**3. Conclusions**

20 New Technologies in the Oil and Gas Industry

(right) electroflocculation.

Note: Data: vol. = 3 L, t = 6 min.

life.

electrode. In the case of AC, the cyclical energization retards the normal mechanisms of attack on an electrode and makes this attack more uniform, thus ensures longer electrode

**Figure 8.** EF tests with high-salinity effluent. Legend: 60g / L NaCl: a) raw wastewater containing 60g / L of O&G; b) raw wastewater being mixed salt, for EF testing; c) effluent treated with AC (left) and DC

**a c b** 

**Parâmeters Oily wastewater AC DC**  pH 6.4 6.7 6.7 Turbidity (NTU) 11050 8 10 Color (Abs.) 7.57 0.03 0.04 Salinity (g/L) 50.8 47.5 47.8 Conductivity (mS/cm) 91.5 87.4 87.0 TDS (g/L) 64.9 61.9 61.5 Phenols (mg/L) 0.5 0.2 0.2 Sulfide (H2S) (mg/L) 2.8 1.2 1.0 Ammonia nitrogen (mg/L) 36 4 5 O&G (mg/L) 60000 32 30 Mass electrode (g) - 0.18 0.26 Current (A) - 2.5 2.5 Tension (V) - 1.5 2.0

**Table 3.** Results of treating high-salinity effluent with AC and DC electrolysis.

In the present study, we could confirm that the EF process produces satisfactory results for treatment of oily wastewater, allowing its discharge into water bodies or reinjection in oil formations. The AC technology was highly effective, both with the original oily water as received and with the simulated produced water after addition of salt.

Overall, the results confirm the potential of the technique, which through simple and compact equipment, can be employed for the decontamination of organic compounds. The results of tests on oily water resulted in high organic load removal efficiencies, reaching 99% removal of oil and grease, color and turbidity, along with high removal of phenols, ammonia and sulfides.

The biggest advantage of AC versus DC electroflocculation is the lower electrode wear with the former technique. When using the same testing conditions and time of 6 minutes for both technologies, the efficiency was above 30%. The AC electroflocculation technique seems to be a promising alternative in the treatment of oily wastewater from the oil industry.
