पर्यावरणानुकूल उद्योगाचे "रसायन'

डॉ. अनिल लचके
"ग्रीन केमिस्ट्री'चा पाठपुरावा करताना ते पर्यावरणानुकूल हवे; त्याचबरोबर आर्थिकदृष्ट्याही किफायतशीर हवे. काळाची गरज ओळखून नवे तंत्रज्ञान वापरून रसायननिर्मिती केली पाहिजे.

आपला देश रसायननिर्मिती उद्योगात अग्रेसर आहे. या उद्योगाची वार्षिक उलाढाल एक लाख पंधरा हजार कोटी रुपये आहे. भारत चौदा हजार कोटी रुपयांची आणि 750 प्रकारची विविध रसायने निर्यात करतो. अमेरिका - युरोपमधील प्रगत राष्ट्रेही भारताकडून रसायने खरेदी करतात. जगात कीटकनाशक रसायन उत्पादनात भारत दुसऱ्या क्रमांकावर, पेट्रोकेमिकल्समध्ये पाचव्या, तर औषधनिर्मितीच्या बाबतीत बाराव्या क्रमांकावर आहे. हे सगळं अभिमानास्पद असलं तरी त्यामुळे होणाऱ्या प्रदूषणामुळे पर्यावरणप्रेमी सचिंत असतात. साहजिक भारतीय संशोधक पर्यावरणअनुकूल रसायननिर्मिती करण्यासाठी गेली वीस वर्षे संशोधन करीत आहेत. 2020 सालापर्यंत अशा पद्धतीने उत्पादित केलेल्या रसायनांची जागतिक किंमत शंभर अब्ज डॉलरहून जास्त वाढू शकेल. पुनर्निर्मितिक्षम कच्च्या मालापासून पुनर्वापर करता येईल अशा रसायनांची निर्मिती जेव्हा सुरक्षित पद्धतीने केली जाते, तेव्हा त्याला "सस्टेनेबल केमिस्ट्री' (अक्षय रसायनशास्त्र) म्हणतात. यात प्रदूषण टळून पर्यावरणाला बाधा पोचत नाही म्हणून "ग्रीन केमिस्ट्री' (हरित रसायनशास्त्र) म्हणतात. या क्षेत्रात भरीव कामगिरी करण्यासाठी आता भारतीय संशोधक व तंत्रज्ञ सज्ज होत आहेत. "ग्रीन केमिस्ट्री'चा अनुनय करताना ते पर्यावरणअनुकूल हवे; पण आर्थिकदृष्ट्या फायदा देणारेही हवे. नेमके इथंच आपले उद्योजक चाचपडून बघत असताना बरीच वर्षं गेली. आता काळाची गरज असल्यानं नवं तंत्रज्ञान वापरून रसायननिर्मिती करावी लागेल.

यासाठी मुळातूनच अपायकारक रसायनांचा वापर टाळावा लागतो. उदाहरणार्थ मोटारीच्या पेंटमध्ये शिसं (लेड) असेल, तर तिथं अन्य रसायन किंवा "यट्रियम' धातूचा वापर करता येतो. रासायनिक प्रक्रिया या बहुतांशी द्रवमाध्यमात घडवून आणतात. विरघळवणारा द्रवपदार्थ म्हणून पेट्रोलियम इथर, क्‍लोरोफॉर्म, अल्कोहोल अशा विद्रावकांचा वापर करतात. ही विद्रावकं महाग असून प्रदूषकही ठरतात. याऐवजी आता "सुप्रा मॉलेक्‍यूलर केमिस्ट्री'चं तंत्र विकसित होतंय. यामध्ये प्रक्रिया घन माध्यमात घडवून आणतात. त्यासाठी "मायक्रोवेव्ह'चा उपयोग केला जातो. लोकरीचे कपडे ड्रायक्‍लिनिंग करताना "परक्‍लोरो एथिलिन' हे अपायकारक विद्रावक वापरलं जातं. आता त्याकरिता कार्बन डाय ऑक्‍साईडचा वापर करण्याची पद्धत निघालीये. हा वायू वातावरणाच्या शंभरपट दाबाखाली 25 अंश सेल्सिअस तापमानाला घाटदार द्रवपदार्थ बनतो. तो हवेतून घेतला जातो आणि हवेतच सोडला जातो. त्यामुळे "समतोल' राहतो. या वायूपासून इंधन बनवण्यासाठी "सायनेकॉकस एलेगंट' या जिवाणूचा उपयोग करून आयसोब्युटाल्डेहाईड बनवता येतंय, हे आणखी एक वैशिष्ट्य.

