Colmatage microbien des forages et circulation de l'eau - Résultats d'un « colmatomètre » expérimental

Un modèle physique est constitué de quatre éprouvettes de sable percolées à des vitesses de flux différentes par L'eau d'un forage colmaté.On a pu ainsi obtenir, en quelques semaines, un colmatage différentiel de deux éprouvettes percolées à des vitesses supérieures à 1 cm/s, et confirmer les hypothèses émises sur l'influence de La vitesse réelle des filets liquides dans L'apparition du colmatage, et sur ta nature bactérienne du processus colmatant.Ce modèle constitue un véritable "colmatomètre" qui a donné lieu au dépôt d'un brevet (BOURGUET et al., 1985). Avant La réalisation d'un champ captant nouveau, L'emploi d'un tel colmatomètre devrait permettre d'apprécier les risques de colmatage spécifiques au site, et de définir Les normes de crépinage et d'exploitation permettant de Les éviter, ou du moins de les minimiser.INTRODUCTIONA study on 300 wells drilled in the Ypresian aquifer, over 60 % of which were clogged, revealed that there were significant statistic relationships between the frequency of ctogging, the high velocities of the water close to the well screens and the presence of hydrogen sulfide in the water; the latter means the existence of sulfato-reducing bacterial activity.The experimental model described here was designed to check the effect of the velocity of the water in the aquifer on the creation of clogging, as well as its relationship with the development of the bacterial population induced by a sufficient nutrient flow rate.This model, comprising sterilized sand, through wich water from a clogged well percolated, was set up prior to a model which will soon be built, consisting of cores of Ypresian sand containing its own microorganisms.APPARATUS AND METHODSFour stainless-steel tubes (length 14 cm, inner diameter 26 mm) were filled with sterilized siliceous sand, the initial porosity of which was 35 %. The particle size distribution (40 to 140 µm) and the permeability were similar to those of the Ypresian sand. Tube seeding was carried out for a week by percolation with water from a clogged well; no clogging in the tubes was observed. This water was then percotated simultaneously through the tubes (figure 2) for 58 days at rates, maintained by weekly corrections, close to 1, 3, 12 and 30 mm/s respectively (figure 3).The microbiological analyses consisted in : direct numeration of bacterial bodies by epifluorescence microscopy, indirect numeration by counting revivifiable heterotrophic aerobic bacteria after 15 days incubation within a medium chosen to be the least selective possible and, lastly, the numeration of both permanent and casual anaerobia, as well as sulfatoreducing bacteria following Hungate's method.HYDRODYNAMIC RESULTS (figure 4)The reduction of permeability, which results from clogging, after 58 days of percolation was the following :- tube nb 1          0 % for an average percolation rate of 0.8 mm/s,- tube nb 2         2 % for an average percolation rate of 2.5 mm/s,- tube nb 3         29,5 % for an average percolation rate of 11.5 mm/s,- tube nb 4         59 % for an average percolation rate of 30.8 mm/s.Tubes nb 1, 2 and 4 were destroyed in order to carry out microbiological analyses. Tube nb 3, maintained in percolation, reached 99,4 % clogging after 142 days.MICROBIOLOGICAL RESULTS AND DISCUSSIONSampling procedures for analyses were set up by using tube nb 2. Three different samples of sand were used for analyses : from the inlet, from the middle and from the outlet of tubes nb 1 et 4. Moreover analyses were made on the percolation water upstream and downstream of tube nb 4.The revivifiable heterotrophic aerobic bacteria are more numerous in the water at the outlet of tube nb 4 than at the inlet, white direct counting shows a slight decrease.There are greater quantities of microorganisms in the sand than in the percolation water. The presence of sulfato-reducing bacteria can even be observed whereas they are too few to be counted in the percolation water. The filtering effect of the sand is not the only, element responsible for the increase amount of bacteria. Indeed the ratio between the number of revivifiable heterotrophic bacteria in the clogged tube and the non clogged tube was about 3 times greater than the ratio between their flow rates.The higher velocity in tube nb 4 induced favorable conditions for the development of certain species of bacteria, some of which generate hydrogen producing organic molecules, thus allowing the development of sulfato-reducing bacteria.Clogging itself should depend either on the increase of the biomass or on the development of microorganisms producing a significant quantity of organic molecules outside the cells. By taking into account the amount of bacteria and the volumes of percolated water, it can be seen that 2.01 x 1011 cells, i.e. 0.2 cm3 , were retained by filtration in tube nb 1, and 0.7 cm3 in tube nb 4. Basing the estimations on bacterial counts in the sand, biovolumes of 0.2 mm3 are obtained for tube nb 1 (non clogged), and 8 mm3 for tube nb 4 (clogged). Consequently the clogging substances consist mainly of products situated outside the cells.The tube is the center of chemolithotrophic organisms (made evident by C14 tracers), thus the aerobic heterotrophic microflora and the sulfato-reducing species are no doubt linked to the use of the metabolism products of these organisms.After 142 days percolation, the sand in tube nb 3 (clogged at 99,4 %) had a cell content of 1011 cells/cm3 of sand at the inlet (filamentous aggregates) and 107 cells/cm3 at the outlet (no aggregates). On an average, roughly a third of the pore volume is filled with cells, which is in agreement with a decrease in porosity from 35 to 27 % and therefore with the clogging in the tubes.CONCLUSIONTubes of sand could be clogged experimentalty and rapidly. The most significant clogging was obtained for the fastest percolation rate.It seems as though clogging is due to a proliferation of bacteria, essentially oligotrophic, and to the creation of a nutrient-chain rising to the sulfato-reducing bacteria (which are heterotrophic).The clogging process described in the case of the Ypresian sand aquifer is certainly similar to the processes occurring in other granular aquifers.The model " clog-meter" could be used by water supptiers exploiting aquifers fiable to clogging. Indeed it can determine the best flow rate, to avoid clogging in newly exploited pumping fields and decide on the most adequate well equipment, the number of wells needed in newly exploited areas and their exploitation yield in order to obtain the desired flow rates

