Engineering Headway Vol. 23

Abstract: Electrochemical methods, such as electrocoagulation, have proved to be incredibly successful in the treatment of wastewater and the reduction of pollutants, specifically in terms of color content. The objective of this investigation is to enhance the treatment effectiveness of color content in wastewater produced by the textile industry. To accomplish this, a continuous tubular-based reactor for electrocoagulation is employed. The reactor system comprises of stainless steels rods and a helical structure for the cathodic component (SS 304), as well as an iron pipe for the anodic component (Fe). By conducting trial tests and varying the current density within a range of 465.28 A/m² to 823.19 A/m², with a current value ranging from 125-200 amperes and a voltage of 5-22 volts, significant reduction in color content in textile industry wastewater is achieved. The inclusion of an iron anode in the tubular-based electrocoagulation reactor results in a substantial reduction in color parameters, with levels reaching as high as 94.0-99.9%. The energy consumption required to achieve this level of efficiency varies from 0.25 to 1.69 kWh/m³. Ultimately, the treated water produced by the tubular reactor system demonstrates exceptional effectiveness in reducing the color parameters of wastewater generated by the textile industry.

Abstract: This investigation was carried out in a lab setting with the aid of a filter set. This study aimed to lower the level of clean water contamination and assess the filter media's performance in Fitu Village, Ternate City, using physical and chemical criteria. Temperature, turbidity, total dissolved solids (TDS), and odour are physical parameters. While pH, Mn (manganese), and Fe (iron) are the chemical parameters. Sand-activated carbon made of silica and zeolite is the filter medium. One hundred eighty litres of water from a resident's well make up the sample. The physical characteristics, namely the TDS of 1250 mg/L, the turbidity of 27 NTU, and the temperature of 25 °C, show the outcomes of investigating healthy water as raw water in the Kelurahan Fitu. Fe concentration was 1.3 mg/L, Mn concentration was 0.6 mg/L, and pH was 9. Water is passed via silica sand, zeolite, and activated carbon filters before entering the filter after further inspection. According to the results, the TDS has dropped to 897 mg/L, the turbidity has changed to 24, and the temperature is 24 °C. The filtered water meets the chemical standards for Fe concentration with only 0.91 mg/L of Fe, 0.45 mg/L of Mn, and a pH of 7.9. According to the study's findings, inhabitants of Fitu Village in Ternate City can efficiently reduce pollutants and metal levels in their healthy water by employing a filtering system that uses silica sand filter media, zeolite, and activated carbon.

Abstract: During the period 1991 to 1995, floods in Indonesia caused trillions of rupiah in losses with 4,246 deaths, 6,635 injuries, around 7 million people suffering and 324,559 houses damaged (BNPB, 2013). In Lampung Province, there are 3 (three) River Basin Units (SWS), those are: Mesuji-Tulang Bawang SWS, Seputih-Sekampung SWS and Semangka SWS. Of these three SWS Way Sulan is a tributary of the Way Sekampung, a river length of 46,24 km and a watershed area of ​​238,58 km². This research uses HEC-RAS, Global Mapper, ArcGIS applications. The research method used is a flood inundation simulation using HEC-RAS with an unsteady flow type and displaying the simulation results on a race mapper. After going through several stages, the flood inundation area was obtained Q₂ = 248.74 km², Q₅ = 257.59 km², Q₁₀ = 263.07 km², Q₂₀ = 267.49 km², Q₂₅ = 268.32 km², Q₅₀ = 271.92 km², Q₁₀₀ = 274.14 km², so that we get the equation of the relationship curve between maximum discharge and inundation area: y = 220.86 + 0.0331x with R2 = 0.998 and the equation of the relationship curve between maximum discharge and inundation height : y = 4,2043 + 0,1057x with R2 = 0,9337

Abstract: Indonesia is an archipelagic nation situated geographically at the intersection of two continental plates and on the equator. Consequently, Indonesia has a tropical climate and varied precipitation. Due to the country's strategic location, it receives numerous advantages, however there are also negative consequences, including the flood calamity. This study's objective was to investigate the parameters that influence the hydrology and characteristics of the upstream watershed so that the results can be used as a reference when developing models for flood disaster mitigation. This study employs quantitative methodology. The data used are both primary and secondary, consisting of field surveys and river topography and rainfall data from the BMKG post, respectively. Climate change is one of the parameters that affect hydrology. Climate change has a significant impact on the increase in rainfall, which can lead to flooding in the Remu river basin (Das). Changes in the characteristics of rain in the Das, such as high annual rainfall and maximal daily rainfall, tend to increase, in addition to the effects of land use, soil type, slope, and riverside residents, resulting in flooding in the Remu Das. The highest discharge occurred at the 2-year return period of 171.50 m3/s, the 5-year return period of 250.28 m3/s, the 10-year return period of 307.26 m3/s, the 25-year return period of 384.61 m3/s, the 50 year birthday of 446.25 m3/s, and the 100 year birthday of 511.38 m3/s. According to the results of the simulation model, the inundation area for a 2-year return period is determined to be 300.98 hectares. The pool area for the 5-year return period is 347.18 ha, for the 10-year return period it is 679.07 ha, for the 25-year return period it is 1,023.88 ha, for the 50-year return period it is 1,295.61 ha, and for the 100-year return period it is 1,547.14 ha. In order to combat flooding, non-structural methods, such as the flood forecasting and warning system (FFWS), where the principle of FFWS is to carry out forecasting, detection, early warning systems and flood information management systems. This is done to reduce the impact of flood hazards on the Remu watershed.are required. The magnitude of flooding in the Remu watershed is significantly affected by the potential for climate change and alterations in watershed characteristics, according to the findings of this study. In addition, to enhance the accuracy of the flood forecasting warning system in the Remu Basin, the locations of the Rainfall Post and Water Estimation Post must be added.

