http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?board=general Water & Wastewater Treatment Forum - Water and Wastewater.com Help Forums en-us Water and Wastewater.com Help Forums Sat, 18 May 2013 23:37:45 +0000 http://blogs.law.harvard.edu/tech/rss 30 http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368927351 Water and Wastewater.com Help Forums/Water & Wastewater Treatment Forum http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368927351 Sat, 18 May 2013 20:35:51 +0000 Hi,<br />Positive charge density is an important parameter of PAM, it relates to PAM cost and dewatering efficiency. I want to know how to test positive charge density?<br /><br />Regards<br />Chen<br /><br /> http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368736255 Water and Wastewater.com Help Forums/Water & Wastewater Treatment Forum http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368736255 Sat, 18 May 2013 13:35:38 +0000 freezing (to solid) activated sludge definitely kills the bacteria!<br /><br />the bugs can cope with slow temerature changes. at say 4°C metabolism stops, but the bugs stay alive.<br /><br />you can also leave the bacteria without food for quite some days without harming them. but you should lower aeration; having a DO of 0.3 till 1 mg O2/L (but without feeding!!) helps them surviving.<br /><br />if you change aeration to fine bubble diffused aeration, your heat losses will be much lower during winter. http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368422438 Water and Wastewater.com Help Forums/Water & Wastewater Treatment Forum http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368422438 Fri, 17 May 2013 22:08:55 +0000 Hi <br /><br />You should give bit more detail about your process because it is not possible to give good advice according to the info you have given. <br />For inlet you are talking about BOD but you limit is COD. what is your BOD.<br /><br />Check your nutrient levels, as has been commented on before.<br /><br /><br />However I recommend you run according to sludge age and not F/M. The latter can be quite misleading if you have nonbiodegradable colloidal or solid organic matter in the influent. a microscopic analysis will also help you very much to find the correct sludge age.<br /><br /><br /><br /><br /><br /> http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1358820267 Water and Wastewater.com Help Forums/Water & Wastewater Treatment Forum http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1358820267 Fri, 17 May 2013 21:49:35 +0000 My recommendation based on experience in sludge treatment in many different plants and effluents.<br /><br />1. Never believe there is only on perfect solution. There isnt<br />2.In an existing plant ask suppliers to visit and make a jar test with polymer of their choosing. Also chek that they know how to do a jar test for sludge dewatering.<br />3. Give realistic values to suppliers concerning ash content etc.<br />4. Most important . Ask for references from equivalent sludge handling plants and if possible make a visit to see the equipment in operation. http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368689444 Water and Wastewater.com Help Forums/Water & Wastewater Treatment Forum http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368689444 Fri, 17 May 2013 17:35:31 +0000 I'm uncertain what TPA and IPA are chemically. However, I do understand biodegradability and chemical oxygen demand. Biological oxidation does not cease after 5 days and so your assumption that the COD remaining after the 5 day BOD test is refractory to biological oxidation may not be correct.<br /><br />I've run 10 and 20 day BODs on a variety of wastewaters to determine how resistant the wastes are to biological oxidation. Also, don't forget that the COD test also measures the oxidizeable suspended solids as well as the dissolved organics and this may be a function of the efficiency of your secondary clarifier.<br /><br />grrun http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368200265 Water and Wastewater.com Help Forums/Water & Wastewater Treatment Forum http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368200265 Wed, 15 May 2013 07:23:50 +0000 Thanks for the answer.<br /><br />It is the design stage (no differential pressure available). Want to figure out how often the filters need to be replaced. <br /><br />You are right. TSS is measured using 0.45 micron filter. It's pore size is much smaller than 10 micron cartridge filter. Not all TSS can be captured by the 10-micron filter.<br /><br />If have the particle size distribution diagram, may be able to calculate the real replacement frequency.