Microalgal-based systems for wastewater treatment: Effect of applied organic and nutrient loading rate on biomass composition

2012 ◽  
Vol 49 ◽  
pp. 112-117 ◽  
Author(s):  
B. Riaño ◽  
D. Hernández ◽  
M.C. García-González
Keyword(s):  
Wastewater Treatment ◽  
Treatment Effect ◽  
Nutrient Loading ◽  
Loading Rate ◽  
Biomass Composition ◽  
Nutrient Loading Rate

Effects of Daphnia on the response of mesotrophic lakes to experimental enrichment

1995 ◽  
Vol 32 (4) ◽  
pp. 157-163 ◽  
Author(s):  
K. L. Cottingham ◽  
S. E. Knight
Keyword(s):  
Simulation Model ◽  
Nutrient Loading ◽  
Loading Rate ◽  
Experimental Results ◽  
First Year ◽  
Model Simulations ◽  
Loading Rates ◽  
N:P Ratios ◽  
Nutrient Loading Rate ◽  
Experimental Enrichment

We are currently involved in a whole-lake experiment designed to assess how Daphnia affect the response of mesotrophic lakes to increased nutrient loading. In the first year of the experiment, we wished to demonstrate that there are P loading rates which eutrophy lakes without Daphnia but not lakes with Daphnia. In order to do this, we needed to choose an appropriate level and schedule for the experimental enrichment. This paper describes how we made that choice, then evaluates whether our choice was successful. Based on the literature, a simulation model, and a mesocosm experiment, we decided that enriching at a rate of 1 μg P L−1 d−1 would create the desired contrast between lakes with and without Daphnia. Model simulations indicated that mean algal response to enrichment would be comparable under monthly, weekly, or continuous additions. We chose to add nutrients continuously at ambient N:P ratios. Experimental results from 1993 suggest that we achieved a nutrient loading rate consistent with our goal: chlorophyll responded less to enrichment in the lake with Daphnia than in the lake without Daphnia. The modeling, mesocosm, and whole-lake studies summarized here support the idea that Daphnia reduce chlorophyll at P loads ≤1 μg P L−1 d−1. However, cyanobacteria may escape control by all grazers at relatively low P loading rates.

scholarly journals The Sensitivity Analysis of a Lake Ecosystem with the Conditional Nonlinear Optimal Perturbation Method

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Bo Wang ◽  
Peijun Zhang ◽  
Zhenhua Huo ◽  
Qianqian Qi
Keyword(s):  
Nutrient Loading ◽  
Loading Rate ◽  
Initial Perturbation ◽  
Finite Amplitude ◽  
Lake Ecosystem ◽  
Conditional Nonlinear Optimal Perturbation ◽  
Optimal Perturbation ◽  
Amplitude Parameter ◽  
Nutrient Loading Rate ◽  
Method Show

The instability and sensitivity of a lake ecosystem to the finite-amplitude perturbations related to the initial condition and the parameter correspondingly are studied. The CNOP-I and CNOP-P methods are adopted to investigate this nonlinear system. The numerical results with CNOP-I method show that the lake ecosystem can be nonlinearly unstable with finite-amplitude initial perturbations when the nutrient loading rate is between the two bifurcation points. A large enough finite amplitude initial perturbation, that is, CNOP-I, can induce a transition from an oligotrophic (eutrophic) state to an eutrophic (oligotrophic) state. With CNOP-P method, it is shown that the lake ecosystem can be transformed from an oligotrophic (eutrophic) state to an eutrophic (oligotrophic) state with a large enough finite amplitude parameter perturbation, that is, CNOP-P, no matter how large the nutrient loading rate is.

