http://irplus.eng.usm.my:8080/ir_plus/viewInstitutionalCollection.action;jsessionid=2C3EFD6822B00F54465275A8382CFC5A?collectionId=12 EngLib USM http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action;jsessionid=2C3EFD6822B00F54465275A8382CFC5A?institutionalItemId=7473 Baru-baru ini, fenomena gelombang panas El Nino telah menyerang negara Malaysia dan akibatnya, paras air tiga empangan di Malaysia telah jatuh di bawah tahap kritikal. Bagi menyelesaikan krisis kekurangan air ini, air bawah tanah sememangnya sumber air yang terbaik untuk manusia kerana sifatnya yang terletak di bawah permukaan bumi yang terlindung daripada gelombang panas, oleh itu, air bawah tanah tidak akan kering cepat berbanding air permukaan. Walau bagaimanapun, pencemaran air bawah tanah tidak dapat dielakkan dan tidak terkawal, namun ia masih boleh dirawat secara ekonomi. Dalam kes ini, telaga tiub 55.6 m yang terletak di dalam Kampus Kejuruteraan Universiti Sains Malaysia digunakan sebagai sampel air bawah tanah dalam kajian ini. Didapati bahawa air bawah tanah sangat tercemar oleh sumber semula jadi dan aktiviti manusia. Pada asalnya, warna air bawah tanah berwarna hijau kekuningan dan mengeluarkan gas H2S, tetapi akibat tindak balas pengoksidaan, air tersebut segera berubah warna menjadi hitam iaitu mendakan FeS dalam masa 40 saat selepas terdedah kepada udara. Kepekatan saliniti yang tinggi (5.1 ± 0.1 ppt), kepekatan NH3N yang tinggi, dan pelbagai unsur juga telah dikesan dalam sampel air bawah tanah. Oleh hal yang demikian, air bawah tanah dikelaskan sebagai kelas IV berdasarkan kualiti indeks air Malaysia dan dianggap berbahaya kepada manusia. Untuk mengatasi masalah ini, satu penyelidikan telah dijalankan untuk mencari jalan bagi menjadikan air bawah tanah menjadi sumber air yang selamat kepada manusia dan telah terbukti bahawa marmar merupakan salah satu media penapis terbaik untuk sumber air bawah tanah. Sifat-sifat marmar yang terdiri daripada 97% CaCO3 telah berjaya meningkatkan reaksi redoks pencemar, kemudian meningkatkan kadar pemendakannya dan memudahkan proses penapisan. Dari segi saiz media penapis, telah didapati bahawa saiz pasir jauh lebih baik daripada saiz kerikil untuk menghilangkan pencemaran air bawah tanah. Saiz pasir marmar dapat menghilangkan sebahagian besar bahan pencemar air bawah tanah dengan peratusan di atas 90% dan manakala beberapa unsur lain seperti Al, Ba, dan Ca dapat dibuang hanya melebihi 70%. Walau bagaimanapun, kepekatan unsur-unsur ini selepas penapisan masih di bawah had ambang standard air minuman berdasarkan NWQS Malaysia, EPA, dan WHO. Hasil daripada penyingkiran bahan pencemar air bawah tanah, ia telah mencapai hasil kualiti air kelas I dan kelas II. Sebaliknya, marmar dalam saiz kerikil menghasilkan kualiti air di kelas III. _______________________________________________________________________ Recently, El Nino heatwave phenomena has attacked Malaysia and consequently, the water level of three dams in Malaysia have fallen below the critical level. In order to solve this water shortage crisis, groundwater is indeed the best source of water for human beings as its nature of being located deep down beneath the earth has protected it from the exposure to the heatwave, thus would not be dried up as fast as compared to the surface water. However, the contamination of groundwater is inevitable and uncontrollable, yet it can still be treated economically. In this case, a 55.6m tube well located inside the Engineering Campus of Universiti Sains Malaysia was used as a groundwater sample in this research. It is found that the groundwater is highly contaminated by natural sources and human activities. Originally, the colour of the groundwater is yellowish green and emits H2S gas, but due to the oxidation reaction, it immediately changes its colour to black which is FeS precipitate in 40 seconds after being exposed to the air. A high concentration of salinity (5.1 ± 0.1 ppt), high concentration of NH3N, and various elements have also been detected in the groundwater sample. Due to this condition, groundwater is classified as class IV based on the water quality index Malaysia standards and considered to be harmful to human. To overcome this issue, a research has been carried out to find a way to make the groundwater to become a safe water resource to human beings and it has been proven