<br /><br />Regards, http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368018812 Water and Wastewater.com Help Forums/Water & Wastewater Treatment Forum http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368018812 Wed, 15 May 2013 02:07:27 +0000 Thank you to all you guys who find time to look at my request for help.<br />But I already found the one that I was looking for. It is called &quot;ripcord&quot; for blow-in ventilation in confined spaces, but I am not really sure as to whether it can be used in inlet channels, screen and grit area below cover and especially to wet wells.<br /><br />Thanks again.<br /><br />Gerry http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368582878 Water and Wastewater.com Help Forums/Water & Wastewater Treatment Forum http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368582878 Tue, 14 May 2013 20:54:38 +0000 Hello<br />We add fluoride in a few of our water treatment plants. Recentlya national anti fluoride movement started. I am just keen to know if this is a topic of interest in your part of the world.<br /><br />Some input/discussion from you will be really beneficial. &nbsp;<br /> http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368503918 Water and Wastewater.com Help Forums/Water & Wastewater Treatment Forum http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368503918 Mon, 13 May 2013 23:01:39 +0000 <a href="http://znaki.webservis.ru/" target="_blank">ЗДЕСЬ МОЖНО ВСЕ <img src="http://www.waterandwastewater.com/yabbfiles/Templates/Forum/default/wink.gif" border="0" alt="Wink" /> ИНТИМ ЗНАКОМСТВА</a> <br /><a href="http://znaki.webservis.ru/" target="_blank">Более 10000 новых анкет.</a> <br /><a href="http://znaki.webservis.ru/" target="_blank"><img src="http://savepic.ru/4477042m.jpg" alt="" border="0" /> <img src="http://savepic.ru/4466802m.jpg" alt="" border="0" /></a> <br /><a href="http://znaki.webservis.ru/" target="_blank">Всего анкет: 7453343</a> <br /><a href="http://znaki.webservis.ru/" target="_blank">Фотографий: 17166726 &nbsp;</a> <br /><a href="http://znaki.webservis.ru/" target="_blank"><img src="http://savepic.org/3352941m.jpg" alt="" border="0" /> <img src="http://savepic.org/3353965m.jpg" alt="" border="0" /></a> <br /><a href="http://znaki.webservis.ru/" target="_blank">Видео-роликов: 1217863</a> <br /><a href="http://znaki.webservis.ru/" target="_blank">Веб-камеры: 1217821 &nbsp;</a> <br /><a href="http://znaki.webservis.ru/" target="_blank"><img src="http://savepic.ru/4465778m.jpg" alt="" border="0" /> <img src="http://savepic.ru/4469874m.jpg" alt="" border="0" /></a> <br /><a href="http://znaki.webservis.ru/" target="_blank">Сейчас на сайте: 31087 &nbsp;</a> <br /><a href="http://znaki.webservis.ru/" target="_blank">Присоединяйся! <img src="http://www.waterandwastewater.com/yabbfiles/Templates/Forum/default/wink.gif" border="0" alt="Wink" /> &nbsp;</a> http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368444887 Water and Wastewater.com Help Forums/Water & Wastewater Treatment Forum http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368444887 Mon, 13 May 2013 17:03:55 +0000 Hi Stefan,<br /><br />that is a good one...<br />you made two mass balances: one for water (expressed in kg water and kg water per day) and one for the dry matter (kg DM).<br />I think that the HRT should be rather seen as a volumetric exchange rate, rather then in terms of mass flow, although your point of view deserves quite good points (it is all a matter of definition...);<br /><br />the SRT is obviously: 10 kg DM/0.25 kg DM/d = 40 days.<br /><br />for the HRT, I would say that this is rather 100 days (100 kg/(1 kg/d)) or assuming the same density of all flows and volumes, (e.g. density = 1 kg/L) 100 L/(1 L/d) = 100 d. provided that all densities are equal<br /><br />again, it is a matter of how you define things, and a mass balance on the water fraction certainly isn't wrong if you define it clearly... http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368352548 Water and Wastewater.com Help Forums/Water & Wastewater Treatment Forum http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368352548 Mon, 13 May 2013 13:30:12 +0000 I You have received 3 different comments from your 2 inquiries. Basically, you need to better <u>characterize the composition of your wastewater</u>. Jar tests are one tool, but you also should include targets for the composition of the discharge. I'm a little confused about your reference to direct filtration. Is this a pretreatment for potable water or other water treatment rather than a wastewater treatment?<br /><br />grrun http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368256033 Water and Wastewater.com Help Forums/Water & Wastewater Treatment Forum http://www.waterandwastewater.com/cgi-bin/yabb/YaBB.pl?num=1368256033 Sat, 11 May 2013 02:07:13 +0000 Robert Griffin III had a great rookie season, both on and off the field. 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