A method of concentrating lithium containing solutions includes inputting a feed brine solution to an initial separation stage, the feed brine solution including lithium sulfate and one or more of sodium sulfate, potassium sulfate, calcium sulfate, and sodium chloride dissolved in water. In the initial separation stage, the feed brine solution is introduced to a pre-treatment membrane at a pressure that is less than the osmotic pressure of the feed brine solution. An initial permeate that passes through the pre-treatment membrane becomes the feed to a final separation stage, and an initial retentate that does not pass through the pre-treatment membrane includes a precipitate of at least one of the salts other than lithium sulfate. In the final separation stage, the initial permeate is introduced to a nanofiltration membrane at a pressure that is less than the osmotic pressure of the initial permeate. A final retentate that does not pass through the nanofiltration membrane is combined with the initial retentate to obtain a product solution having a higher concentration of dissolved lithium sulfate than the feed brine solution.

The present invention includes: a first sealing portion which has a first entry/exit selectively opened or closed by a first opening/closing valve and a second entry/exit selectively opened or closed by a second opening/closing valve and is configured to seal one end of a housing; a second sealing portion which has a third entry/exit selectively opened or closed by a third opening/closing valve and a fourth entry/exit selectively opened or closed by a fourth opening/closing valve, and is configured to seal the other end of the housing; and a controller which is configured to control the supply of raw water through any one of the first entry/exit and the second entry/exit or control the supply of raw water through any one of the third entry/exit and the fourth entry/exit.

The present invention includes: a first sealing portion which has a first entry/exit selectively opened or closed by a first opening/closing valve and a second entry/exit selectively opened or closed by a second opening/closing valve and is configured to seal one end of a housing; a second sealing portion which has a third entry/exit selectively opened or closed by a third opening/closing valve and a fourth entry/exit selectively opened or closed by a fourth opening/closing valve, and is configured to seal the other end of the housing; and a controller which is configured to control the supply of raw water through any one of the first entry/exit and the second entry/exit or control the supply of raw water through any one of the third entry/exit and the fourth entry/exit.

A flow path spacer (13) of the present disclosure includes a plurality of first linear portions (21) and a plurality of second linear portions (22). There are a first pair (P1), a second pair (P2), and a third pair (P3), the first pair (P1) is at least one selected from a pair of the first linear portions (21) adjacent to each other and disposed at a first interval (W1) and a pair of the second linear portions (22) adjacent to each other and disposed at a first interval (W1), the second pair (P2) is at least one selected from a pair of the first linear portions (21) adjacent to each other and disposed at a second interval (W2) narrower than the first interval (W1) and a pair of the second linear portions (22) adjacent to each other and disposed at a second interval (W2) narrower than the first interval (W1), and the third pair (P3) is at least one selected from a pair of the first linear portions (21) adjacent to each other and disposed at a third interval (W3) narrower than the second interval (W2) and a pair of the second linear portions (22) adjacent to each other and disposed at a third interval (W3) narrower than the second interval (W2).

A flow path spacer (13) of the present disclosure includes a plurality of first linear portions (21) and a plurality of second linear portions (22). There are a first pair (P1), a second pair (P2), and a third pair (P3), the first pair (P1) is at least one selected from a pair of the first linear portions (21) adjacent to each other and disposed at a first interval (W1) and a pair of the second linear portions (22) adjacent to each other and disposed at a first interval (W1), the second pair (P2) is at least one selected from a pair of the first linear portions (21) adjacent to each other and disposed at a second interval (W2) narrower than the first interval (W1) and a pair of the second linear portions (22) adjacent to each other and disposed at a second interval (W2) narrower than the first interval (W1), and the third pair (P3) is at least one selected from a pair of the first linear portions (21) adjacent to each other and disposed at a third interval (W3) narrower than the second interval (W2) and a pair of the second linear portions (22) adjacent to each other and disposed at a third interval (W3) narrower than the second interval (W2).

According to the present invention, it is possible to obtain a separation membrane element which has an element configuration having high fresh water production performance and high removal performance, has an improved membrane surface linear velocity whereby fouling due to hardly-soluble salts (scales) or organic matters is less likely to occur on the membrane surface particularly in high recovery ratio operation, and is excellent in fresh water production performance and removal performance over a long period of time.

According to the present invention, it is possible to obtain a separation membrane element which has an element configuration having high fresh water production performance and high removal performance, has an improved membrane surface linear velocity whereby fouling due to hardly-soluble salts (scales) or organic matters is less likely to occur on the membrane surface particularly in high recovery ratio operation, and is excellent in fresh water production performance and removal performance over a long period of time.

Provided is a feed side spacer comprising a network structure, wherein the network structure includes a hexagonal eye, the hexagonal eye includes a pair of parallel portions parallel to a flow direction of a supply liquid, and an inclined portion disposed in a diagonal direction with respect to the flow direction of the supply liquid; the parallel portion has a length of 1 mm to 5 mm; the inclined portion has a length of 5.1 mm to 10 mm; and an angle formed by sides in contact with each other of the inclined portion is from 50° to 80°, and a separation membrane element comprising same.

Provided is a feed side spacer comprising a network structure, wherein the network structure includes a hexagonal eye, the hexagonal eye includes a pair of parallel portions parallel to a flow direction of a supply liquid, and an inclined portion disposed in a diagonal direction with respect to the flow direction of the supply liquid; the parallel portion has a length of 1 mm to 5 mm; the inclined portion has a length of 5.1 mm to 10 mm; and an angle formed by sides in contact with each other of the inclined portion is from 50° to 80°, and a separation membrane element comprising same.

The disclosure relates to systems and methods for improving the manufacturing of silk solutions and powders containing silk fibroin obtained from silkworm cocoons. The solutions and powders can be used to improve the post-harvest preservation of perishables and to improve the performance of packaging, including biodegradable packaging.