even funny -- like the comment about the little boy coliforms and the little girl coliforms. Had me laughing all day. You'll have to find it.

RE: Note to Moderator...

TerryF — Tue, 30 Oct 2007 16:41:12 GMT

I vote to keep them visible to those who don't log in.

Regards

TerryF

RE: Note to Moderator...

Admin — Tue, 30 Oct 2007 15:17:43 GMT

I've added a Help Request & Feedback to Administrator discussion at the top of the Discussion Forum groupings. Hopefully this will make it easier for WEF administrators and discussion forum members to report problems, issues or suggestions for the forums.

As far as the visibility of the discussion forums go, you are correct that anyone doing a search can read the postings; however, you can only reply to them if you are a registered discussion forum member that is logged in. I can investigate making the posts not visible unless you log in; however, this may reduce the usefulness of the discussion forums so we would need to consider if this is the best way to go.

RE: Note to Moderator...

SRB — Wed, 24 Oct 2007 14:54:52 GMT

Thanks for your replies to my post. It was suggested by folks attending a recent WEF IT committee sponsored event that this might be a good forum for exchange between folks interested in IT issues at water and wastewater treatment plants. I am going to have to recommend to the them that this is not the place for it. So, yes, we will go elsewhere. Too bad, since it was a group of WEF members that wanted to interact. Probably a secure group like is offered by Google or Yahoo will be the answer as some other WEF committees have done.

ANYONE interested in IT issues for water and wastewater from an operations, laboratory or regulatory compliance is welcome to PM me as this forum does not have much to offer in that respect. I will receive notice of the PM. I am from one of the biggest and best municipal organizations in the country and my focus is regulatory compliance, but the WEFTEC workshop opened many eyes that water and wastewater are behind the curve on IT issues and that industry interaction would be useful.

RE: Note to Moderator...

John Sansalone — Sun, 21 Oct 2007 15:04:18 GMT

Agree with "Old Lag", as to my approach to this site. Should note that all my comments are strictly personal - if I can help clarify a reg., or the thinking behind it, will do so, but doesn't represent any "official" position.

Victor - maybe its me, but I haven't noticed that much change in Jerry. (Jerry - hope this won't insult you) - I've always tended to think of Jerry as a sort of Andy Rooney - a little crusty and cranky, but interesting and entertaining. And as I get older, and am gaining geezer staus, I find myself being more the same way.

So - Old Lag - does your bar also carry "Bass Ale" ? Or even "Newcastle" ?

RE: Note to Moderator...

TerryF — Sun, 21 Oct 2007 00:50:09 GMT

I agree with nearly all the comments here. To get back to the original point , if you don't like the "security" go somewhere else.

TerryF

RE: Note to Moderator...

Dedalus — Sat, 20 Oct 2007 18:49:43 GMT

I'm trying to get up to speed on municipal. The only part of it I'm truly familiar with is the laboratory testing part. Industrial water treatment is in something of a slump, in the outsourced, de-industrialized US of A these days. However, people are not liable to outsource their bodily functions anytime soon.

I'm interested in anaerobic digestors. Specifically, the production of methane from the glycerol that's a byproduct of biodiesel prodution. Apparently it's far from an ideal substrate, it must undergo what I gather is called acetogenic fermentation before a second set of organisms comes along and does methanogenic fermentation to generate the CH4. It seems like sulfate would be a very undesirable thing to have in such a process, because of its tendency to yield H2S. Though, of course, that burns too.

Perhaps one of you gentlemen has a pertinent link.

To get remotely back on topic, this has got to be the most civilized forum I participate in. It doesn't seem to take much moderation. And, I'm permitted to post my url, not all forums allow that.

Thanks for the kind words, Victor. And, thanks to Jerry, for giving me a rare opportunity to display my knowledge of entomology. It's how I got started in science; once, I caught an Aphrodite Fritillary.

RE: Note to Moderator...

Old lag — Sat, 20 Oct 2007 11:23:34 GMT

An interesting post and topic.

Like (I suspect) many people who visit and post here I am not a member of WEF, although I do still treasure my tiepin as evidence of my election to the Select Society of Sanitary Sewage Shovelers many years ago, when I was a member of WPCF. I visit these pages because sometimes I am looking for an answer to a problem I have at work; and sometimes I am in a position to provide an answer for someone else. I am anonymous because I work for a private company; my views are mine and not theirs; and I don’t want to embarrass them if I say something I shouldn’t.