Optimasi Metode Spektrofotometri Untuk Penentuan Tiosianat Berdasarkan Pembentukan Senyawa Hidrindantin Menggunakan Oksidator Hipoklorit

Tiosianat adalah senyawa yang mempunyai sifat goitrogenik. Sifat ini akan menyebabkan gangguan akibat kekurangan iodium (GAKI). Penentuan tiosianat dapat dilakukan dengan mereaksikan ninhidrin 1% dan oksidator hipoklorit membentuk senyawa hidrindantin biru dalam suasana basa. Senyawa hidrindantin biru yang terbentuk dianalisa secara spektrofotometri pada panjang gelombang maksimum 590 nm. Variabel penelitian ini meliputi waktu pengukuran dari 10-40 menit, pH larutan 9-14, dan konsentrasi hipoklorit 0,02-0,2 M sebagai oksidator dalam reaksi oksidasi tiosianat menjadi sianida untuk pembentukan senyawa hidrindantin. Hasil penelitian menunjukkan waktu optimum reaksi oksidasi tiosianat menjadi sianida untuk pembentukan senyawa hidrindantin adalah 10 menit dan stabil sampai menit ke-20. Reaksi oksidasi tiosianat menjadi sianida dan pembentukan senyawa hidrindantin secara optimum terjadi pada pH 12,5, konsentrasi optimum hipoklorit yang digunakan pada proses oksidasi tiosianat adalah 0,15 M

Sosialisasi Es Krim Daun Kelor Kaya Antioksidan untuk Peningkatan Imunitas Tubuh dan Rintisan UMKM dalam Rangka Pencapaian SDG’s bidang Kesehatan dan Ekonomi pada Ibu-Ibu Rumah Tangga di Desa Kadipaten, Kecamatan Selomerto, Kabupaten Wonosobo

