Growth of Gynura procumbens and oreochromis spp. by using cocopeat media in aquaponics system

Lightweight expanded clay aggregate (LECA) and gravel are common growing media that are used to support plants in hydroponic system. However, LECA is quite expensive and gravel causes the presence of algae. Therefore, alternative media from local source are required. The study evaluates the growth rate of Gynura procumbens plants by using four different growing media (LECA, cocopeat, rice husk and mixture of cocopeat with rice husk) in an aquaponic system. The media were analysed based on the physical and chemical properties before being used as growing media in the aquaponics system for water quality, nutrients level and growth of Gynura procumbens plants and Hybrid red Nile Tilapia fish. Results attained signified the suitability of utilizing rice husk and cocopeat as alternative media compared to commercial media such as LECA because there was a significant difference (P< 0.05) between all analytical tests. Commercial media such as LECA did not require water treatment unit but the usage of cocopeat is not guaranteed by its effectiveness in treated water in the aquaponics system. Therefore, extra filtration system (single or combined) filter was required and the study of four different water treatment units (mechanical, biological, combination and media) by using cocopeat as media in the aquaponics system. The water treatment unit was being compared based on water quality, nutrients level and growth of plants and fish. All the aquaponics systems were operated for twelve weeks and the values of pH, temperature, and dissolved oxygen level measured to be within the range of 6.4-6.9 (± 0.07), 27.7-29.0°C, and 5.5-7.0mg/L (± 0.09), respectively. Satisfactory reduction (50-70%) was achieved for total suspended solids (TSS) and the nitrogen compounds within the systems. The results revealed that cocopeat was insufficient to act as a water treatment unit in the aquaponics system studied. The aquaponics system required at least a biological or mechanical filter for effectiveness in treating water of the system

Carbonized rice husk and cocopeat as alternative media bed for aquaponic system

The study evaluates the suitability of carbonized rice husk and cocopeat substrates as alternative media bed in aquaponics unit for cultivation of red Nile tilapia and Gynura procumbens. Area occupied by the aquaponics unit is about 4.5 m2 and it was operated under equatorial climate conditions. Various substrates namely lightweight expanded clay aggregate (LECA), cocopeat, carbonized rice husk and a mixture of cocopeat-rice husk at ratio 1:1 were prepared using polybags for growing of the longevity spinach. The resultant effects from fish cultivation and plants growth on the water qualities and nitrification efficiency of the aquaponics unit were reported. The aquaponics unit were operated for twelve weeks and the values of pH, temperature, and dissolved oxygen level were measured to be within the range of 6.4-6.9, 27.7-29oC, and 5.5-7 mg·L-1, respectively. Survival rate for fish was 98% with specific growth rate (SGR) and food conversion ratio (FCR) of 6.9% per day and 1.13, respectively. Nutrient deficiency was not evident and plants showed healthy growth with harvest yield ranging between 3.6 and 3.9 kg·m-2. Results attained signified the suitability of utilizing carbonized rice husk and cocopeat as alternatives media bed compared to commercial media bed such as LECA

The effects of conventional and microwave heating techniques on extraction yield of orthosiphon stamineus leaves

The heating technique in a solid-liquid extraction system plays a significant role in the design and economic potential for the extraction of active components from herbs. This paper focused on the effects of extraction parameters such as ratio of sample to solvent, temperature and time of processing on the extraction yield of Orthosiphon stamineus leaves in conventional and microwave heating extraction techniques. The extracts were concentrated and dried using a rotary evaporator and freeze dryer in order to relate the yield to the processing parameters quantitatively in both heating techniques. The analysis results revealed that the processing parameters; ratio of sample to solvent, temperature and time of extraction had essential effects on the extraction yield of Orthosiphon stamineus leaves. Microwave heating extraction produced a comparable yield to conventional heating extraction with a relatively small deviation of approximately 2.8 % in average. Furthermore, microwave heating extraction reduced processing time, where this technique required about 25 % of the conventional heating time in heating up the extraction mixture to set-point temperature (60 ºC). This study concludes that microwave heating extraction, which is a green technology, has great potential in reducing the carbon foot print due to a shorter processing time and reduced energy consumption (~77 % less) compared to conventional heating extraction