I have been around a long time in this business (hence the handle) but I have come fairly late to this site. The nearest equivalent I can think of is a bunch of people taking time out from a busy conference in the coffee shop, swapping work horror stories and trading “We did it this way” tales. A cheerful, friendly, knowledgeable crowd, none of whom is out to screw you.

And now if you will excuse me I have to try to find a bar in this town (where college basketball and high school football rule) where I can watch England win the Rugby World Cup.

RE: Note to Moderator...

Jerry — Fri, 19 Oct 2007 18:56:10 GMT

The wisdom of Solomon

RE: Note to Moderator...

Victor — Fri, 19 Oct 2007 18:25:33 GMT

Jerry:

It appears that you are starting to be everybody's whipping boy. Dedalus is a hard working chemist with lots of experience in industrial chemistry and has proven himself by posting considerable information relevant to his field of expertise. Jerry, he is on the side of common sense and will debunk any snake oil vendors that happen to pop up here and there--that makes him a good guy.

Dedalus:

Jerry is an excellent operator but seems to have become onerous and sarcastic lately. Maybe been snipped up too many times by crabs or got tired of the sand. Here, I thought I was the Grand Master of Sarcasm. He has considerable acumen when it comes to running treatment plants. Though, don't ask him to run an anaerobic digestor.

Now that both of you have been introduced I am hopping that you can set your differences to rest.

RE: Note to Moderator...

Jerry — Fri, 19 Oct 2007 17:27:00 GMT

Victor

Are you going to let a competitor harass your old buddy. You all thought I was a grate speler, didnt youse.

The Boll Weaver

RE: Note to Moderator...

Dedalus — Fri, 19 Oct 2007 09:35:47 GMT

You mean 'weevil'?

This is an insect of the order Hemiptera, more commonly known as a bug.

They all have what are called "piercing and sucking mouth parts."

We're pretty hard to discourage at

http://www.dedalusenviro.com

RE: Note to Moderator...

Jerry — Thu, 18 Oct 2007 22:23:02 GMT

John, I'm from the Government and I'm here to help you.

Actually guys and gals, I'm leaving paradise. I've had enough of this sandy sewage. Going back to the States the first of November. So, like the Boll Weavel, I'll be lookin for a home.

RE: Note to Moderator...

John Sansalone — Thu, 18 Oct 2007 18:52:05 GMT

Here ! Here ! Second much of what Victor said.

I do wish, though, that there was a better way of notifying WEF directly from the forum, when there is blatant advertizing taking place, or glitches in the system.

In response to the initial inquirery, I am a regulator, but not on this forum to "get" someone. If someone talked about doing something grossly illegal, I couldn't very well ignore it, but I can't recall ever seeing anything like that. I find the site interesting, and educational. Just as when I do a plant inspection, I talk to operators, to get their take about various equipment, ways of running a plant, problems and solutions, etc., I get on here to get feedback, and to (hopefully) sometimes clarify some regulations and their interpretation. Although I don't think I've ever met any of the regulars, I think I somewhat "know" some of them, and consider them peers. Who knows - maybe someday actually get to sit around a bar someplace, with a couple of brews, and talk shop (or maybe, in Jerry's case, sit on the beach, drinking something out of a coconut).

RE: Note to Moderator...

Victor — Thu, 18 Oct 2007 16:00:33 GMT

Rotifer:

You are absolutely correct in that the use of an identifier "handle" can be for fun. There have been too many instances of individuals utilizing the Forum as a means to sell their wares. I have no problem if you identify yourself as a vendor and assist with problems that some of the forum users have in their plants. But I am not the forum moderator and some of you probably could care less what I think. Been participating in this Forum for the past 5 years and know with some degree of certainty who are the individuals that come to this Forum to help and who comes to profit. Mind you, in order to assist those in need you must have the time, knowledge, and patience.

RE: Note to Moderator...

Rotifer — Thu, 18 Oct 2007 08:31:02 GMT

I agree with you Victor to a point. The goal of this site is to help others or receive help with the every day problems we encounter. As for hiding behind a name...........my email address is available to all and if asked I would provide any or all information about my qualifications , location and any other information requested. I choose the name rotifer to but a little humor in my post........NOT TO HIDE!!!

