ADSORPTION OF MERCURIC ION FROM AQUEOUS SOLUTIONS USING MODIFIED FLY ASH

In this study, fly ash was treated with NaOH solution (FAN) before modifying with (3-mercaptopropyl) triethoxysilane - MPTMS (FAMPS). By using FTIR, FESEM, XRD, EDX, and BET techniques, the change in structure, composition and morphology of FAN and FAMPS was evaluated. The FTIR spectra of FAN and FAMPS showed that there is no chemical reaction between the MPTMS and FAN. After modification, the FAMPS has a rough surface with composition difference from the FAN. Mercuric ion adsorption behavior as well as adsorptionisotherm models (Langmuir and Freundlich) of the FAN and FAMPS were also investigated and discussed. Thanks to FAN modification, the mercuric ion removal percent of the FAMPS was higher than that of the FAN. Owing to the adsorption data, Freundlich isotherm modelwas fitted for the mercuric ion adsorption process

Effects of oil and grape seed tannin extract on intakes, digestibility, milk yield and composition of Saanen goats

An experiment was conducted as a 4×4 Latin square design using 4 lactating Saanen goats, 19 months old and 47.9±1.04 kg of body weight, to evaluate the effect of oil and grape seed tannin extract (GSTE) supplementation on feed intake, digestibility, milk yield and milk composition. Each experimental period lasted for 21 days including 16 days for adjustment and 5 days for sampling. Goats were fed a control diet (Ctrl) consisting of 60% concentrate and 40% fresh Para grass (dry matter, DM, basis) while other 3 treatments were supplementation of 2.5% soybean oil (SO); 2.5% soybean oil + tuna fish oil at 3:2 w:w (SFO); 2.5% soybean oil + tuna fish oil at 3:2 w:w + 0.8% GSTE (OCT). The results showed that oil and GSTE did not affect feed intake, digestibility, milk yield and composition of goats (P > 0.05). However, digestibility of EE was higher (P < 0.05) in SFO and OCT diets (85.4% and 84.7%, respectively) compared with Ctrl (76.2%). Combined data suggested that feeding 2.5% oil blend with or without 0.8% GSTE increased EE digestibility in goats without affecting intake, animal performance and milk composition

ĐIỀU TRA TÌNH HÌNH CỎ LỒNG VỰC PHÁT SINH TRỞ LẠI TRÊN RUỘNG LÚA GIEO SẠ SAU KHI SỬ DỤNG THUỐC TRỪ CỎ Ở THỪA THIÊN HUẾ

Studying herbicide resistance in Vietnam is limited, and there are very few reports on the regrowth of weed after applying herbicides. A survey to investigate the cultivating habit and the barnyard grass regrowing in the direct-seeded rice fields after applying herbicides in Thua Thien Hue shows that the main labourers of rice cultivation are male with a low educational level to understand scientific and technical knowledge. The most common grass regrowing in direct-seeded rice fields after applying herbicides includes Barnyard grass (Echinochloa crus-galli), Grass-like fimbry (Fimbristylis miliacea), Bermuda grass (Cynodon dactylon), and Sprangletop (Leptochloa chinensis). The yield decreases from 12.1 to 14.0% because of regrowing of barnyard grass. The herbicides commonly used in Thua Thien Hue are Sofic 300EC (Pretilachlor) and Sunrice 15WDG (Ethoxysulfuron), but their effectiveness has decreased in recent time owing to farmers’ inappropriate spraying skills and the decrease in the effectiveness of herbicides. A more thorough assessment of the factors that cause grass regrowing after spraying herbicides is required for better weed management.Nghiên cứu sự kháng thuốc trừ cỏ ở Việt Nam còn hạn chế và có rất ít báo cáo về sự phát sinh của cỏ dại sau khi sử dụng thuốc trừ cỏ. Kết quả điều tra về tập quán canh tác và tình hình cỏ lồng vực phát sinh trở lại trên ruộng lúa sau khi sử dụng thuốc trừ cỏ ở Thừa Thiên Huế cho thấy lực lượng lao động chính canh tác lúa là nam giới, trình độ dân trí không cao nên khả năng tiếp thu kiến thức khoa học – kỹ thuật hạn chế. Các loại cỏ gây hại phổ biến trên ruộng lúa gieo sạ là cỏ lồng vực (Echinochloa crus-galli), cỏ chác (Fimbristylis miliacea), cỏ chỉ (Cynodon dactylon), cỏ đuôi phụng (Leptochloa chinensis) là các loại cỏ xuất hiện trở lại sau khi đã sử dụng thuốc trừ cỏ. Cỏ lồng vực mọc trở lại có thể gây giảm năng suất cây lúa 12,1–14,0%. Các loại thuốc trừ cỏ được sử dụng phổ biến là Sofic 300EC (Pretilachlor) và Sunrice 15WDG (Ethoxysulfuron). Hiệu quả thuốc trừ cỏ lúa có xu hướng giảm trong thời gian gần đây do kỹ thuật sử dụng và sự giảm hiệu quả của các sản phẩm thuốc trừ cỏ. Chúng tôi kiến nghị cần đánh giá đầy đủ hơn về các yếu tố gây nên tình trạng cỏ dại mọc trở lại sau khi phun thuốc để có định hướng quản lý cỏ dại tốt hơn

