scholarly journals Geological and Geochemical Characteristics of Low-Arsenic Groundwater in The Karamay Area Between Two High Arsenic Areas of Xinjiang, China

Author(s):  
Qiao Li ◽  
Hongfei Tao ◽  
Mahemujiang Aihemaiti ◽  
Youwei Jiang ◽  
Wenxin Yang ◽  
...  

Abstract The groundwater of several regions in Xinjiang, China, including the Kuitun and the Manas River Basins in the Junggar Basin, is heavily polluted with arsenic. However, the arsenic content of the groundwater of the Karamay area located within the Junggar Basin is relatively low and below the recommended drinking water limit. In our study, we analyze the factors that result in this anomaly. The geological and geochemical characteristics of the water-bearing system in this area were investigated by analyzing water samples, carrying out hydrogeological surveys, and statistical techniques. Since the Carboniferous, the geological development and subsequent structural evolution resulted in a lower arsenic concentration in groundwater of the Karamay region than that of the Kuitun River Basin and the Manasi River Basin. The missing high-energy sedimentary environment in the Middle-Upper Permian and the composition of sediments controlled the characteristics of the multi-layer aquifer in this area. We find that the lack of arsenic sources, neutral and slightly alkaline environment, water injection to extract oil, and the Irtysh River Diversion to Urumqi Project, result in better groundwater quality and lower arsenic pollution in this area.

2019 ◽  
Vol 70 (7) ◽  
pp. 2330-2334
Author(s):  
Mihaela Ciopec ◽  
Adina Negrea ◽  
Narcis Duteanu ◽  
Corneliu Mircea Davidescu ◽  
Iosif Hulka ◽  
...  

Arsenic content in groundwater�s present a wide range of concentration, ranging from hundreds of micrograms to thousands of micrograms of arsenic per litter, while the maximum permitted arsenic concentration established by World Health Organization (WHO) is 10 mg L-1. According to the WHO all people, regardless of their stage of development and their social economic condition, have the right to have access to adequate drinking water. The most efficient and economic technique used for arsenic removal is represented by adsorption. In order to make this remediation technique more affordable and environmentally friendly is important to new materials with advance adsorbent properties. Novelty of present paper is represented by the usage of a new adsorbent material obtained by physical - chemical modification of Amberlite XAD polymers using crown ethers followed by iron doping, due to well-known affinity of arsenic for iron ions. Present paper aims to test the obtained modified Amberlite polymer for arsenic removal from real groundwater by using adsorption in a fixed bed column, establishing in this way a mechanism for the adsorption process. During experimental work was studied the influence of competing ions from real water into the arsenic adsorption process.


Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3662
Author(s):  
Hongzhi Yang ◽  
Liangbiao Lin ◽  
Liqing Chen ◽  
Yu Yu ◽  
Du Li ◽  
...  

The Longtan Formation of the Upper Permian in the Sichuan Basin has become a significant target for shale gas exploration in recent years. Multiple methods, including outcrop observations, thin sections, total organic matter content, X-ray diffraction and scanning electron microscopy were used to investigate the mineralogy, shale lithofacies assemblages and their relationships with the deposition environment. The mineral composition of the Longtan Formation has strong mineral heterogeneity. The TOC values of the Longtan Formation have a wide distribution range from 0.07% to 74.67% with an average value of 5.73%. Four types of shale lithofacies assemblages of the Longtan Formation could be distinguished, as clayey mudstone (CLS), carbonaceous shale (CAS), siliceous shale (SS) and mixed shale (MS) on the basis of mineral compositions. The TOC values of various types of shale lithofacies assemblages in the Longtan Formation varied widely. The shore swamp of the Longtan Formation is most influenced by the terrestrial input and mainly develops CLS and MS. The tidal flat is influenced by the terrestrial input and can also deposit carbonate minerals, developing CLS, CAS and MS. The shallow water melanged accumulation shelf develops CAS and MS, dominated by clay and carbonate minerals. The deep water miscible shelf develops CLS and SS, whose mineral composition is similar to that of the shore swamp, but the quartz minerals are mainly formed by chemical and biological reactions, which are related to the Permian global chert event. The depositional environment of the Longtan Formation controls the shale mineral assemblage of the Longtan Formation and also influences the TOC content.


