No abstract

MgAl based layered double hydroxide (MgAl-LDH) was used as adsorbent for the removal of chromium oxyanion from an aqueous solution. MgAl-LDH was synthesized successfully using coprecipitation method, and was characterized by X-Ray Diffractometer (XRD), Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). MgAl-LDH was thermally treated for improving the chromium adsorption. Samples were treated at 220°C and 450°C. A negligible difference of total chromium adsorption capacities was observed between MgAl-LDH 000 and MgAl-LDH 220 as 12.56 mg/g and 11.01 mg/g. The maximum chromium adsorption capacity of MgAl-LDH was 88.07 mg/g at 500g/l chromium concentration for MgAl-LDH which has been thermally treated at 450°C (MgAl-LDH 450 ). The results indicated that memory effects of thermally treated MgAl-LDH at certain temperatures were retained and enhanced chromium removal effi ciency.

Abstrak: Analisis Debit Emitter Pada Sistem Irigasi Vertical Garden. Vertical garden merupakan salah satu solusi untuk mengurangi dampak pemanasan global. Banyak faktor penting yang perlu diperhatikan dalam perencanaan vertical garden, salah satunya adalah sistem irigasi. Penelitian ini menggunakan sistem irigasi tetes dengan emitter. Emitter merupakan bagian penting dalam sistem irigasi terkait dengan kebutuhan air untuk tanaman. Penelitian ini bertujuan untuk menganalisis debit emitter dan menilai kinerja irigasi. Analisis pada debit emitter menggunakan variabel bukaan keran dan waktu. Sedangkan, parameter untuk menilai kinerja irigasi terdiri dari coefficient of variation discharge rate, statistical uniformity, field emission uniformity, emission uniformity, absolute emission uniformity, dan variation of emitter flow. Hasil penelitian menunjukkan bahwa debit maksimum didapat pada bukaan keran 900 dengan waktu 1 menit dan debit minimum diperoleh dari bukaan keran 300 dengan waktu 1 menit. Selain itu, untuk menilai kinerja irigasi diperoleh bukaan keran 300 tidak memenuhi semua parameter dan bukaan keran 900 memenuhi semua parameter. Oleh karena itu, dapat disimpulkan bahwa bukaan keran 900 dapat diterapkan pada bentuk vertical garden yang digunakan pada penelitian karena memiliki debit emitter maksimum dan kinerja irigasi yang baik. Abstract: Analysis of Emitter Discharge in Vertical Garden Irrigation Systems A vertical garden is one solution to reduce the impact of global warming. Many essential factors need to be considered when planning a vertical garden, including the irrigation system. This study uses a drip irrigation system with an emitter. The emitter is a vital part of the irrigation system related to plant water requirements. This study aims to analyze emitter discharge and assess irrigation performance—analysis on emitter discharge using faucet opening and time variables. Meanwhile, the parameters to assess irrigation performance consist of coefficient of variation discharge rate, statistical uniformity, field emission uniformity, emission uniformity, absolute emission uniformity, and variation of emitter flow. Results showed that obtained the maximum discharge at faucet openings of 900 with a time of 1 minute, and the minimum release from faucet openings of 300 with a time of 1 minute. In addition, to assess irrigation performance, the 300 faucet opening did not meet all the parameters, and the 900 faucet opening met all the parameters. Therefore, we can conclude that applying 900 faucet openings to the vertical garden form is used in this study. Because it has a maximum emitter discharge and good irrigation performance.

Indonesia has a potential of renewable energy resources for mini-hydropower up to 450 MW. The energy resources development in Indonesia refers to Presidential Decree No.5/2006 on National Energy Policy, where the government aims to increase the capacity installed in micro-hydro power plants become 2,846 MW by year 2025. Pagar Alam City is a hilly area with an altitude range of 400 m-3,400 m above sea level. The topography varies from 0°-15°, to 45° slope. The average rainfall ranges 1,462-5,199 mm per year. In addition, Pagar Alam has several rivers, one of them is Lematang River. These conditions make Pagar Alam supposed to become potential area to develop micro-hydro power plants. This study deals with the planning of a micro-hydro power plant within Lematang River based on engineering and economic aspects. The study was done through several steps, i.e. 1) surveying and collecting data of river discharges, rainfall intensity, climatology parameters, and topographic map; 2) analysis of water availability, 3) hydraulic head analysis, 4) analysis of generated power for micro-hydro power plant, and 5) investment feasibility analysis for the constructions. The results of this study show that the availability of water in the river is 3.076 m3/s, the net hydraulic head is 11.442 m, the generated power is 165 kW for total efficiencies 47.9%, and the annual hydroelectricity production is 1.3 GWh/year. The investment feasibility analysis for the construction indicates that the planning of micro-hydro power plant development is feasible to implement.

As the population increases and infrastructure development continues to increase, the need for green open space is decreasing. A vertical garden is an efficient solution with a vertically modern garden concept that the functions of green open spaces can be fulfilled. The irrigation system in a vertical garden gives a major role because plants can be grown well if they have a great irrigation system. Drip irrigation is one type of irrigation system that is widely applied and the best method that has been used in the world because it is considered more efficient with a small discharge, can reduce runoff, and can reduce water loss due to evaporation. This study aims to analyze the uniform of water distribution in the drip irrigation system and the average variation of water distribution in the row and column direction using a statistical test with Kruskal-Wallis. Based on the statistical analysis, it is obtained the coefficient of variation (Cv) of 0.27, the uniformity statistic (Us) of 73.2%, and the coefficient of uniformity (Uc) of 71.7% which means that the three parameters are categorized as good and acceptable while for statistical tests Kruskal-Wallis has a difference in the average variation of water distribution for the row and column groups.