Pakistan’s Water Security Issue & Impacts of Floods

Mir Sher Baz Khetran(Mir Sher Baz Khetran ) 아시아사회과학학회 2023 Jornal of Asia Social Science Vol.10 No.1

Water security is a crucial issue for Pakistan due to its heavy dependence on agriculture and limited water resources. The country has been facing multiple challenges in managing its water resources, including population growth, climate change, and water pollution. Among these challenges, floods pose a significant threat to Pakistan's water security, as they not only cause significant damage to infrastructure but also have long-term impacts on water availability and quality. This paper examines the impacts of floods on Pakistan's water security and highlights the key factors that contribute to the country's vulnerability to flooding. The paper reviews the existing literature on Pakistan's water resources and flood management strategies and identifies gaps in knowledge and policy. It also analyzes the socioeconomic impacts of floods on the local communities and the wider economy, emphasizing the role of water security in achieving sustainable development.The findings of this study suggest that Pakistan needs to adopt a holistic approach to water management that takes into account the complex interplay of factors that affect water security. This approach should involve the development of sustainable water use practices, the promotion of water conservation, and the implementation of effective flood management strategies. The study concludes that addressing Pakistan's water security challenges requires a coordinated effort by the government, civil society, and private sector, and calls for the development of a national water policy that prioritizes water security and sustainability.

Ultra-fine SnO₂ nanoparticles doubly embedded in amorphous carbon and reduced graphene oxide (rGO) for superior lithium storage

Sher Shah, Md. Selim Arif,Lee, Jooyoung,Park, A. Reum,Choi, Youngjin,Kim, Woo-Jae,Park, Juhyun,Chung, Chan-Hwa,Kim, Jaeyun,Lim, Byungkwon,Yoo, Pil J. Elsevier 2017 ELECTROCHIMICA ACTA Vol.224 No.-

<P><B>Abstract</B></P> <P>SnO<SUB>2</SUB> is a well-studied anode material for lithium ion batteries (LIBs). However, it undergoes severe capacity fading because of a large volume change (∼300%) during cycling. Composites of SnO<SUB>2</SUB> with electro-conductive graphene would deliver improved capacity and rate performance. Nevertheless, achieving the theoretical capacity of SnO<SUB>2</SUB> is still elusive, mainly because of disintegration of the active material from graphene and severe aggregation of SnO<SUB>2</SUB>, or Sn nanoparticles produced upon cycling. To surmount these limitations, in this work, nanocomposites containing ultra-fine sized SnO<SUB>2</SUB> nanoparticles (UFSN) with reduced graphene oxide and amorphous carbon were synthesized in a single step at low temperature and environmentally benign way, in which ascorbic acid was employed as the carbon source and reducing agent. UFSN could decrease the lithium ion diffusion path length. As a result of effective buffering effect afforded by the mesoporous structure against volume change and improved lithium ion diffusivity, the ternary nanocomposite achieves ultra-high capacity of 1245mAhg<SUP>−1</SUP> after 210 cycles at 100mAg<SUP>−1</SUP> and excellent cycling stability. Since the proposed approach is facile, straightforward, and highly reproducible, it is anticipated that this system would be a potential alternative to the conventional graphite anode for LIBs.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Characterization of Runoff and Discharge from LID System Applied in Different Types of Catchment Area

( Sher Bahadur Gurung ),( Franz Kevin F. Geronimo ),( Jungsun Hong ),( Lee-hyung Kim ) 한국물환경학회(구 한국수질보전학회) 2018 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2018 No.-

Green Synthesis of Biphasic TiO₂–Reduced Graphene Oxide Nanocomposites with Highly Enhanced Photocatalytic Activity

Sher Shah, Md. Selim Arif,Park, A Reum,Zhang, Kan,Park, Jong Hyeok,Yoo, Pil J. American Chemical Society 2012 ACS APPLIED MATERIALS & INTERFACES Vol.4 No.8