that marble is one of the best filter media for groundwater resources. The properties of marbles which consist of 97% of CaCO3 have successfully enhanced the redox reaction of the contaminants, subsequently increase its precipitation rate and ease the filtration process. In term of the filter media size, it has found that the sand size is much better than the pebble size in removing the groundwater contaminants. The sand size of marble able to remove most of the groundwater contaminants with a percentage of above 90% and whereas some other elements such as Al, Ba, and Ca could be removed only above 70%. Nonetheless, the concentration of these elements after filtration are still below the threshold limit of the drinking water standard based on NWQS Malaysia, EPA, and WHO. As a result of the high removal efficiency of groundwaters' contaminants, it has achieved a water quality result of class I and class II. On the other hand, marble in pebble size produce a water quality in class III. Wed, 23 Dec 2020 13:26:04 +0800 institutional_item_version_id:7473 http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action;jsessionid=2C3EFD6822B00F54465275A8382CFC5A?institutionalItemId=7351 Isu keselamatan makanan dan air telah diutarakan secara konvensional dan bebas, dan kini, perhubungan tersebut telah muncul sebagai agenda global yang rumit. Hari ini, pengairan air sisa telah muncul sebagai satu strategi meluas untuk memenuhi keperluan mendesak terhadap sumber air bukan-konvensional. Sumber buangan tersebut mengandungi unsur toksik, melebihi had maksimum yang dibenarkan, dan merupakan penanda risiko terhadap tanaman makanan dan rantaian makanan. Logam berat merupakan juzuk karsinogenik, teratogenik dan mutagenik, yang terkumpul dalam air pengairan. Kromium trivalen [Cr (III)], plumbum [Pb (II)] dan nikel [Ni (II)] merupakan bahan pencemar yang paling berbahaya, berasaskan sifat kimia elektronik yang kompleks, ketakterbiodegradan, kelarutan dan mobiliti. Kajian ini bertujuan untuk menyiasat salinghubungan kompleks antara pengairan air yang diperkayakan dengan logam terhadap Vigna radiata, Ipomoea aquatica dan Brassica chinensis, dalam perhubungannya dengan pertumbuhan fizikal; ciri-ciri fisiologi: pigmen fotosintesis, proline, tindak balas anti-oksidatif [guaiacol peroxidase (POD), catalase (CAT) dan ascorbate peroxidase (APX)], dan keupayaan antioksidan; serta ciri morfologi. Implikasi toksik telah dinilai dengan pengujian in vitro. Pengairan air yang diperkayakan dengan logam berat menginduksikan perencatan permanjangan akar dan pucuk secara ketara berasaskan kepekatan dan tempoh pengairan. Perawatan Cr (III) mencatatkan kadar perencatan tertinggi dalam Vigna radiata dan Brassica chinensis, sebanyak 68.04% untuk akar dan 75.69% untuk pucuk. Ipomoea aquatica adalah amat sensitif terhadap perawatan Ni (II), dengan catatan perencatan pertumbuhan sebanyak 83.78% dan 87.33% masing-masing pada akar dan pucuk. Kandungan klorofil-a, klorofil-b, dan karotenoid berkurangan pada 83.92%, 75.86%, dan 63%. Lipid peroxidasi yang ketara (170.30%) dan peningkatan proline (201.08%), dikesan selaras dengan perubahan aktiviti POD, APX dan CAT yang nyata. Penindasan aktiviti antioksidan yang ketara melebihi paras ambang kepekatan 0.50 mM Pb (II), 0.20 mM Cr (III) dan 0.05 mM Ni (II) dalam ketiga-tiga model tumbuhan, menunjukkan bahawa mekanisme pertahanan antioksidan tidak dapat melindungi sistem tumbuhan daripada kerosakan oksidatif. Gangguan ini disokong dengan herotan xilem dan floem, serta gangguan ke atas stomata. Kesan sitotoksik yang ketara dengan penurunan 50% dalam keupayaan sel HepG2 dapat diperhatikan, pada kepekatan 0.20 mM Pb (II), 0.40 mM Ni (II) dan 1.20 mM Cr (III). Kesan genotoksik pada momen ekor dan kerosakan ekor DNA dicatatkan pada kepekatan terendah, iaitu 0.04 μg/mL dalam ketiga-tiga ion logam berat. Kesimpulannya, ancaman kesihatan yang berkait rapat dengan tekanan oksidatif dan kemerosotan terhadap tanaman makanan akan berleluasa, dengan pengamalan pengairan air sisa tercemar dengan logam berat secara tidak terkawal, yang memberikan tamparan hebat terhadap kelestarian hubungan nexus makanan-air. _______________________________________________________________________ The issues of food and water security have conventionally been addressed independently, and to date, their nexus has emerged to be the