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A topic about DBP

A topic about DBP# Environmental - 环境科学与工程

a*r2008-01-30 08:01

1 楼

Postdoc on H1B. EB1A 140已批准，485 RFE。要求letter from intended permanent
employer,describing job title, duty, starting date, salary。感觉很奇怪，因为
EB1A似乎不需要employer sponsor。
填140表时，已写明是postdoctoral scholar，但律师让在permanent position一项选
yes。
RFE回复如何写？谢谢。

y*g2008-01-30 08:01

2 楼

看网上的图片还行，紫丁香
是不是那种丁香香料的味道啊？
多谢多谢

c*s2008-01-30 08:01

3 楼

l*u2008-01-30 08:01

4 楼

I recently started a thread on Yahoo's Water Forum that I've been
subscribing to. The discussion is getting interesting. I'm going to post my
original message as well as a few replies for those of you who are looking
for interesting stuffs to read during the lunch break.
Also, if you have any ideas, thoughts about the WWTP disinfection problem,
please let me know. We are going to meet the plant operator and lab team
next Monday.

l*d2008-01-30 08:01

5 楼

你先种，闻完了告诉大家！

l*u2008-01-30 08:01

6 楼

Original:
Dear all,
I am a consulting engineer. Recently, one of our clients, owner of a WWTP,
reported a noncompliance issue that we have been trying to solve. This WWTP
has been operated since 1996. Everything had been running ok. However,
starting from the summer of 2007, they detected sporadic outbreaks of fecal
coliform at the discharge point.
The treatmet process is quite conventional (primary-activated sludge-
secondary clarifier-disinfection). One thing that's unique about their
disinfec

L*A2008-01-30 08:01

7 楼

国内时父母家里有１棵，非常好养，很香！只是１年就开１次。

l*u2008-01-30 08:01

8 楼

A reply:
My recommendation would be to question the need of disinfection, especially
with chlorine, which has proven to form chlorinated organics or also called
DBP (Disinfection By Products). When EPA implemented the CWA in 1972 it
also set a standard for bacteria and everybody started to use chlorine, as
testing for residual chlorine is cheap. This however introduced chlorinated
organics, among them THM's (trihalomethanes) in our open water, used for
drinking water. EPA recognized the problem

y*g2008-01-30 08:01

9 楼

是那种丁香香料的味道？

【在 L****A 的大作中提到】

: 国内时父母家里有１棵，非常好养，很香！只是１年就开１次。

l*u2008-01-30 08:01

10 楼

One more:
Peter,
I don't understand why you question the need for disinfection. Is there a
paper or other documentation from the CDC or GAO in the 70s that you could
send to me?
It is my understanding that the predominant literature suggests that fecal
coliform and E. coli are used as indicator bacteria to determine to degree
of contamination by fecal matter. The presence of fecal matter indicates
the potential presence of any number of harmful (and sometimes deadly)
pathogens. Children and

T*m2008-01-30 08:01

11 楼

丁香在5区很好种的，在你们南方不清楚。
这是我去年的丁香。开花时，一阵阵的幽香，很好闻的味道。

l*u2008-01-30 08:01

12 楼

3rd:
Personally I think any form of disinfection of treated sewage is a waste of
money and when we apply disinfection (also on drinking water), we should
first accept that our original treatment (removing all solids) was not 100%
effective, so we need a post-treatment. Secondly we should know how this
disinfection really works, with other words how does it kill bacteria. UV,
as mentioned in the literature, destroys the DNA of cells and thus kills
bacteria. To do so it must penetrate the cell w

y*g2008-01-30 08:01

13 楼

唉～，太热的地方啥好花花都种不成
谢谢

【在 T*******m 的大作中提到】

: 丁香在5区很好种的，在你们南方不清楚。
: 这是我去年的丁香。开花时，一阵阵的幽香，很好闻的味道。

l*u2008-01-30 08:01

14 楼

4th:
First and foremost, this plant should not be dumping sewage effluent
directly to public waters because it carries a heavy load of complex
chemical compounds of unknown toxicity and synergistic effect. A review of
USGS and academic literature searching with hormone - estrogen - EDC will
reveal the enormity of this problem. The brain development of your children
and your own masculinity are clearly endangered by drinking from waters that
carry this effluent because municipal filters are not c