आपल्या भोजनातील ताकाला लॅक्‍टिक आम्लामुळे आंबटपणा येतो. आता मक्‍यापासून जैवतंत्रज्ञान वापरून मोठ्या प्रमाणात लॅक्‍टिक आम्ल बनवलं जातं. त्यापासून पॉलिलॅक्‍टिक हे प्लॅस्टिक बनवतात. त्याची वस्‌, पॅकिंग मटेरियल, प्लेट्‌स, ग्लासेस, बाटल्या, टूथब्रश वगैरे तयार करतात. या पॉलिमर - प्लॅस्टिकपासून पुन्हा लॅक्‍टिक आम्ल बनवता येतं. यातील कच्चा माल आणि पक्का माल- दोन्ही पुनर्निर्मित, पुनर्वापर करता येण्यासारखा आहे. एरवी प्लॅस्टिकसाठी खनिजतेलजन्य कच्चा माल लागतो. ते सहजासहजी विघटनशील नसते.

रसायननिर्मितीसाठी सर्वसाधारणतः सुरवातीचा मुख्य कच्चा माल म्हणून खनिजतेलजन्य पदार्थ किंवा अल्कोहोल वापरतात. आता संशोधक - तंत्रज्ञ वाया गेलेल्या "बायोमास'चा वापर करून सक्‍सिनिक आम्लाचे उत्पादन करू शकलेत. अशा प्रकारच्या रसायनांचा ("प्लॅटफॉर्म केमिकल'चा) वापर करून इतर अनेक रसायनं "इकोफ्रेंडली' पद्धतीनं तयार करता येतील. कॉम्प्युटरचा प्रिंटर वापरून जगभर लेसर प्रिंट काढतात. त्यासाठीचा "टोनर' काही अमेरिकन कंपन्या प्रतिवर्षी 20 कोटी किलोग्रॅम बनवीत आहेत. हा एकदा कागदाला चिकटला तर परत "सुटत' नाही आणि त्याचं "रिसायकलिंग' अवघड बनतं. सध्या सोयाबीन तेलापासून पर्यावरणअनुकूल टोनर तयार होतोय. परिणामी लेसर प्रिंटच्या कागदाचा पुनर्वापर शक्‍य होईल. कॅलिफोर्नियातील एका मोठ्या कारखान्यात "इकोफ्रेंडली वाईन' तयार करण्यासाठी संपूर्णतः सौर ऊर्जेचा वापर केला जातोय. भारतात सूर्यप्रकाश भरपूर असल्यानं आपल्यालाही तसे प्रयोग (आणि व्यावसायिक उत्पादन) करता येईल. रायझोबियम किंवा ऍझेटोबॅक्‍टर जिवाणू हवेतील नत्र जमिनीत आणू शकतात. रासायनिक खतांची निर्मिती करताना खूप ऊर्जा खर्च होते. जैव खतांचा वापर करून "ग्रीन केमिस्ट्री'चे प्रयोग साधता येतील. सध्या जगभर बायोडिझेलचा बोलबाला आहे. ते तयार होताना बायप्रॉडक्‍ट म्हणून भरपूर ग्लिसरीन तयार होतं. त्याचं काय करायचं, ही एक समस्या होती. ते ग्लिसरीन वापरून प्रो. गॅलेन सप्पेस यांनी शेकडो उपयोग असणारा प्रॉपिलिन ग्लायकॉल हा पदार्थ बनवलाय. भावी काळात "फ्युएल सेल' (इंधनघट) वापरून मोटारी धावतील. त्यासाठी ग्रीन केमिस्ट्री उपयुक्त ठरते.

