In collaboration with the Ministry of Marine Affairs and Fisheries, JAPFA, and the Sustain Aqua Indonesia Foundation, the Indonesian Shrimp Forum organized and managed the ” WWTP Minimalist Model for Shrimp Ponds as A Practical Solution for the Pond Waste Treatment ” Webinar Series on August 24, 2021.
Dr. TB. Haeru Rahayu, A.Pi, M.Sc, who is currently the Director-General of Aquaculture, presented the first material of the webinar, titled “Shrimp Pond WWTP Practical Solution for the Pond Waste Treatment.” In this section, Dr. Haeru described three KKP strategies for shrimp farming, specifically solutions in treating shrimp pond waste. The first strategy was by increasing non-tax state revenues (PNBP) from the capture fisheries sector that will benefit the welfare improvement of fishers. Next was aquaculture development to boost export by getting support from marine and fisheries research. Last, developing freshwater, brackish water, and marine aquaculture villages based on local wisdom. It can be done by adopting the local wisdom practices such as those in Pasaman, Gunung Kidul, and other areas in Indonesia.
In this webinar forum discussion, however, the efficiency and effectiveness of WWTPs is a concern of the Indonesian Shrimp Forum because it turns out that WWTPs require an area of about 30% or even 40% based on data from 100 ponds. Hence, such WWTP problem must be fixed first, so shrimp farmers can effectively manage their ponds.
Dr. Haeru briefly explained why shrimp is the second most targeted commodity by customer in the fisheries sector today. According to Central Statistics Bureau (BPS) regarding the market value of global fishery products, shrimp production volume is 239,230 tons, or when monetized equally to USD 2,040,070 followed by lobster in seventh place, seaweed is in the 11th position. Dr. Haeru further elaborates that currently, KKP is developing a dashboard for fisheries data derived from BPS and KKP’s internal data with an expectation to reach an accuracy of approximately 80-90 % by next year.
Even though there are several versions of fisheries data, but more or less are similar in general. For instance, the total area of aquaculture ponds is approximately 804,000 hectares, of which 68% (546,732 ha) are shrimp ponds, whereas 32% are designated for milkfish ponds and other commodities. The shrimp farmers own 90% of those 546,732 ha shrimp ponds. However, 50% of those shrimp ponds are categorized as idol ponds or have changes in their functions, and only 55.35 % are active. Semi-intensive ponds that are currently active are 95%, while only 5% are inactive, whereas 97% of intensive ponds are active and inactive ponds count for 3% only.
In the last two years, the total area of intensive, semi-intensive, and traditional shrimp aquaculture has been 300,000 ha. Intensive pond produces 30 tons/ha/yr, semi-intensive ponds 10 tons/ha/yr, and traditional ponds 0.6 tons/ha/yr, respectively. Hence, with this current condition, a revitalization program is needed by traditional shrimp farmers such converting their traditional ponds to intensive system to increase productivity from 0.6 tons per hectares to meet the shrimp production target of 2 tons/ha by 2024. The proposed revitalization program is carried out by conducting interventions in the field, such as windmill support, technical guidance, etc.
According to Dr. Haeru, there are five strategies to increase national shrimp production: (1) Map areas for potential shrimp development; (2). Technology improvement in terms of effectiveness and efficiency; (3). Simplify licensing process support; (4). Synergy among stakeholders to obtain more factual shrimp fisheries information; and (5). Environmentally friendly and sustainable inventions in management.
Dr. Haeru concluded the presentation by explaining how waste management of WWTPs and technologies related to WWTPs are very efficient. It does not take up much space and is inexpensive, technologically simple to master/user-friendly and has no environmental impact.
The second material of the webinar with the title “Minimalistic WWTP for Shrimp Ponds Practical Solution for Shrimp Pond Waste Treatment” was presented by Mr. Itang Hidayat who currently serves as Aquaculture Technology and Development at PT STP JAPFA Aquaculture.
Pak Itang divided his presentation into several sections. First is about the background of the minimalist WWTP concept for shrimp ponds, which can be a practical solution for waste treatment in shrimp ponds. Shrimp cultivation is a sustainable economic activity that is in line with the increasing fulfilment of the world’s animal protein needs. With a program from the KKP to increase shrimp production in Indonesia, these activities will inevitably produce waste and side effects in the form of liquid and solid waste during production. The shrimp pond waste has the characteristics of not having a high pollutant concentration but involves a large water volume. The pollutant concentration value is also affected by the cultivation age, density, and stocking of the cultivation system, which can be traditional, semi-intensive, super-intensive, or construction. Pond water is, as we all know, is the raw waste material. Water nutrition issues frequently arise because nutrient retention in ponds is only 22%, and an average of 78% nitrogen and 90% phosphorus is wasted from the pond. Nutrient pollution is the primary pollutant emitted by WWTPs.
