No abstract

Cengklik Reservoir is a reservoir for water from agricultural irrigation flows that use chemical fertilizers so that there is an increase in nutrients in the waters. Eutrophication is an environmental problem caused by an increase in nutrients such as nitrogen and phosphorus in aquatic ecosystems. Phytoremediation is a technique that is more efficient and economical than conventional techniques in degrading excess nutrients in polluted air. In phytoremediation, plants absorb air pollutants such as NO3-, NH4+ and PO43- directly. The purpose of this study was to examine the potential of aquatic plants in wastewater phytoremediation and provide recommendations for phytoremediation potential for the waters of the Cengklik Reservoir. The method used in this research is Systematic Literature Review (SLR). Based on the research that has been done, the Pistia stratiotes plant has been widely used as agricultural and domestic wastewater treatment. Pistia stratiotes has the potential to remove 80-95% of the phosphate content. So that the Pistia stratiotes plant is a suitable plant to be applied in the waters of the Cengklik Reservoir. The phytoremediation application was carried out in an inflow reservoir with a plant cover area of 75% of the phytoremediation area, and harvesting was carried out on the 14th day of treatment. The harvest can be utilized or managed by the community or related agencies to become a bioenergy generator.

Eutrophication in the Cengklik Reservoir has become a problem that occurs every year which results in the faster growth of water hyacinth (Eichhornia crassipes) around the reservoir waters. This occurs due to increased utilization of the reservoir causing a large amount of waste input into the waters, one of which is from floating net cages aquaculture. Based on the analysis of satellite imagery in 2022, there are approximately 1.355 floating net cage units. The application of intensive aquaculture is considered not optimal because only 70% of the feed is eaten by fish and the rest settles to the bottom of the water. Therefore, there is also an increase in oxygen consumption by fish and microbes for the decomposition process of organic matter.This study aims to increase dissolved oxygen in the waters using injection aeration technology in floating net cages by pumping microbubbles with a diameter of 1 m-1 mm into the water. Aeration was carried out in one floating net cage with a size of 6 m × 6 m for 8 h with 3 stages of dissolved oxygen testing, namely 06.00 (before aeration), 10.00 (after 4 h aeration) and 14.00 (final aeration). The results showed that aeration injection in floating net cages could increase dissolved oxygen 42-58% higher than non-aerated cages. In addition, aeration also increases the appetite of fish in consuming feed. Aeration injection technology can be recommended to improve water quality in Cengklik Reservoir, especially when oxygen is low in the morning.

Technology to optimize the potential of rainwater that utilizes rainwater harvesting technology (PAH) cannot simply be accepted by the community, especially in urban areas. Urban areas have limited land to support rainwater storage which has large dimensions with the shape of a tube. Therefore, a modular form was developed that can help urban communities who do not have large lands to optimize the potential for rainwater that falls and is used as clean water to supply daily needs. These components are collected and classified according to urban infrastructure systems (UIS). The planned reservoir with dimensions that are more effective and easy to apply in various places is planned to have a maximum dimension of 1 meter high and 0.5 meters wide made of modular plastic. After going through the stages of analysis of the discharge that can be accommodated in the engineering of a modular rainwater reservoir, then proceed with the design process and provide clarity of designation examples. By utilizing the form with a capacity of 32 liters, this rainwater reservoir can be arranged and adjusted according to the designation of the people who want to use it.

Cengklik Reservoir is one of the water sources that has the main function for irrigation and aquaculture. Based on satellite imagery of the Cengklik Reservoir 2000-2020, about 30% of the waters of the Cengklik Reservoir have been covered by water hyacinth. The use of chemical fertilizers, pesticides and fish farming activities using floating net cages are the main factors causing eutrophication. Therefore, the purpose of this study was to analyze the water quality of the Cengklik Reservoir at the inlet and outlet points of the Cengklik Reservoir and then determine the level of pollution using the Pollution Index (PI) method. The water quality parameters tested were temperature, pH, TSS, DO, BOD, COD, TSS, Total-P, and Total N. Based on the results of the PI analysis, the water quality of Cengklik Reservoir was categorized as lightly polluted and does not exceed the quality standard value of Government Regulation No. 22 years 2021 other than phosphate. Phosphate parameter values at inflow 1, inflow 2, inflow 3 and outflow locations are 0.166 mg/L; 0.166 mg/L; 0.723 mg/L and 0.166 mg/L which are estimates of the cause of eutrophication in the Cengklik Reservoir.