Uptake of phosphorus and nitrogen by Myriophyllum aquaticum (Velloza) Verd. Growing in a wastewater treatment system

1985 ◽  
Vol 36 (4) ◽  
pp. 493 ◽  
Author(s):  
PM Nuttall

The potential of the aquatic macrophyte M. aquaticum to remove nitrogen and phosphorus from secondarily treated wastewater effluent was investigated over 13 months. The flow-through wastewater treatment system consisted of three separate lagoons, the first lagoon with a floating mat of aquatic plants, the second with aquatic plants and aerated, and the third with aquatic plants under a polythene canopy and aerated. The aerated, canopy-covered lagoon was more efficient than the two other lagoons at removing influent ammonia- nitrogen (41 .I%), total nitrogen (16.7%), total phosphorus (4.2%), suspended solids (65%) and biochemical oxygen demand (18.1%). Influent phytoplankton numbers were also reduced by 98.6%. Following an initial planting density of 10 kg m-2 on a wet weight basis, the standing crop of aquatic plants in the aerated, canopy-covered lagoon had a mean daily growth rate of 6.27 g m-2 from May to October, resulting in daily accumulation rates of phosphorus and nitrogen of 0.12 g m-2 and 0.22 g m-2, respectively. Test pieces of M. aquaticum grown in separate enclosures within each lagoon had a mean daily growth rate of 7.0 g m-2 on a dry weight basis through winter in the aerated, canopy-covered lagoon and 18.0 g m-2 through summer in the exposed. aerated lagoon. Highest daily accumulation rates of the macronutrients were obtained in the exposed, aerated lagoon during spring and summer, with 0.43 g m-2 phosphorus and 1.26 g rn-2 nitrogen. Harvesting of plants resulted in an increase in ammonia-nitrogen in the lagoon effluent, caused by the removal of bacterial nitrifiers present on plant roots. Without harvesting, aufwuch accumulation on M. aquaticum and light restriction by the canopy resulted in a decrease in the phosphorus and nitrogen demand.

Author(s):  
Riris Yuli Valentine ◽  
I Nyoman Sudiarsa ◽  
Sartika Tangguda ◽  
Dimas Rizky Hariyadi

Seagrapes (Caulerpa sp.) is one of the aquatic plants which tends to grow slowly according to the environmental conditions where sea grapes live. This study aims to determine the growth performance of sea grapes given different shelters. The method used in this study was three treatments, each treatment was repeated three times, with differences in the shade (P1 = paranet), (P2 = without roof), and (P3 = coconut leaves). Data analysis used a non-factorial completely randomized design (CRD). The results of this study are at absolute weights (P1 =1163.3 ± 260a g), (P2 = 210 ± 79.3b g), (P3 = 922 ± 199.5a g), absolute length (P1 = 5.75 ± 1.74a cm), (P2 = 0.59 ± 0 , 07b cm), (P3 = 4.82 ± 0.22a cm), daily growth rate (4.40 ± 0.1a %), (3.76 ± 0.09b %), (4.29 ± 0.09a) and the number of ramuli (P1 = 56.2 ± 21.3a), (P2 = 19.5 ± 2.3b), (P3 = 46.3 ± 3.1a). The conclusion of this study each parameter (absolute weight, absolute length and number of ramuli) has a significant difference.


