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Abstracts
Panel: Advancing Sound Chemical Management for Sustainable Development and a Toxic Free Asia
Capacity building programme for environment and sound management of persistent organic pollutants and heavy metals in Nepal
The role of civil society in advancing sound chemical management for sustainable development and a toxic free Asia
Toxicity evaluation of personal care products: Moving towards sound chemical management in cosmetic industry
Evaluation of activated carbon amendment for reclamation of a DDT contaminated site in Pakistan
Environmental pollution: Hazardous chemical wastes management in Kazakhstan
Early Plantation of Crops (BT Cotton): The Impact on Chemical Use, Profitability and Sustainability - A Case Study
Removal of residual toxic metals for cleaner environment through liquid membrane using calixarenes -A case study
Capacity building programme for environment and sound management of persistent organic pollutants and heavy metals in Nepal
Ram Charitra Sah*
The level of awareness about persistent organic pollutants (POPs) and heavy metals like mercury, lead and cadmium is extremely low as reflected by the National Implementation Plan (NIP) to the Stockholm Convention of Nepal which ranked public awareness raising, information and education priority areas with regard to the management of POPs in Nepal.
Based on these, Center for Public Health and Environmental Development (CEPHED) has launched a sound chemicals management campaign comprising research, public awareness, capacity building, and public participation to reduce and eliminate the sources of heavy metals and POPs. This paper aims to share our research findings, achievements and learning from our public awareness raising and capacity building programmes on POPs and heavy metals.
Methodology includes research; preparation, production, dissemination of the Information, Education and Communication (IEC) materials such as fact sheets, posters, news articles, video documentaries and radio jingles; organising regional and districts level training programmes; policy dialogue for policy, standard and law formulation.
Research on mercury in the health sector clearly shows a high use of mercury contained in mercury measuring devices e.g. thermometers, sphygmomanometers, dental amalgams, preservatives and mercury lighting systems like CFL, etc. but the correct methods of destroying these devices so that there is no exposure to the chemicals that emanate from mercury have not been addressed, therefore doctors, nurses and the public alike continue to remain exposed to mercury. Mercury free health care initiatives in Nepal would be new in addressing mercury issues. The study of lead in decorative paints available in Nepal shows very high lead level ranges from 3.98 ppm to 73966.4 ppm coupled with a low awareness about its health and environment consequences. (Lead can also be found in soft plastic children toys, which is something few people are aware of).
In addition the study on health care and waste management in many health care institutes was found to be particularly poor. Thus infectious waste mixed with city garbage are either dumped in vacant open spaces or burned either openly or in incinerators on hospital premises thus resulting in air pollution, land pollution, water pollution, and toxic ash is released into the environment. CEPHED has started developing a model hospital for environmentally sound management of health care and waste, curbing the release of POPs such as dioxin and furan and creating a model metal workshop with alternative welding machine technology to avoid the use of PCBs contaminated transformer oil. These initiatives have a wide scope so that they can be replicated in other similar situations in developing countries, which is why it is suggested that these findings be shared with others through this conference.
 *Ram Charitra Sah is Executive Director of Center for Public Health and Environmental Development (CEPHED), Kathmandu, Nepal having about 15 years of working experience of environment and chemical management field.
The role of civil society in advancing sound chemical management for sustainable development and a toxic free Asia
Mahmood A. Khwaja*
The importance of engaging major groups and stakeholders as partners has been gradually recognised by national governments, as civil society can help implement their programmes beyond the government’s own capacities, especially in Asia. Civil society provides the baseline data, expertise, “advocacy to foster accountability, raising public awareness, effective information dissemination and formal and informal education at all levels” 1. In recent years, major groups of civil society have also played an active supporting role in developing some of the multilateral environmental agreements (MEAs) on chemicals related issues by the states governments, such as Stockholm, Basal & Rotterdam Conventions, Strategic approach to International Chemical Management (SAICM) and in on-going intergovernmental committee negotiations for a legally binding instrument on mercury.