तमिळनाडूमध्ये कातडी कमावण्यासाठी हजारो लघू किंवा कुटीरोद्योग आहेत. त्यामुळे पाणी, जमीन आणि हवा खूप प्रदूषित होते. आता या उद्योगासाठी जैविक उत्प्रेरकांची निर्मिती आपले सूक्ष्मजीवशास्त्रज्ञ करीत आहेत. रसायनांची पर्यावरणअनुकूल निर्मिती करण्यासाठी उत्तम जैविक उत्प्रेरकांचा शोध घेतला जातोय. एखादं रसायन तयार करताना 8 ते 10 प्रक्रिया करणं आवश्‍यक असतं. त्याऐवजी 4 ते 8 प्रक्रियांमध्ये किमान ऊर्जा, रसायनं व वेळ वापरून त्यांची निर्मिती केली जात आहे. मुंबईला नुकतीच भेट दिलेल्या प्रो. पॉल ऍनास्तास यांनी 1991 मध्ये पर्यावरणपूरक रसायनशास्त्रासाठी "ग्रीन केमिस्ट्री' शब्द प्रथमच वापरले. वीस वर्षांनंतर भारतीय संशोधक या क्षेत्रात आता आघाडी घ्यायला सिद्ध होत आहेत, ही समाधानाची बाब आहे. 

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Greens worried over rising footfalls in Lalbagh

The increasing number of visitors to the Lalbagh Botanical Gardens during flower shows has become a cause of worry for the greens and some officials from the Horticulture department who are now contemplating a change in the venue. 



The Mysore Horticulture Society, the organiser of the Republic Day flower show at Lalbagh, may be hoping of a good profit by the end of the flower show this time, but many of them are of the opinion that the show should be stopped at the historic garden  for its good. The Lalbagh Botanical Gardens, with a history of over 250 years, is home to several rare plants and bird species and is the most preferred destiny for bird watchers in the concrete jungle that Bangalore has become over the years. The place, a favourite among morning walkers and joggers is now a subject of discussion due to the nuisance caused by the public at the flower show.

“It has turned a nuisance not only because of the increasing number of visitors, but also due to the garbage strewn everywhere, around the garden. There should be a change in the venue,” says Suresh Kumar, a botanist who visits the show every year.

Many bird watchers and nature lovers too have been voicing the same concern. Dr M B Krishna,  a City-based ornithologist says, “Let them shift it to other agriculture or horticulture areas. There will be better participation by the people. The number of people visiting this place is alarming. On January 26, we heard as many as 2.5 lakh visitors came to Lalbagh and this place is not designed to take this load,” he said.

M Sunil Kumar, an environmentalist, expressing his shock over the sea of people, who thronged the garden, and the piles of garbage around it, said that shows of these kinds should not happen in Lalbagh and the place designated as botanical garden, should be retained as one.

“It is not an amusement park. It is shocking to see the historic place, including the rock (Peninsular Gneiss of the region, dated 2,500 to 3,400 million years) is full of litter,” he said. Even some of the Horticulture department officials, on condition of anonymity, shared similar view saying that the show should be held at more than one place - by identifying a few BBMP parks.

Lalbagh officials said that more than six lakh people visited the park during this flower show. While 2.3 lakh people visited on January 26, it was 1.2 lakh last Sunday.

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Flesh-eating plant traps worms with sticky underground leaves

Philcoxia couldn’t look more unassuming. It’s a small herb that lives in Brazil’s Campos Rupestres region, a sparse plateau of rocky outcrops and white sands. All you’d see of it are a handful of twigs sticking out from the grains, topped with small purple flowers and even smaller leaves. You wouldn’t think that it’s the type of plant that can kill animals.

To find Philcoxia’s grisly secret, Caio Pereira had to look underground. The plant biologist from Unicamp, Brazil, found that the plant traps and digests  tiny worms with sticky underground leaves.