Author(s):  
Farida . ◽  
Eka Indah Raharjo ◽  
Arnis Maylinda Sari

ABSTRAKPenelitian bertujuan untuk mengetahui penggunaan fermentasi bungkil kelapa sawit dalam pakan buatan.Penelitian menggunakan Rancangan Acak Lengkap (RAL) yang terdiri dari 4 perlakuan 3 ulangan.Susunan perlakuan adalah Perlakuan A : bungkil kelapa sawit 12%, Perlakuan B : fermentasi bungkil kelapa sawit 15%, Perlakuan C : fermentasi bungkil kelapa sawit 18%, Perlakuan D : fermentasi bungkil kelapa sawit 21%. Penelitian ini dilakukan selama 60 hari untuk mengetahui laju pertumbuhan spesifikberat, laju pertumbuhan harianpanjang, konversi pakan, kelangsungan hidup dan kualitas air sebagai penunjang.Hasil penelitian menunjukkan pemberian pakan buatan dengan fermentasi bungkil kelapa sawit menghasilkan respon yang baik terhadap pertumbuhan ikan gurami. Pemberian pakan buatan dengan fermentasi bungkil kelapa sawit 18% (perlakuan C), memberikan hasil terbaik dengan laju pertumbuhan dengan rata – rata laju pertumbuhan spesifik berat 1.502%, laju pertumbuhan harian panjang 4.06%, nilai konversi pakan rata – rata 3.48 dan kelangsungan hidup rata – rata 90%.Kata Kunci : Fermentasi Bungkil Kelapa Sawit, Ikan Gurami, Laju PertumbuhanThe study aims to determine the use of fermentation residue oil palm in artificial feed .Research using a completely randomized design ( CRD ), which consists of 4 treatment three replications.The composition of the treatment is the treatment  A : 12 % of palm oil cake , Treatment B : fermented palm oil cake 15 % , Treatment C : fermented palm oil cake 18 % , Treatment D : fermentation residue palm oil 21 %.This research was conducted for 60 days to determine the specific growth rate of heavy , long daily growth rate , feed conversion , survival and quality of water as a supporter.The results showed the artificial feeding with fermented palm cake to produce a good response to the growth of carp.Feeding artificially by fermentation cake palm oil 18 % ( treatment C ) , gives the best results with a growth rate with the average - average growth rate of the specific weight of 1.502 % daily growth rate long- 4:06 % , the value of feed conversion average - average 3:48 and median survival - average of 90 % .Keywords : Fermentation Palm Kernel Oil, Fish carp, Growth Rate


1997 ◽  
Vol 35 (6) ◽  
pp. 63-70 ◽  
Author(s):  
Yoshimasa Watanabe ◽  
Yoshihiko Iwasaki

This paper describes a pilot plant study on the performance of a hybrid small municipal wastewater treatment system consisting of a jet mixed separator(JMS) and upgraded RBC. The JMS was used as a pre-treatment of the RBC instead of the primary clarifier. The treatment capacity of the system was fixed at 100 m3/d, corresponding to the hydraulic loading to the RBC of 117 L/m2/d. The effluent from the grid chamber at a municipal wastewater treatment plant was fed into the hybrid system. The RBC was operated using the electric power produced by a solar electric generation panel with a surface area of 8 m2 under enough sunlight. In order to reduce the organic loading to the RBC, polyaluminium chloride(PAC) was added to the JMS influent to remove the colloidal and suspended organic particles. At the operational condition where the A1 dosage and hydraulic retention time of the JMS were fixed at 5 g/m3 and 45 min., respectively, the average effluent water quality of hybrid system was as follows: TOC=8 g/m3, Total BOD=8 g/m3, SS=8 g/m3, Turbidity=6 TU, NH4-N=7 g/m3, T-P=0.5 g/m3. In this operating condition, electric power consumption of the RBC for treating unit volume of wastewater is only 0.07 KWH/m3.


2021 ◽  
pp. 003335492110112
Author(s):  
Hongjie Liu ◽  
Chang Chen ◽  
Raul Cruz-Cano ◽  
Jennifer L. Guida ◽  
Minha Lee

Objective We quantified the association between public compliance with social distancing measures and the spread of SARS-CoV-2 during the first wave of the epidemic (March–May 2020) in 5 states that accounted for half of the total number of COVID-19 cases in the United States. Methods We used data on mobility and number of COVID-19 cases to longitudinally estimate associations between public compliance, as measured by human mobility, and the daily reproduction number and daily growth rate during the first wave of the COVID-19 epidemic in California, Illinois, Massachusetts, New Jersey, and New York. Results The 5 states mandated social distancing directives during March 19-24, 2020, and public compliance with mandates started to decrease in mid-April 2020. As of May 31, 2020, the daily reproduction number decreased from 2.41-5.21 to 0.72-1.19, and the daily growth rate decreased from 0.22-0.77 to –0.04 to 0.05 in the 5 states. The level of public compliance, as measured by the social distancing index (SDI) and daily encounter-density change, was high at the early stage of implementation but decreased in the 5 states. The SDI was negatively associated with the daily reproduction number (regression coefficients range, –0.04 to –0.01) and the daily growth rate (from –0.009 to –0.01). The daily encounter-density change was positively associated with the daily reproduction number (regression coefficients range, 0.24 to 1.02) and the daily growth rate (from 0.05 to 0.26). Conclusions Social distancing is an effective strategy to reduce the incidence of COVID-19 and illustrates the role of public compliance with social distancing measures to achieve public health benefits.


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