t*02008-01-30 08:01

15 楼

记忆中二十多年前的丁香很香，和调料的味儿不一样。初中的时候学校旁边有一丛紫丁
香，一个女同学告诉我如果能找到5瓣丁香（好像大多数都是4个花瓣）将来就是个幸福
的人，俺俩都找到了：）
后来就再也没有看到过丁香，也想种一棵

l*u2008-01-30 08:01

16 楼

There are about a dozen replies, including a few back and forth arguements
between three people. If you are interested in reading them all, let me know
. :)

L*A2008-01-30 08:01

17 楼

游帅，你这丁香叶子很奇怪啊，怎么不是圆边的？MS应该是圆形尖角的.

【在 T*******m 的大作中提到】

: 丁香在5区很好种的，在你们南方不清楚。
: 这是我去年的丁香。开花时，一阵阵的幽香，很好闻的味道。

j*o2008-01-30 08:01

18 楼

I don't think your problem is related to DBP. My best guess is the chlorine
loss withing the 12-mile main (what's the residence time?) due to
nitrification (need to check the ammonia level in the source water). Once
the chlorine disappears, there will be biological regrowth problems,
especially in wastewater.

y*g2008-01-30 08:01

19 楼

呵呵～，幸福的人：香味类似于啥子的味道啊？

【在 t*********0 的大作中提到】

: 记忆中二十多年前的丁香很香，和调料的味儿不一样。初中的时候学校旁边有一丛紫丁
: 香，一个女同学告诉我如果能找到5瓣丁香（好像大多数都是4个花瓣）将来就是个幸福
: 的人，俺俩都找到了：）
: 后来就再也没有看到过丁香，也想种一棵

l*u2008-01-30 08:01

20 楼

我们这个client的问题确实跟DBP没关系，但是由此引发的一些讨论跟DBP挺有关系的。
让人觉得这个世上真是有不少坐者说话不嫌腰痛的人。或者说是一些工业出于私利，雇
用些有PHD学位的人混淆大众。
In case you are interested, the residence time in the force main is about 12
hours. The level of ammonia-N at the discharge point was in the range of 0.
3-1 mg/L.

chlorine

【在 j*******o 的大作中提到】

: I don't think your problem is related to DBP. My best guess is the chlorine
: loss withing the 12-mile main (what's the residence time?) due to
: nitrification (need to check the ammonia level in the source water). Once
: the chlorine disappears, there will be biological regrowth problems,
: especially in wastewater.

t*02008-01-30 08:01

21 楼

呵呵，记不清具体什么香味了，不过总之是一种好闻的香味儿。最近的花香闻多了，鼻
子有点晕：茉莉、夜来香、栀子，连桂花的味儿也闻不出来了：）

【在 y****g 的大作中提到】

: 呵呵～，幸福的人：香味类似于啥子的味道啊？

V*72008-01-30 08:01

22 楼

有具体的文献或则试验数据支持“ Once the chlorine disappears, there will be
biological regrowth problems, especially in wastewater”吗，尤其是对于FECAL
COLIFORM而言？个人觉得regrowth的影响因素太多了，光看chlorine level恐怕偏颇。

chlorine

【在 j*******o 的大作中提到】

x*n2008-01-30 08:01

23 楼

香！

a*a2008-01-30 08:01

24 楼

Hi Man,
If possible, please give me a big picture of this WWTP process diagram. I
assume the standard P&ID
Primary clarifier --> Secondary clarifier (activated sludge) --> sand
filter --> disinfection chamber --> dechlorination chamber --> 12-mile force
main to the river.
First question, what's the chlorine demand for effluent leaving the
secondary clarifier at chlorination chamber?
Second question, Do you have any baffle walls in the disinfection chamber?
I guess you probably do not have baffl

【在 l********u 的大作中提到】

: I recently started a thread on Yahoo's Water Forum that I've been
: subscribing to. The discussion is getting interesting. I'm going to post my
: original message as well as a few replies for those of you who are looking
: for interesting stuffs to read during the lunch break.
: Also, if you have any ideas, thoughts about the WWTP disinfection problem,
: please let me know. We are going to meet the plant operator and lab team
: next Monday.
:

