Water organic chemical load

In spite of the superiority mentioned above, biotransformations are usually not satisfactory in industry without being carefully modulated. One dominant advantage, and sometimes also a drawback, encountered in biotransformations is that enzymatic reactions are traditionally performed in aqueous environments. However, the majority of organic chemicals are water-immiscible, resulting in very low substrate loading and low volumetric productivity. 

The data in Table V indicate that runoff of CGA-72662 from 12 applications would result in extremely low concentrations of CGA-72662 in ponds and lakes. The water column in all cases would contain all of the chemical, the sediment little or no CGA-72662. It follows from these data that exposure of CGA-72662 to aquatic organisms would be low. The data in Table V also shows that CGA-72662 would be persistent only in eutrophic lake environments. After the load is removed, the half-life of CGA-72662 in ponds, eutrophic lakes and oligotrophic lakes was 13, 62, and 5 days respectively. Self purification times were 9, 12, and 3 months respectively. 

The relative importance of both activities is well reflected on the population labor distribution per activity 70% is dedicated to agriculture and 15% to shellfish production [14] however, these two activities are not very compatible. Aquatic organisms are currently being exposed to multiple chemical and environmental stressors with different mechanisms of toxicity, each contributing to a final overall adverse effect [16]. Recently, the shellfish farmers in the Ebro River delta have complained about a loss of production in the periods of rice cultivation that they attribute to the heavy pesticide loads discharged after rice field treatment, and this has raised also public concern about the quality of the water in this area. 

---