Recycling produced water for algal cultivation for biofuels

Neal, Justin N.¹  Sullivan, Enid J.¹  Dean, Cynthia A.¹  Steichen, Seth A.¹ 

[1]Los Alamos National Laboratory

关键词: ALGAE;    BIOFUELS;    BIOREACTORS;    CULTIVATION;    FRESH WATER;    NUTRIENTS;    OIL WELLS;    OPACITY;    RECYCLING;    SALINITY;    SILICA;    SOLUTES;    WATER;   

DOI  :  10.2172/1048383
RP-ID  :  LA-UR-12-23976
PID  :  OSTI ID: 1048383
Others  :  TRN: US201217%%39

美国|英语

来源: SciTech Connect

【 摘 要 】

Algal growth demands a continuous source of water of appropriate salinity and nutritional content. Fresh water sources are scarce in the deserts of the Southwestern United States, hence, salt water algae species are being investigated as a renewable biofuel source. The use of produced water from oil wells (PW) could offset the demand for fresh water in cultivation. Produced water can contain various concentrations of dissolved solids, metals and organic contaminants and often requires treatment beyond oil/water separation to make it suitable for algae cultivation. The produced water used in this study was taken from an oil well in Jal, New Mexico. An F/2-Si (minus silica) growth media commonly used to cultivate Nannochloropsis salina 1776 (NS 1776) was prepared using the produced water (F/2-Si PW) taking into account the metals and salts already present in the water. NS 1776 was seeded into a bioreactor containing 5L of the (F/2-Si PW) media. After eleven days the optical density at 750 nm (an indicator of algal growth) increased from 0 to 2.52. These results indicate algae are able to grow, though inhibited when compared with non-PW media, in the complex chemical conditions found in produced water. Savings from using nutrients present in the PW, such as P, K, and HCO{sub 3}{sup -}, results in a 44.38% cost savings over fresh water to mix the F/2-Si media.