Plants have evolved to eat animals at least six times, and over 600 species of them now do so. They catch their prey with slippery water-filled pitchers, fast-snapping traps, sticky leaves and sucking bladders. Their strategies are diverse, but they all tend to grow in areas that are poor in nutrients. For example, familiar species like the Venus’ fly trap and the sundew live in bogs and swamps. In such inhospitable environments, these plants supplement their supplies of nitrogen, phosphorus, and other nutrients by feasting on the flesh of animals.

Philcoxia is no different. When Peter Taylor described the plants in 2000, he noted that they have several features that resemble those of other meat-eating species. Its mountain home is poor in nutrients and frequently starved of rain. Its roots are unusually sparse and lack the fungal partners that help other plants to survive. And it has tiny underground leaves – just a millimetre wide and coated with sticky glands, of the type found in other carnivorous plants.

There was just one problem. There were no signs of captured animals, or bodies nearby. If Philcoxia ate animals, it wasn’t doing so obviously. In 2007, Peter Fritsch found a possible answer. He noticed nematode worms stuck to the underground leaves, and reasoned that the plant was trapping and digesting them. Pereira, working with Fritsch, has now confirmed this hypothesis.

He found that Philcoxia’s underground leaves are littered with the bodies of dead nematodes. To check that the deaths aren’t coincidental, Pereira bred nematodes so that their bodies were full of nitrogen-15 – a rare and heavier-than-usual version of the element. He then “fed” the nematodes to Philcoxia. Two days later, Pereira found that 15 percent of the nitrogen-15 in the worms has been incorporated into the plant’s leaves. It was clear proof that Philcoxia was digesting the nematodes and absorbing the remains into their bodies.
Many meat-eating plants digest their prey with high concentrations of enzymes called phosphatases. Philcoxia does so too. Pereira found loads of the enzymes on Philcoxia’s leaves, which means that the plants are probably digesting the nematodes directly.

Pereira still wants to find out how Philcoxia lures its prey towards its traps. But for the moment, he has shown that its diet of worms greatly raises the level of nitrogen in its leaves, boosting it even above the levels of neighbouring plants that aren’t carnivorous.

That’s interesting, because some scientists have suggested that eating animals is a relatively inefficient way of coping with nutrient-poor environments. This would explain why carnivorous plants are relatively rare. But Philcoxia clearly shows that a fleshy menu can provide more nutrients the strategies of other plants in the same conditions.

Indeed, Philcoxia’s murderous habits suggest that we may have underestimated the true number of meat-eating plants in the world. After all, if this rare species feeds on microscopic prey using hidden traps, perhaps other plants do so too. As Mark Chase wrote a few years back, “we may be surrounded by many more murderous plants than we think”.

Reference: Pereira, Almenara, Winter, Fritsch, Lambers & Oliveira. 2011. Underground leaves of Philcoxia trap and digest nematodes. PNAS http://dx.doi.org/10.1073/pnas.1114199109

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Scientists discover lizards on verge of leap from egg-laying to live births

Scientists have caught the process of evolution in action as a species of Australian lizard abandons egg-laying for live births. The variety of skink, which is snake-like with four tiny legs, has been found laying eggs along the coast of New South Wales. However, the same yellow-bellied three-toed lizard living in the colder mountainous region is giving birth to offspring like a mammal does.

Rare study: The Australian lizard has been found laying eggs along the warm coast of New South Wales while the same species gives birth to live young in the colder mountainous region 

There are only two other types of modern reptiles which use both types of reproduction methods – another skink species and a European lizard.One in five snakes and lizards gives birth to live young, with records showing nearly a hundred reptile lineages have changed from egg-laying in the past.

Study co-author James Stewart, a biologist at East Tennessee State University, in America, told National Geographic that the discovery provided scientists with a rare opportunity. ‘By studying differences among populations that are in different stages of this process, you can begin to put together what looks like the transition from one [birth style] to the other,’ he said. Mr Stewart said the transformation could be linked to how newborns get nourishment. Or it could be a way of protecting the young in harsher climates.

