Methane Production and Water Quality Improvements in Agricultural Biodigesters in Costa Rica

2006 ◽  
Author(s):  
Stephanie L. Lansing ◽  
Jay F. Martin ◽  
Raúl Botero Botero
Keyword(s):  
Water Quality ◽  
Costa Rica ◽  
Methane Production ◽  
Quality Improvements

scholarly journals Declining bacteria, lead, and sulphate, and rising pH and oxygen in the lower Mississippi River

AMBIO ◽  
2021 ◽  
Author(s):  
R. Eugene Turner
Keyword(s):  
Water Quality ◽  
Mississippi River ◽  
Pollution Abatement ◽  
National Policy ◽  
Quality Improvements ◽  
Sulfur Dioxide Emissions ◽  
Dramatic Decline ◽  
Before And After ◽  
Lower Mississippi River ◽  
The 1960S

AbstractVarious air and water pollution issues in the US were confronted in the last 60 years using national policy legislation, notably the Clean Water Act and the Clean Air Act. I examine changes in the concentrations of bacteria, oxygen, lead, and sulphate at the terminus of the Mississippi River before and after these pollution abatement efforts. Microbial concentrations increased or were stable from 1909 to 1980 but decreased about 3 orders of magnitude after the 1970s, while the average oxygen content increased. A large decline in lead concentration occurred after the 1960s, along with a less dramatic decline in sulphate concentrations. The pH of the river dropped to a low of 5.8 in 1965 as sulfur dioxide emissions peaked and averaged 8.2 in 2019 after emissions declined. Decades of efforts at a national scale created water quality improvements and are an example for addressing new and existing water quality challenges.

scholarly journals Treatment of arsenic-contaminated water using in-line electrolysis, co-precipitation and filtration in Costa Rica

2017 ◽  
Vol 18 (1) ◽  
pp. 40-48 ◽  
Author(s):  
Sylvie Kunz ◽  
Luis G. Romero-Esquivel ◽  
Philipp Otter ◽  
Ulrike Feistel ◽  
Thomas Grischek ◽  
...  
Keyword(s):  
Water Quality ◽  
Costa Rica ◽  
Arsenic Removal ◽  
Water Quality Monitoring ◽  
Water Tank ◽  
Mean Values ◽  
Treated Water ◽  
Catalytically Active ◽  
Co Precipitation ◽  
Maintenance Requirements

Abstract A novel treatment was tested with groundwater to investigate its arsenic removal under natural conditions. The system utilised in-line electrochlorination to oxidise water constituents without the need for external chemical supply. The oxidised arsenic and iron co-precipitated and were filtered via Greensand Plus™. The filter was catalytically active and provided an emergency oxidant. The system had only a few maintenance requirements due to online water quality monitoring. The contaminant removal during the field test in Costa Rica was impaired by strong fluctuations in water quality including low iron concentrations. However, the system removed on average 68% of the arsenic. Mean values of arsenic were 40 ± 23 μg/L in groundwater and 13 ± 6 μg/L in treated water. Iron was removed from an average of 2.8 ± 2.4 mg/L to 0.2 ± 0.2 mg/L (93% removal). Free chlorine produced and available in the treated water tank had a mean concentration of 1.25 mg/L and 0.64 mg/L, respectively.

Water quality improvements in the Sudbury, Ontario, Canada area related to reduced smelter emissions

1986 ◽  
Vol 31 (3-4) ◽  
pp. 765-774 ◽  
Author(s):  
W. Keller ◽  
J. Roger Pitblado ◽  
N. I. Conroy
Keyword(s):  
Water Quality ◽  
Quality Improvements ◽  
Smelter Emissions
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