Environmental isues of mining activities in Tay Nguyen

Intensive mining activities, specially illegal, negatively affect environment in Tay Nguyen. Mining of gold and tin placers, sand and pebble disturbed the landscape, changed river bed caussing river bank erosion. Exploited wastes from mine, for example, kaolin mine in Loc Chau (Lam Dong province) destroyed and retrograded tea land. There observed evidences of acid mine drainage and pollution of heavy metal including Cu, Pb, Hg, et.c in surface water, stream sediments and soils from some gold mines such as Dak Ripen (Kon Tum), Krong A (Dak Lak) and Tra Nang (Lam Dong). Main causes of mining environmental problems are failure of management, so the first and most important measure of mitigation is to improve the management of mining activities.ReferencesBorisenko A.S., Trần Trọng Hòa, V.I. Vasilev, N.K. Morsev, Vũ Văn Vấn, Ngô Thị Phượng, Hoàng Hữu Thành, Trần Tuấn Anh, Phạm Thị Dung, 2008: Phát hiện lần đầu tiên khoáng vật Jonassonite - AuBi5S4 ở Việt Nam. Tạp chí Các Khoa học về Trái Đất, T.30, (3), tr.193-198. Damigos D., 2006: An overview of environmental valuation methods for the mining industry. Journal of Cleaner Production, Volume 14, Issues 3-4, P. 234-247 Dixon-Hardy, D.W. Engels, J.M., 2007: Guidelines and Recommendations for the Safe Operation of Tailings Management Facilities. - Environmental Engineering Science, 24 (5), 14-26. Doolittle, J.J., Frisbee, N.M. and Hossner, L.R., 1992: Evaluation of acid-base accounting techniques used in surface-mine reclamation, Proc. 1992 Meeting of the American Society of Surface Mining and Reclamation, 14-18 June, Duluth, MN, p68-76. Trần Trọng Hòa, Ngô Thi Phượng, Borisenko A.S., Izokh A.E., Vũ Văn Vấn, Bùi Ấn Niên, Trần Tuấn Anh, Phạm Thị Dung, 2005: Đặc điểm địa hóa-đồng vị của quặng hóa vàng Mesozoi sớm và Mesozoi muộn trong mối liên quan với hoạt động magma rìa Đông Nam địa khối Đông Dương. Tạp chí Địa chất, Loạt A, số 295, tr.15-24. Nguyễn Kim Hoàng, Nguyễn Văn Mài, 2010: Đặc điểm khoáng hóa và triển vọng vàng gốc Trà Năng, tỉnh Lâm Đồng. Đại học Quốc gia Tp. HCM. Nilsson J-A, Randhem J., 2008: Environmental Impacts and Health Aspects in the Mining Industry. Department of Energy and Environment. Division of Environmental Systems Analysis. Chambers University of Technology. Göteborg, Sweden, 2008. publications.lib.chalmers.se/records/fulltext/85984.pdf‎ Plumlee, G.S. and Nash, J.T., 1995: Geoenvironmental models of mineral deposits--fundamentals and applications. U.S. Geol. Survey Open-File Report 95-831, p.1-18. Lê Văn Thành, 2004: Khai thác khoáng sản và tác động đến môi trường. Địa chất, N.281 Vũ Văn Vấn, Trần Trọng Hòa, A.S. Borisenko, Ngô Thị Phượng, Trần Tuấn Anh, Trần Hồng Lam, Đặng Trung Thuận, Phạm Thị Dung, 2007: Quặng hóa vàng Tà Năng, đới cấu trúc Đà Lạt: Điều kiện hình thành và bối cảnh địa động lực. Tạp chí Các Khoa học về Trái Đất, T.29, (2), tr.154-160. Báo cáo hiện trạng môi trường tỉnh Lâm Đồng giai đoạn 2006 - 2010: Sở Tài nguyên và Môi trường Lâm Đồng. http://www.lamdong.gov.vn/vi-VN/a/sotnmt/du-lieu-so/moi-truong/Pages/baocaohientrang2006-2010.aspx. Guidebook for Evaluating Mining Project EIAs, 2010: www.elaw.org/files/mining-eia-guidebook/Chapter1.pdf Global Acid Rock Drainage Guide (http://www.gardguide.com/index.php/Main_Page) UNEP, 1997: Industry and environment, mining and sustainable development. http://www.uneptie.org/vol20no4.htmO; 1997.