“Sound management of chemicals is essential if we are to achieve sustainable
development, including the eradication of poverty and disease, the improvement of
human health and the environment, and the elevation and maintenance of the standard of
living in countries at all levels of development.”2 Chemical management is of the prime problems being faced by governments in Asia. Over 50,000 chemical substances with one million combinations are being used daily in agriculture, industries and houses” However, guidance for any chemicals consuming sector for managing chemicals and chemicals containing wastes is not readily available. In addition, environmental regulatory compliance and enforcement continue to be a major problem too. Hence, hazardous releases and wastes “cause immediate short-term public health problems as well as long-term environmental pollution” 3
This paper aims to look at the prospects and problems of sound chemical management in countries of the Asia-Pacific region, especially South Asia, with a focus on the civil society role in advancing sound chemical management through the implementation of Strategic Approach to International Chemical Management (SAICM). A brief account of the involvement of civil society major groups would be given, as envisaged in SAICM’s overarching policy strategy, high-level declaration and global plan of action.
An assessment of the activities (285) within the work areas (69), as enlisted in SAICM’s global plan of action for meeting SAICM objectives, has indicated, among others, “ Strengthening Knowledge and Information,” (both development as well as dissemination) to be the main area and focus of involvement for non-governmental organizations (NGOs).
References:
1. Khwaja, Mahmood A., March 2008. Strengthening the Role of Civil Society “Major Groups” in Sustainable Development, SDPI Research & News Bulletin, 15 (p. 1)
2. Dubai Declaration, Strategic Approach to International Chemical Management (SAICM) February 2006, United Nations Environment Program (UNEP) (p.6)
3. Hazardous Waste Management – Policies and Practices in Asian Countries 2001 (p.p. 1-2) Asia Productivity Organization, Tokyo
 * Dr. Mahmood A. Khwaja is a Senior Adviser, Chemicals and Sustainable Industrial Development, SDPI, Islamabad, Pakistan
Toxicity evaluation of personal care products: Moving towards sound chemical management in cosmetic industry
Anjum Rasheed*
Chemical substances are being used in the production of personal care products. Some of these may be highly toxic and their use is harmful to human health and environment. This paper indicates the risk associated with the personal care products. Ingredients used in some of the personal care products have been assessed for their toxicity and possible health effects. This paper shows the usage of many carcinogenic, hormone-disrupting and toxic chemicals used in the cosmetic industry.
Phthalates used in perfumes act as endocrine disruptors and may cause obesity and reproductive and developmental harm. Diethyl phthalate (DEP) also causes sperm damage in men. Synthetic musk used in perfumes may disrupt hormones. Sodium Laureth Sulfate is used in face wash which produces nitrosamines in combination with other chemicals that is a potent class of carcinogens. Mineral oils are used in skin moisturisers which can be contaminated with cancer causing PAH‘s. Fragrance used in personal care products can indicate the presence of up to 4,000 separate ingredients, many toxic or carcinogenic. Fragrance also contains 1-4, dioxin as a contaminant. Clinical observation proves fragrances can affect the central nervous system, causing depression, hyperactivity, and irritability. Ammonium Laureth Sulfate used in shampoos when combined with other chemicals produces nitrosamine, a potent class of carcinogens. Blue 1 (coal tar) a human carcinogen is also used in shampoos. PEG-5 Cocamide used to adjust the melting point and thickens products is potentially carcinogenic petroleum ingredient that increases the appearance of aging and makes skin more vulnerable to bacteria.
