SU1747393A1 - Method of sewage treatment - Google Patents

Abstract

Use: for sewage treatment. The essence of the invention: Flocculant 3- {2-hydroxyethyl) -oxazolidinium-pentadecanoate of the general formula I fl o N f Xcn2cn2on CWH29COO 1 is introduced.

Description

The invention relates to methods for the purification of waste water, in particular to the treatment of wastewater from clay suspensions formed in the mining industry during the development of placer deposits.

The presence of both dispersed and highly dispersed solid phases in the process water makes it difficult to reuse wastewater when washing placers on dredges. In addition, there are strict standards for the discharge of sewage drains into open watercourses. The content of suspended substances should not exceed 20 mg / l.

There is a method of treating water containing suspended solids using flocculant polyacrylamide (PAA),

The disadvantages of this method are low cleaning efficiency and high flocculant consumption.

The closest to the proposed proposed method is the purification of wastewater from suspended substances, including

cationic flocculation followed by separation of the precipitate by settling using flocculate NTV -cetyl-M, M-diethyl-M- (2-hydroxyethyl). ammonium bromide.

The disadvantages of this method are low sedimentation rate of suspended particles, high consumption and high residual concentrations of the reagent in water, as well as low efficiency of the reagent when cleaning dredge solutions with a high concentration of suspension.

The aim of the invention is to increase the speed and degree of sewage treatment.

This goal is achieved in that according to the proposed method of sedimentation of suspended solids from sewage drains, consisting in treating water with cationic flocculation followed by separation of sediment by settling, the flocculant uses

(L

WITH

2

v | Oj

h with

US:

cwH29cocf

sn sn2sn2on

Synthesis and properties of OPD are not described in the literature.

OPD is a light yellow waxy substance, f-odor, soluble in water, alcohols, acetone.

HPD is prepared in a known manner by reacting 3- (2-hydroxyethyl) -oxazolidine with pentadecanoic acid. CB2-CH2

About N-CH2CH2OH + ClЈfH29COOH CH2

About N UHo

H

ns, chn29soo

sn2sn2on

The output for the genus is that quantitative.

The introduction of HPD as a cationic flocculant in the process of sewage purification from clay suspensions is different from the prototype, in which KLA reagent uses M-cetyl-M, M-diethyl-M- (2-hydroxyethyl) ammonium bromide. From the known properties of the proposed reagent, its ability to change the colloidal-dispersed-molecular state of suspended solids obviously does not follow, providing the aggregability of particles, thus increasing the rate of gravitational sedimentation and the efficiency of clarification.

Under laboratory conditions, the method of precipitating suspended substances in wastewater from dredging incisions is carried out as follows.

The wastewater collected in the dredge section is transferred to a plexiglass cuvette mounted with a mudmeter and chart recorder, and the kinetics of natural sedimentation of suspensions is recorded. Then the reagent is mixed again and the reagent is injected and the kinetics of the precipitation process is recorded again. At the end of the process, the residual content of suspended substances is estimated by known methods.

F1 p and mera 1. Synthesis of 3- (2-hydroxyethyl) oxazolidinip decadeca noate.

11.7 g (0.1 mol) of 3- {2-hydroxyethyl) -oxazolidine was added to 24.2 g (0.1 mol) of pentadecanoic acid at 60 ° C and kept at this temperature for 1 hour. 35 After cooling, 35 9 g (100%) HPD as a light yellow waxy substance with a melting point of 58-60 ° C.

Found,%: C 66.42, 66.54; H 11.69, 11.74; N3,81.3,93.

C20H41N04.

Calculated,%: C, 66.81; H 11 „49: N 3.90.

IR spectrum (thin layer), cm: 1060,

1170, 1195 oxazolidine cycle), 1385, 1450,2830.2895 (СН2, СНз) 1550 (С001, 3300 (ОН).

Example2. Sample wastewater

0 (500 ml) with a suspended matter content of 5 g / l add a certain volume of the solution of the reagent proposed (dose 1-50 mg), after mixing in a cuvette, turn on automatic recording and fill in sediment kinetics of suspensions. The resulting curves are calculated using the first-order equation on the Spark 1256 computer. The process is characterized by the gravitational deposition index — the ratio Ko / Ko 0 of the deposition constant with the reagent to the deposition constant without the reagent. The residual content of suspended substances is determined by the gravimetric method.

The table shows the indicators of gravitational sedimentation of clay suspensions.

wastewater depending on the dose

reagent (concentration suspended 5 g / l)

The table shows that the proposed

the reagent at a dose of 1 mg / g provides

0 the sedimentation rate of suspended solids is 1.5 times higher and the degree of purification is 13.6% more than with the same concentration of the prototype reagent.

Comparable deposition rate and

The 5 degree of purification using the prototype is achieved only at a dose of 10 mg / g, i.e. ten times higher than for the proposed reagent HPD.

A study of the toxicity of the proposed ODD reagent and the prototype reagent on an aquatic plant — Canadian Elodea shows that inhibition of the growth of Elodea by both reagents at their concentration in water up to 500 mg / l is not observed.

Claims (1)

5 claims The method of sewage purification from vzva, sheny substances by treatment with cationic flocculant followed by separating the sediment by settling, about tl and h a0 y i and so that 3- (2-hydroxyethyl) -oxazolidine pentadecano-this formula is used as flocculant to increase the speed and degree of purification of dram sewage 5 CH2-CH2 I j & -h with, AND Chf2 NCH2CH2OH WH29COCT