Pak Itang also discussed the disposal of liquid and solid waste from shrimp ponds directly into the surrounding environment without prior processing in the second part of his presentation, which can result in:
- The dominance of the organotherapy bacteria system over the natural photoautotroph system (plankton as the primary marine producer) due to the abundance of organic matter in seawater, as indicated by an increase in organic matter concentration and a decrease in ORP;
- Expansion of the siltation zone in river estuaries and coastal waters;
- The formation of anoxia (low oxygen) and euxinia (high sulphide) layers in the sea;
- During the rotation of its natural life cycle (when upwelling occurs in the sea), Vibrio parahaemolyticus (Vp) colonies are dispersed in seawater and reattached to other substrates such as plankton, water filter sand, dang, fish, shellfish, or seaweed;
- Vibrio parahaemolyticus biofilm colonies have high resistance to antibiotics, probiotics, and disinfectants.
- 70% of PirA & PirB VPAMPNO toxins were found in sludge and 30% in water and other substrates such as wild crustaceans.
In the third part of the presentation, Pak Itang discussed the main goal for the success of a minimalist WWTP. The goal is to keep solid waste (suspension and sludge) from leaving the shrimp pond environment, both solid waste from wastewater discharge and daily wastewater discharge from aquaculture activities, as well as the procurement of a suitable waste treatment system. However, according to SNI, complete WWTP standards in shrimp ponds are still considered for farmers due to limited land, financial ability, and complexity level of the wastewater treatment plant design technology used. The basic design system of WWTP for shrimp farming must follow regulations from KKP and KLHK. Also, the design must follow the assumptions of the type of waste and pollutant concentration, available equipment and energy, land availability, costs, processing methods, and the purpose of processing, whether it is to be disposed of or recycled.
Moreover, the basic principle of WWTP processing is to convert organic materials into simple molecular forms that are non-polluting, such as carbohydrates, proteins, fats, and other compounds found in feed. Waste treatment can be accomplished physically, biologically, or chemically. For example, the minimalist wastewater treatment plant for shrimp ponds employs a combination of three biological sewage treatment systems: an aerated lagoon, an SBR (sequencing batch reactor), and an aerobic-anaerobic facultative pond, where nitrification and denitrification occur concurrently in a single WWTP pond. The three processes are combined simultaneously by utilizing existing land, being simple to maintain, and having low operating costs.
For the fourth part of the presentation, Pak Itang explains how to calculate the dimensions of a minimalist WWTP pond, with an optimum ratio of 5% of the total water volume of the aquaculture pond. A minimalist WWTP can be used in conjunction with a central or modular system. For example, suppose the expanse of the pond consists of 100 cultivation ponds with uniform pond sizes. In that case, it can use a modular WWTP, with 1 unit of minimalist WWTP installed in every 20 aquaculture ponds.
The design and scenario of minimalist WWTP operations as described above accommodates the company’s needs for the simplest WWTP procurement with the lowest operating costs. Especially in the operation of the aerator to reduce the cost of operation with an aerobic-anaerobic SR system where the aerator is not operated for 24 hours and the only type of aerator used is the waterwheel.
However, if the farmer is willing to spend more to improve the quality of waste water shrimp ponds or the quality of effluent / wastewater is still not optimal, they can apply additional aeration pond /biofiltration/ disinfection with an additional area of 20% of the existing WWTP minimalist area. Then the modification of minimalist WWTP can be:
- Variation 1: Minimalist WWTPpool with aerobic biofiltration pool;
- Variation 2: Minimalist WWTPpool full aeration with biofiltration/disinfection pool
The key to the successful operation of a minimalist WWTP is the regular expenditure of mud from the minimalist WWTP central drain to the drying bed pool so that there are no mud deposits in the minimalist WWTP pool left, and It’s just liquid waste. The priority of mud removal is regulated in PERMEN-KP number 75 of 2016. Dried and composted sludge can be used as organic fertilizer in agriculture before allocating funds and resources to develop a complex and comprehensive WWTP. At least in the early stages of farmers can apply a minimalist WWTP to maintain the sustainability of the surrounding environment and the continuity of cultivation of ponds. Minimize the risks and losses caused by the disposal of shrimp pond wastewater without prior treatment to the aquatic environment around shrimp ponds. Of the two variations of minimalist WWTP that exist, farmers can select WWTP variations that suit their condition, considering funds and resources.