Propylene Glycol (PG) penetrates the skin and can weaken protein and cellular structure. These are considered to be so toxic that workers are required to wear protective gloves, clothing and goggles and practise safe disposal. Inhalation may cause respiratory and throat irritation, central nervous system depression, blood and kidney disorders. Skin contact causes irritation and dermatitis and eye contact causes irritation and conjunctivitis. DMDM Hydantoin contains formaldehyde, which is a carcinogen. Animals exposed to Ammonium Lauryl Sulfate (ALS) experience eye damage, central nervous system depression, laboured breathing, diarrhoea, severe skin irritation, and even death. Young eyes may not develop properly if exposed to ALS because proteins are dissolved. ALS may also damage the skin's immune system by causing layers to separate and inflame. Methylchloroisothiazolinone causes cosmetic allergy and potential dangerous neuro-toxic effects. Alcohol Denatured used in perfumes is a known or suspected teratogen. Methyl & Propyl Parabens used as inhibitors of microbial growth and to extend shelf life of products are highly toxic and cause reproductive system toxicity. Butylated Hydroxytoluene (BHT) causes allergic contact dermatitis. It contains toluene which may affect liver, kidneys, blood stream, or the Central Nervous System (CNS). PEG-6 Stearate & PEG Glyceryl Stearate is a potentially carcinogenic petroleum ingredient that can alter and reduce the skin's natural moisture factor. The majority of lanolin used in cosmetics is highly contaminated with chlorinated organo pesticides like DDT. Imidazolidinyl Urea releases formaldehyde, a carcinogenic chemical, into cosmetics at over 10°C.
There is no system in place to regulate the usage of chemicals in cosmetics. This toxicity evaluation of chemicals can be used to formulate some action plan for the regulation of these chemicals in the cosmetic industry. There is a need to prepare a Chemical Management Plan and Regulations in the country so that some of the chemicals used in cosmetics may be banned and other toxic chemicals be regulated depending upon the level of toxicity. Furthermore, a ban may be put on import of the products if these do not follow the regulations of chemical management. Rules may be formulated to indicate the risk substances along with their possible health impacts separately in the ingredient list in order to raise mass awareness. Urgent action is required in order to raise global awareness on the value of human health which is more important as compared to the profits that are made due to the sale of these harmful products.
Bibliography:
Al-Saleh, S. Al-Enazi, N. Shinwari, 2009. Assessment of Lead in Cosmetic Products. Regulatory Toxicology and Pharmacology 54 (2009) 105–113.
A.M. Api, 2010. Toxicological Profile of Diethyl Phthalate: A Vehicle for Fragrance and Cosmetic Ingredients. Food and Chemical Toxicology 39 (2001) 97-108.
G. J. Nohynek, E. Antignac, T. Re, H. Toutain, 2010. Safety Assessment of Personal Care Products/Cosmetics and Their Ingredients. Toxicology and Applied Pharmacology 243 (2010) 239–259.
U. Klaschka, 2010. Risk Management by Labeling 26 Fragrances? Evaluation of Article 10 (1) of the Seventh Amendment (Guideline 2003/15/EC) of the Cosmetic Directive. International Journal of Hygiene and Environmental Health xxx (2010) xxx–xxx.
López-Galindo, C. Viseras, P. Cerezo, 2007. Compositional, Technical and Safety Specifications of Clays to be Used as Pharmaceutical and Cosmetic Products. Applied Clay Science 36 (2007) 51–63.
M. Pauwels, V. Rogiers, 2007. Database Search for Safety Information on Cosmetic Ingredients. Regulatory Toxicology and Pharmacology 49 (2007) 208–216.
 **Ms Anjum Rasheed is a research scholar at the Department of Environmental Sciences, Fatima Jinnah Women University, Rawalpindi, Pakistan.
Evaluation of activated carbon amendment for reclamation of a DDT contaminated site in Pakistan
Asma Younas*
Isabel Hilber**
Mahmood Khwaja***
Thomas D. Bucheli****
1. Introduction
Dichlorodiphenyltrichloroethane (DDT) was produced from 1963 to 1994 in a factory in Nowshera, Khyber Pakhtunkhwa, Pakistan. The factory was then officially closed, but was still in operation for many years [p. 1-2, Khwaja et al., 2007]. The production and distribution of the insecticide resulted in a DDT polluted area of about 85 ha (Figure 1). At the factory’s place the soil’s contamination is up to 5000 mg/kg DDT in dry soil.