Elaborating a people-centered approach to understanding sustainable livelihoods under climate and environmental change: Thang Binh District, Quang Nam Province, Vietnam

This paper explores the maintenance of livelihoods under climate, environmental, and economic development pressures, through the case of Thang Binh District in Quang Nam Province, Vietnam. Within widespread recognition of the need to link sustainable livelihoods approaches with climate change adaptation, there is growing awareness of the importance of people-centered approaches which keep the diverse experience, capabilities, and knowledges of the most vulnerable at the heart of sustainable livelihoods thinking. In response, this paper explores the conditions for changes in modes of livelihoods in a case study area where top-down strategies for sustainable livelihoods are met with residents’ diverse experiences of vulnerability, and where climate and environmental changes shape residents’ relations with the landscape. The research is undertaken via interviews with residents, farmers/fishers, and local government officials. Our study finds that whilst government-led initiatives for sustainable livelihoods are welcomed in the locality, inflexible policies can make it challenging for the most vulnerable people to access support. Moreover, residents see the capacity to live with and respond to extreme weather events as a critical component of maintaining a sustainable livelihood. Our findings reinforce international literature, showing that ‘the poor’ are not a homogenous category, and illustrate the importance of attention to the smallest levels of government who are tasked with putting sustainable livelihoods initiatives into practice in relation to people’s daily lives

H2_{2}O2_{2} production in Lactobacillus strains isolated from the intestinal microbiome of healthy people

Lactobacillus sp. in the digestive tract are capable of producing H2O2 to inhibit the growth of harmful bacteria and balance the gut microflora. In this study, we have isolated 115 strains of Lactobacillus spp. from stool samples of healthy people in Ha Noi. Of the 50 tested Lactobacillus strains, 9 strains were capable of producing H2O2, of which the Lac.VFE-14 strain produced highly H2O2 with a concentration of 2.183 mM, followed by Lac.VFE-08 strains (2.081 mM) and Lac.VFE-04 (2.067 mM). All three strains grew well in MRS medium supplemented with bile salts or adjusted to low pH value. With 0.3% of bile salt, the survival rates of these 3 strains were 99%, 95% and 97%, respectively. At pH 3.0, after 3 hours of cultivation, the survival rates of the three strains were 98.54%, 94.15% and 95.27%, respectively. In addition, each of the cell-free culture supernatants of these three strains that inhibit the growth of S. aureus ATCC-23235. The inhibition zone diameters of the three strains were 19.0±1.0 mm, 14.0±1.0 mm and 11.7±1.3 mm, respectively. The results of 16S rRNA gene analyses showed that Lac.VFE-14, Lac.VFE-08 and Lac.VFE-04 had high similarity scores with L. plantarum ZZU 23 (100%), L. rhamnosus JCM 1136 (99%) and L. plantarum S7 (98.65%), respectively. This study indicates that all three strains have the potential to be used as probiotics in the future.