This research aims to analyze the effect of seawater intrusion with measurement of TDS dug well water in Padang Utara Subdistrict. The measurements of TDS carried out in three villages in Padang Utara Subdistrict, namely the Village are Air Tawar Barat, Ulak Karang Selatan, and Ulak Karang Utara with twice sampling frequency: on November 2015 and February 2016. TDS concentration in November 2015 is in the range of 20 to 9000.8 mg / L, while the measurement of TDS concentration in February 2016 is in the range of 160.8 to 735.2 mg / L. Measurement of TDS in November 2015 showed that there were three wells that indicated to seawater intrusion, i.e. the ULS 8 (1101.6 mg / L), ULS 9 (9000.8 mg / L), and ULU 6 (1926.4 mg / L). Correlation between TDS concentration with coastline distance have a value r amounted to 0,118-.095. The results showed that there are some wells that indicated to seawater intrusion along the coast in Padang Utara Subdistrict.Keywords : distance, dug wells Padang Utara Subdistrict, , seawater intrusion, TDSAbstrak-Penelitian ini bertujuan untuk menganalisis pengaruh intrusi air laut dengan pengukuran TDS pada air sumur gali di Kecamatan Padang Utara. Pengukuran TDS dilakukan di tiga kelurahan di Kecamatan Padang Utara yaitu Kelurahan Air Tawar Barat, Ulak Karang Selatan, dan Ulak Karang Utara dengan frekuensi pengambilan sampel sebanyak dua kali yaitu pada bulan November 2015 dan Februari 2016. Konsentrasi TDS pada November 2015 berada dalam rentang 20-9000,8 mg/L, sedangkan pengukuran konsentrasi TDS pada Februari 2016 berada dalam rentang 160,8-735,2 mg/L. Pengukuran TDS pada ovember 2015 menunjukkan bahwa terdapat tiga sumur yang yang terindikasi mengalami intrusi air laut, yaitu ULS 8 (1101,6 mg/L), ULS 9 (9000,8 mg/L), dan ULU 6 (1926,4 mg/L). Hubungan antara jarak sumur dari bibir pantai terhadap nilai TDS memiliki koefisien korelasi sebesar 0,118 0,095, hal ini menunjukkan tidak adanya pengaruh antara jarak dengan nilai TDS. Hasil penelitian menunjukkan bahwa terdapat beberapa sumur yang terindikasi mengalami intrusi air laut di sepanjang pesisir di Kecamatan Padang Utara.Kata kunci : intrusi air laut, jarak, Kecamatan Padang Utara, sumur gali, TDS

This study aims to determine and evaluate the level of noise in the southern area of Universitas Negeri Padang (UNP) Kampus Air Tawar conducted at 23 points of measurement with 16 outside outdoor points and 7 indoor measurement points. Method of measurement under regulation of Indonesian government, KepMenLH Regulation no. 48 thn 1996 which regulate the noise level standard by using SLM (Sound Level Meter). The highest outdoor noise level occurs in front of GOR UNP (S16) at the time of L3 which is 80,91 dBA, while the highest indoor noise level when there was activity as well as no activity in the room was happened in lecture hall FBSS UNP (S7-interior) with value equal to 83, 99 dBA and 64.65 dBA. All points of a total of 16 outdoor and 7 indoor measurement points exceed the standard noise level threshold which is 55 dBA (+3 dB tolerance). However, from the questionnaire results most respondents just feel slightly disturbed by outdoor noise in the study area. The noise control that can be done such as cultivate number of natural vegetation such as heliconia sp, tea, acacia tree and pringgodani bamboo, also the installation of continuous wall from type of clear fiber that serves as building noise absorbers.

The flow profile in the channel will affect the velocity of fluid distribution. One factor that influences the flow profile in a closed channel is its diameter. Therefore, this study aims to analyze the effect of changes in pipe diameter on the nature of fluid flow in closed channels using Osborne Reynold Apparatus. This tool uses a vertical glass pipe with a diameter of 1 cm and 3 cm. The operation of the Osborne Reynolds Apparatus is carried out by flowing the fluid through a channel with a PVC type pipe pumped with a Submersible pump into an acrylic tub, then passing a vertical clear glass pipe. The Reynolds value obtained from each test equipment is 1,323-5,748 with friction factor 0,03-0,04 on Osborne Reynold Apparatus 3 cm diameter and 1,103-4,512 with friction factor value 0,03-0,05 at Osborne Reynold Apparatus 1 cm diameter. It is known that the greater the channel diameter, the greater the Reynolds value will be, while the friction factor will be smaller. Regression and correlation analysis are carried out with the aim to determine the relationship the values obtained and it is obtained that there is a very strong relationship among time, discharge, flow velocity, Reynolds number and friction factor in each test equipment. It is evidenced with the coefficient of determination and the correlation coefficient obtained (R2 = 0.994-1,000 and r = 0.981-1,000).