Figure 1: Contour plot of the predicted DDT contamination in log[mg/kg] at the site (left) and standard deviation (right). The factory was located where x- and y-coordinate [m] cross. The circles in the contour plot indicate measured sites which were taken radially according to the cardinal points. The size of the circles indicates the concentration level.
To reduce DDT exposure to the environment and human beings, this contaminated site has to be remediated. Therefore, the aim of this joint research project is to test a remediation strategy that substantially reduces the bio-available fraction of the aged DDT in the soil. We attempt to bind and immobilize the contaminant and its metabolites in the soil by activated charcoal (AC) amendment. Activated charcoal belongs to the black carbon (BC) category, which pulls highly toxic organic pollutants into sediments and soils by extremely efficient sorption [2]. AC has therefore proven to significantly reduce the bioavailability of organic contaminants in solid matrices due to its high adsorption affinity, capacity, and strength. For this purpose, many researchers already successfully added AC to sediments [3-5]. and soils [6]. The novelty of this project is the application and thorough evaluation of this remediation technique to a field soil contaminated by sequestered DDT and metabolites.
Specifically, in laboratory experiments with different soil contamination levels and different kinds of added AC (granulated AC (GAC), biochar, and ev. Coke) breeze as cheap and locally originated material) the bioavailability of DDT and metabolites will be assessed by depletive and non depletive extraction methods which are Tenax® beads, a porous polymer and polyoxymethylene (POM), respectively. Pilot field studies will be performed after the AC is added to the soil according to the initial laboratory results. The chemical activity of DDT in the soil pore water will be assessed by POM and the bioaccessibility of DDT tested in the lab with Tenax® over a period of about two years. Overall, this technique presents, if successful, an economically sound, effective and feasible way to remediate organically contaminated hotspots in Pakistan and elsewhere.
2. Materials and methods
To single out the most effective AC material, sorption isotherms with DDT and metabolites and different charcoals will be performed according to Hale et al. [3]. Tenax® extractions will be carried out according to Hilber et al. [7], and POM experiments will be performed according to Jonker and Koelmans [8].
3. Results and discussion
Sorption isotherms from the afore mentioned materials will be compared and discussed with the results from Hale et al. [4]. Preliminary Tenax® experiments with 5% GAC added into the Nowshera soil showed that dry AC amendment reduces the desorbable (bioavailable) fraction of DDT considerably (Figure 2). The influence of soil conditioning (dry vs. wet) is subject to current investigations. 
Figure 2: Consecutive Tenax® extractions from the Nowshera soil of p,p’- (left) and o,p’-DDT (right panel). Extractions were performed from control and GAC amended soil with or without prior wetting. The cumulative fraction desorbed refers to the summed ratio of Tenax® extracted concentration of the DDTs over the total concentration in the soil extracted by accelerated solvent extraction.
4. Conclusions
Preliminary Tenax experiments show a considerable reduction of DDT of the Tenax desorbable fraction in the GAC amended soil compared to the control soil. The reduction also shows that this remediation technique works in principle. Desorption of o,p’-DDT seems to have reached a steady state after about 1000 h, whereas p,p’-DDT desorbed fraction is still increasing. Yet, many questions concerning the behaviour of AC in the field remain open and need to be further investigated before this remediation technique can be put into practice, specifically with regard to different AC materials and varying environmental factors like soil moisture and temperature.
References:
[1] Khwaja, M.A.; Jan, R.M.; Gul, K.; 2007. Study of contamination of soil in surrounding of abandoned persistent organic pollutant (DDT) Nowshera Factory in North West Frontier Province (NWFP) Pakistan. SDPI, Islamabad, Pakistan.