<P>A series of TiO<SUB>2</SUB>–reduced graphene oxide (RGO) nanocomposites were prepared by simple one-step hydrothermal reactions using the titania precursor, TiCl<SUB>4</SUB> and graphene oxide (GO) without reducing agents. Hydrolysis of TiCl<SUB>4</SUB> and mild reduction of GO were simultaneously carried out under hydrothermal conditions. While conventional approaches mostly utilize multistep chemical methods wherein strong reducing agents, such as hydrazine, hydroquinone, and sodium borohydride are employed, our method provides the notable advantages of a single step reaction without employing toxic solvents or reducing agents, thereby providing a novel green synthetic route to produce the nanocomposites of RGO and TiO<SUB>2</SUB>. The as-synthesized nanocomposites were characterized by several crystallographic, microscopic, and spectroscopic characterization methods, which enabled confrimation of the robustness of the suggested reaction scheme. Notably, X-ray diffraction and transmission electron micrograph proved that TiO<SUB>2</SUB> contained both anatase and rutile phases. In addition, the photocatalytic activities of the synthesized composites were measured for the degradation of rhodamine B dye. The catalyst also can degrade a colorless dye such as benzoic acid under visible light. The synthesized nanocomposites of biphasic TiO<SUB>2</SUB> with RGO showed enhanced catalytic activity compared to conventional TiO<SUB>2</SUB> photocatalyst, P25. The photocatalytic activity is strongly affected by the concentration of RGO in the nanocomposites, with the best photocatalytic activity observed for the composite of 2.0 wt % RGO. Since the synthesized biphasic TiO<SUB>2</SUB>–RGO nanocomposites have been shown to effectively reduce the electron–hole recombination rate, it is anticipated that they will be utilized as anode materials in lithium ion batteries.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2012/aamick.2012.4.issue-8/am301287m/production/images/medium/am-2012-01287m_0002.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am301287m'>ACS Electronic Supporting Info</A></P>

Status of Constructed Wetlands in Nepal : Recent Developments and Future Concerns

Sher Bahadur Gurung,Franz Kevin F. Geronimo,Soyoung Lee,Lee-Hyung Kim 한국습지학회 2017 한국습지학회지 Vol.19 No.1

네팔은 중국과 인도 사이에 위치한 남부 아시아의 내륙국가로 폐수관리는 도시지역에서 가장 중요한 문제 중 하나이 다. 네팔의 폐수처리 시스템은 비싼 운영비, 불연속적인 전력 공급, 유지관리 및 기술인력의 부족으로 인해 조성과 운 영이 어렵다. 이러한 이유로 인공습지는 폐수처리시설의 대안기술로써 다양한 지역에 적용되고 있다. 일반적으로 인공 습지 기술의 효율 지속 가능성은 적절한 운영과 유지관리 및 적극적인 지역사회 참여에 의존한다. 따라서 본 연구에서 는 26개의 인공습지에서의 제거 효율, 방류수질, 네팔 수질기준, 운영 및 유지관리 활동 등을 조사하고 문제점을 분석 하여 관리방안 등을 도출하였다. 오염물질당 제거효율은 ka-1의 인공습지가 가장 높은 것으로 나타났으며, B-1, L-3, Ka-5, k-1 순으로 높은 것으로 나타났다. 네팔의 인공습지 조성기술은 최근 20년간 기술개발 없이 전통적 방식에 의 존해온 결과 비효율적인 성능으로 인해 많은 습지가 가동이 중단되거나 폐쇄되는 것으로 나타났다. 또한 기술개발의 부족, 자연재해, 대중의 인공습지에 대한 낮은 인식 및 예산 부족 등은 인공습지의 지속적인 개발을 저해하고 있는 것 으로 조사되었지만, 인공습지는 네팔 도시지역의 폐수문제에 대한 해결방안으로 고려되고 있다. Nepal is a landlocked mountainous country in South Asia, located between China to the north and India to the south, east, and west. As such, wastewater management has become one of the most significant problems in urban area of Nepal. In Nepal, the centralized wastewater treatment systems were dysfunctional due to high cost of operation, discontinuous power supply, lack of proper maintenance and proper technical workforce to address the issues. As such, constructed wetlands (CW) were applied to treat various secondary wastewater as alternative to wastewater treatment facilities. Generally, efficiency and sustainability of CW technology depends on proper operation and maintenance and active community involvement. This study summarizes information about 26 CW in Nepal. Specifically, factors including data banking, removal efficiency, quality of discharged water, compliance to water quality standard of Nepal and operation and maintenance were investigated. Considering removal efficiency per pollutant, Ka-1 achieved the greatest reduction for most pollutant followed by B-1, L-3, Ka-5 and K-1. Nepal has practiced CW technology for more than 2 decades but currently, development of technology was interrupted by the inefficient performance of existing facilities. Public awareness about the technology, natural disaster, unavailability of specified substrate materials, lack of fund for further research and experiments has hindered the expansion of technology. In spite of these concerns, CW was still proven as an alternative solution to the present wastewater problems in urban areas of Nepal.