most intricate global agenda. Today, wastewater irrigation has emerged to be a widespread strategy to fulfil the pressing need of non-conventional water resources. These discharges carry toxic elements, exceeding the maximum allowable limits, suggesting the possible risks to food crops and food chain. Heavy metals are the most carcinogenic, teratogenic and mutagenic constituents, accumulating in the irrigation water. Trivalent chromium [Cr (III)], lead [Pb (II)] and nickel [Ni (II)] are the most insidious pollutants, ascribed to their complex electronic chemistry, non-biodegradability, solubility and mobility. This study aimed to investigate the complex interconnection of metals-enriched water irrigation on Vigna radiata, Ipomoea aquatica and Brassica chinensis in relation to the physical growth; physiological characteristics: photosynthetic pigments, proline, antioxidative response [guaiacol peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX)], antioxidant capacities and morphological characteristics. The toxicity implications were evaluated using in vitro bioassays. Metals-enriched water irrigation adversely induced significant concentration- and duration-dependent reductions in the elongation of roots and shoots; with Cr (III) exerted the highest inhibition in Vigna radiata and Brassica chinensis, denoted the reduction of 68.04% and 75.69% for root and shoot. Ipomoea aquatica was specifically sensitive to Ni (II), with the highest root and shoot inhibition of 83.78% and 87.33%. Chlorophyll-a, chlorophyll-b, and carotenoid contents were significantly reduced, up to 83.92%, 75.86%, and 63%. Profound lipid peroxidation (170.30%) and rising proline content (201.08%) were complementary with the pronounced alterations for POD, APX and CAT activities. The marked suppressions of antioxidant activities above the threshold levels of 0.50 mM Pb (II), 0.20 mM Cr (III) and 0.05 mM Ni (II) in the plant models indicated that the antioxidant defense machinery could no longer protect the plant systems against the oxidative damages. These disturbances corroborated with the xylem and phloem distortion, and stomata disruption. Significant cytotoxic effect with 50% reduction in HepG2 cell viability was noted at 0.20 mM Pb (II), 0.40 mM Ni (II) and 1.20 mM Cr (III). Genotoxic effects on DNA tail moment and tail damage were observed at the lowest concentration of 0.04 μg/mL. Conclusively, the oxidative stress-related health threats associated with the deteriorating effects on the food crops could be exacerbated by a wide scale unregulated metals-polluted wastewater irrigation practice, and place alarming threats to the sustainability of water-food nexus. Wed, 04 Nov 2020 15:45:39 +0800 institutional_item_version_id:7351 http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action;jsessionid=2C3EFD6822B00F54465275A8382CFC5A?institutionalItemId=6571 Di Malaysia, Manual Saliran Mesra Alam (MSMA) telah mencadangkan dua kaedah pengiraan untuk mendapatkan luas antara isokron yang telah diamalkan secara meluas pada masa ini. Mereka adalah kaedah Grid dan kaedah Konvensional. Tetapi, kaedah-kaedah ini menimbulkan masalah yang tersendiri. Walaupun kaedah Grid adalah lebih terperinci dan tepat apabila dibandingkan dengan kaedah Konvensional, ia adalah amat membosankan dan memakan masa. Kaedah Konvensional sebaliknya adalah lebih mudah untuk digunakan. Tetapi, keputusannya tidak konsisten. Keputusannya adalah sangat subjektif kerana ia bergantung kepada pengalaman dan penilaian setiap pengguna. Justeru, kaedah pengiraan baru yang dikenali kaedah Rangkaian Penyegitiga Tidak Teratur (TIN) telah direka dan dibangunkan dalam kajian ini untuk meningkatkan pengiraan kaedah Masa-Luas. Kaedah ini adalah berasaskan komputer dan dengan itu algoritma kaedah TIN dibangunkan. Algoritma kaedah TIN telah dijelaskan dalam kajian ini. Satu tapak kajian telah dibina dan lapan set data hujan dikumpul. Semua hasil pengiraan daripada setiap kaedah disahkan dengan data tapak yang dikumpul untuk membandingkan ketepatannya. Siasatan ke atas kecekapan dan kebolehpercayaan kaedah-kaedah ini juga dijalankan dalam kajian ini. Perbandingan ini menunjukkan bahawa kaedah TIN mempunyai ketepatan yang lebih tinggi. Dalam perbandingan pekali korelasi antara kaedah yang ada, kaedah TIN mempunyai ketepatan purata 0.988, kaedah Grid mempunyai ketepatan