Its a chemistry lesson with a difference. The teachers are 1)all ears while their pupils demonstrate an invention they think could help solve Nigerias chronic electricity shortage. Their invention is the ultimate in waste recycling, 2)harnessing the power of pee to make a generator.
Duro-Aina Adebola(student): So we opted for urine. Since, one, its a waste product, and if we use urine as a, in…as a carry out electricities,[sic] and we use urine, our waste products or our exhaust gas is going to be water, and that is not poisonous to our environment.
The system works via an electrolytic cell that breaks the urine down into 3)nitrogen, water and hydrogen. Fourteen-year-old Duro-Aina Adebola is one of four girls at Lagos Doregos Private Academy who devised the generator.
Adebola: This hydrogen oxygen gas mixture goes into our water 4)filter, and the function of the water filter is to remove any 5)impurities from our hydrogen oxygen gas mixture. The hydrogen oxygen gas then goes into a cylinder here, which stores, temporarily stores, the gas whenever we need the gas.
This cylinder contains liquid 6)borax, which purifies the hydrogen making it ready for use. A generator can produce up to six hours of electricity per litre of urine. Their teacher says his pupils have even found a solution to the 7)squeamishness associated with their raw product.
Teacher: (voiceover) You know, people get repelled at the odor of urine. If its their own urine, they dont mind, but somebody elses urine, they dont like touching it. To avoid that they added two 8)molar solution of 9)washing soda at point one percent inside the urine, so it suppresses the odor of the urine.
The 10)quartet, aged between 14 and 15, are hopeful the urine generator will provide an environmentally-friendly energy alternative for the poor. Even though wind and solar energy is harnessed in Nigeria, the options are capital-intensive and not affordable for most rural dwellers. The young innovators have spent just $64.00 on their invention, and believe, with another small investment, they can make the device more 11)compact and more practical in millions of homes throughout the developing world.
這是一堂別開(kāi)生面的化學(xué)課。學(xué)生們演示自己的發(fā)明時(shí),老師們?nèi)褙炞⒌芈?tīng),學(xué)生認(rèn)為此項(xiàng)發(fā)明能有助于解決尼日利亞長(zhǎng)期的“電力缺乏”問(wèn)題。他們的發(fā)明就是要造一臺(tái)能利用尿液的發(fā)電機(jī),這可以說(shuō)達(dá)到了廢物利用的極致。
杜羅-艾娜·安迪博拉(學(xué)生):我們選擇尿液,因?yàn)椋桥判刮?,而如果我們把尿液作為發(fā)電的動(dòng)力,我們使用尿液,最終產(chǎn)生的廢棄物或是廢氣會(huì)是水,那就不會(huì)對(duì)我們的環(huán)境造成污染。
通過(guò)電解槽,尿液會(huì)分解成氮、水、氫。這個(gè)四人小組就讀于拉各斯的多黎戈斯私立學(xué)院,這個(gè)想法最初是由14歲的杜羅-艾娜·安迪博拉提出的。
安迪博拉:這類氫氧氣的混合物經(jīng)過(guò)過(guò)濾器——用來(lái)去除混合氣體中的雜質(zhì)元素。接著這樣的氫氧混合氣體到達(dá)這個(gè)汽缸中,這是用來(lái)儲(chǔ)藏,暫時(shí)儲(chǔ)藏氣體的,什么時(shí)候我們需要,就從這里取。
這個(gè)汽缸裝置里面裝有液態(tài)硼砂,可以純化氫氣以方便使用。這種發(fā)電機(jī)利用每公升尿液可以提供長(zhǎng)達(dá)六小時(shí)的電力。她們的老師說(shuō),自己的學(xué)生甚至還為對(duì)使用尿液有不適感的人找到了解決方法。
老師:(畫(huà)外音)你知道人們對(duì)尿液的味道很反感。如果是他們自己的,他們倒不介意,要是是別人的,他們可就不喜歡接觸到了。為了避免異味,她們?cè)谀蛞褐屑尤肓藘赡枬舛葹?‰的洗滌堿溶液,這樣就可以抑制尿液的異味。
這四個(gè)女孩年齡介乎14至15歲之間,她們希望這種尿液發(fā)電機(jī)可以為窮苦大眾提供一種有利于環(huán)保的能源替代物。盡管尼日利亞也在使用風(fēng)能和太陽(yáng)能,但它們都屬于資本密集型的能源,大多數(shù)的農(nóng)村民眾負(fù)擔(dān)不起。這些小發(fā)明家的發(fā)明只花費(fèi)了64美元,而且她們還相信,再多一點(diǎn)投入,她們就能完善裝置,簡(jiǎn)易實(shí)用,在發(fā)展中國(guó)家的萬(wàn)千家庭普及。
尿液發(fā)電,一個(gè)美好的夢(mèng)想
尿液發(fā)電的原理是通過(guò)收集尿液中的氨作為生物燃料來(lái)提供能源。來(lái)自西英格蘭大學(xué)的研究人員說(shuō):“基于每年全球可產(chǎn)生數(shù)萬(wàn)億公升尿液,這項(xiàng)技術(shù)有助于改變世界能量利用方式。其影響力非常深遠(yuǎn),不僅對(duì)于污水處理行業(yè),也使人們對(duì)廢水處理產(chǎn)生了新的轉(zhuǎn)換意識(shí)?!边@是一個(gè)美好的愿景,然而,尿液發(fā)電卻存在致命的缺陷。
一、收益較低:尿液電解產(chǎn)生氫氣需要一種電輸入,就其本身而言尿液在沒(méi)有一種現(xiàn)存的能源供應(yīng)的地區(qū)是不能夠被用于發(fā)電的。
二、壽命較短:曼徹斯特大學(xué)的一位研究人員解釋:“尿液不僅是由尿素組成的,其中有很多的鹽,而且鹽水的電解除了產(chǎn)生氫還有氯,氯離子能夠和氫離子結(jié)合形成鹽酸,這不利于發(fā)電機(jī)的長(zhǎng)期使用?!?/p>
雖然實(shí)用性有待商榷,但是,這為人類進(jìn)行廢物利用提出了一個(gè)可供參考的途徑。這在人人都喊環(huán)保的今天,切實(shí)地想方設(shè)法解決環(huán)境問(wèn)題還是非常值得贊賞的。