Enterohepatic Recycling of Estrogen and its Relevance with Female Fertility

Sher, Alam,Rahman, M.Ataur The Pharmaceutical Society of Korea 2000 Archives of Pharmacal Research Vol.23 No.5

Enterohepatic recycling of estrogen after oral administration of 1 mg non-radioactive estriol was studied in fourteen women selected as the control subjects and ten infertile women in whom the infertility was appearing to be of endocrine origin. The extent of enterohepatic recycling of estriol ($E_3$) during the early follicular phase of menstrual cycle was assessed by monitoring during 48 h the urinary excretion of its two major metabolites i.e; estriol 16 $\alpha$-glucuronide ($E_3-16$$\alpha-G$) and estriol-3 glucuronide ($E_3$-3-G). The change in urinary level of $E_3$-3-G with respect to ($E_3-16$$\alpha-G$G was considered to reflect the extent of enterohepatic recycling of estriol. Lower values of urinary output of both metabolites in the infertile women as compared with the control subjects and the urinary excretion profile of both metabolites during 48 h after estriol ingestion reveal that the reduced extent of enterohepatic recycling could possibly be one of the factors which contribute towards the incidence of infertility in women.

Assessment of antibacterial cellulose nanocomposites for water permeability and salt rejection

Sher Bahadar Khan,Khalid A. Alamry,Elham N. Bifari,Abdullah M. Asiri,Muhammad Yasir,Lassaad Gzara,Rehan Zulfiqar Ahmad 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.24 No.-

Anti-bacterial nanocomposites (NC1–NC4) based on cellulose acetate were prepared by dispersing ZnO nanofillers in the cellulose acetate matrix. Anti-bacterial nanocomposites were structurally and morphological examined by XRD (X-ray powder diffraction), FESEM (field emission scanning electron microscopy), and FT-IR (Fourier transform infrared) spectroscopy. All the spectroscopic techniques suggested that nanocomposites are successfully synthesized. All the nanocomposites showed antibacterial activity which increased as a function of zinc oxide. Further the selectivity of anti-bacterial nanocomposites was investigated toward different metal ions, including Zn2+, Cd2+, Pb2+, Mn2+, Ni2+, Fe2+, Al3+, Sb3+, and Sr3+. The selectivity data suggests that nanocomposites are more selective toward Fe2+. NC1 displayed highest uptake aptitude for Fe2+ with highest distribution coefficient of 7549.123 mL g1. Therefore, NC1 was subjected to water permeability to explore the role of antibacterial nanocomposite as membrane for water purification. The results suggest that these materials are possibly appropriate for water treatments.

PPC와 Organo-Clay 나노 조성물의 합성과 실리카층의 수분흡수와 열적특성에 대한 영향

Sher Bahadar Khan,Jongchul Seo,Eui Sung Jang,Joon Suk Choi,Seunghyuk Choi,Haksoo Han 한국막학회 2009 멤브레인 Vol.19 No.4