RE: Note to Moderator...

Victor — Wed, 17 Oct 2007 17:55:07 GMT

SRB (10/17/2007)

There doesn't appear to be anywhere to post general comments or questions about this forum, so I'm posting here in the first forum marked as a "moderated forum".

Anyone else have concerns or a moderator like to jump in and explain WEF's position on hosting a forum that is not secure and open to be viewed by anyone on the web?

SRB:

Here is my two cents worth. I can understand your frustration but with due hesitation. As with any forum, any posting you perform will be seen by someone, whether it be Joe Public or Joe Private. Either way, WHAT you type will be seen as a reflection of your knowledge or lack of it, enthusiasm, cordialness and so forth. Whether you hide behind a "handle" or post your real name can also reflect your intentions. If you have nothing to hide then why worry? We are in this business (wastewater, water treatment) to perform a public service and to do it in a professional, courteous manner.

As far as maintenance of WEF Forum, well, frankly there is zero to none. Spam postings are not erased, and moderator feedback is rare to none. And yes, I am a WEF member.

Dispersion Modeling of Air Pollution - Sources of information

mbeychok — Wed, 10 Oct 2007 14:55:20 GMT

For those of you who may be interested in the dispersion modeling of airborne pollution, here are some good sources of information:

Books:
● Beychok, Milton R. (2005). Fundamentals of Stack Gas Dispersion, 4th Edition, author-published. ISBN 0=9644588-0-2
● Schnelle, Jr., Karl B. and Dey, Partha R. (2000). Atmospheric Dispersion Modeling Compliance Guide. McGraw-Hill. ISBN 0-07-058059-6
● Turner, D.B. (1994). Workbook of atmospheric dispersion estimates: an introduction to dispersion modeling, 2nd Edition, CRC Press. ISBN 1-56670-023-X.

Links to Internet websites:
● Air pollution dispersion terminology
● Compilation of atmospheric dispersion models
● AP42 Compilation of Air Pollutant Emission Factors
● Error propagation in dispersion modeling
● EPA's Support Center for Regulatory Atmospheric Modeling

Conversion of air pollution concentration units

mbeychok — Wed, 10 Oct 2007 14:04:02 GMT

Various governmental agencies involved with environmental protection and with occupational safety and health have promulgated regulations limiting the allowable concentrations of gaseous pollutants in the ambient air or in emissions to the ambient air. Such regulations involve a number of different expressions of concentration. Some express the allowable concentrations as volume of a specific gaseous pollutant per million volumes of ambient air or, more simply as parts per million by volume (ppmv). Others express the allowable concentrations as mass of a specific gaseous pollutant per volume of ambient air or usually as milligrams per cubic meter (mg/m³).

The equations for conversion between ppmv and mg/m³ depend on the temperature at which the conversion is wanted (usually about 20 to 25 °C). At an ambient air pressure of 1 atmosphere of 101.325 kiloPascal (kPa), the general conversion equation is:

ppmv = (mg/m³) × (0.08205) × (T) / (M)

and for the reverse conversion:

(mg/m³) = (ppmv) × (M) (12.187) / (T)

where:

ppmv = air pollutant concentration, in parts per million by volume
mg/m³ = milligrams of air pollutant per cubic meter of air
T = ambient air temperature, in kelvins (K) = 273.15 + °C
0.08205 = Universal Gas Law constant, in [atm·L]/(mol·K)
M = molecular weight of the air pollutant (dimensionless)

Notes:

-- Pollution regulations in the United States typically reference their air pollutant limits to an ambient temperature of 20 to 25 °C as noted above. In most other nations, the reference ambient temperature for pollutant limits may be 0 °C or other values.
-- 1 percent by volume = 10,000 ppmv
-- atm = absolute atmosperic pressure in atmospheres
-- mol = gram mole
-- L = liter

RE: Odor Control and H2O2

John Walton — Thu, 23 Aug 2007 15:41:20 GMT

The standard grade of municipal commerce is 50% w/w, though 35% is also widely available, and in certain geographies 27%.

Odor Control and H2O2

Waterbug — Mon, 16 Jan 2006 18:56:01 GMT

Recently my wastewater plant coducted a series of air analyses from our on site scrubber units. The results indicated a combination of both mercaptans and hydrogen sulfide. I have been trying to collect information on the effects of hydrogen peroxide addition to belt filter press influent however this seems to be an infrequently used chemical. Can anyone give me an idea of what I might be looking at as far as dewatering interferance with Polymers and lime stabilization?

