scholarly journals Removal of calcium and magnesium ions from shale gas flowback water by chemically activated zeolite

2017 ◽  
Vol 76 (3) ◽  
pp. 575-583 ◽  
Author(s):  
Haiqing Chang ◽  
Teng Liu ◽  
Qiping He ◽  
Duo Li ◽  
John Crittenden ◽  
...  

Shale gas has become a new sweet spot of global oil and gas exploration, and the large amount of flowback water produced during shale gas extraction is attracting increased attention. Internal recycling of flowback water for future hydraulic fracturing is currently the most effective, and it is necessary to decrease the content of divalent cations for eliminating scaling and maintaining effectiveness of friction reducer. Zeolite has been widely used as a sorbent to remove cations from wastewater. This work was carried out to investigate the effects of zeolite type, zeolite form, activation chemical, activation condition, and sorption condition on removal of Ca2+ and Mg2+ from shale gas flowback water. Results showed that low removal of Ca2+ and Mg2+ was found for raw zeolite 4A and zeolite 13X, and the efficiency of the mixture of both zeolites was slightly higher. Compared with the raw zeolites, the zeolites after activation using NaOH and NaCl greatly improved the sorption performance, and there was no significant difference between dynamic activation and static activation. Dynamic sorption outperformed static sorption, the difference exceeding 40% and 7–70% for removal of Ca2+ and Mg2+, respectively. Moreover, powdered zeolites outperformed granulated zeolites in divalent cation removal.

2021 ◽  
Vol 9 ◽  
Author(s):  
Lin Zhang ◽  
Dan Liu ◽  
Yongjin Gao ◽  
Min Zhang

The chemical and isotopic compositions of the natural gas and the co-produced flowback water from the XJC 1 well in Junggar Basin, China, were analyzed to determine the origin of gases in the Permian Lucaogou Formation (P2l) and the Triassic Karamay Formation (T2k) in the Bogda Mountain periphery area of the Southern Junggar Basin. The value of carbon isotope composition of the P2l lacustrine shale gas in the Junggar Basin was between the shale gas in Chang 7 Formation of Triassic (T1y7) in the Ordos Basin and that in the Xu 5 Formation of Triassic (T3x5) in the Sichuan Basin. The difference in gas carbon isotope is primarily because the parent materials were different. A comparison between compositions in the flowback water reveals that the P2l water is of NaHCO3 type while the T2k water is of NaCl type, and the salinity of the latter is higher than the former, indicating a connection between P2l source rock and the T2k reservoir. In combination with the structural setting in the study area, the gas filling mode was proposed as follows: the gas generated from the lacustrine source rocks of the Permian Lucaogou Formation is stored in nearby lithological reservoirs from the Permian. Petroleum was also transported along the faults to the shallow layer of the Karamay Formation over long distances before it entered the Triassic reservoir.


2019 ◽  
Vol 26 (1) ◽  
pp. 45-57
Author(s):  
Przemysław Drzewicz ◽  
Grzegorz Nałęcz-Jawecki ◽  
Agata Drobniewska ◽  
Anna Zgadzaj ◽  
Adam Smoliński ◽  
...  

Abstract The oil containing drilling waste is a worldwide environmental problem associated with oil and gas exploration. In Poland, the problem of the drilling waste has become important since starting of shale gas exploration. The results of thermal treatment of drilling waste from shale gas exploration are presented. It has been shown that organic content vaporized completely at temperature up to 500 °C. The main problem is high content of chloride, sulfate, sodium, potassium, magnesium in the waste and its water leachate. Toxicity tests confirmed that high salinity of the samples pose important risk for environment. Due to the high content of barium, the drilling waste may be utilized in production of cement with high chemical and heat resistance and opaque to X-ray. Thermal treatment process is a viable option for remediation of the drilling waste; however, the product of the process needs further treatment in order to remove its high salinity.