Poly propylene carbonate (PPC)와 cloisite 20B (PPC/C-20B)을 solution method를 통하여 합성하였고, 이를 통해 합성된 나노 조성물의 morphology, 열적 특성, 수분 흡수의 특성을 평가하였다. 나노 조성물의 구조는 X-ray diffraction (XRD) 로 확인하였고, 열적 특성은 thermal gravimetric analysis (TGA)와 differential scanning calorimetric (DSC)를 이용해 분석하였다. TGA와 DSC의 결과를 통해 나노 조성물은 기존의 PPC에 비해 높은 열적 안정성을 가짐을 확인할 수 있었다. DSC측정에서 5 wt%의 clay를 포함한 nanohybrid의 유리전이온도는 순수한 PPC의 21℃에서 30℃로 9℃ 증가하였고, TGA 측정을 통해 확인한 열분해온도(Td50%)는 순수 PPC에 비해 23℃가 높아졌음을 확인하였다. 또한 PPC 나노 조성물의 수분 흡수량은 기존의 PPC에 비해 상당히 감소하였다. 이는 clay의 PPC matrix 구조 내에 존재함으로 인해 수분 흡수를 감소시킨 것으로 해석할 수 있다. 수분 흡수는 코팅 막의 분해를 유발하고 물리적, 기계적 성능에 영향을 미친다. 따라서 나노 조성물로 인한 PPC의 열적 안정성, 수분흡수도 향상은 PPC의 사용과 실제 공정에 중요한 변수로 작용할 수 있다. Nanohybrid based on environmentally friendly and biodegradable polymer, poly propylene carbonate (PPC) and cloisite 20B (PPC/C-20B) have been synthesized by solution blending method and their morphology, thermal and water absorption properties have been evaluated. The structure of PPC/C-20B nanohybrid was confirmed by X-ray diffraction (XRD). The thermal property of PPC and PPC/C-20B nanohybrid were investigated by thermal gravimetric analysis (TGA) and differential scanning calorimetric (DSC). The experimental results demonstrated that nanohybrid showed the highest thermal stability in TGA and DSC. TGA tests revealed that the thermal decomposition temperature (Td50%) of the nanohybrid increased significantly, being 23℃ higher than that of pure PPC while DSC measurements indicated that the introduction of 5 mass% of clay increased the glass transition temperature from 21 to 30℃. Further the water absorption capacity of the PPC was significantly decreased by the incorporation of clay. Water absorption cause degradation of the coating by the moistures and affect the physical and mechanical performance. This result indicates that organic modifiers have effect on thermal and water absorption capacity of PPC and are of importance for the practical process and application of PPC.

인공습지의 비점오염 물질의 특성 및 최종 결과

( Sher Bahadur Gurung ),( Franz Kevin F. Geronimo ),( Jungsun Hong ),( Lee-hyung Kim ) 한국물환경학회 2017 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2017 No.-

Rain garden (RG) also called bioretention are depressed landscape planted with different types of vegetation which can be functional in commercial and residential area to treat storm water runoff and pollutants transported. The main objective of this study is to understand the hydrology and nitrogen removal mechanism in RG system. The inflow volume of stormwater was reduced by 96% after passing through the system. The average TN removal efficiency of RG was observed to be 47% where the average NH₄⁺-N and NO₃-N nitrogen constituents’ removal efficiency was observed to be 73% and 30%, respectively. The study concludes that RG can be used as best management practices (BMP) to reduce stormwater runoff in urban area. Furthermore, Nitrogen removal mechanism in RG was mainly influenced by nitrification coupled with denitrification, plant uptake, volatilization and ammonification.

Analysis of the Factors Affecting Nutrients Removal in Hybrid Constructed Wetland Treating Stormwater Runoff

Sher Bahadur Gurung,Franz Kevin F. Geronimo,최혜선,홍정선,김이형 한국습지학회 2018 한국습지학회지 Vol.20 No.1

Nutrients generated from various land uses lead to eutrophication during the influx of water, and it is necessary to apply the LID techniques to reduce nutrients from nonpoint sources in order to mitigate the occurrence of the algal bloom. This study was carried out to derive the design factors of hybrid artificial wetland (HCW) to increase the removal efficiency of nutrients. HCW system was constructed in the year 2010 for the treatment of rainfall runoffs from parking lots and roads composed of 100% impervious floors in the Cheonan campus of Kongju University. The average nutrients removal efficiency of TN and TP was 74% and 72%, respectively. Both TN and TP removal efficiencies were higher than those of free surface wetlands and subsurface flow wetlands due to activated physical and ecological mechanisms. The critical design parameters for the efficient nutrients removal in the artificial wetlands were the ratio of the surface area to the catchment area (SA/CA), land use, the rainfall runoff, and the rainfall intensity. The optimal carbon to nitrogen (C/N) ratio was estimated at 5: 1 to 10.3: 1. The results of this study can be applied to the efficient design of hybrid artificial wetlands to treat nutrients in urban runoff with high efficiency.