[2] Koelmans, A.A.; Jonker, M.T.O.; Cornelissen, G.; Bucheli, T.D.; Van Noort, P.C.M.; Gustafsson, O.; 2006. Black carbon: The reverse of its dark side. Chemosphere 63: 365-377, viewed 30 September 2010, web of science, https://webvpn.ethz.ch/.
[3] Tomaszewski, J.E.; Werner, D.; Luthy, R.G.; 2007. Activated carbon amendment as a treatment for residual DDT in sediment from a superfund site in San Francisco Bay, Richmond, California, USA. Environ. Toxicol. Chem. 26: 2143-2150, viewed 30 September 2010, web of science, https://webvpn.ethz.ch/.
[4] Cho, Y.M.; Smithenry, D.W.; Ghosh, U.; Kennedy, A.J.; Millward, R.N.; Bridges, T.S.; Luthy, R.G.; 2007. Field methods for amending marine sediment with activated carbon and assessing treatment effectiveness. Mar. Environ. Res. 64: 541-555, viewed 30 September 2010, web of science, https://webvpn.ethz.ch/.
[5] Hale SE, Tomaszewski J, Luthy RG, Werner D. 2009. Sorption of dichlorodiphenyltrichloroethane (DDT) and its metabolites by activated carbon in clean water and sediment slurries. Water Res, 43: 4336-4346, viewed 30 September 2010, web of science, https://webvpn.ethz.ch/.
[6] Brändli RC, Hartnik T, Henriksen T, Cornelissen G. 2008. Sorption of native polyaromatic hydrocarbons (PAH) to black carbon and amended activated carbon in soil. Chemosphere 73: 1805-1810, viewed 30 September 2010, web of science, https://webvpn.ethz.ch/.
[7] Hilber I, Bucheli T, Wyss G, Schulin R. 2009. Assessing the phytoavailability of dieldrin residues in charcoal-amended soil using Tenax® extraction. J Agric Food Chem 57: 4293-4298, viewed 30 September 2010, web of science, https://webvpn.ethz.ch/.
[8] Jonker MTO, Koelmans AA. 2001. Polyoxymethylene solid phase extraction as a partitioning method for hydrophobic organic chemicals in sediment and soot. Environ Sci Technol 35: 3742-3748, viewed 30 September 2010, web of science, https://webvpn.ethz.ch/.
 *Asma Younas is a Ph.D student at the Environmental Science Department (ESD), Peshawar University, Peshawar, Pakistan. She has studied environmental sciences and is now working out remediation strategies for a DDT polluted site in Nowshera.
**Isabel Hilber has a Ph.D in environmental sciences. Her research focus is the sorption processes of organochlorine pesticides to activated charcoals in soil in general as well as in agricultural soil.
***Dr. Mahmood A. Khwaja is a Senior Advisor Chemicals & Sustainable Industrial Development and Visiting Fellow at SDPI. He holds a Ph.D from La Trobe University of Science and Technology, Melbourne, Australia and an M.Sc. from the University of Peshawar. He has over 60 publications to his credit.
***Thomas Bucheli has a Ph.D in environmental sciences and is head of the Organic Trace Analysis group at Agroscope ART Zurich, Switzerland and of the Pakistani-Swiss project. The focus of his research group is the monitoring of mycotoxins, phytoestrogens, pesticides, antibiotica, and other xenobiotica in soil and water as well as sorption processes of these compounds to nanoparticles and black carbon in its different forms.
Environmental pollution: Hazardous chemical waste management in Kazakhstan
Abubakirova Kalkash*
Economic growth in Kazakhstan is mainly due to the increase in commodity prices on world markets which use a significant amount of natural resources. As a result, we face social, ecological and economic issues. “The growth of GDP is accompanied by large detriment to the environment. Based on the current data, over 75 percent of the country’s area is exposed to high environmental risks. The problem of desertification is critical. Over 60 percent of land in Kazakhstan is subject to natural processes of desertification. ‘Historical pollutions’, stored wastes, growing toxic emissions from the stationary and movable sources, - all these represent enormous threat to the environment and people’s health” (Public Association n.d).
