Tube wells

All rubber connections of this apparatus must be of thick tubing, well greased inside. 

Add the cut tubing to the sodium bicarbonate/EDTA solution and heat to 90°C for 30 min. Stir the tubing periodically with a polished glass rod (see Note 11). Rinse the tubing well with several changes of deionized water. Store tubing in 20% ethanol at 4°C until needed. 

Add 1.5 ml Coomassie Plus Protein Assay Reagent to each tube. Mix each tube well by vortexing 2 to 3 sec. 

Rinse the prepared tubing well in distilled water before use, ensuring water flushes through the tubing as well as over the outside. 

Flush tubes well with argon or nitrogen gas (to remove all traces of air) and cap tightly using a screw cap with Teflon-lined insert. Vortex to mix, taking care not to spread the solid material above the level of the liquid. 

In Bihar state, north of Jharkhand, arsenic contamination was first discovered in Semria Ojha Patti village of Bhojpur district in June 2002 by Chakraborti et al. (2003) (Table 6.3). Bhojpur is one of the westernmost districts of Bihar, where the Ganges enters the district from Uttar Pradesh. Chakraborti et al. (2003) analyzed 206 drinking water tube wells (about 95 % of the wells in the village). Fifty-seven percent of the tested wells had >50pgL 1 of arsenic and another 25% had 10-50 pgL-1. Twenty... 

Perhaps 150000 tube wells, most of which are private, exist in the Red River delta (Smedley and Kinniburgh, 2002). Groundwater is withdrawn both from shallow, hand-pumped tube wells at depths of <45 m and from public-supply wells, which tap the Pleistocene aquifer beneath the city of Hanoi at depths of 30-70 m (Smedley, 2005). In recent years, the rate of groundwater abstraction in and around Hanoi has increased dramatically with an annual water table decline of about 1 m (Tong, 2002) and a seasonal decline of about 30 m (Trafford el al., 1996). 

In the Quaternary alluvial aquifers of the Hetao plain, 96 % of the sampled wells in the Wuyuan area and 69 % of the sampled wells in the Alashan area had arsenic >50 pgL-1. The highest arsenic concentrations were in 15- to 30-m deep tube wells with a peak value of 1350 pg L-1 (Smedley, 2005). In the Ba Men area, 30% of the sampled wells had arsenic > 50 pgL-1 with a maximum concentration of 1800 pgL-1... 

Ma, Xia and Wu, 1999). The contamination in this area extends over 6000 km2 and is mostly found in 10- to 35-m deep tube wells that tap Quaternary lacustrine sediments (Smedley, 2005). 

Garai, R., Chakraborty, A.K., Dey, S.B. and Saha, K.C. (1984) Chronic arsenic poisoning from tube-well water. Journal of the Indian Medical Association, 82(1), 34-35. 

Leupin, O.X., Hug, S J. and Badruzzaman, A.B.M. (2005) Arsenic removal from Bangladesh tube well water with filter columns containing zerovalent iron filings and sand. Environmental Science and Technology, 39(20), 8032-37. 

Community-based tube-well-attached defluoridator... 

The following protocol is based on Laird et al. (17). To each tail fragment, add 0.5 mL Tail Lysis Buffer (100 mM Tris HC1, pH 8.5, 5 mM EDTA, 0.2% SDS, 200 mM NaCl). Then add 5 pL of stock Proteinase K (10 mg/mL in H20) to each sample and seal the tubes well. Shake vigorously in a 55°C water bath overnight. 

For temporary supplies, Abyssinian Tube wells ax e useful, consisting of iron tubes, perforated below, which are driven into the ground, a pump being attached to the top. For domestic purposes, however, shallow well water is open to grave suspicion in this country. 

Khan, M.M., Sakauchi, F., Sonoda, T., Washio, M., and Mori, M. 2003. Magnitude of arsenic toxicity in tube-well drinking water in Bangladesh and its adverse effects on human health including cancer Evidence from a review of the literature. Asian Pacific Journal of Cancer Prevention, 4 7-14. 

Figure 8-26. Adapter for the centrifugation of small capped plastic vials (Beckman Corp.). This adapter is for use with the Sorvall swinging bucket rotor or its equivalent. The centerpiece (A) extends to the bottom of the 50 ml tube well. Disk C is used as a means of centering the adapter in eonjunetion with the upper disk (B) of identical diameter. The test tubes are suspended by a lip from the upper disk. Centrifuging speed should not exceed 9000 rpm when this apparatus is used. Similar small plastic tubes (without caps) and four-place adapters are available commericially from the Sorvall Corp. These tubes may be centrifuged at significantly higher speeds without damage.

A) Preparation of Toluene (Sm.). Clean an eight-inch tube well, dry it by heating over a flame to drive all the moisture out. Cork the tube while hot, and allow to cool. 

I) To 5 ml of the clear soap solution add 2 drops of kerosene and shake well. To another tube containing 5 ml of water add the same amount of kerosene. Shake both tubes well and note any differences in the appearance of the liquid, and of the walls of the tubes. 

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