Anammox process is a more practical alternative in biological nitrogen removal compared to conventional nitrification-denitrification processes. This process conducted at the optimum temperature of 370C. Indonesia, as a tropical country, has the potential for the application of anammox processes to remove nitrogen in wastewater. The purpose of this study was to analyze the efficiency of nitrogen removal in the anammox process using the Up-Flow Anaerobic Sludge Blanket (UASB) reactor at ambient temperature with variations in the hydraulic retention time (HRT) of 24 hours and 12 hours, at the laboratory scale. Samples are measured twice a week using a UV-Vis spectrophotometer. As a seeding sludge for start-up, the reactor was inoculated with granular anammox bacteria genus Candidatus Brocadia. At the stable operation, the ratio of ΔNO2--N:ΔNH4+-N and ΔNO3--N:ΔNH4+-N approach the stoichiometry of the anammox process were 1.20 and 0.21, respectively. The performance of nitrogen removal with 24-hour HRT obtained a maximum nitrogen removal rate (NRR) of 0.113 kg-N/m3.d with nitrogen loading rate (NLR) 0.14 kg-N/m3.d, and at 12-hour HRT, maximum NRR  of 0.196 kg-N/m3.d with NLR 0,28 kg-N/m3.d. Ammonium Conversion Efficiency (ACE) and Nitrogen Removal Efficiency (NRE) maximum for HRT 24 hours were 82% and 77%, respectively while HRT 12 hours were 72% and 68%, respectively. The anammox process operated stably in the tropical temperature with a temperature range of 23-280C on a laboratory scale using the UASB reactor.Keywords: anammox, nitrogen, temperature, tropical, uasb.ABSTRAKProses anammox menjadi alternatif yang lebih efektif dalam penyisihan nitrogen secara biologi dibandingkan dengan proses konvensional nitrifikasi-denitrifikasi. Proses ini berlangsung optimum pada suhu 370C. Indonesia sebagai negara tropis memiliki potensi untuk aplikasi proses anammox untuk menghilangkan nitrogen pada air limbah. Penelitian ini bertujuan untuk menganalisis efesiensi penyisihan nitrogen pada proses anammox menggunakan Up-Flow Anaerobic Sludge Blanket (UASB) reaktor pada suhu ambien dengan variasi Waktu Tinggal Hidrolik (WTH) 24 jam dan 12 jam, pada skala laboratorium. Sampel diukur dua kali setiap minggu menggunakan spektrofotometer UV-Vis. Sebagai seeding sludge (lumpur biakan) untuk start-up (memulai) reaktor digunakan bakteri anammox genus Candidatus Brocadia berbentuk granular. Berdasarkan hasil pengukuran, didapatkan nilai rasio ΔNO2--N:ΔNH4+-N dan ΔNO3--N:ΔNH4+-N mendekati stoikiometri proses anammox yaitu 1,20 dan 0,21. Kinerja penyisihan nitrogen dengan WTH 24 jam didapatkan nilai tingkat penyisihan nitrogen (TPyN ) maksimum 0,113 kg-N/m3.h pada tingkat pemuatan nitrogen (TPN) 0,14 kg-N/m3.h, dan WTH 12 jam nilai TPyN  maksimum 0,196 kg-N/m3.h pada TPN 0,28 kg-N/m3.h. Nilai efisiensi konversi amonia (EKA) dan efisiensi penyisihan nitrogen (EPN) maksimum pada WTH 24 jam berturut-turut adalah 82% dan 77%, sedangkan pada WTH 12 jam berturut-turut adalah 72% dan 68%. Penelitian membuktikan bahwa proses anammox dapat berlangsung stabil pada daerah tropis dengan suhu terukur 21-290C pada skala laboratorium menggunakan UASB reaktor. Kata kunci: Anammox, nitrogen, temperatur, tropis, uasb.

This study aims to determine the purification ratio (reaeration and deoxygenation ratio) in the epilimnion layer of Lake Maninjau. The parameters studied were BOD, COD, and environmental parameters such as temperature, pH, DO, wind speed and water velocity. Sampling was taken at three sampling station at east-and west side of the lake at 0, 2, 4, 6 m depth, and at 10 m depth of the center of the lake in the rain and not rain condition. The water quality of Lake Maninjau showed that the organics parameters had exceeded the quality standard. The organic substances measured as BOD ranged in average 12 mg/L and COD ranged in average 193 mg/L in rain conditions, whereas under dry conditions the BOD were higher i.e. in range of 22 mg/L and COD 218 mg/L. The deoxygenation rate (K1) during rain and dry were ranged in 0.047-0.371/day and 0.038-0.967/day respectively, whereas the reaeration rate (K2) of those were in the range of 0.117-0.647/day and 0.161-0.691/day respectively. The overall value of the purification ratio (K2/K1) of Lake Maninjau was in the range of 1.282-5.048 in rain condition and 1.107-7.230 in dry condition. It indicated, that Lake Maninjau in the epilimnion zone still has selfpurification ability to assimilate the organic pollutants.