2020 ◽  
Vol 139 ◽  
pp. 93-102 ◽  
Author(s):  
MF Van Bressem ◽  
P Duignan ◽  
JA Raga ◽  
K Van Waerebeek ◽  
N Fraijia-Fernández ◽  
...  

Crassicauda spp. (Nematoda) infest the cranial sinuses of several odontocetes, causing diagnostic trabecular osteolytic lesions. We examined skulls of 77 Indian Ocean humpback dolphins Sousa plumbea and 69 Indo-Pacific bottlenose dolphins Tursiops aduncus, caught in bather-protecting nets off KwaZulu-Natal (KZN) from 1970-2017, and skulls of 6 S. plumbea stranded along the southern Cape coast in South Africa from 1963-2002. Prevalence of cranial crassicaudiasis was evaluated according to sex and cranial maturity. Overall, prevalence in S. plumbea and T. aduncus taken off KZN was 13 and 31.9%, respectively. Parasitosis variably affected 1 or more cranial bones (frontal, pterygoid, maxillary and sphenoid). No significant difference was found by gender for either species, allowing sexes to be pooled. However, there was a significant difference in lesion prevalence by age, with immature T. aduncus 4.6 times more likely affected than adults, while for S. plumbea, the difference was 6.5-fold. As severe osteolytic lesions are unlikely to heal without trace, we propose that infection is more likely to have a fatal outcome for immature dolphins, possibly because of incomplete bone development, lower immune competence in clearing parasites or an over-exuberant inflammatory response in concert with parasitic enzymatic erosion. Cranial osteolysis was not observed in mature males (18 S. plumbea, 21 T. aduncus), suggesting potential cohort-linked immune-mediated resistance to infestation. Crassicauda spp. may play a role in the natural mortality of S. plumbea and T. aduncus, but the pathogenesis and population level impact remain unknown.


2019 ◽  
Vol 3 (1) ◽  
pp. 1-14
Author(s):  
Miriam R. Aczel ◽  
Karen E. Makuch

High-volume hydraulic fracturing combined with horizontal drilling has “revolutionized” the United States’ oil and gas industry by allowing extraction of previously inaccessible oil and gas trapped in shale rock [1]. Although the United States has extracted shale gas in different states for several decades, the United Kingdom is in the early stages of developing its domestic shale gas resources, in the hopes of replicating the United States’ commercial success with the technologies [2, 3]. However, the extraction of shale gas using hydraulic fracturing and horizontal drilling poses potential risks to the environment and natural resources, human health, and communities and local livelihoods. Risks include contamination of water resources, air pollution, and induced seismic activity near shale gas operation sites. This paper examines the regulation of potential induced seismic activity in Oklahoma, USA, and Lancashire, UK, and concludes with recommendations for strengthening these protections.