RE: Odor Control and H2O2

Dvant — Tue, 21 Aug 2007 12:01:23 GMT

What % H2O2 are we talking about? I don't think we are talking about the stuff you pour on cuts.

Mark

RE: Odor Control and H2O2

Diana — Tue, 21 Aug 2007 10:37:04 GMT

Ouplant utilizes magnesium hydroxide / Thioguard with great success in the reduction of H2S throughout the plant that also improves clarification and lower sludge odors.

Controlling Digestor Odor at Treatment Plants..

primey — Tue, 03 Jul 2007 22:33:37 GMT

What is a good chemical to control odors in Digestors which Septic Trucks primarily dump their waste into? Thanks for any info....

RE: Controlling Digestor Odor at Treatment Plants..

Jerry — Wed, 04 Jul 2007 17:02:55 GMT

Aerobic or Anaerobic digesters?

RE: Odor Control and H2O2

Jeff Naumann — Tue, 29 May 2007 11:51:35 GMT

The BOD of 300 mg/l and 3 m3/sec. pertain to the total plant flow. We receive in our collector system a waste from a fish processing, which has a high BOD and oil & grease concentration because of their treatment before discharging their waste to the sewer in many cases is not effective. We are thinking to treat a part of the total effluent that comes from fish industry separately maybe with DAF treatment systems, too. However, now we haven't a solution yet, because we have to define the place and the maximum flow that could be possible treat with this technology.[quote]

[quote]I don't know if they use seawater in their processes, it`s a good advice, thank you.[quote]

[quote]In resume our local plants nowadays receive an total effluent with hight DBO. We only have a pre-treatment before discharging our waste to sea (outfall), and the environment is not affected.[quote] What, exactly, is your treatment process?

[quote]We are trying to abate the odor in the collection system with chemical treatment, so that why I wanted to know if the use of H2O2 near the plant could be a partial solution despite the high DBO content of the total effluent or it is ridiculous.[quote]

Actually we are using ferric chloride. but we go on studying another alternatives.

From you information, I assume that your plant, and the fish processing operations, are located near the sea.

If in fact your total plant flow is 3 m3/second, the amount of H2O2 required could be quite large. That equates to a total plant flow of 68 MGD, which is a fairly large plant. Is that correct? Where are you located? I would suggest that your better option might be to concentrate on the "upstream" causes of the problem (fish processing, and possibly other causes).
What is the total flow, oil & grease, TSS, and BOD from the fish processing? Can you find that information? DAF treatment is effective with oily wastes, such as fish processing. What might the possibility of the fish plants operating a DAF system. Note that the DAF system must be "Operated Properly" or it will be a ineffective effort (this is from my personal experience).

RE: Odor Control and H2O2

Paula — Tue, 29 May 2007 11:13:44 GMT

Hello

After same days in bed because of a flu, I am here again.

I don't know if they use seawater in their processes, it`s a good advice, thank you.

In resume our local plants nowadays receive an total effluent with hight DBO. We only have a pre-treatment before discharging our waste to sea (outfall), and the environment is not affected.

We are trying to abate the odor in the collection system with chemical treatment, so that why I wanted to know if the use of H2O2 near the plant could be a partial solution despite the high DBO content of the total effluent or it is ridiculous.

Actually we are using ferric chloride. but we go on studying another alternatives.

Thank you for your answers

RE: Odor Control and H2O2

Odorguy — Fri, 11 May 2007 12:10:16 GMT

Industrial discharges can sometimes influence odor production but they are rarely the sole cause. If the odors began after the upgrade, did the industries just start up after the upgrade? I doubt it, therefore, something to do with the upgrade is causing the odors. You will need an independent odor survey performed since the engineers that did the upgrade will be biased. The survey should locate the sources that are causing complaints and recommend control solutions. Get an engineering firm to do this since vendors are also biased.

It sounds like your headwords is the cause, which means that H2S is coming in with the flow. Depending upon the concentration you may be able to add chemicals upstream. If your flow is too much then you could capture and treat the air. There are some really good new biological technologies that don't require chemicals and can remove H2S using only plant reuse water. If you want to contact me offline I could give you some names.