Blazo Lalevic

Constructed wetlands as an alternative restoration measure for shallow lakes.

This paper deals with the consequences of cultural eutrophication and unconventional solutions for shallow lake restoration. Cultural eutrophication is the primary problem that affects especially shallow lakes, due to their physical characteristics (e.g. shallow depth, lack of stratification). Palic Lake, a very shallow Pannonian lake, received treated municipal wastewaters coming from the lagoons of a wastewater treatment plant. The sewage discharge mainly increased the nutrient load to the lake in the last decades. The lake sustainability is affected by inappropriate quality of water that flows into the lake, and abundance of deposited sediment. The technology that can provide both improvement of water quality and resolution of the sediment problem is a constructed wetland, which is designed to utilise the natural processes involving wetland vegetation, soil and their associated microbial assemblages to assist in additional water treatment. The technical solution is based on three key aspects: quality and quantity of deposited sediment, enriched by nutrients; effluent quality; desired lake water quality. A designed constructed wetland can accomplish the desired water quality and gradually remediate deposited sediment.

Hygiene in Primary Production

Biological agents, bacteria, viruses and parasites can, directly or indirectly, contaminate food. Similarly chemicals such as veterinary drugs used to combat animal illnesses, mycotoxins particularly aflatoxins, pesticides and environmental contaminants (e.g. dioxins, heavy metals) in animal feeds can also be a source contamination of food. Contamination of agricultural, animal and fish products is the result of the presence of human pathogenic bacteria and/or toxic substances, which can contaminate products in any part of the production chain. Examples are of the presence of a wide range of pathogens such as Salmonella spp., pathogenic Escherichia coli and Shigella , hepatitis A virus on fresh fruits and vegetables, E. coli O157:H7 in meats, Campylobacter spp., Brucella spp. in milk, Vibrio sp. and ciguatera toxin in fish. Thus the importance of good practices at the primary production level to prevent diseases and infections in animals, minimize risk of transmission to humans and/or contamination of food as well as to ensure animal health and welfare. The authors address three main primary production systems and the challenges to reduce the safety threats inherent to each. Good animal farming, fish health and good agricultural practices are described extensively so as to provide a clear picture of the complexity of the food production chains and the many factors that need to be under control to ensure the safety of food products.