purata 0.936 dan kaedah Konvensional mempunyai ketepatan purata 0.948. Apabila mengira peratus perbezaan mereka terhadap data yang dicerap, kaedah TIN mempunyai perbezaan purata 14.29%, kaedah Grid mempunyai perbezaan purata 25.67% dan kaedah konvensional mempunyai perbezaan purata 24.52%. Apabila menggunakan aliran puncak bagi perbezaan terhadap data yang diperhatikan, keputusan menunjukkan bahawa kaedah TIN mempunyai perbezaan purata 3.48%, kaedah Grid adalah 5.88% dan kaedah konvensional ialah 7.72%. Akhir sekali, dengan menggunakan jumlah isipadu aliran, kaedah TIN hanya mempunyai 0.19% perbezaan dengan data yang diperhati, kaedah Grid mempunyai 0.43% dan kaedah Konvensional mempunyai perbezaan sebanyak 4.80%. Kaedah TIN menunjukkan ketepatan dan kebolehpercayaan yang lebih tinggi berbanding dengan dua kaedah yang lain. Selain itu, kajian ini juga menunjukkan bahawa algoritma kaedah TIN yang baru dibangunkan adalah lebih mudah untuk digunakan, memakan masa yang kurang dan lebih dipercayai. _______________________________________________________________________ In Malaysia, Manual Saliran Mesra Alam (MSMA) has proposed two calculation methods to obtain areas between the isochrones that have been widely practiced at the moment. They are Grid method and Conventional method. However, these methods pose certain problems of their own. Although the Grid method is more detail and accurate when compared to the Conventional method, but that is extremely tedious and time consuming. Conventional method on the other hand is simpler to use. But, the results are not consistent. The results are very subjective because it depends on each user’s experience and judgement. Therefore, a new calculation method named Triangulated Irregular Network (TIN) method has been designed and developed in this research to improve the Time-Area method calculation. This method is computer based and thus the algorithm of TIN method was developed. The algorithm of the TIN method is explained in this research. A study site was constructed and eight sets of rainfall data were collected. All the results from each calculation method were verified with the collected site data to compare their accuracy. Investigation upon their efficiency and reliability were also presented in this research. The comparison showed that TIN method has higher accuracy. In the correlation coefficient comparison among the methods, TIN method has average accuracy of 0.988, Grid method has average accuracy of 0.936 and Conventional method has average accuracy of 0.948. When calculating their difference against the observed data in percentage, TIN method has average difference of 14.29%, Grid method has average difference of 25.67% and Conventional method has average difference of 24.52%. When using the peak flow comparison for the difference against the observed data, the results shows that TIN method has average difference of 3.48%, Grid method has average difference of 5.88% and Conventional method has average difference of 7.72%. Lastly, the methods were compared using the total flow volume. It was demonstrated that the TIN method has different of 0.19%, Grid method has different of 0.43% and Conventional method has different of 4.80% when compared to the observed data. The TIN method has the highest accuracy and reliability among the three methods. Besides, this research also showed that the newly developed TIN method algorithm is easier to use, less time consuming and more reliable. Tue, 11 Aug 2020 15:50:03 +0800 institutional_item_version_id:6571 http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action;jsessionid=2C3EFD6822B00F54465275A8382CFC5A?institutionalItemId=6320 Pada masa dahulu, kerugian akibat banjir hanya dapat dinilai selepas kejadian tersebut. Namun begitu, dengan perkembangan teknologi maklumat terutama perkembangan teknologi komputer, kejadian banjir boleh di model dengan permodelan berkomputer dan anggaran kerosakan dan kerugian akibat banjir boleh dinilai dengan lebih cepat atau sebelum kejadian banjir tersebut berlaku. Gabungan teknik permodelan 1D di dalam saluran sungai dan 2D pula di dataran banjir dapat memberi keseimbangan dalam masa yang diperlukan untuk membina model dan ketepatan simulasi. Dengan bantuan teknologi sistem pengurusan geografi (GIS), hasil simulasi dapat dianalisis dan dipersembahkan dalam bentuk visual yang