T*m2008-01-30 08:01

25 楼

丁香有很多品种。最常见的是心型叶子的，我图上的是尖叶子。我有一棵丁香，叶子只
有指甲那么大，但花很香。

【在 L****A 的大作中提到】

:
: 游帅，你这丁香叶子很奇怪啊，怎么不是圆边的？MS应该是圆形尖角的.

a*a2008-01-30 08:01

26 楼

I really could not understand your process flow based on your description.
I believe any WWTP has to dechlorinate the water from disinfection chamber
prior to leaving the plant through 12-mile force main to the river.
Otherwise, fish in the river will be killed.
Also, 0.3 - 1.0 mg/L as Total-ammonia or free ammonia ??
The best ratio of chlorine / ammonia is 5:1

12
0.

【在 l********u 的大作中提到】

: 我们这个client的问题确实跟DBP没关系，但是由此引发的一些讨论跟DBP挺有关系的。
: 让人觉得这个世上真是有不少坐者说话不嫌腰痛的人。或者说是一些工业出于私利，雇
: 用些有PHD学位的人混淆大众。
: In case you are interested, the residence time in the force main is about 12
: hours. The level of ammonia-N at the discharge point was in the range of 0.
: 3-1 mg/L.
:
: chlorine

L*A2008-01-30 08:01

27 楼

太崇拜你了！总让我长学问。

【在 T*******m 的大作中提到】

: 丁香有很多品种。最常见的是心型叶子的，我图上的是尖叶子。我有一棵丁香，叶子只
: 有指甲那么大，但花很香。

l*u2008-01-30 08:01

28 楼

Primary clarifier --> Secondary clarifier (activated sludge) --> sand
filter --> disinfection chamber --> dechlorination chamber --> 12-mile force
main to the river.
(Should be Primary clarifier --> Rotating Biological Contactor (don't ask me
why they put a RBC there. It was designed and built in 1993 and upgraded in
1996) --> Secondary clarifier (activated sludge) --> Chlorine added --> 12-
mile force main --> dechlorination --> discharged to the river)
First question, what's the chlorine deman

t*g2008-01-30 08:01

29 楼

MA很多
特别香，我觉得有点熏的慌

a*a2008-01-30 08:01

30 楼

(Not sure about the chlorine demand. I've designed a 12 hr bench test to
measure the actual demand of the supernatant taken out of the secondary
clarifier. They've been adding 8-10 ppm of chlorine to the effluent after
the 2nd clarifier)
(no chamber. Disinfection is done in the force main)
Disinfection in the 12-inch force main seems to complete mixing and
eliminate the short circuiting flow. I think you request the plant
discharge flow rate from plant operators and determine the detention time

p*M2008-01-30 08:01

31 楼

MM在哪个区呀？要是在TX不适合中丁香。这是俺的最爱，去苗铺问过了，TX太热，丁香
长不好的，俺哭了好。。。。。久啊！

【在 y****g 的大作中提到】

: 看网上的图片还行，紫丁香
: 是不是那种丁香香料的味道啊？
: 多谢多谢

l*u2008-01-30 08:01

32 楼

Disinfection in the 12-inch force main seems to complete mixing and
eliminate the short circuiting flow. I think you request the plant
discharge flow rate from plant operators and determine the detention time in
the pipe. Bench scale test will not help you in this case to determine the
chlorine demand unless you can using the existing force main as the coupon
test. It is very possible that biofilm has been built up inside the 12-inch
force main to eat the chlorine residual. In addition, what typ

b*y2008-01-30 08:01

33 楼

丁香很好闻的，不特别浓郁的那种，清香型的。

a*a2008-01-30 08:01

34 楼

(We will inspect the site on Monday and look at the corrosion problem, along
with other issues such as infiltration, etc)
Infiltration ?? - for me, it seems to be made by prestressed concrete
cylinder pipe (PCCP). There are several service companies could identify
the pipe leaking by accoustic technology.

