TREATMENT OF WASTE WHEY IN THE HEBRON DAIRY INDUSTRY

Abstract

The dairy industry consumes large quantity of water. Between 75% and 95% of the water intake volume is discharged as effluent. The dairy factories in the Hebron Governorate received and processed the milk and throw wastewater into public sewerage system. Wastewater from dairy manufacturing and processing industry are characterizes by a very high organic load and a high fat content. The inevitable wastage of milk and milk products contributes greatly to pollution loads discharged by dairies.

While larger dairy factories in the Hebron city dispose of their effluent into municipal sewers, causes of effluent disposal into wastewater stream of the Hebron city running in Wadis. In contrast to this, smaller dairy factories dispose of their effluent by irrigation onto lands or pastures. Surface and ground water pollution is therefore a potential threat posed by these practices.

Efforts to utilize the huge amount of dairy by products have led to the development of various whey treatment methods. Despite of the different possibilities of whey utilization, approximately half of the cheese whey produced worldwide is discarded without treatment. Liquid whey can be used in whey cheese production, bakery and meat industries, animal feed, and as an agricultural fertilizer. In the Hebron area, some large factories tried to process whey to produce special type of cheese, but most of them disposed whey into the municipal wastewater network. Over the past decades, several cost-effective treatment technologies comprising anaerobic, aerobic and facultative processes have been developed for the treatment of whey. Aerobic treatment, such as aerated lagoon, activated sludge process, and Sequencing Batch Reactors (SBR) has been commonly used for wastewater from food industry. Recently, anaerobic treatment leading to biogas production has become an effective biological process for the treatment of many industrial organic wastewaters. The UASB anaerobic reactor is one of the chosen innovative bioreactors.

The aim of this study was to firstly survey the Hebron city dairy industry to determine the present situation, requirements and need for effluent treatment; find out the quantity of wastewater from large dairy factories. Secondly, determine the extent of effluent related problems experienced by the dairy industry in the Hebron city. Thirdly, measure the characteristics of wastewater from the dairy large factory. Finally, investigate the use of the anaerobic digestion system for the treatment of dairy waste water, and study the application of the UASB-system into an efficient process for the treatment of waste water produced by dairy factories in Hebron Governorate.

In this study, which focused on the anaerobic treatment of dairy wastewater, UASB reactor will be designed and built inside the laboratory and laboratory batch experiments will be conducted during the research work, in order to evaluate the efficiency of using UASB technology. The anaerobic UASB reservoir could remove above 75% of the BOD and COD all year round.

At the end of work, the feasibility of using the anaerobic hybrid digester for the treatment of dairy factory wastewater has to be determined, and anaerobic treatment technology for large and medium size dairy factories in the Hebron area that have growing disposal problems and can not offered high investment costs for whey valorization technologies (such as protein and lactose recovery, spray drying, etc.) will be find out.