A significant portion of persistent organic pollutions (POPs) are found in pesticides, residues of which remain in the soil and plants for years. Industrial POPs are produced and used at the enterprises of energy generation, petrochemical and chemical industry. According to a regional assessment report, 40 billion tonnes of waste has accumulated in Kazakhstan. The main volume of waste is formed by mining and processing enterprises. In Kazakhstan, the total amount of waste by mining and smelting of non-ferrous, rare, precious and radioactive metals is comparable to the reserves of fairly large fields. Out of the 40 billion tonnes, 6.7 billion tonnes are toxic, which are sources of pollution for land, surface and groundwater and the atmosphere (UNEP 2006a). According to another UNEP assessment report on Central Asia 2006, “These wastes are located in Karaganda region (29.4 percent), East-Kazakhstan region (25.7 percent), Kostanay region (17 percent), and the Pavlodar region (14.6 percent.). In more than 100 storage locations, about 230 million tonnes of radioactive waste uranium are accumulated with a total activity of more than 250 thousand curies.” Annually about four billion tonnes of such waste is produced, but only about 7 percent is recycled.
On the territory of the Republic, there are 118 dumps of sub-standard ores and wastes resulting from processing of radioactive ores amounting to 56 million m3 (UNEP 2006a). For fifteen years, 56.3 million tonnes of municipal solid waste (MSW) has accumulated in the country, an average of 2.2 m3 per person (Ibid). Accumulation of MSW is increasing with each passing year, reaching at present 325-550 kg per urban resident per year/ 6/. With limited financial resources, illegal dumps and landfills are the cheapest method of long-term landfill storage. The bulk of the waste (without sorting the components), is taken out and stored in open dumps and landfills, 97 percent of which do not meet the ecological requirements and the sanitation regulations. Only about 5 percent of MSW is recycled. Thus, the reconstruction of existing landfills, in accordance with international specifications is a must (Ibid).
“Air pollution is mainly caused by emissions from ferrous and non-ferrous metallurgy, power engineering, oil and gas industry and transportation. The state of the air pollution is monitored in 19 cities. About five million people in Kazakhstan live in conditions of air pollution, 2 million - in extremely high levels of pollution. The highest level of contamination is observed in the cities Ridder, Shymkent, Ust-Kamenogorsk, Karaganda, and Almaty” (CARNet, n.d).
According to a 2006b UNEP report about air pollution in Central Asia, sometimes the maximum concentrations of pollutants exceed the established standards by 10-20 times (for example, in the cities of Balkhash, Ust-Kamenogorsk with sulfur dioxide). Foreign and domestic companies in their investment policy follow the residual principle of environmental financing. The system of state control over the environment and natural resources management systems are still in the initial stages of development and require continuous improvement. The current state regulation basis is non-systematic characterised by the lack of standardised indicators.
References:
CARNet, n.d. viewed on 29 Nov. 2010, <http://aarhus.kz/index.php?option=com_content&task=view&id=199>
Public Association-The Network of Experts for Sustainable Development of the Central Asia n.d., ‘Conception of Republic of Kazakhstan transition to sustainable development for 2007-2024’, United Nations Environment Programme, Regional Resource Centre for Asia and the Pacific (UNEP RRC.AP), viewed on 24 Nov. 2010, <http://www.rrcap.unep.org/nsds/pub/ATT00032.pdf>
Republic of Kazakhstan 2004, ‘The Action Plan for 2004-2006 on implementation of the concept of ecological security of the Republic of Kazakhstan for 2004-2015.
UNEP 2006, ‘Assessment reports on priority environmental problems in Central Asia’, Ashkhabad.
UNEP 2006a, ‘Management of Production and Consumption Waste- Regional assessment report’, United Nations Environment Programme, Ashkhabad, viewed on 24 Nov. 2010, <http://ekh.unep.org/files/priority%20issues.pdf>
UNEP 2006b, ‘Air pollution in Central Asia- Evaluation report on priority areas’, United Nations Environment Programme, Ashkhabad.