L*A2008-01-30 08:01

35 楼

我得考虑是否也种１棵。对了，这个花记得好象也可以插的，我妈妈家里那棵就是她插
活的，２－３年时间就长得挺大了。它还有种子。

y*g2008-01-30 08:01

36 楼

嗯呐。同郁闷，我在9a
种桂花吧，我的最爱，觉得比米兰，白兰，茉莉，栀子花都好闻

【在 p***M 的大作中提到】

: MM在哪个区呀？要是在TX不适合中丁香。这是俺的最爱，去苗铺问过了，TX太热，丁香
: 长不好的，俺哭了好。。。。。久啊！

y*g2008-01-30 08:01

37 楼

我们这都没有，那还能有枝条插哦，种子肯定也找不到的撒

【在 L****A 的大作中提到】

: 我得考虑是否也种１棵。对了，这个花记得好象也可以插的，我妈妈家里那棵就是她插
: 活的，２－３年时间就长得挺大了。它还有种子。

p*M2008-01-30 08:01

38 楼

刚败了棵四季桂（OSMANTHUS FRAGRANS），不知道种哪，这树会长很大很高吗？另外，
无比向往的金桂咱这买不到吧？

【在 y****g 的大作中提到】

: 嗯呐。同郁闷，我在9a
: 种桂花吧，我的最爱，觉得比米兰，白兰，茉莉，栀子花都好闻

p*M2008-01-30 08:01

39 楼

用种子能种出来么？

【在 L****A 的大作中提到】

: 我得考虑是否也种１棵。对了，这个花记得好象也可以插的，我妈妈家里那棵就是她插
: 活的，２－３年时间就长得挺大了。它还有种子。

z*n2008-01-30 08:01

40 楼

四季桂淡淡的幽香，得靠量取胜，好几株一起开能闻到的
肯定不浓烈

【在 p***M 的大作中提到】

: 刚败了棵四季桂（OSMANTHUS FRAGRANS），不知道种哪，这树会长很大很高吗？另外，
: 无比向往的金桂咱这买不到吧？

R*a2008-01-30 08:01

41 楼

估计还要有年头。。

【在 z*********n 的大作中提到】

: 四季桂淡淡的幽香，得靠量取胜，好几株一起开能闻到的
: 肯定不浓烈

S*52008-01-30 08:01

42 楼

以前大学校园有很多丁香
一开花
我就过敏得厉害
别的花草类都没事。。。

p*M2008-01-30 08:01

43 楼

谢谢YOYOGG!在你给的那个网上找到了金桂，准备败棵。请问一棵够吗？这个能长很高
吗？种前院还是后院好？喜阴喜阳？

【在 y****g 的大作中提到】

: 嗯呐。同郁闷，我在9a
: 种桂花吧，我的最爱，觉得比米兰，白兰，茉莉，栀子花都好闻

y*g2008-01-30 08:01

44 楼

你要是买小的要3-4年才开。大的不晓得是几年的苗，你问清楚是不是买来就能开花
的。
桂花长得慢，我见过10年的金桂大约也就2米左右。
一棵够吗---看你自己了。
半阴，早上的阳光最好（你是ARIZONA的哇），那夏天可能要早上10点之前的阳光。
小苗的话养盆子里，大点再下地。

【在 p***M 的大作中提到】

: 谢谢YOYOGG!在你给的那个网上找到了金桂，准备败棵。请问一棵够吗？这个能长很高
: 吗？种前院还是后院好？喜阴喜阳？

p*M2008-01-30 08:01

45 楼

谢谢回付，准备去你给的那个网站买棵１GALAN的苗，不知道要等几年才能开花。
俺在AUSTIN，TX，夏天这么毒的太阳是不是金桂会长不好呀？

。

【在 y****g 的大作中提到】

: 你要是买小的要3-4年才开。大的不晓得是几年的苗，你问清楚是不是买来就能开花
: 的。
: 桂花长得慢，我见过10年的金桂大约也就2米左右。
: 一棵够吗---看你自己了。
: 半阴，早上的阳光最好（你是ARIZONA的哇），那夏天可能要早上10点之前的阳光。
: 小苗的话养盆子里，大点再下地。