2018 ◽  
Vol 1 (2) ◽  
pp. 114
Author(s):  
Wahdaniah Wahdaniah ◽  
Sri Tumpuk

Abstract: Routine blood examination is the earliest blood test or screening test to determine the diagnosis of an abnormality. Blood easily froze if it is outside the body and can be prevented by the addition of anticoagulants, one of which Ethylene Diamine Tetra Acetate (EDTA). Currently available vacuum tubes containing EDTA anticoagulants in the form of K2EDTA and K3EDTA. K3EDTA is usually a salt that has better stability than other EDTA salts because it shows a pH approaching a blood pH of about 6.4. The purpose of this research is to know the difference of erythrocyte index results include MCH, MCV and MCHC using K3EDTA anticoagulant with K2EDTA. This research is a cross sectional design. This study used venous blood samples mixed with K2EDTA anticoagulant and venous blood mixed with K3EDTA anticoagulants, each of 30 samples. Data were collected and analyzed using paired different test. Based on data analysis that has been done on MCH examination, p value <0,05 then there is a significant difference between samples with K3EDTA anticoagulant with K2EDTA to erythrocyte index value. Then on the examination of MCV and MCHC obtained p value <0.05 then there is no significant difference between samples with K3EDTA anticoagulant with K2EDTA to erythrocyte index value.Abstrak: Pemeriksaan darah rutin merupakan pemeriksaan darah yang paling awal atau screening test untuk mengetahui diagnosis suatu kelainan. Darah mudah membeku jika berada diluar tubuh dan bisa dicegah dengan penambahan antikoagulan, salah satunya Ethylene Diamine Tetra Acetate (EDTA). Dewasa ini telah tersedia tabung vakum yang sudah berisi antikoagulan EDTA dalam bentuk  K2EDTA dan  K3EDTA. K3EDTA  biasanya berupa garam yang mempunyai stabilitas yang lebih baik dari garam EDTA yang lain karena menunjukkan pH yang mendekati pH darah yaitu sekitar 6,4. Tujuan dari penelitian ini adalah untuk mengetahui perbedaan hasil indeks eritrosit meliputi MCH, MCV dan MCHC menggunakan antikoagulan K3EDTA dengan K2EDTA. Penelitian ini merupakan penelitian dengan desain cross sectional. Penelitian ini menggunakan sampel darah vena yang dicampur dengan antikoagulan K2EDTA dan darah vena yang dicampur dengan antikoagulan K3EDTA, masing-masing sebanyak 30 sampel. Data dikumpulkan dan dianalisis menggunakan uji beda berpasangan. Berdasarkan analisis data yang telah dilakukan pada pemeriksaan MCH didapatkan nilai p < 0,05 maka ada perbedaan yang signifikan antara sampel dengan antikoagulan K3EDTA dengan K2EDTA terhadap nilai indeks eritrosit. Kemudian pada pemeriksaan MCV dan MCHC didapatkan nilai p < 0,05 maka tidak ada perbedaan yang signifikan antara sampel dengan antikoagulan K3EDTA dengan K2EDTA terhadap nilai indeks eritrosit.


2017 ◽  
Vol 1 (1) ◽  
pp. 89
Author(s):  
Indah Purwaningsih ◽  
Supriyanto Supriyanto

Abstract: Chlorine is a green halogen-shaped halogen gas at normal temperature and serves as bleach, stain remover and disinfectant. Chlorine is now widely used for bleaching rice so that less quality rice looks like quality rice. Chlorine is very toxic and causes mucous membrane irritation, highly reactive and very powerful oxidizer. The purpose of this research was to determine the difference of chlorine level in chlorinated rice washed once, twice and 3 times. The sample in this study amounted to 11 samples calculated by replication formula. Each sample was treated 3 times, ie 1 washed once, 2 washed twice and washed 3 times. The samples then examined by iodometric titration method. Based on the results of the study using ANOVA test, 11 samples obtained the average value of chlorine after washed once amount of 0.0176%, after washed twice amount of 0.0111%, and after washed 3 times amount of 0.0052% with the value significance p = 0.03 (p <0.05) at 95% confidence level which means there was a significant difference between chlorine levels in chlorinated rice washed once, twice and 3 times.Abstrak: Klorin merupakan unsur halogen berbentuk gas berwarna kuning kehijauan pada suhu normal danberfungsi sebagai pemutih, penghilang noda maupun desinfektan. Klorin sekarang banyak digunakan untuk bahan pemutih beras agar beras yang kurang berkualitas tampak seperti beras berkualitas. Klorin sangat toksik dan menyebabkan iritasi membran mukosa, sangat reaktif dan merupakan oksidator yang sangat kuat. Tujuan dari penelitian ini ialah untuk mengetahui perbedaan kadar klorin pada beras berklorin yang dicuci sebanyak 1 kali, 2 kali dan 3 kali. Sampel dalam penelitian ini berjumlah 11 sampel yang dihitung dengan rumus replikasi. Setiap sampel diberi perlakuan sebanyak 3 kali, yaitu 1 kali pencucian, 2 kali pencucian dan 3 kali pencucian. Sampel penelitian kemudian diperiksa dengan metode titrasi iodometri. Berdasarkan hasil penelitian menggunakan uji Anova secara komputerisasi terhadap 11 sampel diperoleh nilai rata-rata kadar klorin setelah 1 kali pencucian sebesar 0,0176 %, setelah 2 kali pencucian sebesar 0,0111 %, dan setelah 3 kali pencucian sebesar 0,0052 % dengan nilai signifkansi p = 0,03 (p<0,05) pada tingkat kepercayaan 95% yang artinya ada perbedaan yang bermakna antara kadar klorin pada beras berklorin yang dicuci sebanyak 1 kali, 2 kali dan 3 kali.


