New Technology For Water Production And Zero Liquid Discharge (ZLD)

In this study surveys to membrane manufacturers and water treatment plants regarding the performance of different membrane alternatives have been carried out from January to April 2012. The work has been done as a part of a study of the different membrane alternatives suitable for Kvarnagården Water Treatment Plant. Also in the study experiments regarding water quality parameters have been carried out at the water laboratory at Chalmers University of Technology. The project is carried out at the Department of Civil and Environmental Engineering and is connected to the company VIVAB, the company in charge of Kvarnagården Water Treatment Plant.

Introduction: Desalination using seawater reverse osmosis (SWRO) technology is an important option available to water-scarce coastal regions. Worldwide sea water desalination is a very effective and economical way of producing potable water for drinking and industries. Reverse osmosis plants to convert sea water to potable drinking water and for other usages have been prevalent throughout the world for more than 4 decades. Design and operation of seawater reverse osmosis plants strongly depend on the raw seawater quality to be treated. The performance of desalination reverse osmosis (RO) systems relies upon the production of high quality pre treated water, and the selection of the best pre treatment technology depends on the raw seawater quality and its variations. Number of full-scale experiences has shown that pre treatment is the key for this application of reverse osmosis technology. It is why during these last years, an import effort has been done to identify and to characterise the diverse organic and mineral components present in the seawater in a view to optimise the seawater pre-treatment and to develop advanced analytical methods for feed water characterization, appropriate fouling indicators and prediction tools. This Chapter describes firstly a comprehensive approach to characterize raw seawater samples through analytical tools which allow the knowledge of the characterization of seawater from many aspects: (a) inorganic content, (b) natural organic matter, (c) enumeration of micro-organisms and phytoplankton. Secondly, this Chapter describes the effect of each of these parameters on the fouling of the reverse osmosis membrane. Finally, this chapter describes the different possible pre treatments available to reduce or remove the elements or substances up-stream reverse osmosis stage.

Darigold operates a milk products facility in Lynden, Washington. Production processes include evaporation of milk, which generates what is referred to as condensate of whey (COW) water. COW water contains low molecular weight organic compounds including traces of lactic acid, alcohols, acetoin, and non-protein nitrogen (Möslang, 2017). COW water and non-contact cooling water from the Darigold Lynden facility are currently discharged to Outfall 001, which combines with stormwater and the City of Lynden’s wastewater treatment plant (WWTP) effluent discharge to the Nooksack River through the City’s outfall. Darigold’s discharge is regulated under National Pollutant Discharge Elimination System (NPDES) Permit No. WA0002470 administered by the Washington Department of Ecology (Ecology). In the future, Darigold’s COW Water and non-contact cooling water will be directly discharged to the Nooksack River in a new outfall pipe (Outfall 002) currently being constructed by the City.

All over the world the presence of arsenic in water sources for human consumption has been raising great concern in terms of public health since many epidemiologic studies confirm the potential carcinogenic effect of arsenic. Because arsenic removal is the most frequent option for safe drinking water, the development of more efficient and sustainable technologies is extremely important. Membrane separation processes are suitable for water treatment because they can provide an absolute barrier for bacteria and viruses, besides removing turbidity and colour. Their application is a promising technology in arsenic removal since it does not require the addition of chemical reagents nor the preliminary oxidation of arsenite required in conventional treatment options. However, since membrane technologies such as reverse osmosis can be a very expensive and unsustainable treatment option for small water supply systems, it becomes crucial that alternative methods are developed. This work presents a few conclusions based on a laboratorial study performed to evaluate the efficiency of arsenic removal using ultrafiltration, microfiltration and solar oxidation processes under different experimental conditions for relevant parameters. The results showed removal efficiencies higher than 90%. Key-words: safe drinking water, arsenic removal, membranes, public health.

Introduction: Activated carbon filtration (AC) is effective in reducing certain organic chemicals and chlorine in water. It can also reduce the quantity of lead in water although most lead-reducing systems use another filter medium in addition to carbon. Water is passed through granular or block carbon material to reduce toxic compounds as well as harmless taste- and odor-producing chemicals. This fact sheet discusses the principles and processes of typical activated carbon filtration systems.