lebih menarik. Objektif kajian ini adalah untuk menghasilkan peta banjir melalui teknik permodelan komputer, menentukan kawasan yang terlibat dan seterusnya menaksir kerugian yang mungkin akan dihadapi. Kawasan yang dipilih untuk kajian ini ialah Sungai Tupai yang mempunyai kawasan tadahan seluas lebih kurang 950 hektar dan 7.5km panjang yang merangkumi kawasan perumahan dan perindustrian dan bertindak sebagai salah satu daripada sistem saliran Bandar Taiping. Hasil daripada kajian yang telah dijalankan, didapati pada kala ulangan 100 tahun, hanya 1.19 peratus daripada keseluruhan kawasan tadahan Sungai Tupai yang digenangi air banjir. Jumlah kerugian yang ditaksirkan menggunakan kaedah yang diperkenalkan oleh JICA (1995) adalah menghampiri RM700,000.00 dengan melibatkan lebih kurang 303 buah rumah dan 1333 penduduk. _______________________________________________________________________ In the past, flood losses or damages can only be determined after the incident. However, with the development of information technology, especially computer technology, a flood can be modelled using desktop computer and estimation of damages and losses due to flooding can be assessed quicker or even before the flooding occurs. The combination of 1D modelling techniques in the river channels and 2D on floodplains balanced the time required to build the model and accuracy of the simulation. With the advancement of Geographical Information System (GIS) technology, simulation results can be analyzed and presented in a more visually appealing manner. The objective of this study is to produce flood maps through computer modeling technique, determine the area involved and further assess the losses that may be encountered. The area selected for this study is Tupai River with a catchment area of approximately 950 hectares and 7.5km in length of Tupai River that includes residential and industrial areas and served as one of the Taiping City drainage system. Finding from the study reveals that in 100 years Average Recurrence Interval of Rainfall, only 119 percent of the total catchment area of Tupai River inundated with flood waters. Total losses estimated using the method introduced by JICA (1995) is approximately RM700,000.00 that involved 303 houses and 1333 resident. Wed, 22 Jul 2020 12:40:07 +0800 institutional_item_version_id:6320 http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action;jsessionid=2C3EFD6822B00F54465275A8382CFC5A?institutionalItemId=5831 Satu kaedah baru bagi pengubahsuaian tanah liat semulajadi, montmorilonit dan bentonit kepada satu siri penjerap berfungsi melalui rawatan kimia telah dilaporkan. Penggunaannya untuk perawatan racun makhluk sekunder, ametryn dan metolachlor, yang selalu diaplikasikan untuk pengawalan serangga perosak, tumbuhan dan kulat telah dikaji. Pengubahsuaian tanah liat telah dijalankan dengan menggunakan rawatan asid dan hexadecyltrimethylammonium bromida (HDTMA), manakala pembolehubah manipulasi telah dikaji menggunakan penjerap berkelompok dengan megubahsuai kepekatan asal, masa sentuhan, dan larutan pH dengan menggunakan kajian kumpulan penjerap. Pemeriksaan ke atas ciri-ciri fizikal dan kimia termasuk morfologi permukaan, sifat-sifat struktur berlubang, permukaan kumpulan berfungsi, dan titik capaian arus sifar (pHzpc) telah dianalisis. Data keseimbangan telah disimulasikan menggunakan model isotherma, Langmuir, Freundlic dan Temkin, manakala model kinetik ditetapkan menggunakan persamaan pseudo-first order, pseudo-second order dan Elovich. Hasil kajian menunjukkan prestasi yang signifikan dalam penyingkiran ametryn dan metolachlor. Penjerapan racun perosak didapati sangat dipengaruhi oleh larutan pH, menjurus penjerapan ametryn dan metalachlor kepada larutan berasid. Peningkatan kepekatan asal dari 25 mg/L kepada 150 mg/L dan 50 mg/L kepada 400 mg/L, menunjukkan peningkatan penjerapan ametryn dari 23.89-132.09 mg/g, 23.36-128.46 mg/g, 12.49- 50.12 mg/g, dan 24.88-148.91 mg/g, untuk montmorillonit, AM, ANC dan AB, manakala penjerapan metolachlor meningkat dari 7.23-38.69 mg/g, 7.32-26.15 mg/g dan 18.45-48.98 mg/g bagi HM, HNC dan AB, masing-masing Penjerapan data keseimbangan mematuhi model Langmuir, manakala model kinetik mengikut persamaan pseudo-second order. Pemeriksaan struktur tekstur mengesahkan pembentukan liang dengan siri berongga di sekitar permukaan, dengan