Baby mammals are fed via a placenta which is connects the foetus to the ovary wall. Through this it can breathe and pass back waste. Embryos of egg-laying species get nutrients from the yolk while absorbing calcium from the porous shell, which also protects them from the external environment.However, some fish and reptiles are using a mix of both birthing styles.

Mothers form an egg which she keeps inside her body until the last stages. The shells thin, allowing the embryos to breathe until birth – but, according to scientists, this poses a nourishment problem, as it contains less calcium. This discovery prompted Mr Stewart and his colleagues to investigate the nutrient issue in the structure and the chemistry of the Australian lizard’s uterus.

Full Story: http://www.dailymail.co.uk/sciencetech/article-1308772/Evolution-action-Scientists-discover-lizards-verge-leap-egg-laying-live-births.html

Hunting for species in rain

Prof Dr G K Bhat, who leads a team of researchers, has found five new species of animals, a rare feat for any zoologist

While the rest of the city lets out a collective groan when the monsoon rains come around each year, Prof Dr G K Bhat couldn’t be happier. For him, its time to leave for the forests of the Western Ghats where he spends his time searching for new animal species.

What began as work on a PhD has turned into a passion, one that has earned the professor rare distinctions in the field of zoology. Although retired, Bhat continues his relentless search for new species and the search has often taken him to obscure and remote places. The city-based professor has introduced the world to as many as five new species of animals, a rare feat for any zoologist. He and his team of researchers have discovered two more new species which are yet to be named and classified. 

Their latest discovery is a snake-like non-toxic creature, which measures only a few inches and produces a sort of mucus. 

 

Dr. G K Bhat (third from left) seen with his research team, says it takes tremendous patience to discover a new species

“In fact they have been referred to as Blind Snakes by local residents, but that is a separate variety altogether,” Bhat said. “These creatures feed on earthworms, termites, other insects and soil microbes. They are basically nocturnal in nature and burrow deep into the soil. Males are smaller in size and they reproduce by laying eggs. The female sits on the eggs for two months without consuming either food or water. While a normal adult weighs 20 to 25 gms, the female could lose around 5 gms in body weight during this time.”

Bhat himself might call the find sheer luck, but there is no lack of effort and the searches have been painstaking.  “Discovering a new species is nothing but a gamble,” Bhat said. “Every year, during the rainy season, we head to the forests of the Western Ghats and camp in remote corners while searching for a new species. There have been several years when we have returned empty-handed. It requires tremendous patience and determination. Had it not been for the support of local residents and the forest department, we would not have discovered these creatures.” 

Last month, for a record fifth time, Bhat was honoured by the Zoological Survey of India (ZSI) for discovering yet another limbless yellow striped caecilian near Chorla village in Khanapur taluk near the Goa border in Belgaum. That species has been named Ichthyophis davidi, after Bhat’s teacher in London. 

Apart from the yellow-striped caecilian - the fifth species found by the team — Bhat’s team had also discovered a tail-less caecilian in Kundapura in 2004 which was named Gegeneophis madhavai, after Prof Madhav Gadgil another teacher. The team discovered Gegeneophis nadakarnii in 2004 in the Bondla Wildlife Sanctuary of Goa, Gegeneophis goaensis in 2007 in north Goa and Gegeneophis mhadeiensis in 2007 near Belgaum.

“You need to find at least five species before you can report it to the ZSI. We have found two more species, but we haven’t reported it,” said a member of the team.

Although the species are a treasure in the world of zoology, these creatures are routinely killed by local villagers and residents.

“These species are non-poisonous and bio-indicators in nature,” Bhat said. “But people kill these creatures as they mistake them for snakes. This apart, intense use of chemical fertilisers and pesticides in nearby areas has affected their life cycle. Because of soil pollution, many have died.”
 

Despite his voluntary retirement from academics, Bhat has remained active and currently teaches students at a private coaching institute.

“I plan my research well in advance and obtain permission to carry out my research,” Bhat said. “Rainy days are completely dedicated to finding these creatures as we roam around forests. On other days I engage myself with students.”

 

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