 * Dr. Abubakirova Kalkash has a PhD in Agricultural Sciences and is a professor at the University of International Business, Almaty, Kazakhstan.
Early Plantation of Crops (BT Cotton): The Impact on Chemical Use, Profitability and Sustainability - A Case Study
Khuda Bakhsh, Faisal Rasool and Sarfraz Hassan*
Currently Pakistani farmers growing cotton are facing severe problems of water availability, disease and pest attacks. Farmers make intensive use of pesticides to protect cotton crops from pest attacks. Out of total plant protection chemicals used in Pakistan, more than 58 percent are used in cotton production. Historical data on pesticide consumption in cotton show that pesticide use was 7955 M tons during 1975-76 which has increased many times over the years (54406 M tons during 2006-70; recording an increase of 584 percent). This intensive use is creating health and environmental problems. Pesticide applicators, farmers and cotton pickers suffer from pesticide residual effects. Studies indicate substantial health cost to cotton pickers and other farm workers. Moreover, pesticides also cause contamination of water, having adverse impacts on human and animal health. So, there is dire need to introduce practices/varieties for sustainability of cotton production.
Bt cotton has been introduced with an objective of reduced use of pesticides, since it has resistance against bollworms. However, reports show that some farmers have started planting Bt cotton as early as Feb-March (off-season), whereas the actual time of planting is May (seasonal). The reason is that early plantation of Bt cotton has two types of benefits. It can lead to high production and high output prices as a result of early harvesting and is less prone to attacks by different pests and diseases. However, farmers planting Bt cotton in the months of February and March have to forego wheat crop (a staple crop) and mostly these farmers are able to grow only one crop i.e. Bt cotton during a year. Such a farming practice can create several issues including food security and sustainability of production practices.
The question arises whether planting Bt cotton off-season brings enough returns for farmers to compensate returns foregone in the form of wheat? The present study is designed to determine whether growing Bt cotton earlier is economically viable or not; and to explore factors responsible for early growing of Bt cotton. Data collected for mixed cropping zone of the Punjab province during 2009-2010 is used in the present study. Results of the study show that gross margin of off-seasonal Bt cotton growers and of those who are growing both seasonal Bt cotton and wheat are not statistically different from each other. However, off-seasonal cotton growers make more use of pesticide and irrigation, compared to those of seasonal cotton growers. Logit model was used to estimate probability of growing Bt cotton during February and March. Results of the model show that farm size, off-farm income, family size and family assets are positively related with off-seasonal Bt cotton planting, whereas age of the farmers and contacts with extension staff or other organisations are negatively related with planting of off-season Bt cotton.
Findings of the study suggest that the objective of declining pesticide use by adopting Bt cotton diminishes when farmers grow it during February-March and this practice results in severe environmental consequences in the form of more use of pesticide and irrigation on the one hand and on the other hand, it can adversely affect food security. So, we conclude that there is an urgent need to make farmers aware of the advantages and disadvantages of growing Bt cotton in the months of February-March and May. Although early plantation of cotton is not allowed in the country, the need is to implement this in full letter and spirit. Fines should be imposed on violators in order to discourage early plantation of cotton. It will help in making use of natural resources more sustainably, especially water resources. Moreover, farmers would be able harvest true benefits of Bt cotton in the form of reduced pesticide use, thereby resulting in rising earnings if Bt cotton is planted in its recommended time period. Similarly, banning or restricting early plantation of cotton will have positive impact on sustainability of irrigation water, since results of the study show that cotton growers are paying more to purchase tube-well water in off-season cotton production.
* The authors are affiliated with the Department of Environmental and Resource Economics at the University of Agriculture, Faisalabad, Pakistan.