peningkatan jarak kawasan permukaan Brunaeur-Emmet-Teller (BET) dari 2.12 ke 245.64 m2/g. Kajian morfologi menyokong anggapan bahawa interkalasi hexadecyltrimethyammonium bromida (HDTMA) dan proses pengubahsuaian asid telah berjaya dicapai. Pengubahsuaian spektrum Fourier-Transform Infrared Spektroskopi menandakan pengubahsuaian dan pembangunan fungsi baru pada terbitan tanah liat. Hasil kajian mendapati terbitan tanah liat ini mempunyai potensi yang besar sebagai satu penyelesaian ekonomi dan teknik yang mudah untuk pemulihan berterusan air yang dicemari racun makhluk perosak. __________________________________________________________________________________ A new route for the conversion of natural clay, montmorillonite and bentonite into a series of new functionalized adsorbents via simple chemical treatment has been presented. The unique application for the effective remediation of secondary pesticides, ametryn and metalachlor, widely applied for the control of nuisance insects, plants and fungi has been attempted. The clays were subjected to hexadecyltrimethylammonium bromide (HDTMA) and acid modifications, while the novel application was examined using batch adsorption experiments by varying the operational parameters, initial concentration, contact time, and solution pH. The physical and chemical characteristics including the surface morphology, pore structural properties, surface functional groups, and zero-point-of-charge (pHzpc) were evaluated. Equilibrium data were simulated using the Langmuir, Freundlich and Temkin isotherm models, while the kinetic model was fitted to the pseudo-first order, pseudo-second order and Elovich kinetic equations. Result illustrated an encouraging performance towards the removal of ametryn and metolachlor. The adsorptive uptake of pesticides was found to be highly pH dependent, favouring the adsorption uptake of ametryn and metolachlor at the acidic condition. Increasing the initial concentrations from 25 mg/L to 150 mg/L, and 50 mg/L to 400 mg/L showed a greater adsorption uptake for ametryn of 23.89-132.09 mg/g, 23.36-128.46 mg/g, 12.49-50.12 mg/g, and 24.88-148.91 mg/g, for montmorillonite, AM and ANC, and AB, while the adsorption uptake of metolachlor increased from 7.23-38.69 mg/g, 7.32-26.15 mg/g and 18.45-48.98 mg/g, respectively for HM, HNC, and AB. Equilibrium data was satisfactory fitted to the Langmuir isotherm model, while the adsorption kinetic was best described by the pseudo-second order model. Examination of the textural structure verified pore development, with a series of cavities distributed around the surface, with the Brunauer-Emmett-Teller (BET) surface areas ranging from 2.12 to 245.64 m2/g. Morphological study supported the presumption that the intercalation of hexadecyltrimetylammonium bromide (HDTMA) and acid modification process was successfully attained. Alteration of Fourier-transform infrared spectroscopy (FTIR) bands signified the modification and development of the new functionalities on the clay derivatives. The findings supported the great potential of these clay-derivatives as an economically advantageous solution and viable technique for the successive remediation of pesticides contaminated water. Thu, 27 Feb 2020 12:27:05 +0800 institutional_item_version_id:5831 http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action;jsessionid=2C3EFD6822B00F54465275A8382CFC5A?institutionalItemId=2204 Input nutrien daripada aliran air bandar terutamanya nitrogen (N) dan fosforus (P), merupakan masalah utama dalam perlindungan ekosistem akuatik. Kajian makmal ini bertujuan menyiasat penambahbaikan sistem bioretention untuk mengetahui prestasi dan mengoptimumkan komposisi bahan tambahan dalam media bioretention bagi menyingkirkan nutrien, dan menyiasat potensi fitopemulihan Hibiscus rosa-sinensis (bunga raya) dalam sistem bioretention melalui kajian tanah dan tumbuhan. Kajian ini dijalankan dalam dua peringkat. Pada Peringkat 1, kajian dilakukan dengan mengubahsuai media bioretention dengan 10% (mengikut isi padu) bahan tambahan dari pelbagai bahan-bahan buangan (kulit kerang, akhbar, kertas bercetak, sabut kelapa, dan remah tayar) dan ditanam dengan Hibiscus rosa-sinensis. Hasilnya, media yang diubahsuai dengan hirisan akhbar (NP) menunjukkan jumlah penyingkiran pepejal terampai (TSS) tertinggi (98.4%), berbanding dengan media bioretention