Silage storage runoff characterization: Annual nutrient loading rate and first flush analysis of bunker silos

2018 ◽  
Vol 264 ◽  
pp. 85-93 ◽  
Author(s):  
Michael A. Holly ◽  
Rebecca A. Larson ◽  
Eric T. Cooley ◽  
Aaron M. Wunderlin
Keyword(s):  
Nutrient Loading ◽  
Loading Rate ◽  
First Flush ◽  
Nutrient Loading Rate

The Research on the Lake Eutrophication with CNOP Method

2012 ◽  
Vol 599 ◽  
pp. 705-708 ◽  
Author(s):  
Bo Wang ◽  
Zhen Hua Huo ◽  
Qian Qian Qi ◽  
Pei Jun Zhang
Keyword(s):  
Nutrient Loading ◽  
Loading Rate ◽  
Initial Perturbation ◽  
Finite Amplitude ◽  
Lake Ecosystem ◽  
Initial Condition ◽  
Parameter Perturbation ◽  
Conditional Nonlinear Optimal Perturbation ◽  
Optimal Perturbation ◽  
Nutrient Loading Rate

Using a dynamical model for nutrient cycling in shallow lakes, the approach of conditional nonlinear optimal perturbation (CNOP) was adopted to investigate the instability and the sensitivity of the lake ecosystem to finite-amplitude perturbations both related to the initial condition and the parameter. The results show that the ecosystem can be transformed from an oligotrophic (eutrophic) state to an eutrophic (oligotrophic) state with a CNOP as the perturbation, no matter how large the nutrient loading rate is. Above all, with the same restraints related to the initial perturbation and the parameter perturbation, CNOP has the largest effect on the lake ecosystem, which may be helpful to govern the lake ecosystem.

Plant-based versus metal-based coagulants in aquaculture wastewater treatment: Effect of mass ratio and settling time

2021 ◽  
Vol 43 ◽  
pp. 102269
Author(s):  
Azmi Ahmad ◽  
Siti Rozaimah Sheikh Abdullah ◽  
Hassimi Abu Hasan ◽  
Ahmad Razi Othman ◽  
Nur 'Izzati Ismail
Keyword(s):  
Wastewater Treatment ◽  
Treatment Effect ◽  
Settling Time ◽  
Mass Ratio ◽  
Aquaculture Wastewater

Influence of Hydraulic Loading Rate on Horizontal Zeolite Wetland Effluent Quality

2012 ◽  
Vol 573-574 ◽  
pp. 659-662
Author(s):  
Hao Wang
Keyword(s):  
Wastewater Treatment ◽  
Loading Rate ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Secondary Effluent ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Hydraulic Loading Rate ◽  
Effluent Quality ◽  
Hydraulic Loading

In Tangshan area, the secondary effluent of wastewater treatment plants was used for this study. Horizontal zeolite wetland was carried out treating it. Hydraulic loading rate was the parameters for analyzing the nitrogen and phosphorus removal efficiency of pollutants from the secondary effluent of wastewater treatment plant. Zeolite constructed wetlands showed different behaviors for nitrogen and phosphorus removals.Under the optimum hydraulic loading rate, the primary pollutions were removed to a large extent.

scholarly journals Performance of Microbial Fuel Cell for Wastewater Treatment and Electricity Generation

2013 ◽  
Vol 2 (2) ◽  
pp. 131-135
Author(s):  
Z Yavari ◽  
H Izanloo ◽  
K Naddafi ◽  
H.R Tashauoei ◽  
M Khazaei
Keyword(s):  
Wastewater Treatment ◽  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Electricity Generation ◽  
Loading Rate ◽  
Synthetic Wastewater ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Sustainable Operation ◽  
Cell Reactor

Renewable energy will have an important role as a resource of energy in the future. Microbial fuel cell (MFC) is a promising method to obtain electricity from organic matter andwastewater treatment simultaneously. In a pilot study, use of microbial fuel cell for wastewater treatment and electricity generation investigated. The bacteria of ruminant used as inoculums. Synthetic wastewater used at different organic loading rate. Hydraulic retention time was aneffective factor in removal of soluble COD and more than 49% removed. Optimized HRT to achieve the maximum removal efficiency and sustainable operation could be regarded 1.5 and 2.5 hours. Columbic efficiency (CE) affected by organic loading rate (OLR) and by increasing OLR, CE reduced from 71% to 8%. Maximum voltage was 700mV. Since the microbial fuel cell reactor considered as an anaerobic process, it may be an appropriate alternative for wastewater treatment

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