Abstract: Wind data is very necessary in estimating wave height at sea, especially in areas that do not yet have wave data recorded. This research aimed to determine the characteristics of waves in the western waters of Lampung, as well as compare the results of wind data simulations of the Lampung recording station with those in Bengkulu. The results of wind data processing and geographic position would determine the dominant wind direction, retrieval length, and several variables characteristic of ocean waves. The results of the analysis showed the dominant wave generation direction towards the South on the west coast, with a minimum wave height of 0.95m a maximum of 4.3m, and a wave period of up to 11 seconds. The wave broke out at a height of 1.571m depth of 1.49m according to calculations. The average wave rupture occurred at a depth of 1.49m with a wavelength of 1.571m with an average Ks value of 0.53 and an average Kr value of 0.85. The simulation results concluded that wave height using wind data from the Bengkulu recording station had a greater value than using wind data from the Lampung recording station.

Abstract: Flume is an artificial open channel construction tool that holds water in the desired amount and is used as an observation, measurement or test equipped with a water flow that can be controlled and the slope of the channel can be adjusted as needed. The purpose of this study was to obtain a comparison of the accuracy of using several velocity measuring instruments available in the hydraulics laboratory on the experimental flume. There are two measurement methods used in this study, namely the Measured/Aqtual Discharge Method and the Flow Velocity Method. Measurement of flow velocity to obtain discharge carried out in this study using a current meter flow watch (FW), electromagnetic current meter (ECM), Portable velocity meter 0.01-4.0 m/s LS300 A). method to get accuracy, refers to the current meter discharge value with the measured discharge value. From the results of the study it can be concluded that the Measurement Accuracy of flow watch (FW) = 94.23%, electromagnetic current meter (ECM) = 5.90%, and Portable velocity meter 0.01-4.0 m/s LS300 A = 100.23%, The results of verification and validation of measurement accuracy between actual discharge and discharge using velocity measuring instruments show that the value of discharge using Portable velocity meter 0.01-4.0 m/s LS300 A is close to the aqtual discharge value.

Abstract: Pisang Island experiences population growth every year. The local community in this area uses groundwater for daily activities. Utilization was performed through pumping. Utilization has shown signs of negative impacts on the quality of groundwater, with the discovery of well water that tastes fresh and brackish. The purpose of this study is to analyze the parameter values to determine the processes involved in the formation of fresh, brackish/saline groundwater and to determine the level of influence of seawater on Pulau Pisang. Based on field studies including geological data, hydrogeology, groundwater flow patterns, electrical conductivity (EC), total dissolved solids, and pH values, 25 groundwater sampling points are determined. Laboratory testing was conducted on the samples for chemical analysis and the identification of their contents. The geoindicator method was used to assess the influence of seawater on groundwater, with several parameters including chloride (Cl) concentration and EC, Cl/Br ion ratio and Cl concentration, Na/Cl ratio, Ca/Mg and Ca/(HCO3 + SO4) ratios, Base Exchange Index (BEX) value, and trilinear pipe diagram. Based on the values of each parameter, there were three categories of groundwater characteristics: samples that were freshwater, samples influenced by seawater, and samples that were a mixture of freshwater and seawater.

Abstract: The subdistrict of Taebenu in Kupang Regency is classified as an area with low productivity of aquifer, local even scarce groundwater conditions due to its geological condition. This research aims to investigate the occurrence of springs in this region and its correlation to geological conditions. This study was conducted by the method of direct observation of the geological and hydrogeological conditions in the study area. Although groundwater in this study area is scarce, the result of this research reveals the occurrence of at least 13 annual flowing springs that emerged from rocks on a research area of 3.64 Km2. In relation to lithology, one spring occurs in the limestone; six springs occur in the carbonate sandstone; three springs occur in the scaly clay fragmented with exotic blocks; one spring occurs in the contact lithology between carbonate sandstone and scaly clay fragmented with exotic blocks, and the other two springs occur in the alluvium sand sediments. Based on spring occurrence classification, those springs can be classified as follows, ten springs are Contact Springs, and three are Tubular or Fracture Springs. Almost all the springs have less than 1 L/s discharge rate, pH between 6 – 8, and TDS below 500 mg/L and may become a potential source of fresh water for the community in this region.

Abstract: For engineers who are involved in planning and constructing water structures, hydrology is indispensable data. In planning in the field of water resources, especially water structures, it is often necessary to have flood discharge data that are close to real field conditions so that a building that is able to control flood discharge can be planned. There are many models that can be used as references, but doubts often arise in their application in Indonesia, which has a tropical climate. So, we need a calibration model which is an approach to the actual flood discharge in the field. One of the calibration models for river flood discharge is the Creager graph method which is compiled based on Q1000 data of dams spread over the Jeneberang River Region. The purpose of this study is to determine the C value of the Creager graph based on Q1000 dams spread over the Jeneberang River Region, which can later be used in determining the flood discharge method selected for the unmeasured watershed included in the Jeneberang River Region. The results showed that the value of the Creager Coefficient (C) for the Jeneberang River Region based on the technical data of the dam was obtained 38. Based on the value of C which was tested in 4 watersheds, it was found that the selected flood discharge in the Tallo Watershed, is ITB-II SUH and in the Kelara Watershed, Tangka Watershed and Sinjai Watershed, is SCS SUH with a large deviation of 4.05% - 8.66%.