standard (STD, 85.4%), dan menunjukkan peningkatan yang ketara dalam penyingkiran jumlah nitrogen (TN, 80.4%), berbanding dengan STD (57.5%) apabila disiram dengan air larian sebenar. Medium yang diubahsuai dengan hancuran kulit kerang (CS) menunjukkan jumlah penyingkiran fosforus (TP) yang paling tinggi (93.3%), berbanding dengan STD (84.8%), dan media ini juga menunjukkan pertumbuhan pokok yang lebih baik, berbanding dengan media lain. Oleh itu, NP dan CS telah dipilih untuk kajian di Peringkat 2, dan tiga jenis komposisi media (komposit jenis media A, B dan C, CS sebagai lapisan atas dan NP sebagai lapisan bawah, dengan kedalaman yang berbeza) telah direka. Hasilnya, media komposit mencatatkan penyingkiran TSS, TN dan TP sehingga 99.4%, 87.6% dan 96.8%, menandakan bahawa CS dengan ketebalan minimum 300mm dari lapisan atas tanah menggalakkan pertumbuhan pokok dan NP dengan ketebalan minimum 300mm dari lapisan bawah tanah menyediakan zon anaerobik (dibentuk oleh poket mikro daripada akhbar) untuk denitrifikasi. Pengiraan Indeks Kualiti Air (WQI) menunjukkan bahawa media komposit meningkatkan kualiti air dari Kelas V ke Kelas II, dan kekonduksian hidraulik untuk semua jenis media berada dalam julat yang disyorkan. Kajian ke atas pokok menunjukkan bahawa sistem akar yang tebal dan kadar pertumbuhan pesat pokok renek tropika terbukti memberikan sumbangan terhadap penyingkiran TN, dan kandungan tinggi TN dalam daun boleh disingkirkan daripada sistem dengan pencantasan semasa penyelenggaraan. Dua persamaan linear regresi telah diperoleh bagi menggambarkan hubungan antara penyingkiran jisim nitrogen (NMR), pengurangan kepekatan nutrien, kadar pertumbuhan pokok dan penggunaan bahan tambahan. Kesimpulannya, berdasarkan kajian ini, kulit kerang dan akhbar berpotensi menjadi bahan tambahan, dan Hibiscus rosa-sinensis disyorkan untuk meningkatkan sistem bioretention dalam rawatan air larian, terutamanya air larian yang kaya dengan nutrien dari kawasan pembangunan bercampur. _______________________________________________________________________________________________________ Nutrient input from urban runoff, especially nitrogen (N) and phosphorus (P), are primary concern for the protection of aquatic ecosystems. This laboratory study investigated the enhanced bioretention system with the objectives to investigate and optimize the performance of additives in bioretention media for nutrient removal, and to elucidate the phytoremediation potential of Hibiscus rosa-sinensis in bioretention system through soil and plant study. The study was conducted in two stages. In stage 1 test, bioretention media was enhanced with 10% (by volume) additives from various waste materials (cockle shell, newspaper, printed paper, coconut husk and tyre crumb) and planted with Hibiscus rosa-sinensis. It was found that the media enhanced with shredded newspaper (NP) performed the best in total suspended solids (TSS) removal (98.4%), as compared to standard bioretention media (STD) (85.4%), and demonstrated a significant improvement in total nitrogen (TN) removal (80.4%), as compared to STD (57.5%), when dosed with actual runoff. Media enhanced with crushed cockle shell (CS) showed the highest total phosphorus (TP) removal (93.3%), as compared to STD (84.8%), and reflected better plant growth among the media. Therefore, NP and CS were shortlisted for stage 2 experiment, and three types of media compositions (composite media type A, B and C, with different depth of CS on top and NP at bottom) were designed. As a result, composite media recorded TSS, TN and TP removal up to 99.4%, 87.6% and 96.8% respectively, which indicated that CS with minimum thickness of 300mm from the top of soil promotes better plant growth and NP with minimum thickness of 300mm from bottom of soil could provide anoxic zone (created by micro pockets formed by newspaper) for denitrification. Water Quality Index (WQI) calculation showed that composite media improved the water quality from Class V to Class II, and the hydraulic conductivity of all types of media fell within recommended range of various bioretention manuals. Study on plant indicated that the thick root system and rapid growth rate of the tropical shrub was proven contributed to TN removal, and high TN content in leaves could be removed from the system by pruning during maintenance. Two linear