Het estuarium als ontvangend water van grote hoeveelheden afvalstoffen : afvoer van het veenkoloniale afvalwater naar de Eems

In the Fen Settlements in the north of the Netherlands straw-board factories and potato-flour mills discharged large amounts of waste water (estimated at 420 tons of BOD 5 (biological oxygen deficiency) per 24 h during the autumn working season of the potato-flour mills) largely into canals, causing severe water pollution. A radical solution might be to pump the wastes through a pipeline to the Ems estuary about 30 km away. Some of the polluted canal water was already discharged into the estuary.A study was made of how discharge of all the waste would effect the oxygen status of the estuary. This was done by relating waste discharge, distribution of BOD, and distribution of O 2 content over several years, and by calculating the expected distribution of oxygen if the sewage was discharged by pipeline.Finally salt content, BOD 5 , oxygen content and other properties of the estuary water were measured on a boat over more than five years. Further factors included in this study were the rate of decay of the organic matter in the estuary water, the ratio between BOD C+N and BOD 5 and the coefficient of re-aeration.Measured and calculated data agreed well, showing that calculated values for oxygen condition were reliable. Since calculated values were satisfactory, discharge of all the sewage of the Fen Settlements into the Ems estuary could be advised

Increase in treatment of retinopathy of prematurity in the Netherlands from 2010 to 2017

Purpose: Compare patients treated for Retinopathy of Prematurity (ROP) in two consecutive periods. Methods: Retrospective inventory of anonymized neonatal and ophthalmological data of all patients treated for ROP from 2010 to 2017 in the Netherlands, subdivided in period (P)1: 1-1-2010 to 31-3-2013 and P2: 1-4-2013 to 31-12-2016. Treatment characteristics, adherence to early treatment for ROP (ETROP) criteria, outco

Het estuarium als ontvangend water van grote hoeveelheden afvalstoffen : afvoer van het veenkoloniale afvalwater naar de Eems

In the Fen Settlements in the north of the Netherlands straw-board factories and potato-flour mills discharged large amounts of waste water (estimated at 420 tons of BOD 5 (biological oxygen deficiency) per 24 h during the autumn working season of the potato-flour mills) largely into canals, causing severe water pollution. A radical solution might be to pump the wastes through a pipeline to the Ems estuary about 30 km away. Some of the polluted canal water was already discharged into the estuary.A study was made of how discharge of all the waste would effect the oxygen status of the estuary. This was done by relating waste discharge, distribution of BOD, and distribution of O 2 content over several years, and by calculating the expected distribution of oxygen if the sewage was discharged by pipeline.Finally salt content, BOD 5 , oxygen content and other properties of the estuary water were measured on a boat over more than five years. Further factors included in this study were the rate of decay of the organic matter in the estuary water, the ratio between BOD C+N and BOD 5 and the coefficient of re-aeration.Measured and calculated data agreed well, showing that calculated values for oxygen condition were reliable. Since calculated values were satisfactory, discharge of all the sewage of the Fen Settlements into the Ems estuary could be advised

Characterization of a new Bacillus stearothermophilus isolate: a highly thermostable α-amylase-producing strain

A novel strain of Bacillus stearothermophilus was isolated from samples of a potato-processing industry. Compared to known α-amylases from other B. stearothermophilus strains, the isolate was found to produce a highly thermostable α-amylase. The half-time of inactivation of this α-amylase was 5.1 h at 80°C and 2.4 h at 90°C. The temperature optimum for activity of the α-amylase was 70°C; the pH optimum for activity was relatively low, in the range 5.5-6.0. α-Amylase synthesis was regulated by induction and repression mechanisms. An inverse relationship was found between growth rate and α-amylase production. Low starch concentrations and low growth temperatures were favourable for enzyme production by the organism. At the optimal temperature for growth, 65°C, the α-amylase was a growth-associated enzyme. The optimal temperature for α-amylase production, however, was 40°C, with α-amylase increasing from 3.9 units (U)/ml to 143 U/ml when lowering the growth temperature from 65°C to 40°C. Maximal α-amylase production in a batch fermentor run at 65°C was 102 U/ml, which was 26-fold higher than in erlenmeyer flasks at 65°C. The dissolved O2 concentration was found to be a critical factor in production of the α-amylase.