Author(s):  
Nicolas Demougeot ◽  
Jeffrey A. Benoit

The search for power plant sustainability options continues as regulating agencies exert more stringent industrial gas turbine emission requirements on operators. Purchasing power for resale, de-commissioning current capabilities altogether and repowering by replacing or converting existing equipment to comply with emissions standards are economic-driven options contemplated by many mature gas turbine operators. NRG’s Gilbert power plant based in Milford, NJ began commercial operation in 1974 and is fitted with four (4) natural gas fired GE’s 7B gas turbine generators with two each exhausting to HRSG’s feeding one (1) steam turbine generator. The gas turbine units, originally configured with diffusion flame combustion systems with water injection, were each emitting 35 ppm NOx with the New Jersey High Energy Demand Day (HEED) regulatory mandate to reduce NOx emissions to sub 10 ppm by May 1st, 2015. Studies were conducted by the operator to evaluate the economic viability & installation of environmental controls to reduce NOx emissions. It was determined that installation of post-combustion environmental controls at the facility was both cost prohibitive and technically challenging, and would require a fundamental reconfiguration of the facility. Based on this economic analysis, the ultra-low emission combustion system conversion package was selected as the best cost-benefit solution. This technical paper will focus on the ultra low emissions technology and key features employed to achieve these low emissions, a description of the design challenges and solution to those, a summary of the customer considerations in down selecting options and an overview of the conversion scope. Finally, a technical discussion of the low emissions operational flexibility will be provided including performance results of the converted units.


2015 ◽  
Vol 12 (2) ◽  
pp. 74-82 ◽  
Author(s):  
Md. Habibur Rahman ◽  
Md. Mohashin Farazi ◽  
Kohinoor Begum ◽  
Md. Serazul Islam

Rice (Oryza sativa L.) is one of the major food crops in many countries. As the cultivation of rice requires huge volume of water, long term use of Arsenic contaminated groundwater for irrigation may result in the increase of arsenic concentration in the agricultural soil and eventually accumulation in rice grains. A micro level study was conducted to investigate the transfer of arsenic from irrigation water and soil to rice plants in the arsenic affected 8 unions of Chandina upazilla, Comilla district. The level of arsenic in irrigation water (0.12±0.08 and 0.67±0.07 mg l-1) was much above the WHO permissible limit of 0.01 mg l-1 for drinking water and FAO permissible limit of 0.10 mg l-1 for irrigation water. The total soil arsenic concentrations ranged from 3.21±0.80 to 8.74±2.83 mg kg-1 dry weight of soil, which was below the maximum acceptable limit for agricultural soil of 20.0 mg kg-1 as recommended by the European Community. The accumulation of arsenic in the grain ranged from 0.12±0.04 to 0.58±0.06 mg kg-1 in Boro and 0.16±0.04 to 1.06±0.20 mg kg-1 in T. Aman. Except grain sample (T. Aman) of one union, the grains in both Boro and T. Aman of all unions did not exceed 1.0 mg kg-1 dry weight of arsenic (the permissible limit of arsenic in rice according to WHO recommendation). Thus, till now rice has remained harmless for consumption in the study area. The results clearly showed that the arsenic content in the grains of Boro rice is correlated to the intensity of arsenic contamination of irrigation water and soil. The Agriculturists 2014; 12(2) 74-82


Water Policy ◽  
2009 ◽  
Vol 11 (3) ◽  
pp. 362-378 ◽  
Author(s):  
N. Nahar

In attempting to eliminate disease caused by drinking polluted surface water, millions of tube-wells were drilled in Bangladesh. However, owing to arsenic in groundwater, the availability of safe drinking water has declined from earlier achievement of 97% to 51.2%. This article reviews the causes and distribution of arsenic concentration in rural Bangladesh from a wide variety of literature. Scientists have converged to two hypotheses for causes of arsenic in groundwater: the pyrite oxidation hypothesis and the oxy-hydroxide reduction hypothesis. There is a positive correlation between arsenic content in irrigated groundwater and arsenic contained in soils. There is a significant presence of arsenic in rice and leafy vegetables. Today, arsenic is causing toxicity to human health and creating major social problems. This finding implies that, had there been a precautionary measure taken when a new technology tube-well was being introduced, in the form of testing water for harmful metals, the risk that the rural population is facing now could have been drastically reduced. This lack of precautionary measure, before starting a mass installation of tube-wells for drinking and irrigation should be seen as a “human error” and avoided in future water policy and planning.


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