Removal of residual toxic metals for cleaner environment through liquid membrane using calixarenes -A case study
Fozia T. Minhas*, Shahabuddin Memon** and M. I. Bhanger***
“Heavy metals are major pollutants in surface, ground and even in treated waste waters because of its toxicity. It is frequently found in waste waters coming from industrial effluents and also present in natural form in groundwater” (Solangi 2009). However, liquid membranes (LMs) have now emerged as a new technology for heavy metal removal. Their application with “different configurations i.e. bulk liquid membrane (BLM) and supported liquid membranes (SLM) have recently gained substantial practical importance in separation science, macromolecular chemistry and membrane technology” (Ersoz 2007).
“Calixarenes, a versatile class of macrocyclic ion receptors is well renowned in liquid membranes as selective carriers. The highly ordered structure of calixarenes offers not only enormous possibilities for chemical modifications, but also makes them exceptionally practical in the study of selective molecular recognition in LMs” (Minhas et al. 2010; Asfari 2001).
 In this study, calix[6]arene hexaester derivative (1) has been proved to be a successful carrier for the transport of Pb(II) through BLM at ambient temperature. The mass transfer of Pb(II) has been analysed on the basis of kinetic laws of two consecutive irreversible first order reactions. By fitting experimental data, apparent rate constants, i.e. k1, k2, along with tmax, Rmmax and the flux values such as Jdmax, Jamax have been determined. The activation energy values for the extraction and re-extraction were found as 56.33 and 14.79 kJmol-1, respectively. These values demonstrate that the process is diffusionally controlled by Pb(II). Also, the transport behaviour of Hg(II) from aqueous solution through a flat-sheet supported liquid membrane has been investigated by the use of calix[4]arene thioalkyl derivative as carrier and Celgard 2500 as the support. A Danesi mass transfer model was used to calculate the permeability coefficients for each parameter studied (Alpoguz 2007).
Therefore, membrane technology can be employed in chemical industries by making some technical advancement, for treating effluents using fewer amounts of expensive carriers, and for recovery of valuable products.
References:
Alpoguz, H.K., Kaya, A., Memon, S. & Yilmaz, M.J. 2007 ‘Facilitated Supported Liquid Membrane Transport of Hg2+ Using Calix[4]arene Derivatives’ Macromol. Sci. Pure and Appl. Chem., no. 44, p 17-20.
Asfari Z., Böhmer, V. Harrowfield., J. Vicens, J. 2001, Calixarenes, Kluwer Academic Publishers, Dordrecht.
Ersoz, M. 2007 ‘Transport of mercury through liquid membranes containing calixarene carriers’ Adv. Colloid Interface Science, 134-135 pp. 96-104.
Minhas, F.T. Solangi, I.B. Memon, S. and Bhanger, M.I. 2010 ‘Kinetic study of Pb(II) transport through a bulk liquid membrane containing calix[6]arene hexaester derivative as carrier’, Separation Science and Technology, vol.45, no.10, pp. 1448-1455.
Solangi, I.B. Memon, S. and Bhanger, M.I. 2009, ‘Synthesis and application of a highly efficient tetraester calix[4]arene based resin for the removal of Pb2+ from aqueous environment’, Analytica Chimica Acta, vol.638, p. 146–153.
* F.T. Minhas is a PhD student at the National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro-Pakistan and received her M.Sc. in Physical Chemistry from the same university in 2006. Her field of interest is synthesis of calixarene derivatives and their application in membrane technology.
** Dr. S. Memon is working as Assistant Professor at the National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan. He did his PhD from Selcuk University, Turkey. His research interests are synthesis, complexation, reactivity and phase transfer reactions of calixarenes, and their application in various fields of analytical/material science.
*** Dr. M. I. Bhanger is working as a Professor and Director at the National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan. He did his PhD from the University of London, U.K. His research interests include natural and synthetic adsorbents for enrichment and removal of trace organic and inorganic compounds present in water and development of chromatographic methods of analysis for inorganic ions.
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