The ongoing Covid-19 case has caused concern for the community. Since the beginning, the appeal to wear a mask, wash hands regularly and maintain immunity has been emphasized. Good body immunity can keep you from being exposed to the Covid-19 virus. Moringa leaves contain antioxidants that can protect the body from free radicals. The antioxidant compounds in Moringa leaves are flavonoids, ascorbic acid, carotenoids and phenolics. This empowerment program is about making Moringa leaf ice cream for housewives in the Kadipaten Village, Wonosobo,  which is expected to increase the body's immunity of local residents and can help improve the economy of local residents as well as in the context of achieving SDG's in the health and economic field

Dinamika Isu Pernikahan Anak di Indonesia pada Media Baru (The Dynamic Of Child Marriage's Issue In Indonesia On New Media)

Pernikahan anak merupakan salah satu problem serius yang dihadapi Indonesia. Keriuhan perbincangan tentang nikah usia anak tampak di internet. Salah satu peristiwa nikah anak yang viral adalah pasangan siswa SMP Bantaeng, Sulawesi pada bulan April 2018. Masivitas konten nikah anak ini yang menjadi salah satu pemicu signifikansi kajian ini dilakukan. Dengan latar belakang tersebut, rumusan masalah yang muncul dalam kajian ini berfokus untuk memetakan kecenderungan konten nikah anak di media baru. Tujuan riset ini untuk memetakan wacana dan persepsi nikah anak di media baru. Penelitian ini menggunakan metode riset analisis isi kualitatif dan grabbing data dengan fokus pada sejumlah kata kunci nikah anak di Facebook dan Twitter selama 6 bulan, Desember 2017-Mei 2018. Temuan riset ini mengarah pada tebaran konten nikah anak, mulai dari highlight konten, artikel berita, image, top stories serta map. Selain itu, temuan data di media sosial daring mengarah pada perception streams yang beragam dengan titik tekan mulai dari joy sampai trust

Matiere organique presente dans les eaux d'un site hydrothermal actif du Pacific-Est (13 degree N)

Organic matter present in seawater was investigated in various samples collected in an active hydrothermal site of the East Pacific Rise (EPR) near 13 degree N. During three dives of the submersible Cyana, sampling was carried out at the mouth of active chimneys and near animal communities (Alvinellinae, Pogonophora and Serpulidae). The organic C and total N content of particulate material are higher than the mean concentrations of deep water; combined amino-acids do not show a comparative augmentation, but fatty acids and hydrocarbons are higher in the vicinities of Alvinellinae and Pogonophora than in reference samples or near Serpulidae zones. It is suggested that simultaneous determination of the concentrations of organic substances and bacterial activities would favour a better understanding of biological activity in the hydrothermal region

Upaya Meningkatkan Deteksi Dini Kanker Payudara di SMKN 1 Cijulang Kabupaten Pangandaran

EFFORTS TO IMPROVE EARLY DETECTION OF BREAST CANCER IN CIJULANG 1 VOCATIONAL HIGH SCHOOL, PANGANDARAN REGENCY. The high mortality rate of breast cancer (BC) patients in Indonesia is associated with conditions of most patients come to doctor in an advanced stage of BC. This is due to the low BC awareness of Indonesian women. This community service program (PPM) is intended to increase knowledge of adolescent women about early detection of BC. This action was conducted by BC awareness workshop to 114 female students of Vocational High School (SMK) 1 Cijulang, Pangandaran district, West Java. The profile of participants showed that 64% of participants are 17 years old and mostly from Cijulang and Cimerak sub-districts. In addition, the majority of participants were not aware of BC, indicated by lack of knowledge of BC signs and symptoms (97%), and low confident of doing breast self-examination (BSE) (30%). Moreover, there were 7% of the participants were smoking which is known to be one of the major risk factors for BC. These findings point out conducting a program for increasing BC awareness among students. The program was managed by mini-lecture that focuses on BC risk factors, BC early detection and BSE (SADARI) using videos and simulation on a mannequin. This program was expected to have an impact on their families, indirectly. Ultimately, this will increase the finding of new cases of BC which will increase their life expectancy