regression equations were derived to describe the relationship between nitrogen mass removal (NMR), and nutrient concentration reduction, plant growth and use of additives. This study concluded that cockle shell and shredded newspaper can be potential additives and Hibiscus rosa-sinensis is recommended to enhance bioretention system in treating. Tue, 26 Jun 2018 12:24:35 +0800 institutional_item_version_id:2204 http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action;jsessionid=2C3EFD6822B00F54465275A8382CFC5A?institutionalItemId=1144 Hydraulic structures are anything that can be used to divert, restrict, stop, or otherwise manage the natural flow of water. They can be made from materials ranging from large rock and concrete to obscure items such as wooden timbers or tree trunks. Nowadays, there are many hydraulic structures failure such as pipelines, dams and bridge collapsed due to the scour problems. Interactions between the pipeline and its erodible bed under strong current and/or wave conditions may cause scour around the pipelines. This process involves the complexities of both the three-dimensional flow pattern and sediment movement. Scour underneath the pipeline may expose a section of the pipe, causing it to become unsupported. Accurate estimate of the scour depth is important in the design of submarine pipelines (Chiew, 1991). The estimation of the scour characteristics of underwater pipelines continues to be a concern for hydraulic engineers. A number of empirical formulas have been developed in the past to estimate equilibrium scour depth below pipelines, including Chao and Hennessy (1972), Kjeldsen et aI., (1973), Ibrahim and Nalluri (1986), Dutch research group (Bijker and Leeuwestein, 1984), Moncada and Aguirre (1999), and Chiew (1991). However, the main deficiency of these formulas is that the empirical equations do not model actual scour process. Predictive approaches such as artificial neural networks (ANN) (Azmathullah et aI., 2005) and genetic programming have been recently shown to yield effective estimates of scour around hydraulic structures. Wed, 04 Apr 2018 12:43:51 +0800 institutional_item_version_id:1144 http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action;jsessionid=2C3EFD6822B00F54465275A8382CFC5A?institutionalItemId=22 Air pollution and noise pollution have a negative impact on all of society — but some groups are more affected than others. Lower socioeconomic status is generally associated with poorer health, and both air and noise pollution contribute to a wide range of other factors influencing human health. But do these health inequalities arise because of increased exposure to pollution, increased sensitivity to exposure, increased vulnerabilities, or some combination? This In-depth Report presents evidence on whether people in deprived areas are more affected by air and noise pollution — and suffer greater consequences — than wealthier populations. Thu, 21 Sep 2017 15:49:26 +0800 institutional_item_version_id:22 http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action;jsessionid=2C3EFD6822B00F54465275A8382CFC5A?institutionalItemId=21 Sanitation Safety Planning is a tool to help sanitation system operators maximise health benefits and minimise health risk of their system. It guides operators to prioritize and target risk management efforts to where it will have the most impact and to improve over time. The outputs can be used to provide assurance to the public and authorities of the system performance based on sound risk based management Thu, 21 Sep 2017 15:34:26 +0800 institutional_item_version_id:21 http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action;jsessionid=2C3EFD6822B00F54465275A8382CFC5A?institutionalItemId=16 Science for Environment Policy is a free news and information service published by the European Commission’s Directorate-General Environment, which provides the latest environmental policy relevant research findings. Future Briefs are a feature of the service, introduced in 2011, which provide expert forecasts of environmental policy issues on the horizon. In addition to Future Briefs, Science for Environment Policy also publishes a weekly News Alert which is delivered by email to subscribers and provides accessible summaries of key scientific studies. Wed, 20 Sep 2017 14:30:04 +0800 institutional_item_version_id:16