1985 ◽  
Vol 17 (11-12) ◽  
pp. 325-326 ◽  
Author(s):  
H J. G. W. Donker ◽  
P. Opic ◽  
H. P. de Vries

Ca. 60 % of the Dutch activated sludge plants consist of completely mixed systems, experiments have been carried out in completely mixed pilot plants to study the biological P-removal. The research was carried out in two pilot plants. The pilot plants consisted of: anaerobic reactor, anoxic reactor, aerobic reactor and a clarifier. All the reactors were completely mixed. Both plants were fed with settled domestic waste water at a sludge loading of 400 and 250 g COD/kg sludge.day respectively. The results are given below:sludge loading (g COD/kg sludge.day)400400250ratio Anaerobic : Anoxic : Aerobic1: 1:2,71:1:4,11:1:2,7P-removal (%)802875N-removal (%)505065COD-removal (%)858585 It has been shown that there is no significant difference between the results at the two different sludge loadings. Remarkable is the difference between the ratio 1:1:2,7 in combination with the internal recirculation flow anoxic-anaerobic of 160 % and the ratio 1:1:4,1 with a recirculation flow of 30 %. During the start-up at a sludge loading of 250 g COD/kg sludge.day and an internal recirculation flow of 30 %, bulking sludge developed almost immediately. The Premoval was completely disturbed. Increasing the internal recirculation flow to 160% had a positive effect on settling properties and P-removal. This investigation has pointed out that a completely mixed system is suitable for biological P-removal, without negatively affecting the nitrification. Important factors in the process are the ratio anaerobic:anoxic:aerobic and the recirculation flows.


2019 ◽  
Vol 19 (9) ◽  
pp. 699-703
Author(s):  
Shihao Zhou ◽  
Qiong Zhan ◽  
Xiaomei Wu

Background: This study aimed to explore the clinical effect of levetiracetam in the treatment of children with epilepsy. Methods: 136 children with epilepsy were selected from January 2017 to December 2017. According to the random number table method, they were divided into the experimental group and the conventional group, with 68 cases in each group. The conventional group was treated with valproate, while the experimental group was treated with levetiracetam. The effective rate, the cognitive function and the frequency of clonic seizures in the two groups were compared. Results: There was no significant difference in the total effective rate between the two groups (P>0.05). There was no significant difference in attention, executive ability, abstract and orientation scores between the two groups before treatment (P>0.05). After treatment, the focus of attention (106.54±6.56), executive ability (105.76±6.77), abstract and directional score (106.65±6.57) were significantly higher than that of the conventional group. The difference in the two groups was statistically significant (P<0.05). After 3 months of treatment, the frequency of myoclonic seizures (9.22±0.95) and the frequency of tonic-clonic seizures (11.68±1.36) were found to be significantly lower than those of the conventional group, and the difference between the two groups was statistically significant (P<0.05). Conclusion: Levetiracetam is effective in the treatment of children with epilepsy. It can effectively improve the cognitive function of the patients, reduce the frequency of myoclonic seizures and tonic-clonic seizures, and has a high promotion value.


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